The average UK winter has become around 1C warmer and 15% wetter over the past century, new Carbon Brief analysis shows.
The analysis covers more than 100 years of data on temperature, rainfall, wind speed and snow, to assess how UK winters have changed.
The data show that extremely warm and wet winters are becoming more common. Six of the 10 warmest winters on record were in the 21st century, and four of these also rank in the top 10 wettest years on record.
Despite the trend towards milder conditions, extreme cold snaps still hit the UK. The winter of 2009-10, for example, was dubbed the “Big Freeze of 2010” and clocked in as the UK’s least-windy, second-snowiest and eighth-coldest winter on record.
However, extreme cold periods are becoming less common. On average, the UK saw more than 12 snow days each winter in 1971-2000. This dropped to 9.5 snow days each winter by 1991-2020.
As the climate continues to warm, the UK can expect winters to continue getting warmer and wetter. Met Office projections suggest that, under an emissions pathway in line with current global policies, the average UK winter by 2080-99 will be 2C warmer and 11% wetter than they were in 1981-2000.
Warmer winters
The UK Met Office has been collecting meteorological data from thousands of weather stations across the UK since the 1880s. Using this data, it has produced a gridded dataset called HadUK, which provides complete coverage across the UK for a range of climate variables – including rainfall, temperature, snow days and wind speed – on a one-square-kilometre grid.
Carbon Brief has analysed the data for meteorological winters – defined as December, January and February – to determine how weather conditions have changed since records began.
The plot below shows a timeseries of annual winter average temperature (dark blue) over 1884-2021. These are shown as anomalies – that is, the difference compared to a baseline, which in this case is the average winter temperature over 1991-2020.
(Winters are shown on graphs in this article according to the year in which December falls. For example, the winter of December 2021 to February 2022 is shown as 2021.)
The Met Office, in line with the World Meteorological Organisation, uses 30-year averages to assess changes in UK climate. The table below shows average absolute UK winter temperatures for overlapping 30-year time periods across the full data record.
| Time period | Average temperature | Maximum temperature | Minimum temperature |
|---|---|---|---|
| 1881-1910 | 2.96* | 5.77* | 0.18* |
| 1891-1920 | 3.29 | 6.06 | 0.53 |
| 1901-1930 | 3.50 | 6.21 | 0.80 |
| 1911-1940 | 3.51 | 6.21 | 0.83 |
| 1921-1950 | 3.41 | 6.12 | 0.73 |
| 1931-1960 | 3.29 | 6.05 | 0.56 |
| 1941-1970 | 3.09 | 5.84 | 0.35 |
| 1951-1980 | 3.17 | 5.91 | 0.46 |
| 1961-1990 | 3.22 | 5.94 | 0.51 |
| 1971-2000 | 3.65 | 6.40 | 0.91 |
| 1981-2010 | 3.75 | 6.58 | 0.94 |
| 1991-2020 | 4.12 | 6.97 | 1.28 |
Average, maximum and minimum winter temperatures for overlapping 30-year time periods, from 1881 to 2020, using the December-February average of mean monthly temperatures. An asterisk (*) indicates that a full 30 years was not available for this average.
The average UK winter in 1991-2020 was 0.9C warmer than during 1961-90. The most recent 30-year period also includes the warmest maximum, minimum and average temperatures since Met Office records began.
In addition, with an average winter temperature of 4.64C, the most-recent decade (2013-22) – not shown in the table – has seen a further temperature increase of 0.52C above the 1991-2020 average.
Warmer winters are already impacting UK wildlife. For example, Grahame Madge – senior press officer for the Met Office – told the Guardian that animals including hedgehogs, bats and butterflies are emerging from hibernation too early:
“Abnormal warm spells during winter can encourage species out of hibernation. Butterflies such as red admirals and small tortoiseshells and other insects can be particularly challenged as they can emerge largely without access to life-saving food sources like nectar. If the warm spell is followed by a return to colder conditions, the hibernating individuals will have used up valuable energy reserves without being able to replace them, possibly with disastrous consequences.”
Meanwhile, the National Trust says warmer winters have “particularly devastating impacts for trees”, as cold snaps are often not long enough to kill off harmful diseases and pests.
Looking at individual years gives a more detailed picture. The graphic below shows the warmest and coldest 10 winters in the UK since 1884. The dark blue line shows average UK winter temperature, and red and blue dots indicate the warmest and coldest individual winters, respectively. The table below shows the dates and temperatures of these winters.
| Warmest winters | Coldest winters | |||
|---|---|---|---|---|
| Years | Temperature (C) | Years | Temperature (C) | |
| 1 | 1988-99 | 5.76 | 1962-63 | -0.31 |
| 2 | 2006-07 | 5.53 | 1894-95 | 0.42 |
| 3 | 2015-16 | 5.43 | 1946-47 | 0.75 |
| 4 | 1997-98 | 5.40 | 1978-79 | 1.13 |
| 5 | 2019-20 | 5.28 | 1939-4 | 1.23 |
| 6 | 1974-75 | 5.22 | 1916-17 | 1.33 |
| 7 | 2021-22 | 5.20 | 1928-29 | 1.46 |
| 8 | 2013-14 | 5.19 | 2009-10 | 1.63 |
| 9 | 1934-35 | 5.13 | 1885-8 | 1.65 |
| 10 | 2018-19 | 5.09 | 1940-41 | 1.80 |
Warmest and coldest 10 winters in the UK since 1884. The dark blue line shows average UK winter temperature, and red and blue dots indicate the warmest and coldest individual winters. The table beneath shows the dates and temperatures of these winters. Credit: Chart by Carbon Brief, based on the Met Office HadUK dataset.
The graph shows that six of the 10 warmest winters on record have occurred in the 21st century. Conversely, only one of the UK’s coldest 10 winters were in the 21st century – the winter of 2009-10.
The Met Office also provides country-level data for different parts of the UK. The plot below shows 10-year rolling average winter temperature for England (dark blue), Scotland (red), Northern Ireland (light blue) and Wales (yellow).
The plot shows that Scotland consistently sees the coldest winters, while England, Wales and Northern Ireland experience winter temperatures that are an average of around 1.5-2C warmer.
Snow days
As average temperatures rise across the UK, extremely cold days are becoming less common, while record-breaking warm days are becoming more frequent.
Five of the top 10 warmest days ever recorded during UK winters occurred during a single week February 2019.
Carbon Brief analysed the warmest maximum and coldest minimum temperature on record for each UK winter. The table below shows the years with the warmest (red) maximum daily temperatures and coldest (blue) minimum daily temperatures since 1960.
| Warmest maximum temperatures | Coldest minimum temperatures | |||
|---|---|---|---|---|
| Temperature (C) | Year | Temperature (C) | Year | |
| 1 | 16.1 | 2018-19 | -10.2 | 1986-87 |
| 2 | 14.3 | 1997-98 | -10.1 | 1962-63 |
| 3 | 14.0 | 2015-16 | -10.0 | 1981-82 |
| 4 | 13.8 | 1989-90 | -9.9 | 1978-79 |
| 5 | 13.6 | 2003-04 | -9.5 | 1971-72 |
| 6 | 13.5 | 1985-86 | -9.3 | 2010-11 |
| 7 | 13.4 | 2011-12 | -9.1 | 1995-96 |
| 8 | 13.3 | 2016-17 | -8.9 | 1969-70 |
| 9 | 13.3 | 2021-22 | -8.7 | 2009-10 |
| 10 | 13.2 | 1994-95 | -8.7 | 1968-69 |
Years with the 10 warmest (red) maximum temperatures, and coldest (blue) minimum temperatures, based on individual winter days since 1960. Credit: Chart by Carbon Brief, based on the Met Office HadUK dataset.
Most of the warmest winter extremes on record were in the 21st century. Meanwhile, most of the coldest extremes were in the 20th century.
One way of measuring the change in extreme cold days is to count the number of “frost days” – days with a minimum temperature below 0C – recorded throughout the winter. Another way is to count the number of “snow days”, when snow can be seen on the ground at 9am.
Dr Mark McCarthy is the head of the Met Office National Climate Information Centre, which manages the UK’s climate records. He explains that to calculate snow days, an individual looks at a “representative patch of ground” at 9am in the morning, and if at least half of it is covered in snow, then it is counted as “snowy”.
These results are averaged across hundreds or thousands of observations. This means that, for example, “an average of five days of snow might mean that half of that region had 10 days and half the region had no days”, he explains.
The plot below shows the number of frost days since 1960 (red) and snow days since 1971 (blue) over winter. The black lines show the 10-year running average.
The table below shows the total number of first and snow days during UK winters for four overlapping 30-year time periods.
| Time period | Frost days | Snow days |
|---|---|---|
| 1961-1990 | 38.43 | – |
| 1971-2000 | 35.07 | 12.29 |
| 1981-2010 | 35.17 | 11.73 |
| 1991-2020 | 32.75 | 9.54 |
Total number of frost and snow days for 30-year time periods, from 1931 to 2020, using the December-February average of mean monthly temperatures. An asterisk (*) indicates that a full 30 years was not available for this average.
The plot shows that air frost and snow days are closely linked. Snow will generally not form if the ground temperature is above 5C, and in the UK, the heaviest snowfalls tend to occur when the air temperature is between 0C and 2C.
On average, the UK saw 12.3 snow days each winter over 1971-2000. This dropped to 9.5 snow days each winter by 1991-2020.
There is also regional variation in snow days. Over the entire 1971-2020 dataset, Scotland received 18.6 days of snow per winter on average, while the UK, Northern Ireland and Wales received between 7.2 and 8.8.
“Significant and widespread lying snow might have been considered fairly typical for a UK winter of several decades ago,” says the Met Office’s latest State of the UK climate report. However, it adds that “this type of event has become increasingly unusual in a warming climate over the last two or three decades”.
The graph below shows the UK winters with the greatest (light blue dots) and smallest (red dots) number of snow days since 1971.
| Snowiest winters | Least snowy winters | |||
|---|---|---|---|---|
| Years | Snow days | Years | Snow days | |
| 1 | 1978-79 | 35.62 | 2019-20 | 2.12 |
| 2 | 2009-10 | 30.59 | 1991-92 | 2.39 |
| 3 | 1981-82 | 26.90 | 2007-08 | 2.97 |
| 4 | 1985-86 | 23.69 | 1988-89 | 3.15 |
| 5 | 2010-11 | 23.13 | 2021-22 | 3.35 |
| 6 | 1984-85 | 21.54 | 1997-98 | 3.45 |
| 7 | 1976-77 | 20.77 | 2013-14 | 3.49 |
| 8 | 1977-78 | 18.54 | 2016-17 | 3.57 |
| 9 | 1995-96 | 18.43 | 2005-06 | 3.72 |
| 10 | 1990-91 | 18.13 | 1974-75 | 3.90 |
Snowiest and least snowy 10 winters in the UK since 1884. The dark blue line shows seasonal “snow days”, and red and blue dots indicate the snowiest and least snowy individual winters. The table beneath shows the dates and number of snow days of these winters. Credit: Chart by Carbon Brief, based on the Met Office HadUK dataset.
While the climate is becoming milder and snow is becoming less common, very cold and snowy winters can still happen. For example, the winter of 2009-10, dubbed the “Big Freeze of 2010” in parts of the UK media, was the least-windy, second-snowiest and eighth-coldest winter on record in the UK.
Severe snowfall that winter caused “very significant disruption across the UK”, according to the UK Met Office, which adds that “transport was particularly badly affected with snowfalls causing numerous road closures, and train and flight cancellations”.
On 18 December 2009, five Eurostar trains got stuck in the Channel Tunnel after cold temperatures caused electrical failures, trapping 2,000 people for 16 hours. All Eurostar services were cancelled for the next three days.
In January that winter, BBC News reported that “heavy snow and freezing temperatures has caused chaos across Scotland over the past three weeks, with hundreds of schools closed and motorists facing hazardous conditions on the roads”.
Research from the UK Met Office indicates that the odds of the UK having a winter as cold as the one in 2009-10 will drop to less than 1% by the end of the century as global temperatures continue to rise.
Wetter winters
The total volume of rainfall recorded during UK winters is also rising. The plot below shows total winter rainfall in mm over 1836-2021 (blue) and the 10-year rolling average (black).
The table below shows average UK winter rainfall totals for a series of overlapping 30-year time periods across the full data record.
| 30-year period | Average annual winter rainfall (mm) |
|---|---|
| 1831-1860 | 254.69* |
| 1841-1870 | 276.00 |
| 1851-1880 | 284.28 |
| 1861-1890 | 287.46 |
| 1871-1900 | 281.51 |
| 1881-1910 | 279.06 |
| 1891-1920 | 300.55 |
| 1901-1930 | 311.07 |
| 1911-1940 | 314.51 |
| 1921-1950 | 305.00 |
| 1931-1960 | 298.76 |
| 1941-1970 | 290.82 |
| 1951-1980 | 293.23 |
| 1961-1990 | 301.82 |
| 1971-2000 | 329.22 |
| 1981-2010 | 330.01 |
| 1991-2020 | 346.98 |
Average winter rainfall over overlapping 30-year time periods, from 1831 to 2020, using the December-February average of mean monthly temperatures. An asterisk (*) indicates that a full 30 years was not available.
Between 1961-90 and 1990-2020, the UK winters became 15% wetter on average – increasing from around 300mm of rainfall to almost 350mm. The more recent decade of 2012-21 – not shown in the table – has seen further increases, with average winter rainfall of 380mm.
The Met Office also provides country-level rainfall data. The plot below shows 10-year rolling average winter temperature for England (dark blue), Scotland (red), Northern Ireland (light blue) and Wales (yellow).
The graph shows that rainfall is increasing across all four regions of the UK, but remains consistently the lowest in England and the highest in Scotland and Wales.
Looking at the wettest and driest years across the UK shows that individual rainfall extremes are becoming more common. In a ranking going back to 1884, seven of the driest years were in the 19th century, while three were in the 20th. None of the driest years on record have been in the 21st century.
Meanwhile, four of the rainiest winters have been in the 21st century. The graph below shows the wettest (blue dots) and driest (red dots) winters since 1884.
| Rainiest winters (mm) | Least rainy winters (mm) | |||
|---|---|---|---|---|
| Years | Winter rainfall | Years | Winter rainfall | |
| 1 | 2013-14 | 540.3 | 1963-64 | 121.3 |
| 2 | 2015-16 | 505.7 | 1890-91 | 141.4 |
| 3 | 1994-95 | 498.2 | 1844-45 | 164.6 |
| 4 | 1989-90 | 482.2 | 1933-34 | 170.4 |
| 5 | 2019-20 | 474.5 | 1846-47 | 171.3 |
| 6 | 1876-77 | 458.0 | 1962-63 | 171.5 |
| 7 | 1914-15 | 450.7 | 1857-58 | 176.6 |
| 8 | 1868-69 | 439.6 | 1840-41 | 179.6 |
| 9 | 2006-07 | 435.8 | 1937-38 | 186.9 |
| 10 | 1993-94 | 431.4 | 1854-55 | 189.1 |
Wettest and driest 10 winters in the UK since 1884. The dark blue line shows total winter rainfall, and blue and red dots indicate the driest and wettest snowy individual winters. The grey dashed lines the volume of rainfall recorded during the rainiest and least rainy winters on record. The table beneath shows the dates and total rainfall in mm of these winters. Credit: Chart by Carbon Brief, based on the Met Office HadUK dataset.
The fact that UK winters are getting wetter makes sense, McCarthy tells Carbon Brief, because as the atmosphere heats up, it is able to hold more moisture, which can then fall as rain. According to the Clausius-Clapeyron equation, the air can generally hold around 7% more moisture for every 1C of temperature rise.
However, he adds that the observed trend in UK winter rainfall is “somewhat larger than can be explained purely through the thermodynamic process”, and explains that natural variability is also very important when discussing changes in UK winter rainfall.
“We’re in a particularly wet regime at the moment,” McCarthy explains, “so we are seeing lots of winter rainfall records and wetter winters, but it’s the combination of variability and climate change”.
For example, December 2015 topped the charts as the UK’s wettest month on record, after Storm Desmond swept across the UK, bringing very heavy rainfall and gale-force winds to much of northern England, southern Scotland and Ireland. The resulting floods left many homes inundated and at least 60,000 without power.
The winter of 2015-16 was also the third warmest on record. Preliminary analysis conducted at the time suggested that the exceptional rainfall totals were 40% more likely because of rising global temperatures.
The jet stream
The graph below shows the relationship between temperature and rainfall, where warm and wet winters are shown in the top right, while cool and dry winters are in the bottom left. Darker dots indicate more recent years.
The UK’s winter weather regime is strongly linked to the strength of the jet stream. This thin, fast flowing ribbon of air in the troposphere – the lowest layer of the earth’s atmosphere – acts to steer weather systems towards the UK.
A strong jet stream brings warm and damp winds to the UK from the west, resulting in a warm and wet winter.
For example, the winter of 2023-24 has already been dominated by a series of storms. Storm Jocelyn, which swept across the UK at the end of January 2024, was the 10th named storm of the season. “The storms have mainly been driven by a powerful jet stream,” BBC News reported.
Similarly, during the winter of 2013-14, a series of storms brought record-breaking rainfall to the UK, clocking in as the wettest and eighth-warmest winter on record in the UK. Intense rainfall led to “remarkably widespread and persistent flooding”, according to the Met Office. Around 18,700 insurance claims related to flooding were filed across the UK in the aftermath of the storms, costing an estimated £451m.
One study suggests that climate change made the sustained wet and stormy weather seen around 43% more likely, and put an extra 1,000 houses at risk of flooding along the River Thames.
The study attributes about two-thirds of the increase in likelihood to the atmosphere being able to hold more moisture because the world is warming up and the remaining third to the position of the jet stream.
Conversely, a weak jet stream allows cold air from the Arctic and mainland Europe to enter from the east and north. “A slower, more buckled jet stream can cause areas of higher pressure to take charge, which typically brings less stormy weather, light winds and dry skies,” the Met Office says.
This was the case in the winter of 2009-10, which clocked in as the eighth-coldest and least-windy UK winter on record.
Sometimes, the jet stream can even get “stuck” – a phenomenon called blocking – and instead of shunting weather systems from west to east, it can allow a spell of cold, dry weather to sit over the UK for many days.
While there is a clear trend of UK winters getting warmer and wetter, the data on wind speed is less clear-cut. However, cool weather in the UK is often associated with low speeds, while warm weather is often brought by strong gusts.
The plot below shows average UK winter wind speed over 1969-2021 in knots. The darker line shows the 10-year rolling average, and the most and least windy years are shown by red and blue dots, respectively.
| Windiest winters | Least windy winters | |||
|---|---|---|---|---|
| Years | Average windspeed (knots) | Years | Average windspeed (knots) | |
| 1 | 1973-74 | 13.08 | 2009-10 | 7.90 |
| 2 | 1989-90 | 12.77 | 2010-11 | 8.62 |
| 3 | 1974-75 | 12.72 | 2005-06 | 8.81 |
| 4 | 1994-95 | 12.71 | 2008-09 | 9.03 |
| 5 | 2013-14 | 12.47 | 1984-85 | 9.04 |
| 6 | 1982-83 | 12.41 | 1976-77 | 9.31 |
| 7 | 1980-81 | 12.24 | 2018-19 | 9.32 |
| 8 | 1999-2000 | 12.11 | 2000-01 | 9.54 |
| 9 | 1988-89 | 12.11 | 1986-87 | 9.59 |
| 10 | 2019-20 | 12.08 | 2016-17 | 9.68 |
Windiest and least windy 10 winters in the UK since 1969. The dark blue line shows winter average wind speed, and red and blue dots indicate the windiest and least windy individual winters. The grey dashed lines the average wind speed during the windiest and least windy winters on record. The table beneath shows the dates and wind speeds of these winters. Credit: Chart by Carbon Brief, based on the Met Office HadUK dataset.
The table below shows average UK wind speed totals for three overlapping 30-year time periods.
| 30-year averages | Average wind speed (knots) |
|---|---|
| 1971-2000 | 11.06 |
| 1981-2010 | 10.60 |
| 1991-2020 | 10.55 |
Average winter wind speed for overlapping 30-year time periods, from 1971 to 2020, using the December-February average of mean monthly temperatures.
McCarthy tells Carbon Brief that there has been a notable decline in UK wind speed when looking at annual data, which is consistent with the trend of “stilling” – a slowdown in near surface wind speeds – measured globally. However, he says that this trend is less obvious in the winter-only data.
Meanwhile, the UK State of the Climate report 2022 states that there are no compelling trends in storminess when considering maximum gust speeds over the last four decades.
A range of other atmospheric circulation patterns can also impact UK winters.
The North Atlantic Oscillation (NAO) is a large-scale atmospheric pressure see-saw in the North Atlantic region, which describes the difference in air pressure between the high pressure sitting over the Azores, to the west of Portugal, and the low pressure over Iceland.
When the NAO is “positive” and the pressure difference is stronger than usual, the jet stream shifts towards the poles, bringing mild, wet and windy weather to North American and Eurasian winters and leaving the Arctic very cold.
When it is “negative” and the pressure difference weakens, storm tracks shift towards the equator, bringing cold, dry and calm winters to Europe.
Another mechanism is the “stratospheric polar vortex”. This low-pressure weather system sits around 50km above the Arctic in the stratosphere – the layer of the atmosphere above the troposphere. Its main feature is the strong west-to-east winds which encircle the north pole. These winds are known as the “polar night jet” because they only appear during the dark Arctic winter.
As with the jet stream in the troposphere, the polar night jet forms a boundary between the very cold Arctic air and the warmer air over the mid-latitudes. However, if something disrupts the stratospheric polar vortex it can weaken, reverse direction and even split into two. This can trigger a “sudden stratospheric warming” event where air collapses in over the Arctic, causing a spike in temperatures in the stratosphere – by as much as 50C in just a couple of days.
This allows the cold air the polar vortex was holding in to spill out into the mid-latitudes during the weeks that follow. This is what caused the “Beast from the East” snowstorm that hit the UK in 2018. (This is not well reflected in the UK winter data, as the brunt of the storm hit in March 2018 after the end of meteorological winter.)
In general, however, the UK has experienced a run of mild, wet winters in the most recent decade, including the very wet winters of 2013, 2015 and 2019. These are consistent with a positive phase of the NAO and strong polar vortex, according to the latest State of the UK Climate report.
Projections
As the planet continues to warm, the UK’s climate will shift “towards warmer, wetter winters and hotter, drier summers”, the Met Office says.
The UK Climate Projections 2018 (UKCP18) is a series of climate change projections for the UK produced by the UK Met Office, taking advantage of the latest observed data and climate models
The projections include temperature and rainfall changes – for averages and extremes – for each month and season of the year, and for different emissions scenarios and future time periods throughout this century.
The maps below show the probabilistic projections for summer average temperature (top) and winter precipitation (bottom) in the 2080s under the RCP4.5 emissions pathway, relative to a 1961-90 baseline. In this pathway, global temperatures are projected to rise by around 2.7C of warming above pre-industrial levels by 2081-2100, which is broadly in line with the trajectory under current global policies.
The three percentiles (10th, 50th and 90th) reflect the likelihood of those temperatures and rainfall anomalies occurring. The 50th percentile (middle maps) is the “central estimate” across the models, while the 10th (left) and 90th (right) percentiles reflect the lowest 10% and highest 10% of the model results.
The table below shows UKCP18 projections for changes in average UK winter temperature and precipitation under RCP4.5, under the 10th, 50th and 90th percentile, for 2080-99, compared to a 1981-2000 baseline.
| 10th percentile change | 50th percentile change | 90th percentile change | |
|---|---|---|---|
| Change in average winter temperature (C) | +0.7 | +2.0 | +3.5 |
| Change in average winter precipitation (%) | -2.0 | +11.0 | +25.0 |
Source: UKCP18 Key results spreadsheet
As a central estimate, these projections suggest that by 2080-99, UK winters will be 2C warmer and 11% wetter than they were in 1981-2000.
However, the picture is more complex for wind speed. The Met Office explains that storms in the UK are influenced by factors including sea surface temperatures, Arctic sea ice melt and the jet stream.
It says that “under climate change some of these influences will strengthen storms and others weaken them, as well as potentially change the parts of the world that storms affect”.
It adds:
“UKCP18 projected an increase in near surface wind speeds over the UK for the second half of the 21st century for the winter season when more significant impacts of wind are experienced. However, the increase in wind speeds is modest compared to natural variability from month to month and season to season, so confidence is low.”
The post Analysis: How UK winters are getting warmer and wetter appeared first on Carbon Brief.
More than 100 countries have cut their dependence on fossil-fuel imports and saved hundreds of billions of dollars by continuing to invest in renewables, according to the International Energy Agency (IEA).
It says nations such as the UK, Germany and Chile have reduced their need for imported coal and gas by around a third since 2010, mainly by building wind and solar power.
Denmark has cut its reliance on fossil-fuel imports by nearly half over the same period.
Renewable expansion allowed these nations to collectively avoid importing 700m tonnes of coal and 400bn cubic metres of gas in 2023, equivalent to around 10% of global consumption.
In doing so, the fuel-importing countries saved more than $1.3tn between 2010 and 2023 that would otherwise have been spent on fossil fuels from overseas.
Reduced reliance
The IEA’s Renewables 2025 report quantifies the benefits of renewable-energy deployment for electricity systems in fossil fuel-importing nations.
It compares recent trends in renewable expansion to an alternative “low renewable-energy source” scenario, in which this growth did not take place.
In this counterfactual, fuel-importing countries stopped building wind, solar and other non-hydropower renewable-energy projects after 2010.
In reality, the world added around 2,500 gigawatts (GW) of such projects between 2010 and 2023, according to the IEA, more than the combined electricity generating capacity of the EU and US in 2023, from all sources. Roughly 80% of this new renewable capacity was built in nations that rely on coal and gas imports to generate electricity.
The chart below shows how 31 of these countries have substantially cut their dependence on imported fossil fuels over the 13-year period, as a result of expanding their wind, solar and other renewable energy supplies. All of these countries are net importers of coal and gas.
In total, the IEA identified 107 countries that had reduced their dependence on fossil fuel imports for electricity generation, to some extent due to the deployment of renewables other than hydropower.
Of these, 38 had cut their reliance on electricity from imported coal and gas by more than 10 percentage points and eight had seen that share drop by more than 30 percentage points.
Security and resilience
The IEA stresses that renewables “inherently strengthen energy supply security”, because they generate electricity domestically, while also “improving…economic resilience” in fossil-fuel importer countries.
This is particularly true for countries with low or dwindling domestic energy resources.
The agency cites the energy crisis exacerbated by Russia’s invasion of Ukraine, which exposed EU importers to spiralling fossil-fuel prices.
Bulgaria, Romania and Finland – which have historically depended on Russian gas for electricity generation – have all brought their import reliance close to zero in recent years by building renewables.
In the UK, where there has been mounting opposition to renewables from right-wing political parties, the IEA says reliance on electricity generated with imported fossil fuels has dropped from 45% to under 25% in a decade, thanks primarily to the growth of wind and solar power.
Without these technologies, the UK would now be needing to import fossil fuels to supply nearly 60% of its electricity, the IEA says.
Other major economies, notably China and the EU, would also have had to rely on a growing share of coal and gas from overseas, if they had not expanded renewables.
As well as increasing the need for fossil-fuel imports from other countries, switching renewables for fossil fuels would require significantly higher energy usage “due to [fossil fuels’] lower conversion efficiencies”, the IEA notes. Each gigawatt-hour (GWh) of renewable power produced has avoided the need for 2-3GWh of fossil fuels, it explains.
Finally, the IEA points out that spending on renewables rather than imported fossil fuels keeps more investment in domestic economies and supports local jobs.
The post IEA: Renewables have cut fossil-fuel imports for more than 100 countries appeared first on Carbon Brief.
IEA: Renewables have cut fossil-fuel imports for more than 100 countries
Greenhouse Gases
Cropped 8 October 2025: US government shutdown; EU loses green space; Migratory species extinction threat
We handpick and explain the most important stories at the intersection of climate, land, food and nature over the past fortnight.
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Key developments
Forest fund delays and cuts
TFFF BEHIND SCHEDULE: Brazil’s flagship forest fund, the Tropical Forest Forever Facility (TFFF), is “running behind schedule as officials deliberate on how to structure the complex financial vehicle” in time for COP30, Bloomberg reported. The “ambitious” fund aims to raise $125bn to help countries protect rainforests “using investment returns from high-yielding fixed-income assets”, it explained. However, the outlet reported that investor events have either not been held or cancelled, while officials are still mulling “possible structures” for the fund.
CUTS DEEP: Environmentalists fear that “sweeping spending cuts for forest protection” by Argentina’s “pro-business libertarian” president, Javier Milei, could endanger the country’s forests, Climate Home News reported. The impacts of these cuts are “already becoming evident”, contributing to deforestation – particularly in the northern Gran Chaco region, environmentalists told the outlet. According to Argentine government data, the country lost about 254,000 hectares of forest nationwide in 2024. Milei – who has said he wants to withdraw Argentina from the Paris Agreement – faces a “crucial midterm election” in October that could make environmental deregulation even easier, the outlet wrote.
BANKING ON THE AMAZON: A new report found that 298 banks around the world “channelled $138.5bn” to companies developing new fossil-fuel projects in Latin America and the Caribbean, Mongabay reported. The experts behind the study told the outlet: “Some major banks have adopted policies to protect the Amazon, but these have had little impact, as they do not apply to corporate-level financing for oil and gas companies operating in the Amazon.” Mongabay approached every bank, but only JPMorgan Chase responded, declining to comment.
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‘Green to grey’
‘600 FOOTBALL PITCHES’: Europe is losing “green space…at the rate of 600 football pitches a day”, according to a new, cross-border investigation by the “Green to Grey Project”, the Guardian reported. The outlet – part of the Arena for Journalism in Europe collaboration of journalists and scientists behind the project – added that Turkey accounted for more than a fifth of the total loss in Europe. While nature “accounts for the majority of the losses”, the research showed that the EU is also rapidly building on agricultural land, “with grave consequences for the continent’s food security and health”, it continued.
‘TWICE AS HIGH’: Conducted by 40 journalists and scientists from 11 countries, the investigation found that the “natural area” lost to construction in the EU was “twice as high as official estimates”, Le Monde reported. Despite Brussels setting a 2011 target to “reduce the EU’s yearly land take” to 800km2 – “more than 100,000 football fields” – the EU is “artificialising more than 1,000km2 of land per year”, it added.
KEY DRIVERS: While the “main drivers of land loss across Europe” are housing and road-building, Arena for Journalism in Europe found many instances of construction “that serve only a minority or that are not built based on public need”, such as luxury tourism sites. Between 2018 to 2023, “an area the size of Cyprus” in nature and cropland was lost to construction, they added. Researchers who “scrutinised millions of pixels in search of lost natural areas” found that Finland’s tourism boom is “encroaching on the last remaining sanctuaries” in Lapland, another Le Monde story reported.
News and views
‘INTRACTABLE’ OFFSETS: A new review paper found that the failure of carbon offsets to cut emissions is “not due to a few bad apples”, but “down to deep-seated systemic problems that incremental change will not solve”, the Guardian wrote. Study co-author Dr Stephen Lezak told the outlet: “We have assessed 25 years of evidence and almost everything up until this point has failed.” The worst of these “intractable problems” were with “issuing additional credits” for “non-additional”, “impermanent” and double-counted projects, the Guardian noted.
INSTITUTIONALISING AGROECOLOGY: The Cuban government issued a national decree providing a “more explicit legal framework” for the implementation of agroecological principles across the country, according to a release from the Caribbean Agroecology Institute. The decree also announced a new national fund for promoting agroecology. Yamilé Lamothe Crespo, the country’s deputy director of science, innovation and agriculture, “emphasised that agroecology is a model capable of responding to the global climate crisis”, teleSUR reported.
ZERO PROGRESS TO ZERO HUNGER: The world has “made no improvement” towards achieving the “zero hunger” Sustainable Development Goal since it was set in 2015, according to a new report from the UN Food and Agriculture Organization. The report said that “ongoing geopolitical tensions and weather-related disruptions” have contributed to “continued instability in global food markets”. Separately, a new report from the Energy and Climate Intelligence Unit thinktank estimated that a “year’s worth of bread” has been lost in the UK since 2020 due to extreme weather impacting wheat harvests, the Guardian reported.
MEATLESS MEDIA: More than 96% of analysed climate news stories across 11 (primarily US-based) outlets “made no mention of meat or livestock production as a cause of climate change”, according to analysis by Sentient Media. Sentient, a not-for-profit news organisation in the US, looked at 940 stories to assess the reported causes of greenhouse gas emissions. Around half of the stories included mention of fossil fuels, it said. Covering the report, the Guardian wrote: “The data reveals a media environment that obscures a key driver of the climate crisis.”
FRAUGHT PATH: One-fifth of migratory species “face extinction from climate change”, according to a new report by the UN’s migratory species convention, covered by Carbon Copy. The “warning” comes as climate change and extreme weather are “altering their ranges [and] shrinking habitats”, the Mail & Guardian wrote. Oceanographic Magazine noted that the North Atlantic right whale is “forced to make migratory detours into dangerous pockets of the ocean” due to warming seas. Down to Earth reported that the range of Asian elephants is “shifting east” in “response to anthropogenic land-use and climate change”.
GOODBYE, GOODALL: Dr Jane Goodall, the groundbreaking English primatologist, died at the age of 91 last week. BBC News noted that Goodall “revolutionised our understanding” of chimpanzees, our “closest primate cousins. The outlet added that she “never wavered in her mission to help the animals to which she dedicated her life”. CNBC News reported that Goodall followed a vegan diet due to factory farming and the “damage done to the environment by meat production”. She also “encouraged” others to follow her example, the outlet said.
Spotlight
What the US government shutdown means for food, forests and climate
This week, Carbon Brief explains the US government shutdown – now in its second week – and its implications for food, forests, public lands and climate change.
The US federal government shut down at 12:01 eastern daylight time on 1 October, as Congress failed to agree on a bill to keep funding the government and its services.
This is the 11th time that the government has shut down in such a fashion; previous shutdowns have lasted anywhere from a few hours to longer than a month.
As a result of the shutdown, 750,000 federal employees have been furloughed, or placed on unpaid leave. Others, whose work has been deemed “essential”, are working without pay.
(A law passed during a shutdown in US president Donald Trump’s first term guarantees back pay and benefit accrual for furloughed employees. However, the White House has argued that the law does not necessarily guarantee these benefits.)
Some agencies have seen close to 90% of their employees furloughed.
With a reopening date uncertain, Carbon Brief explored what the shutdown means for food, forests and climate.
Food and farming
According to the agency’s “lapse of funding” plan, the US Department of Agriculture (USDA) planned to furlough about half of its employees for the duration of the shutdown.
Among the activities put on hold during the funding lapse are the disbursement of disaster-assistance payments for farmers impacted by extreme weather events. The Farm Service Agency, which oversees these payments, will also not process any new loans during the shutdown, such as those that provide assistance to farmers during the harvest.
The Natural Resources Conservation Service, an arm of the USDA with a mission to help private landowners “restore, enhance and protect forestland resources”, has seen more than 95% of its staff furloughed, effectively halting all conservation efforts within the agency.
Certain animal-health programmes – such as the one addressing the highly pathogenic avian influenza outbreak – will continue, but others will shutter for the duration of the funding lapse. Long-term research on animal and plant diseases will also cease.
Forests and fires
The US Forest Service falls under the purview of the USDA. Employees responsible for “responding [to] and preparing for wildland fires” will continue to work during the shutdown; however, “hazardous fuels treatments” – such as prescribed burns or pruning to reduce fuel loads – will be reduced under the agency’s plan. Furthermore, state grants for fire preparedness and forest management “may be delayed”.
Work on forest restoration projects may potentially continue “on a case-by-case basis”, the plan said.
The Bureau of Land Management (BLM), a subdivision of the Department of the Interior, will furlough around 43% of its employees, according to its contingency plan. Staff dedicated to fire management will continue to work while “carryover balances” are available, but the number of staff working will be reduced once these funds are exhausted.
Climate change and research
Across the federal government, most research activities are being put on hold, including conference travel and the issuing of new grants.
Grant recipients may continue carrying out research “to the extent that doing so will not require federal staff” and while funds are available, according to the National Science Foundation’s operational plan. This does not include researchers at federal agencies, such as the Environmental Protection Agency, US Geological Survey and the National Oceanic and Atmospheric Administration (NOAA).
The funding-lapse plan set out by the Department of Commerce said that NOAA will continue its prediction and forecasting activities, as well as maintain “critical and mission-related” programmes related to research satellites. However, “most research activities” will cease.
Similarly, NASA’s shutdown plan indicates continuing support for satellite operations, but a pause on research activities – except for those “aligned with presidential priorities”.
Watch, read, listen
MORAINE DILEMMA: A new PBS documentary walked through ancient Inca paths in the Andes to understand how modern communities are confronting the loss of Peru’s glaciers.
SUBSIDISING ‘EXPLOITATION’: A DeSmog investigation revealed how farmers convicted of “exploiting migrant workers” continue to claim “millions in taxpayer-funded subsidies”.
GROUND TRUTHING: A podcast from the Hindu looked back at 20 years of India’s Forest Rights Act, meant to “address historic injustices” towards the country’s Indigenous communities.
DEEP DIVE MANUAL: Mongabay journalists shared how they investigated Brazil’s shark-meat purchases that were subsequently served in schools, prisons and hospitals.
New science
- The frequency of “economically disastrous” wildfires increased sharply after 2015, with the highest disaster risk in “affluent, populated areas” in the Mediterranean and temperate regions | Science
- A “strictly protected” forest in Tuscany had maximum summertime temperatures that were, on average, nearly 2C cooler than those of nearby productive forests over 2013-23 | Agricultural and Forest Meteorology
- Between 2010 and 2020, the water consumed by global crop-growing increased by 9%, putting “additional pressure on limited water resources” | Nature Food
In the diary
- 9-15 October: 2025 World Conservation Congress of the International Union for Conservation of Nature (IUCN) | Abu Dhabi, United Arab Emirates
- 10-17 October: World Food Forum 2025 | Rome
- 16 October: World Food Day | Global
- 25 October: Ivory Coast presidential election
Cropped is researched and written by Dr Giuliana Viglione, Aruna Chandrasekhar, Daisy Dunne, Orla Dwyer and Yanine Quiroz. Please send tips and feedback to cropped@carbonbrief.org
The post Cropped 8 October 2025: US government shutdown; EU loses green space; Migratory species extinction threat appeared first on Carbon Brief.
From canola farmers in Canada to car owners in India, biofuels have become the subject of everyday debate across the world.
Liquid biofuels feature heavily in the climate plans of many countries, as governments prioritise domestic energy security amid geopolitical challenges, while looking to meet their climate targets and bolster farm incomes.
Despite a rapid shift towards electrified transportation, biofuels continue to play a leading role in efforts to reduce road-transport emissions, as they work well with many existing car engines.
At the same time, biofuels are expected to play an important role in decarbonising sectors where emissions are particularly challenging to mitigate, such as shipping, trucking and aviation.
Heated debates continue around using food sources as fuel in the face of record hunger levels, given competing demands for land and crops.
Despite these arguments, biofuels are seeing heightened demand bolstered by a strong policy push, particularly in developing countries.
They are expected to feature heavily on the COP30 agenda this year as a key feature of the host Brazil’s “bioeconomy”.
Below, Carbon Brief unpacks what biofuels are, their key benefits and criticisms, plus how they are being used to meet climate targets.
- What are biofuels?
- What are the most common biofuels being used today?
- What are the main arguments for biofuels?
- What are some of the main criticisms of biofuels?
- How are countries using biofuels to meet their climate targets?
- How could climate change impact biofuel production?
What are biofuels?
Bioenergy refers to all energy derived from biomass, a term used to describe non-fossil material from biological sources. Biofuels, in turn, are liquid fuels that are produced from biomass.
These sources are wide-ranging, but commonly include food crops, vegetable oils, animal fats, algae and municipal or agricultural waste, along with synthetic derivatives from these products.
Glossary
Biomass
Non-fossil material of biological origin
Biofuel
Fuels produced directly or indirectly from biomass
Feedstock
Types of biomass used as sources for biofuels, such as crops, grasses, agricultural and forestry residues, wastes and microbial biomass
Bioenergy
All energy derived from biofuels
Bioethanol
A biofuel used as a petrol substitute, produced from the fermentation of biomass from plants like corn, sugarcane and wheat
Biodiesel
A biofuel used as a diesel substitute, derived from vegetable oils or animal fats through a process called transesterification
The different types of biomass are referred to as “feedstocks”. They are converted to fuel through one or more processes, such as fermentation or treating them with high temperatures or hydrogen.
Biofuels are frequently blended with petroleum products in an effort to reduce emissions and reliance on fossil-fuel imports.
Experiments to test whether vegetable oils could run in combustion engines began in the early 1900s. In a 1912 paper, Rudolf Diesel – the inventor of the diesel engine – presciently noted that these oils “make it certain that motorpower can still be produced from the heat of the sun…even when all our natural stores of solid and liquid fuels are exhausted”.
An extract from Rudolf Diesel’s 1912 paper, published in the Proceedings of the Institution of Mechanical Engineers, outlining the importance biofuels could assume in the future. Credit: Proceedings of the Institution of Mechanical Engineers (1912)
Biofuels are divided into four “generations”, based on the technologies and feedstocks used to synthesise them.
| Type of biofuel | Source |
| First-generation | Food crops (eg, sugarcane, corn, wheat, rice) |
| Second-generation | Non-edible crops and materials (eg, straw, grasses, used vegetable oil, forest residues, waste) |
| Third-generation | Aquatic materials (eg, algae) |
| Fourth-generation | Genetically modified algae, bacteria and yeast, as well as electrofuels, synthetic fuels and e-fuels |
First-generation biofuels
The first – and earliest – generation of biofuels comes from edible crops, such as corn, sugarcane, soya bean and oil palm. Large-scale commercial production of these fuels began in the 1970s in Brazil and the US from sugarcane and corn, respectively.
Bioethanol, for instance, is drawn from the fermentation of sugars in corn, sugarcane and rice. Biodiesel is derived from vegetable oils – such as palm, canola or soya bean oil – or animal fats, through a process called transesterification, which makes them less viscous and more suitable as fuels.
Because they are derived directly from food crops, experts and campaigners have expressed concerns over the impacts of first-generation biofuels on forests, food security and the environment, as well as indirect land-use change impacts. (See: What are some of the main criticisms of biofuels?)
Several studies have found that the land-use emissions of first-generation biofuels are severely underestimated, but other experts tell Carbon Brief that this depends on how and where the crops are grown, processed and transported.
According to Dr Angelo Gurgel, principal research scientist at the Massachusetts Institute of Technology (MIT) Center for Sustainability Science and Strategy, the “big image that biofuels are bad” is not always accurate. Gurgel explains:
“Some biofuels can be better than others, varying from place to place and feedstock to feedstock. It depends on where you produce them, how much farmers can increase yields, how effectively a country’s regulations help avoid land-use change and how closely it is connected to international markets.
“Some options may be very, very good in terms of reducing emissions and other options probably will be very bad.”
Second-generation biofuels
Second-generation biofuels are extracted from biomass that is not meant for human consumption.
Feedstocks for these biofuels are incredibly varied. They include agricultural waste, such as straw and corn stalks, grasses, forest residues left over from wood processing, used vegetable oil and solid waste. They can also be made from energy crops grown specifically to serve as biofuels, such as jatropha, switchgrass or pongamia.
Derived from “waste” or grown on “marginal” land, second-generation biofuels were developed in the early 2000s. These fuels aimed to overcome the food security and land-use issues tied to their predecessors, while increasing the amount of fuel drawn out from biomass, compared to first-generation feedstocks.
These feedstocks are either heated to yield oil or “syngas” and then cooled, or treated with enzymes, microorganisms or other chemicals to break down the tough cellulose walls of plants. They can be challenging to process and present significant logistical and land-use challenges.
Third-generation biofuels
Third-generation biofuels are primarily derived from aquatic organic material, particularly algae and seaweed. While the US Department of Energy began its aquatic species programme in 1978 to research the production of biodiesel from algae, algal biofuel research saw a “sudden surge” in the 1990s and “became the darling” of renewable energy innovation in the early 21st century, says Mongabay.
Because algae grows faster than terrestrial plants, is high in lipid (fatty organic) content and does not compete with terrestrial crops for land use, many scientists and industry professionals consider third-generation biofuels an improvement over their predecessors.
However, high energy, water and nutrient needs, high production costs and technical challenges are key obstacles to the large-scale production of algae-based biofuels. Since the early 2010s, many companies, including Shell, Chevron, BP and ExxonMobil, have abandoned or cut funding to their algal biofuel development programmes.
Fourth-generation biofuels
Genetically modified algae, bacteria and yeast engineered for higher yields serve as the feedstock for fourth-generation biofuels. These fuels have been developed more recently – from the early 2010s onwards – and are an area of ongoing research and development.
Some of these organisms are engineered to directly or artificially photosynthesise solar energy and carbon dioxide (CO2) into fuel; these are called solar biofuels.
Others – called electrofuels, synthetic fuels or e-fuels – are produced when CO2 captured from biomass is combined with hydrogen and converted into hydrocarbons through other processes, typically using electricity generated from renewable sources.
Fourth-generation biofuels are technology- and CO2-intensive and expensive to produce. They also run up against public perception and legal limitations on genetically modified organisms, as well as concerns around biosafety and health.
What are the most common biofuels being used today?
Bioethanol is the most commonly used liquid biofuel in the world, followed by biodiesel.
In 2024, global liquid biofuel production increased by 8% year-on-year, with the US (37%) and Brazil (22%) accounting for the largest overall share of production, according to the 2025 Statistical Review of World Energy from the Energy Institute.
Other countries that saw a notable increase in production between 2023-24 were Sweden (62%), Canada (39%), China (30%), India (26%) and Argentina (24%).
Bioethanol is the most commonly used biofuel in the world, with a consumption rate of 1.1m barrels of oil equivalent per day in 2024, according to the report. This is closely followed by biodiesel, at 1m barrels of oil equivalent per day.
In 2024, the US, Brazil and the EU accounted for nearly three-quarters of all biofuels consumed globally. However, while India’s biofuel demand grew by 38%, demand for biofuels in the EU fell by 11% in 2024, according to the review, echoing outlooks that show that middle-income countries are driving biofuel growth.
The chart below shows how biofuel production and consumption have changed since 2000, and how they are projected to change through 2034.
What are the main arguments for biofuels?
From lowered oil imports and emissions through to boosting farm livelihoods, countries that have boosted biofuels programmes cite several benefits in biofuels’ favour.
‘Renewable’ energy and lowered emissions
Biofuels are often described as “renewable” fuels, since crops can be grown over and over again.
In order to achieve this, crops for biofuels must be continuously replanted and harvested to meet energy demand. Growing crops – particularly in the monoculture plantations typically used for growing feedstocks – can require high use of fossil fuels, in the form of machinery and fertiliser. Furthermore, in the case of wood as a feedstock, regrowth can take decades.
While some biofuels offer significant emissions reductions, others, such as palm biodiesel, generate similar or sometimes higher emissions as fossil fuels when burned. However, ancillary emissions for biofuels are much smaller than for oil and gas operations.
One of the main cited benefits of biofuels is that plants capture CO2 from the atmosphere as they grow, potentially serving to mitigate emissions. However, several lifecycle-assessment studies have questioned just how much plants can offset emissions. These studies come up with varying estimates based on feedstock types, geography, production routes and methodology.
This divergence is echoed in the UN Intergovernmental Panel on Climate Change’s (IPCC) Sixth Assessment Report (AR6), which points to “contrasting conclusions” even when similar bioenergy systems and conditions are analysed.
Per the report, there is “medium agreement” on the emissions-reduction potential of second-generation biofuels derived from wastes and residues by 2050.
At the same time, the IPCC adds that “technical land availability does not imply that dedicated biomass production for bioenergy…is the most effective use of this land for mitigation”.
It also warns that larger-scale biofuel use “generally translates into higher risk for negative outcomes for greenhouse gas emissions, biodiversity, food security and a range of other sustainability criteria”.
Along with the IPCC, many other groups and experts – including the UK’s Climate Change Commission – have called for a “biomass hierarchy”, pointing to a limited amount of sustainable bioenergy resources available and how best to prioritise their use.
Use in hard-to-abate sectors
In many countries, such as the US and UK, biofuels are part of a standard grade of diesel and petrol (gasoline) available at most fuel pumps.
Biofuels have also been the leading measure for decarbonising road transport in emerging economies, where electric vehicle systems were not as developed as in many western nations.
According to the International Energy Agency (IEA), most new biofuel demand is coming from these countries, including Brazil, India and Indonesia.
Biofuels are also one of the key options being explored to decarbonise the emissions-heavy, but “hard-to-abate”, sectors of aviation and shipping.
The AR6 report notes that the “faster-than-anticipated adoption of electromobility” has “partially shifted the debate” from using biofuels primarily in land transport towards using them in shipping and aviation.
At the same time, experts question how this can be done sustainably, given the limited availability of advanced biofuels and the rising demand for them.
Government reports – such as those released by the EU Commission – recognise that, in some circumstances, so-called sustainable aviation fuels (SAFs) could produce just as many emissions as fossil fuels when burned in order to power planes.
However, SAFs do generally – although not always – have a lower overall “lifecycle” carbon footprint than petroleum-based jet fuel. This is due to the CO2 absorbed when growing plants for biofuels, or emissions that are avoided by diverting waste products to be used as fuels.
Unlike the road sector, where “electrification is mature…aviation and shipping cannot be electrified so easily”, says Cian Delaney, fuels policy officer at the Brussels-based advocacy group Transport & Environment (T&E).
According to a 2025 T&E briefing, the 2030 demand for biofuels from global shipping alone could require an area the “size of Germany”. Delaney tells Carbon Brief:
“In aviation in particular, where you still need some space to transition, you still need a certain amount of biofuels. But these biofuels should be advanced and waste biofuels derived from true waste and residues, and they are available in truly limited amounts, which is why, in parallel, we need to upscale the production of e-fuels [synthetic fuels derived from green hydrogen] for aviation.”
In February this year, more than 65 environmental organisations from countries including the US, Indonesia and the Netherlands wrote to the International Maritime Organization, urging its 176 member states to “exclude biofuels from the industry’s energy mix”.
The organisations cited the “devastating impacts on climate, communities, forests and other ecosystems” from biofuels, cautioning that fuels such as virgin palm oil are often “fraud[ulently]” mislabelled as used cooking oil – a key feedstock for SAF.
Meanwhile, the AR6 report has “medium confidence” that heavy-duty trucks can be decarbonised through a combination of batteries and hydrogen or biofuels. And despite growing interest in the use of biofuels for aviation, it says, “demand and production volumes remain negligible compared to conventional fossil aviation fuels”.
Energy security and reducing import dependence
In many countries, such as India and Indonesia, biofuels are seen as a part of a suite of measures to increase energy security and lessen dependence on fossil-fuel imports from other countries. This imperative received increasing emphasis after the Covid-19 pandemic and Russia’s war on Ukraine.
In developing countries, the “main motivation” behind biofuel policy is to find an alternative to excessive dependence on imported fossil fuels that are a “major drain” on foreign exchanges and subject to volatility and price shocks, says Prof Nandula Raghuram, professor of biotechnology at the Guru Gobind Singh University in New Delhi.
Raghuram, who formerly chaired the International Nitrogen Initiative, tells Carbon Brief that, in order for developing countries to “earn those precious dollars to finance our petroleum imports”, they have to export “valuable primary commodities”, such as grain and vegetables, at the cost of nutritional self-reliance. He adds:
“And so we have to see the biofuel approach as not so much a proactive strategy, but as a sort of reactive strategy to use whatever domestic capacity we have to produce whatever domestic fuel, including biofuels, to reduce that much burden on the exchequer for imports.”
Boost to agriculture
Many governments also see biofuels as an alternative income stream for farmers and a means to revitalise rural economies.
An increasing demand for biofuels could, for example, offer farmers higher returns on their crops, attract industry and services to agrarian areas and help diversify farm incomes.
In 2023, a report by the International Labour Organization (ILO) and the International Renewable Energy Agency (IRENA) estimated that the liquid biofuel industry employed approximately 2.8 million people worldwide.
The bulk of these jobs were in Latin America and Asia, where farming is more labour-intensive and relies on informal and seasonal employment. Brazil’s biofuel sector alone employed nearly one million people in 2023, according to the report.
Meanwhile, North America and Europe accounted for only 12% and 6% of biofuel jobs in 2023, respectively, according to the report.
The chart below shows the number of jobs in the biofuel sector in the top 10 biofuel-producing countries.
Delaney points out that biofuel-related jobs account for less than 1% of all jobs in the EU, adding that the “most-consumed biofuel feedstocks” in the bloc are vegetable oils that are imported from countries such as Brazil and Indonesia. (See: How are countries using biofuels to meet their climate targets?)
He tells Carbon Brief:
“Despite strong biofuels mandates in the EU, the sector didn’t create as many jobs in the end for EU farmers, but, instead, benefited the big fuel suppliers and industry players.”
What are some of the main criticisms of biofuels?
Despite their widespread use and increasing adoption, experts recognise that biofuels “may also carry significant risks” and cause impacts that can undermine their sustainability, if not managed carefully.
Production emissions, land-use change and deforestation
The different chemical processes involved in making biofuels require varying amounts of energy and, therefore, the associated emissions depend on how “clean” a producer country’s energy mix is.
At the same time, growing biofuel crops often relies on emissions-intensive fertilisers and pesticides to keep yields high and consistent. (See Carbon Brief’s detailed explainer on what the world’s reliance on fertilisers means for climate change.)
Biofuel production processes, such as fermentation, also release CO2 and other greenhouse gases, including methane and nitrous oxide.
MIT’s Gurgel tells Carbon Brief that it is “relatively straightforward” to measure these direct emissions from biofuel production.
However, given how different countries account for deforestation, tracking direct land-use change emissions related to biofuel production is slightly more challenging – although still possible, Gurgel says. These emissions can come from clearing forests or converting other land specifically for growing energy crops.
For example, in many tropical forest countries, native rainforests and peatland have been cleared to grow oil palm for biodiesel or sugarcane for bioethanol.
According to one 2011 study by the Centre for International Forestry Research and World Agroforestry (CIFOR-ICRAF), it could take more than 200 years to reverse the carbon emissions caused by clearing peatland to grow palm oil.
Gurgel tells Carbon Brief:
“What is really very hard – I would say impossible – to measure are the indirect impacts of biofuels on land.”
Indirect land-use change occurs when a piece of land used to grow food crops is used instead for biofuels. This can, in turn, require deforestation somewhere else to produce the same amount of crops for food as the original piece of land.
Indirect land-use change can mean a loss of natural ecosystems, with “significant implications for greenhouse gas emissions and land degradation”, according to a 2024 review paper.
Gurgel explains:
“If you provoke a chain of reactions in the market, that can lead to expansion of cropland in another region of the world and then this can push the agricultural frontier further and cause some deforestation…It’s quite hard to know exactly what’s going to happen and those things are interactions in the market that are impossible to measure.”
The “best that scientists can do” to determine if such a “biofuel shock” could indeed cause land-use change in a forest or grassland elsewhere “is try to project those emissions using models, or do very careful statistical work that will never be complete”, he adds.
Delaney, from Transport and Environment, contends that there is enough scientific research to “show that indirect land-use change is real” and to quantify the expansion of “certain food and feedstocks into high-carbon stock” areas, such as forests.
While this is “not easy” to do, he points to the European Commission’s indirect land-use change directive, the accompanying methodology and its scientific teams who study agricultural expansion rates. Delaney continues:
“What we all agree with at this point is that indirect land-use change exists, that it’s a problem, that certain feedstocks like palm and soya are particularly problematic from this perspective and that it is an issue that we need to tackle and capture in the best possible way.
“You cannot just be vague and descriptive without having proper figures behind it – and I think that’s something that at least the EU have tried and that they continue trying to implement. And I hope that, at the global level as well, this will be more recognised.”
Impacts on food, biodiversity and water security
Biofuel-boosting policies have been subjected to intense scrutiny during periods of global food-price spikes in 2008, 2011 and 2013.
Following the spikes, critics attributed increasing biofuel production as a major factor in the near-doubling of cereal prices. Studies have shown that they played a more “modest” role in some of these spikes and a more substantial one in others.
Severalexperts have linked food-price spikes to protests in north Africa and the Middle-East, including the Arab Spring.
In more recent years, the “food vs fuel debate” has come back to the fore since the start of the war in Ukraine in 2022.
This was in part due to the world’s reliance on Ukraine and Russia’s food and energy systems – particularly some of the most food-insecure countries, who had to contend with record-high food prices that peaked in March 2022, but still persist. The war also saw heightened calls for the US and EU to overturn biofuel-boosting policies to free up land to increase domestic food production and bring down food prices.
In developing countries, such as India, the use of cereals and oils to make biofuels while large sections of the population still lack access to adequate nutrition has attracted criticism from experts.
While first-generation biofuels rely on fertilisers to guarantee consistently high yields, second-generation biofuels could directly compete with feed for livestock or their return to soil as nutrients.
According to a 2013 report by the panel of scientists that advises the UN Committee on World Food Security (CFS):
“All crops compete for the same land or water, labour, capital, inputs and investment, and there are no current magic non-food crops that can ensure more harmonious biofuel production on marginal lands.”
This competition, along with clearing forests and other ecosystems for cropland, has consequences not just for emissions, but also for biodiversity, water and nutrients.
According to one 2021 review paper, local species richness and abundance were 37% and 49% lower, respectively, in places where first-generation biofuel crops were being grown than in places with primary vegetation. Additionally, it found that soya, wheat, maize and palm oil had the “worst effects” on local biodiversity, with Asia and central and South America being the most-impacted regions.
Biofuels’ impact on water resources, similarly, is highly crop- and location-specific.
For instance, growing a “thirsty” crop such as sugarcane in Brazil could have minimal impacts on local water resources, due to the region’s abundant rainfall. But in drought-prone India, experts have estimated that a litre of sugarcane ethanol requires more than 2,500 litres of water to produce and relies entirely on irrigation. Research has also found that nearly half of China’s maize crop requires irrigation to grow.
According to agricultural economist Dr Shweta Saini, meeting India’s 2025-26 biofuels target will require 275m tonnes of sugarcane, 6m tonnes of maize and 5.5m tonnes of rice. According to one 2020 study cited by Bloomberg columnist David Fickling, increasing sugarcane production to meet India’s biofuel targets “could consume an additional 348bn cubic metres of water…around twice what is used by every city” in the country.
Prof Raghuram tells Carbon Brief:
“Water resources are drying up everywhere in the country and by incentivising, through policy, a water-guzzling industry like this, we are inviting a sustainability crisis.”
‘Feedstock crunch’
Another concern surrounding biofuels is that there may not be enough supply to go around to meet rising demand. The IEA described the potential shortfall as a “feedstock supply crunch” in a 2022 report.
Fuels derived from the most commonly used waste and residues, in particular, could be approaching supply limits, the IEA warns, as these fuels satisfy both sustainability and feedstock policy objectives in the US and EU.
Consumption of vegetable oil for biofuel production is expected to soar by 46% over 2022-27, the report says. Meanwhile, the world is estimated to “nearly exhaust 100% of supplies” of used cooking oil and animal fats within the decade.
For the world to stay on a net-zero trajectory, “a more than three times production increase” would be required, the report adds. It warns that if the limited availability of second-generation feedstocks continues unchanged, “the potential for biofuels to contribute to global decarbonisation efforts could be undermined”.
The chart below shows the biofuel demand share of global crop production from 2022-27.
How are countries using biofuels to meet their climate targets?
Broadly, biofuel policies are divided into two categories.
Technology “push” policies focus on the research and development of new technologies and include measures such as research funding, pilot plants and government support for commercialising nascent technologies.
Meanwhile, market “pull” policies drive demand for existing and emerging biofuels through measures such as “biofuel blending mandates” – where countries prescribe a certain percentage of biofuel with fossil fuels – and tax breaks for producers and vehicle owners.
US
The US Renewable Fuel Standard (RFS) is the world’s largest existing biofuel programme. Its mandates are keenly watched and contested by the country’s farm and petroleum lobbies.
Under RFS, the US Environmental Protection Agency sets out minimum levels of biofuels that must be blended into the US’s transport, heating and jet fuel supplies.
Under the policy, oil refiners can either blend mandated volumes of biofuels into the nation’s fuel supply or buy credits – called Renewable Identification Numbers (RINS) – from those that do.
While the programme sets out emissions reduction targets, the environmental impacts of cropland expansion and monoculture driven by the policy have been cause for concern by experts.
According to one 2022 study, the RFS programme increased US fertiliser use by 3-8% each year between 2008-16 and caused enough domestic emissions from land-use change that the carbon intensity of corn ethanol was “no less than that of gasoline and likely at least 24% higher”. Additionally, the programme’s impacts on biodiversity have not yet been fully assessed.
In June 2025, the Trump administration announced plans to expand the biofuel mandate to a “record 24.02bn gallons” next year – an 8% increase from its 2025 target – while seeking to discourage imported biofuels.
EU
In the EU, policymakers have promoted biofuels since 2003 to reduce emissions in the transport system. As part of the EU’s Renewable Energy Directive (RED), biofuels have been explicitly linked to emissions targets.
Under the current iteration of RED (REDIII) – revised as part of the EU’s Fit for 55 package – EU countries are required to either achieve a share of 29% of renewable energy in transport or to reduce the emissions intensity of transport fuels by 14.5%. Additionally, it sets out a sub-target for “advanced biofuels” of 5.5% and excludes the use of food and feed-based biofuels in aviation and shipping.
In 2015, the European Commission acknowledged that the indirect land-use change emissions of first-generation biofuels could “fully negate” any emission savings by biofuels. The commission capped the use of first-generation biofuels in each member country at 7% of all energy used in transport by 2020, but did not announce plans to phase them out.
As of 2021, nearly 60% of all biofuels used in the EU were still made from food and feed crops, according to analysis by Oxfam. While the latest RED legislation continues to push for the use of advanced and waste biofuels, campaigners warn that a lack of clear definitions could increase the risk of “loopholes” and fraud, exacerbated by increased demand.
T&E’s Delaney tells Carbon Brief:
“You’re putting a lot of pressure on the land – you might require a lot of pesticides and irrigation – and there is not even enough land in Europe for this. How can you make sure true sustainability safeguards are in place so that you’re not actually driving additional demand for land in [biodiverse countries such as] Brazil?”
Brazil
Brazil has the world’s oldest biofuels mandate, dating back to the 1970s, established in a bid to insulate the country from expensive oil imports.
In 2017, Brazil announced a state policy called RenovaBio that set out national carbon intensity reduction targets for transport, decided biofuel mandates and created an open market for biofuel decarbonisation carbon reduction credits called CBIO.
In October 2024, Brazil enacted a “Fuels of the Future” law that replaced RenovaBio, with president Lula declaring that “Brazil will lead the world’s largest energy revolution”. The law aims to boost biofuel and sustainable aviation fuel (SAF) use, increasing biodiesel blending mandates by 1% every year starting in 2025 until it reaches 20% by March 2030.
Biofuels now account for 22% of the energy that fuels transport in Brazil and its ethanol market is “second in size only” to the US.
In June this year, Brazil announced that the country was increasing its biofuel blending mandates from 1 August in a bid to make the country “gasoline self-sufficient for the first time in 15 years”, reported Reuters.
Indonesia
As the world’s biggest palm oil producer, Indonesia has continued to raise its biodiesel blending mandates to meet its domestic energy needs.
The country first introduced mandatory biodiesel blending in 2008, at 2.5%. The mandate is currently at 40% in 2025 and, starting next year, could go up to 50% with an eventual goal of 100%.
While Indonesia’s president Prabowo Subianto has stated that implementing 50% blending could save the country $20bn in reduced diesel imports, the move would need an estimated 2.3m hectares of land, including protected forests, resulting in the “country’s largest-ever deforestation project”, according to Mongabay.
It could also compete with palm oil meant for domestic and international food markets, impacting already soaring prices and signalling the “end of cheap palm oil”.
India
India has quickly joined the ranks of major biofuel producers, due to high-level political support, policies and a diversity of feedstocks. In 2023, India launched the Global Biofuels Alliance as one of its key priorities of its G20 presidency.
Biofuel mandates are outlined in the country’s National Policy on Biofuels, first published in 2009 and subsequently amended in 2018 and 2022. In 2022, India achieved its 10% ethanol blending target ahead of schedule and is pursuing a 20% blending target by 2025, as well as a 5% biodiesel blending target by 2030.
India’s rapid biofuel push, however, has been criticised by food security experts as hunger levels rise, for its impact on endemic rainforests and, most recently, by vehicle owners for the impact of blended fuel on car engines.
Prof Raghuram says:
“From a sheer governance angle and sustainability angle, there are a lot of compromises being made to somehow push this whole thing. Even the land available in India is shrinking, as various reforms and dilution of environmental safeguards in the last 10 years have made it relatively easier to convert farm and forest land for non-agricultural purposes.”
China
China developed its first biofuel policies over 20 years ago and is one of the world’s biggest biofuel producers.
In 2017, China announced a new mandate expanding the use of fuel including bioethanol from 11 trial provinces to the entire country by 2020. However, Reuters and South China Morning Post reported that this was suspended in 2020. Only 15 provinces still maintain biofuel mandates, according to the US Department of Agriculture, which notes that a “lack of meaningful support for domestic biofuel consumption while aggressively promoting electric vehicles indicates a strategic choice to pursue transportation decarbonisation through electrification rather than liquid biofuels”.
At the same time, biofuel production in China grew by 30% in 2024, according to the Energy Institute’s Statistical Review.
While most of China’s biofuel production is grain-based, tax incentives for ethanol production have been gradually phased out and alternative biofuels have been incentivised, according to the IEA. China is currently piloting a scheme to increase biodiesel consumption at home, even as it exports biodiesel and used cooking oil to the EU and US.
How could climate change impact biofuel production?
Despite the well-documented impacts of climate change-induced extreme weather on land, agriculture and forests, there is currently little scientific literature examining how continued warming will impact global biofuel production.
One 2020 study found that bioethanol availability globally could drop – by 23% under a “very high emissions scenario” and by 4.3% under a “low emissions” scenario by 2060 – “if climate change risk is not adequately mitigated” and corn continues to be the dominant feedstock.
The study “encourages” changing out corn for switchgrass as a key source of bioethanol.
Another 2021 study examining the viability of China’s planned biofuel targets estimated that energy crop yields in China in the 2050s will decrease significantly compared to the 2010s, due to the impacts of climate change.
It found that climate change is expected to have a “substantial impact” on the land available for biofuel production in the 2050s, under both scenarios used in the study.
Gurgel, from MIT, tells Carbon Brief that it is “very hard to take into account how much climate change will damage bio-energy production” at this point, given the uncertainty of what emissions pathway the world will follow.
While most climate models “do a very good job” at forecasting average temperature change in the future, they do an “average job” at projecting rainfall change, or how many extreme weather events countries will see in the future, he says.
This is important because many biofuel crops, such as sugarcane and palm oil, are water-intensive and thrive in regions with abundant rainfall, but yields may fail in drier parts of the world that could see more drought.
Given this “cascade of uncertainties”, he continues, “we don’t have a clear picture of how bad the future [of agriculture] will be – we just know it will be more challenging than today”.
Delaney, meanwhile, asks whether investing in biofuels, which will be impacted by climate change, is a “good investment” for the long term. He tells Carbon Brief:
“I think these are the questions that we need to ask ourselves when we see – not just in India, but Indonesia, Brazil, everywhere around the world right now – this growing appetite for biofuels. Can we really keep the promises that we made at the end of the day?”
The post Q&A: How countries are using biofuels to meet their climate targets appeared first on Carbon Brief.
Q&A: How countries are using biofuels to meet their climate targets
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