Over the past year, there has been a vigorous debate among scientists – and more broadly – about whether global warming is “accelerating”.
This, in turn, has led to questions about whether the world is warming “faster than scientists expected”.
Here, Carbon Brief takes a detailed look at the issue and finds that there is increasing evidence of an acceleration in the rate of warming over the past 15 years.
However, this acceleration is broadly in line with projections from the latest generation of climate models and the recent sixth assessment report (AR6) from the Intergovernmental Panel on Climate Change (IPCC). They all expect the world to warm notably faster in both current and future decades than the rate the world has experienced since 1970.
Carbon Brief’s analysis also reveals that the speed up in warming projected in the latest climate models (known as CMIP6) is similar to the acceleration estimated by prominent climate scientist Dr James Hansen and colleagues in their much-discussed 2023 paper in Oxford Open Climate Change.
The IPCC’s AR6 also produced a set of “assessed warming projections” that incorporate multiple lines of evidence. While these project future warming levels a bit below the average of CMIP6 models, they still expect the rate of warming up to 2050 to be around 26% faster than the world has experienced to date since 1970.
Even with an apparent acceleration in recent warming, there remain major questions regarding drivers of 2023’s record-breaking heat relative to 2022, though annual temperatures still remain well within the range of climate-model projections.
An accelerating debate
Between 1970 and 2008, the world warmed at an approximately linear rate – by 0.18C per decade.
However, in recent years, the rise in global surface temperatures has climbed above this long-term trend, with eight of the past nine years showing warming levels above what would be expected given the historical warming rate.
In December 2022, former NASA scientist Dr James Hansen and colleagues published a preprint (later published as a peer-reviewed paper in 2023) projecting an acceleration in the rate of warming over the next few decades. Hansen and colleagues argued that the rate of warming would increase to between 0.27C and 0.36C per decade – or a 50-to-100% increase in the warming rate since 1970 – over the next 30 years.
These projections – coupled with the exceptional and unusual temperatures in 2023 – has fuelled a debate within the scientific community and among the broader public about a potential acceleration in warming in recent years.
This potential acceleration is illustrated in the figure below, which shows a composite of global surface temperatures from five different groups – NASA GISTEMP, NOAA’s GlobalTemp, the UK Met Office/University of East Anglia’s HadCRUT5, Berkeley Earth and Copernicus’ ERA5 – following an approach used by the World Meteorological Organization.
The circles indicate individual years and the dashed lines show the trend over 1970-2008 (blue) and 2009-23 (red). (The past 15 years are highlighted here as that is the time period that has previously been used to assess potential changes in the underlying trend in the scientific literature.)
Annual global average surface temperatures from a composite of NASA GISTEMP, NOAA’s GlobalTemp, the UK MET Office/UEA’s HadCRUT5, Berkeley Earth, and Copernicus’ ERA5 following an approach used by the World Meteorological Organization, with linear trends between 1970 and 2008 (blue) and 2009 and 2023 (red) shown by the dashed lines. Chart by Carbon Brief.
The chart shows how the warming rate of 0.18C per decade seen since 1970 has almost doubled to roughly 0.3C per decade over the past 15 years.
Researchers have proposed a number of potential contributors to the increased rate of warming seen in recent years.
One is the significant decline in global air pollution over the past few decades, as well as a 2020 phase-out of sulphur in marine fuels, which have reduced the levels of cooling aerosols in the atmosphere.
Other suggested factors include an approaching peak in the 11-year solar cycle, the 2022 eruption of the Hunga Tonga volcano and the continued increases in atmospheric greenhouse gas concentrations.
The fact that the past 15 years ended on a particularly high point due to the current El Niño event might also result in higher warming rates – although the contribution of El Niño to overall 2023 temperatures remains an area of vigorous scientific debate.
It is possible to remove the estimated influence of some of the natural factors – such as El Niño and La Niña events, volcanic eruptions and variations in solar output – from the global temperature record.
The figure below shows a version of the temperature record above where these natural factors are removed. The recent warming (red dashed line) is even more evident in this chart compared to the prior trend (blue).
Composite of five annual global average surface temperature records with the El Niño-Southern Oscillation (ENSO), volcanic eruptions and solar variations removed. Linear trends between 1970 and 2008 (blue) and 2009 and 2023 (red) shown by dashed lines. Data from Tamino following an updated version of the methodology in Foster and Rahmstorf 2011. Chart by Carbon Brief.
However, despite this spate of very warm years, it is challenging to draw firm conclusions on the overall rate of global warming based on a time period as short as 15 years.
Even though recent trends appear to show significant acceleration, the long-term trend remains – just barely – within the full range of uncertainty in climate model projections.
There is a risk of conflating shorter-term climate variability with longer-term changes – a pitfall that the climate science community has encountered before.
Parallels with the warming ‘hiatus’
The debate around a potential acceleration in warming shares similarities with another scientific contretemps – the so-called “hiatus” in warming of the early 21st century.
During the 15-year period from 1998 to 2012, the rate of warming at the surface appeared to nearly “pause” – or at least slow down dramatically compared to climate-model projections.
The debate so consumed the scientific community – and some sections of the media – that there was a running joke among scientists that the journal Nature Climate Change should be renamed “Nature Hiatus” for the number of studies it published trying to explain the apparent slowdown.
In retrospect, the apparent hiatus and associated disagreement between climate models and observations was caused by a number of different factors. Key among them were natural variability (in the form of more heat uptake by the oceans), disparities in surface temperature records associated with a transition from ship engine room to automated buoy-based measurements of sea surface temperatures, and incomplete comparisons between climate models and observations that excluded areas such as the Arctic that had sparser observational coverage.
With the development of the 2015-16 “super” El Niño, any sign of a “pause” in warming quickly vanished and the argument faded away – though it made a brief return in climate-sceptic circles in more recent years. However, it left behind a lasting appreciation among many scientists for the danger of overinterpreting short-term climate variability and is one of the reasons why there has been reticence in some circles about current claims of an acceleration.
Nonetheless, there are a number of reasons to expect that what the world is currently experiencing is not just the influence of natural variability on top of human-caused warming. An acceleration of warming in recent decades also shows up in ocean heat content and in satellite measurements of the Earth’s energy imbalance.
And, perhaps most importantly, an acceleration in the rate of warming in recent years – and over the coming decades – is exactly what is seen in climate models under a scenario in keeping with current global policies (known as SSP2-4.5). Under this scenario, greenhouse gas emissions remain around current levels until the middle of the century, alongside a decline in emissions of planet-cooling aerosols such as sulphur dioxide.
An expected acceleration
The most notable thing about the current apparent acceleration in warming is that it was expected.
Climate models have long shown a faster rate of warming in current and future decades than has been observed to date, though there is some disagreement among modelling estimates.
The table below shows a compilation of both observed rates of warming to date and different model projections out to 2050.
| Projection | Time period | Trend (C/decade) |
|---|---|---|
| Observed trend since 1970 | 1970-2023 | 0.19 (0.17 to 0.21) |
| Observed trend since 2009 | 2009-2023 | 0.30 (0.17 to 0.43) |
| Estimated human contribution (Forster et al, 2023) | 2013-2022 | 0.23 |
| IPCC AR6 assessed warming projections under SSP2-4.5 | 2015-2050 | 0.24 (0.17 to 0.34) |
| Full CMIP6 ensemble under SSP2-4.5 | 2015-2050 | 0.29 (0.2 to 0.4) |
| Hansen et al, 2023 | 2011-2050 | 0.32 (0.27 to 0.36) |
Global surface temperatures have warmed at a rate of 0.19C per decade between 1970 and 2023. They have warmed at a faster rate (~0.3C per decade) over the past 15 years – though with large uncertainties of 0.17C to 0.43C given the shorter time period.
The estimated human contribution to global warming of 0.23C for the past decade (2013 to 2022), as published in Earth System Science Data by Prof Piers Forster and colleagues, is based on a climate model emulator that is driven by an updated estimate of factors including the influence of greenhouse gases and aerosols on the Earth’s climate in recent years.
The IPCC’s AR6 provided “assessed warming projections” based on CMIP6 models – weighted based on their ability to accurately reproduce historical temperatures – and the recent synthesis of climate sensitivity estimates. These assessed warming projections show 0.24C warming per decade between 2015 and 2050 with an uncertainty range of 0.17C to 0.34C in the current-policy-type SSP2-4.5 scenario. This represents approximately 26% faster warming than the world has experienced since 1970.
The full CMIP6 ensemble of models has notably more warming than the IPCC-assessed warming projections. CMIP6 models, on average, warm by 0.29C per decade with a range of 0.2C to 0.4C, or 53% faster than historical warming since 1970.
The recent projections by Dr James Hansen and colleagues has a very similar projection of future warming rates to the CMIP6 ensemble, estimating warming of around 0.32C per decade with an uncertainty of 0.27C to 0.36C.
These estimates are summarised in the charts below, which show the historical warming rate (top left), the AR6 assessed range under SSP2-4.5 (top right), the CMIP6 models under SSP2-4.5 (bottom left) and Hansen et al’s future warming projection (bottom right). The blue dots and red dashed lines show observed data and the long-term trend, while the black lines and yellow shading show the average of model projections and their ranges.
Comparison of historical and future warming projections from a continuation of the 1970-2023 linear trend (top left), the IPCC AR6 assessed warming range for SSP2-4.5 (top right), the CMIP6 multimodal mean and range for SSP2-4.5 (bottom left) and Hansen et al 2023 (bottom right). Blue dots and red dashed lines show observations and trends, while the black lines and yellow shading show model projections and their ranges. Chart by Carbon Brief.
In all three cases, there is an expectation of acceleration of warming both at present and in coming decades compared to the warming the world has experienced since 1970.
However, this does not mean that the world will pass climate limits such as 1.5C sooner than expected. The current best estimates of when these thresholds will be passed are based on climate models that include the near-term warming acceleration.
The apparent acceleration of warming in recent years is well in line with climate model projections, which lends confidence that what the world is experiencing is a result of human activity rather than a result of natural variability.
However, this does not mean that the world will not experience cool years in the future; the next La Niña year – likely in 2025 – will probably end up well below some of the prior record-setting years.
But, as long as global emissions of CO2 and other greenhouse gases fail to decline and the world continues to tackle aerosol pollution, the world will likely warm faster than experienced in the past.
The post Factcheck: Why the recent ‘acceleration’ in global warming is what scientists expect appeared first on Carbon Brief.
Factcheck: Why the recent ‘acceleration’ in global warming is what scientists expect
Climate Change
Millions of kilograms of marine life taken from Australia’s marine protected areas every year, FOI finds
SYDNEY, Tuesday 11 August 2026 — New data obtained by Greenpeace Australia Pacific has found millions of kilograms of marine life are being taken from Australian marine parks by commercial fishers annually, as the government begins its review of the country’s Marine Parks Network.
The data, released to Greenpeace in response to a Freedom of Information request, relates to 18 of Australia’s 60 Commonwealth marine parks, and shows almost 2.2 million kg of marine life is being fished each year, raising concerns about the true catch numbers across all marine protected areas.
Greenpeace is calling for the Labor government to use the once-in-a-decade Marine Parks Network review, announced last fortnight, to ban industrial activities, including bottom trawling, longlining and oil and gas mining, from Australia’s Marine Parks Network, and increase fully-protected ocean sanctuaries within the network.
Elle Lawless, Senior Campaigner at Greenpeace Australia Pacific, said:
“It’s chilling to think of the true scale of destruction happening inside all of Australia’s marine parks, and how much of our precious ocean wildlife, like dolphins, turtles or seabirds, could be pulled out of protected areas as bycatch.
“We’re talking about 6,600 kilograms of wildlife in one day, and that does not include what’s caught in the other 42 marine parks, many of which allow destructive fishing like longlining.
“Australia has made significant progress in securing 52% of its oceans in marine parks; however, this intent is undermined by zones that allow damaging industrial fishing activities, such as bottom trawling and longlining. The review of Australia’s Marine Parks Network is a critical opportunity to fix what isn’t working and finally give our oceans the real protection they deserve.
You wouldn’t expect someone to bulldoze a national park on land, so why should they be allowed to trawl in a marine park?”
“Greenpeace Australia Pacific welcomes the Albanese Government’s review of the Commonwealth Marine Parks Network as a rare opportunity to strengthen our marine parks and ban industrial fishing in Australia’s marine protected areas.”
The documents reveal that the south-west network has the largest catch volume, at 887,160kg per year, followed by the Coral Sea network, which extends out from the Great Barrier Reef, losing significant wildlife at 808,840kg annually.
—ENDS—
Notes:
- More than half of Australia’s Marine Parks Network allow extractive industries, including industrial fishing and oil and gas mining.
- The data, supplied by the Department of Agriculture, Fisheries and Forestry, does not specify how much of the catch is fish or bycatch, like non-target fish, turtles or seabirds, and is available on request.
- Read Greenpeace’s new report: Trawling the Bottom Line
Australia’s network of marine parks is the largest in the world, covering more than half (52%) of Australia’s Commonwealth waters. You could be forgiven for assuming that a marine park is much like a national park on land: a highly protected place where people can enjoy nature while conservation efforts help habitats recover and wildlife thrive. You wouldn’t expect someone to bulldoze a national park, so why should they be allowed to bottom trawl in a marine park?
The reality is that not all marine parks are equally protected. Australia’s Marine Parks Network is divided into different zoning categories, with each zone determining which activities are permitted and the level of protection provided.
More than half of the Commonwealth Marine Parks Network allows industrial activities like oil and gas mining, and industrial fishing.
Our survival, and the survival of our planet, depends on the ocean. The ocean produces more oxygen than all of our forests combined, sustains communities and regulates the earth’s temperature. It’s home to wondrous wildlife and important ecosystems like coral reefs and kelp forests.
We love our big blue backyard
Australia’s ocean is teeming with life that is found nowhere else on earth. Schools of colourful fish, vibrant coral reefs, endemic shark nurseries, pods of dolphins, families of whales, playful seal pups and threatened Jurassic-era turtles call Australian waters home.
Since time began, from the turquoise waves to the deep blue, the ocean has connected our shorelines and communities, fed us, guided us and grounded us. We are intrinsically connected to our big blue backyard – more than 85% of us live within 50km of the shoreline. For tens of thousands of years, people have lived in harmony with the ocean and the wildlife within it, caring for and being sustained by its rich waters. Australia’s waters are some of the most unique and abundant places on Earth but our Marine Parks Network is falling short to properly protect them.
Australia’s marine parks aren’t living up to their name
The Australian Commonwealth Marine Parks Network covers commonwealth waters 5.5km from the coast. The network is divided into 7 regional management areas, overall the network contains 60 marine parks. Zoning types determine what activities are allowed in each area. Over half of the network allows industrial activities, risking our most precious and threatened ocean wildlife.
Within many of our marine parks, destructive industries are allowed to fish, trawl, dig and mine using barbaric and cruel methods. Here are some of the zones explained:
- Bottom Trawling: Special Purpose (trawl) zones allow bottom trawling. This covers 10 marine parks totalling almost 13 million hectares. Bottom trawlers bulldoze the seafloor with weighted nets, deforesting our underwater forests; a cruel, indiscriminate and inefficient way to fish.
- Other Industrial Fishing: Includes “Habitat Protection Zones, ““Multi Use Zones” and “Special Purpose Zones.” Fishing methods vary from park to park but many marine parks in these zones allow industrial fishing like longlining. Longlining involves setting lines that can be 100km long, bristling with deadly hooks designed to catch a specific fish species. But longlining is not a selective method of fishing – significant numbers of sharks, rays, turtles, dolphins and seabirds can be harmed or killed as bycatch in the process.
- Oil and Gas Mining: Many “Special Purpose” and “Multi Use” zones allow seismic blasting and oil and gas mining. 30 marine parks or 65 million hectares of Australia’s highest conservation value areas for ocean wildlife are open for mining and exploration of oil and gas.
- Ocean Sanctuaries: National Park and Sanctuary zones are fully and highly protected marine parks designed to conserve wildlife and their habitat, where fishing, mining, and other industrial activities are not allowed.
Industrial fishing is one of the biggest threats to the ocean
In May, Greenpeace Australia Pacific sailed our campaigning vessel Oceania through some of Australia’s most beautiful and threatened marine parks. Our crew visited Jervis and Hunter marine parks to document their beauty, showcase what’s at risk and aim to expose the industrial fishing activities in these protected waters. Both of these marine parks allow bottom trawling and longlining methods of industrial fishing.
Industrial fishing is ripping the ocean apart across the planet. Longlining, also known as longline fishing, is an industrial fishing method that involves the use of a fishing line with thousands of baited hooks. These fishing lines can stretch over 100 kilometers in length and are set to capture a fish species, often tuna or billfish species. But it is not a selective method of fishing and often results in significant bycatch. This includes a range of non-target species like sharks, rays, sea turtles, marine mammals, and seabirds which are often injured or killed as bycatch.
Bottom trawling involves dragging heavy weighted nets along the ocean floor. This fishing method is popular with commercial fishing companies, because it makes it easy to catch large quantities of fish in one go. But it also damages the seafloor, releasing carbon and can kill or injure non-target ocean life like coral, fur seals, dolphins and seabirds. You may have watched the reality of bottom trawling (and the benefits of ocean sanctuaries) in Ocean with David Attenborough, if not, add it to your watch list!
Fully protected ocean sanctuaries that ban industrial fishing and mining can protect ocean wildlife and underwater wonderlands for generations to come. Vast, robust sanctuaries create blue havens where ocean wildlife are safe from nets and hooks, and can truly rest, recover, thrive and replenish out into the surrounding waters. Ocean sanctuaries ensure a healthy ocean full of life.
A once-in-a-decade chance to fix what’s falling short
We have a unique opportunity to turn the tide.
The Australian Government is asking for your feedback on how our Commonwealth Marine Parks Network is managed. This is our once-in-a-decade chance to protect ocean wildlife, ban industrial fishing and create more ocean sanctuaries.
As part of the review the Government is asking for submissions from the public to hear from you on what improvements are needed to better protect our vast network of marine parks. Writing a submission is a powerful way to influence government decisions and create real change.
This is the moment to ban industrial activities like bottom trawling and oil and gas mining. But only if they hear from YOU. Add your name!
Greenpeace is calling on the Australian government to:
1. Ban industrial activities from Australia’s Marine Parks Network: Ban industrial activities, such as industrial fishing, seismic blasting and oil and gas mining, from Australia’s marine parks.
2. Create more ocean sanctuaries: Increase fully protected sanctuaries in Australia’s marine parks based on science principles.
3. Connect Australia’s Marine Parks Network to the High Seas: mCreate seascape connectivity by linking Australian marine parks to new high seas ocean sanctuaries.
References
Substantiation that more than half of the Marine Parks Network permits industrial activity comes from a peer-reviewed systematic literature review (Phillips et al. 2025, PLOS One, https://doi.org/10.1371/journal.pone.0307324). The study found that within the Commonwealth Marine Parks Network specifically, “all zones are considered partially protected areas, meaning areas where extractive activities are permitted, except ‘Pink zones’ (Preservation Zones; IUCN Ia) and ‘Green Zones’ (IUCN II).” In other words, every Commonwealth marine park zone type other than the network’s strict no-take sanctuary and national park zones (IUCN Ia and II) permits some form of extractive industrial activity. Since no-take zones are the minority zone type across the network by area, this supports the conclusion that the majority of the network’s area is zoned to permit industrial activity.
DCCEEW Australian Marine Parks spatial dataset (https://fed.dcceew.gov.au/datasets/erin::australian-marine-parks/explore), filtered by zone type. This confirms that 38.43% of the network’s area is zoned as Sanctuary or National Park zones (IUCN Ia and II). These are the no-take categories excluded from the peer-reviewed study’s definition of partially protected/industrial-permitting zones. The remaining 61.57% of the network falls within the zone categories the study classifies as permitting industrial activity (per The MPA Guide definition of “industrial” applied in Phillips et al. 2025), directly corroborating the peer-reviewed finding with current Commonwealth-specific spatial data.
For further information on activities permitted within the Marine Parks Network Zoning, you can refer to the Management Plans zoning and rules for each Marine Parks Network area, for example: Temperate East, Coral Sea, North.
A new report from Greenpeace Australia Pacific advocates for the closure of bottom trawling in Australia’s Commonwealth Marine Parks Network. Bottom trawling continues to be a pervasive threat to ocean life in Australia, with 10 marine parks totalling almost 13 million hectares, allowing bottom trawling.
Australia’s network of marine parks, which is the biggest in the world, covers more than half (52%) of Australia’s Commonwealth domestic waters, but not all parks are created equal. Australia’s Marine Parks Network is divided into different zoning categories, with each zone determining which activities are permitted and the level of protection provided. More than half of the Marine Parks Network allow industrial activities like industrial fishing and oil and gas mining. This includes zoning types that allow destructive fishing by longliners and bottom trawlers, who pillage underwater wonderlands, rip up coral and indiscriminately and violently catch any animal in their path, including turtles, seals and dolphins, all within areas labelled a marine park.
The Federal government has commenced a review into the majority of Australia’s Commonwealth Marine Parks Network management plans. This presents an opportunity to ban industrial activities from our marine parks and create more ocean sanctuaries.
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