US president Donald Trump’s tariffs might only shave 0.3% off global carbon dioxide (CO2) emissions this year, according to Carbon Brief analysis.
While the Trump administration is setting back international climate action through policies such as the “one big beautiful bill”, some analysts have argued that his tariffs would inadvertently cut carbon by throwing sand into the engine of the global economy.
However, Carbon Brief’s analysis, based on changing projections of economic growth since the tariffs were announced, shows that this effect is likely to be very limited.
The slew of new tariffs – initially announced on 2 April, dubbed by the president as “liberation day” – might only knock 110-150m tonnes of CO2 (MtCO2) off global emissions in 2025 (0.3-0.4%), the analysis shows.
For 2026, the tariffs could have a slightly higher impact, but still only 190-300MtCO2 (0.5-0.8%).
Trump’s “liberation day” tariffs included a 10% universal levy on all imported goods, alongside additional “reciprocal tariffs” on a number of countries he claimed had “cheated” the US.
The announcement sent the world’s stock markets into “turmoil”. The move has hit a range of diverse industries, including steel and aluminium, oil and more.
Despite initially saying he had no plans to pause the tariffs, Trump announced on 10 April that he would pause them for 90 days.
This pause was set to come to an end on 9 July, but, just days before this, he announced a further extension to 1 August. On his social-media network, Truth Social, Trump said countries would receive “letters and/or deals” on tariffs in the interim.
More recently, he has signed tariff deals with the European Union and countries such as the UK, Japan, the Philippines and others.
These deals reduce the headline tariff rates relative to the “liberation day” situation, as well as typically including a range of carve-outs and exemptions.
However, they do not end uncertainty over tariff levels and still leave US import levies at their highest levels “since the 1930s”, reducing expectations for trade and growth.
Since returning to office at the beginning of 2025, Trump – a climate sceptic – has rolled back a large number of environmental policies and protections.
Most recently, his “one big beautiful bill” was passed on 4 July, bringing an end to a number of former president Joe Biden’s policies, such as the Inflation Reduction Act (IRA), which provided support for electric vehicles, clean-technology manufacturing and more.
In combination with other Trump administration policies, this means the US will breach its now-defunct emissions reduction for 2030 target by a cumulative total of 7bn tonnes of CO2, previous Carbon Brief analysis found.
Nevertheless, numerous people suggested that the economic damage from Trump’s tariffs could “unintentionally” lead to a drop in carbon emissions.
For example, an April 2025 article in the New York Times stated: “Trump’s economic approach may inadvertently reduce greenhouse gas emissions, as consumption slows in response to a global trade war.”
The piece noted that the “reprieve for the planet” was likely to be short-lived, with longer-term impacts potentially hitting clean-energy deployment as international supply chains are hampered.
Similarly, an April 2025 Associated Press article quoted Global Carbon Project head Prof Rob Jackson saying that tariffs “might help the climate in the first year or two”. However, it quoted him continuing that this would come at a high cost and might backfire:
“I would say it might help the climate in the first year or two if we have a downturn in economic activity or a recession, which no one wants. But it will hurt the climate long-term because tariffs impact clean tech more than most other industries because of trade with China.”
Carbon Brief’s analysis shows that the emissions impact, even in the short term, is expected to be minimal.
It assessed the expected emissions impact of reduced global GDP by looking at changes to GDP forecasts from the International Monetary Fund (IMF), Organisation for Economic Cooperation and Development (OECD) and the World Bank, before and after Trump’s tariffs announcements.
The OECD suggests the biggest impact from the tariffs, as shown in the chart below.
The medium- to long-term impact of Trump’s trade wars is expected to be negative for climate action. In a recent interview, UK climate envoy Rachel Kyte told Carbon Brief that it created uncertainty and was likely to slow down clean-energy investment. She said:
“Investment flows when everybody feels confident, right?…[I]f I don’t know if the tariff is 10%, 20%, 25%, 56%, whatever, well, let me put it off till the next quarter to make that investment decision.”
Kyte added: “It’s the hesitancy that it puts in the mind of government, but also in the mind of investors and the private sector…[T]he sort of tariff era we’re in, the risk is that it slows down the investment in the clean-energy transition at a time when it needs to speed up.”
Methodology
Carbon Brief estimated the impact of Trump’s tariffs on global GDP by comparing growth forecasts published during June and July 2025 by the IMF World Economic Outlook, OECD Economic Outlook and World Bank Global Economic Prospects against corresponding forecasts published in December 2024 or January 2025, before Trump’s tariff announcements.
While Trump’s tariffs are not the only factor to have changed in these forecasts over the time period in question, they do represent a singular and sudden effect, which would be expected to have a significant impact on the global economic outlook.
The analysis estimates global GDP over 2025/2026 by applying the growth forecasts to historical GDP from the World Bank.
The reductions in forecast global GDP growth are translated into estimated emissions impacts by assuming that the “carbon intensity” of the world’s economy continues to improve at a steady rate, with or without the tariffs. Carbon intensity is the emissions per unit of GDP and has been improving slowly and steadily over many years.
The analysis only considers CO2 emissions from fossil fuels and cement production. Historical CO2 emissions data is taken from the Global Carbon Budget.
The range of estimated CO2 impacts stems from the varying GDP forecasts of the three different organisations.
For comparison, the International Energy Agency (IEA) has revised down its forecasts for global oil demand growth in 2025 by some 350,000 barrels of oil per day since the start of the year. This is equivalent to cutting global emissions this year by 40MtCO2.
The IEA’s forecasts for global coal demand in 2025 are broadly unchanged since the start of the year, with demand expected to grow 0.2% this year.
The post Analysis: Trump’s tariffs could cut just 0.3% from global CO2 emissions in 2025 appeared first on Carbon Brief.
Analysis: Trump’s tariffs could cut just 0.3% from global CO2 emissions in 2025
Drought and heatwaves occurring together – known as “compound” events – have “surged” across the world since the early 2000s, a new study shows.
Compound drought and heat events (CDHEs) can have devastating effects, creating the ideal conditions for intense wildfires, such as Australia’s “Black Summer” of 2019-20 where bushfires burned 24m hectares and killed 33 people.
The research, published in Science Advances, finds that the increase in CDHEs is predominantly being driven by events that start with a heatwave.
The global area affected by such “heatwave-led” compound events has more than doubled between 1980-2001 and 2002-23, the study says.
The rapid increase in these events over the last 23 years cannot be explained solely by global warming, the authors note.
Since the late 1990s, feedbacks between the land and the atmosphere have become stronger, making heatwaves more likely to trigger drought conditions, they explain.
One of the study authors tells Carbon Brief that societies must pay greater attention to compound events, which can “cause severe impacts on ecosystems, agriculture and society”.
Compound events
CDHEs are extreme weather events where drought and heatwave conditions occur simultaneously – or shortly after each other – in the same region.
These events are often triggered by large-scale weather patterns, such as “blocking” highs, which can produce “prolonged” hot and dry conditions, according to the study.
Prof Sang-Wook Yeh is one of the study authors and a professor at the Ewha Womans University in South Korea. He tells Carbon Brief:
“When heatwaves and droughts occur together, the two hazards reinforce each other through land-atmosphere interactions. This amplifies surface heating and soil moisture deficits, making compound events more intense and damaging than single hazards.”
CDHEs can begin with either a heatwave or a drought.
The sequence of these extremes is important, the study says, as they have different drivers and impacts.
For example, in a CDHE where the heatwave was the precursor, increased direct sunshine causes more moisture loss from soils and plants, leading to a drought.
Conversely, in an event where the drought was the precursor, the lack of soil moisture means that less of the sun’s energy goes into evaporation and more goes into warming the Earth’s surface. This produces favourable conditions for heatwaves.
The study shows that the majority of CDHEs globally start out as a drought.
In recent years, there has been increasing focus on these events due to the devastating impact they have on agriculture, ecosystems and public health.
In Russia in the summer of 2010, a compound drought-heatwave event – and the associated wildfires – caused the death of nearly 55,000 people, the study notes.
The record-breaking Pacific north-west “heat dome” in 2021 triggered extreme drought conditions that caused “significant declines” in wheat yields, as well as in barley, canola and fruit production in British Columbia and Alberta, Canada, says the study.
Increasing events
To assess how CDHEs are changing, the researchers use daily reanalysis data to identify droughts and heatwaves events. (Reanalysis data combines past observations with climate models to create a historical climate record.) Then, using an algorithm, they analyse how these events overlap in both time and space.
The study covers the period from 1980 to 2023 and the world’s land surface, excluding polar regions where CDHEs are rare.
The research finds that the area of land affected by CDHEs has “increased substantially” since the early 2000s.
Heatwave-led events have been the main contributor to this increase, the study says, with their spatial extent rising 110% between 1980-2001 and 2002-23, compared to a 59% increase for drought-led events.
The map below shows the global distribution of CDHEs over 1980-2023. The charts show the percentage of the land surface affected by a heatwave-led CDHE (red) or a drought-led CDHE (yellow) in a given year (left) and relative increase in each CDHE type (right).
The study finds that CDHEs have occurred most frequently in northern South America, the southern US, eastern Europe, central Africa and south Asia.
Threshold passed
The authors explain that the increase in heatwave-led CDHEs is related to rising global temperatures, but that this does not tell the whole story.
In the earlier 22-year period of 1980-2001, the study finds that the spatial extent of heatwave-led CDHEs rises by 1.6% per 1C of global temperature rise. For the more-recent period of 2022-23, this increases “nearly eightfold” to 13.1%.
The change suggests that the rapid increase in the heatwave-led CDHEs occurred after the global average temperature “surpasse[d] a certain temperature threshold”, the paper says.
This threshold is an absolute global average temperature of 14.3C, the authors estimate (based on an 11-year average), which the world passed around the year 2000.
Investigating the recent surge in heatwave-leading CDHEs further, the researchers find a “regime shift” in land-atmosphere dynamics “toward a persistently intensified state after the late 1990s”.
In other words, the way that drier soils drive higher surface temperatures, and vice versa, is becoming stronger, resulting in more heatwave-led compound events.
Daily data
The research has some advantages over other previous studies, Yeh says. For instance, the new work uses daily estimations of CDHEs, compared to monthly data used in past research. This is “important for capturing the detailed occurrence” of these events, says Yeh.
He adds that another advantage of their study is that it distinguishes the sequence of droughts and heatwaves, which allows them to “better understand the differences” in the characteristics of CDHEs.
Dr Meryem Tanarhte is a climate scientist at the University Hassan II in Morocco, and Dr Ruth Cerezo Mota is a climatologist and a researcher at the National Autonomous University of Mexico. Both scientists, who were not involved in the study, agree that the daily estimations give a clearer picture of how CDHEs are changing.
Cerezo-Mota adds that another major contribution of the study is its global focus. She tells Carbon Brief that in some regions, such as Mexico and Africa, there is a lack of studies on CDHEs:
“Not because the events do not occur, but perhaps because [these regions] do not have all the data or the expertise to do so.”
However, she notes that the reanalysis data used by the study does have limitations with how it represents rainfall in some parts of the world.
Compound impacts
The study notes that if CDHEs continue to intensify – particularly events where heatwaves are the precursors – they could drive declining crop productivity, increased wildfire frequency and severe public health crises.
These impacts could be “much more rapid and severe as global warming continues”, Yeh tells Carbon Brief.
Tanarhte notes that these events can be forecasted up to 10 days ahead in many regions. Furthermore, she says, the strongest impacts can be prevented “through preparedness and adaptation”, including through “water management for agriculture, heatwave mitigation measures and wildfire mitigation”.
The study recommends reassessing current risk management strategies for these compound events. It also suggests incorporating the sequences of drought and heatwaves into compound event analysis frameworks “to enhance climate risk management”.
Cerezo-Mota says that it is clear that the world needs to be prepared for the increased occurrence of these events. She tells Carbon Brief:
“These [risk assessments and strategies] need to be carried out at the local level to understand the complexities of each region.”
The post Heatwaves driving recent ‘surge’ in compound drought and heat extremes appeared first on Carbon Brief.
Heatwaves driving recent ‘surge’ in compound drought and heat extremes
Greenhouse Gases
DeBriefed 6 March 2026: Iran energy crisis | China climate plan | Bristol’s ‘pioneering’ wind turbine
Welcome to Carbon Brief’s DeBriefed.
An essential guide to the week’s key developments relating to climate change.
This week
Energy crisis
ENERGY SPIKE: US-Israeli attacks on Iran and subsequent counterattacks across the Middle East have sent energy prices “soaring”, according to Reuters. The newswire reported that the region “accounts for just under a third of global oil production and almost a fifth of gas”. The Guardian noted that shipping traffic through the strait of Hormuz, which normally ferries 20% of the world’s oil, “all but ground to a halt”. The Financial Times reported that attacks by Iran on Middle East energy facilities – notably in Qatar – triggered the “biggest rise in gas prices since Russia’s full-scale invasion of Ukraine”.
‘RISK’ AND ‘BENEFITS’: Bloomberg reported on increases in diesel prices in Europe and the US, speculating that rising fuel costs could be “a risk for president Donald Trump”. US gas producers are “poised to benefit from the big disruption in global supply”, according to CNBC. Indian government sources told the Economic Times that Russia is prepared to “fulfil India’s energy demands”. China Daily quoted experts who said “China’s energy security remains fundamentally unshaken”, thanks to “emergency stockpiles and a wide array of import channels”.
‘ESSENTIAL’ RENEWABLES: Energy analysts said governments should cut their fossil-fuel reliance by investing in renewables, “rather than just seeking non-Gulf oil and gas suppliers”, reported Climate Home News. This message was echoed by UK business secretary Peter Kyle, who said “doubling down on renewables” was “essential” amid “regional instability”, according to the Daily Telegraph.
China’s climate plan
PEAK COAL?: China has set out its next “five-year plan” at the annual “two sessions” meeting of the National People’s Congress, including its climate strategy out to 2030, according to the Hong Kong-based South China Morning Post. The plan called for China to cut its carbon emissions per unit of gross domestic product (GDP) by 17% from 2026 to 2030, which “may allow for continued increase in emissions given the rate of GDP growth”, reported Reuters. The newswire added that the plan also had targets to reach peak coal in the next five years and replace 30m tonnes per year of coal with renewables.
ACTIVE YET PRUDENT: Bloomberg described the new plan as “cautious”, stating that it “frustrat[es] hopes for tighter policy that would drive the nation to peak carbon emissions well before president Xi Jinping’s 2030 deadline”. Carbon Brief has just published an in-depth analysis of the plan. China Daily reported that the strategy “highlights measures to promote the climate targets of peaking carbon dioxide emissions before 2030”, which China said it would work towards “actively yet prudently”.
Around the world
- EU RULES: The European Commission has proposed new “made in Europe” rules to support domestic low-carbon industries, “against fierce competition from China”, reported Agence France-Presse. Carbon Brief examined what it means for climate efforts.
- RECORD HEAT: The US National Oceanic and Atmospheric Administration has said there is a 50-60% chance that the El Niño weather pattern could return this year, amplifying the effect of global warming and potentially driving temperatures to “record highs”, according to Euronews.
- FLAGSHIP FUND: The African Development Bank’s “flagship clean energy fund” plans to more than double its financing to $2.5bn for African renewables over the next two years, reported the Associated Press.
- NO WITHDRAWAL: Vanuatu has defied US efforts to force the Pacific-island nation to drop a UN draft resolution calling on the world to implement a landmark International Court of Justice (ICJ) ruling on climate, according to the Guardian.
98
The number of nations that submitted their national reports on tackling nature loss to the UN on time – just half of the 196 countries that are part of the UN biodiversity treaty – according to analysis by Carbon Brief.
Latest climate research
- Sea levels are already “much higher than assumed” in most assessments of the threat posed by sea-level rise, due to “inadequate” modelling assumptions | Nature
- Accelerating human-caused global warming could see the Paris Agreement’s 1.5C limit crossed before 2030 | Geophysical Research Letters covered by Carbon Brief
- Future “super El Niño events” could “significantly lower” solar power generation due to a reduction in solar irradiance in key regions, such as California and east China | Communications Earth & Environment
(For more, see Carbon Brief’s in-depth daily summaries of the top climate news stories on Monday, Tuesday, Wednesday, Thursday and Friday.)
Captured
UK greenhouse gas emissions in 2025 fell to 54% below 1990 levels, the baseline year for its legally binding climate goals, according to new Carbon Brief analysis. Over the same period, data from the World Bank shows that the UK’s economy has expanded by 95%, meaning that emissions have been decoupling from growth.
Spotlight
Bristol’s ‘pioneering’ community wind turbine
Following the recent launch of the UK government’s local power plan, Carbon Brief visits one of the country’s community-energy success stories.
The Lawrence Weston housing estate is set apart from the main city of Bristol, wedged between the tree-lined grounds of a stately home and a sprawl of warehouses and waste incinerators. It is one of the most deprived areas in the city.
Yet, just across the M5 motorway stands a structure that has brought the spoils of the energy transition directly to this historically forgotten estate – a 4.2 megawatt (MW) wind turbine.
The turbine is owned by local charity Ambition Lawrence Weston and all the profits from its electricity sales – around £100,000 a year – go to the community. In the UK’s local power plan, it was singled out by energy secretary Ed Miliband as a “pioneering” project.
‘Sustainable income’
On a recent visit to the estate by Carbon Brief, Ambition Lawrence Weston’s development manager, Mark Pepper, rattled off the story behind the wind turbine.
In 2012, Pepper and his team were approached by the Bristol Energy Cooperative with a chance to get a slice of the income from a new solar farm. They jumped at the opportunity.
“Austerity measures were kicking in at the time,” Pepper told Carbon Brief. “We needed to generate an income. Our own, sustainable income.”
With the solar farm proving to be a su