During the 2024 UK general election campaign, politicians and newspapers have used a series of “scary-sounding numbers” to mislead voters about net-zero.
While some of the numbers are accurate in isolation, they have been used in false or misleading ways, shaved of context and typically designed to exaggerate the cost of cutting emissions.
Current prime minister Rishi Sunak, his energy secretary Claire Coutinho and a string of right-leaning newspapers have all been guilty of this approach.
The most common tactics for misleading voters about net-zero include: focusing on the cost of action without mentioning the cost of business-as-usual; mentioning the costs of cutting emissions but not the benefits; and omitting the costs of failing to tackle dangerous climate change.
Below, Carbon Brief factchecks a series of claims made around the election campaign, each of which involves a big number about “costs”. The article explains who made each claim, where the relevant number came from – and the missing context that makes the claim false or misleading.
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MISLEADING
Hundreds of billions
“We’ve just found a recording that they have put out there from the deputy chancellor from the Labour Party admitting that their [climate] plans will cost hundreds of billions of pounds.”
– Rishi Sunak during BBC leaders’ debate – 26 June 2024
Where it comes from
In what appears to have been a coordinated move, Sunak attacked Labour’s net-zero plans during the final leaders’ debate hosted by BBC News, by citing an article published online the same evening in the Daily Telegraph. The article, which appeared on the newspaper’s frontpage the following morning, is based on public comments by Labour’s Darren Jones in March 2024 about the cost of reaching net-zero emissions by 2050, which is also government policy. The target was legislated in 2019 under Conservative former prime minister Theresa May.
What it excludes
Sunak misleads voters by omitting the fact that his own government – as well as the Conservative manifesto – also support the net-zero by 2050 target. He also ignores the costs of inaction on climate change and the evidence that accelerated action would yield significant economic benefits.
In 2019, the Climate Change Committee estimated that the net cost to the whole economy of reaching net-zero by 2050 would amount to £1.4tn, offset by savings from lower fossil fuel bills of £1.1tn. As set out by the Office for Budget Responsibility (OBR) in 2021, this amounted to a net cost of £321bn over nearly 30 years – consistent with the “hundreds of billions” cited by Labour’s Darren Jones. Furthermore, the OBR estimated that only a quarter of the costs of reaching net-zero would come from public spending and that delaying action towards the target could double the overall cost to the UK. It added that failing to act on climate change would have far greater impacts on the economy and public finances, concluding: “Unmitigated climate change would ultimately have catastrophic economic and fiscal consequences.”
In a 2023 report, the OBR found that continued reliance on gas could be more than twice as costly for the exchequer as reaching net-zero. Separate analysis for trade group Energy UK concluded: “[A]n accelerated transition [to net-zero] could boost the UK’s economy by £240bn in 2050 more than current trajectories…Under the most ambitious scenario, the GDP of each area of the UK would be 5.4%-7.5% greater in 2050 than under the current trajectory.”
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FALSE
£116bn
“Labour are still not being honest about the costs of their energy policy. Independent energy experts have warned that Labour’s 2030 target would need an extra £116bn of investment, which means one thing…higher taxes for millions of Brits.”
– Claire Coutinho tweet – 25 June 2024
Where it comes from
The figure is based on analysis by consultancy Aurora, which said a total of £116bn would need to be invested during 2025-2035 to reach Labour’s 2030 clean power target. This works at an average of £10.6bn per year, according to Aurora.
What it excludes
The current secretary of state’s phrasing is false. The same Aurora analysis said a total of £105bn would need to be invested during 2025-2035 to meet the government’s own target of clean power by 2035, averaging £9.5bn per year. As such, the “extra” investment is only £11bn over 11 years, or £1bn a year.
Coutinho’s claim that higher investment would mean higher taxes is also false, as electricity sector investment is predominantly from the private sector and paid for via bills. Moreover, Aurora has said, based on the same analysis, that consumer energy bills would be lower under Labour’s 2030 target than under a 2035 clean power goal – or under the current, less ambitious trajectory. Aurora said: “Either scenario will be highly challenging to implement, stretching the limits of deliverability. However, if delivered, increased investment could lead to lower total system costs once the long-term savings from lower gas consumption are included.”
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FALSE
£30bn
“Ditching Net Zero could save the public sector over £30bn per year for the next 25 years.”
– Reform manifesto – 17 June 2024
Where it comes from
Reform, a climate-sceptic party led and majority owned by Nigel Farage, offers almost no information on how it arrived at this figure. According to the OBR, public-sector spending on net-zero is estimated at around £8bn per year. The only other number mentioned by Reform is for renewable energy subsidies, which it puts at £10bn per year. These are paid by consumers, not the government, such that scrapping them would not save the public sector any money. Instead, Reform proposes to tax renewables by an equivalent amount, which would likely end investor confidence in the UK across the board.
What it excludes
Reform is claiming, implausibly, that the government could save more than it currently spends. It also focuses on the costs of reaching net-zero while ignoring benefits, as well as the cost of business-as-usual. The CCC has estimated that reaching net-zero will entail net investment costs of £44bn per year out to 2050, offset by operational cost savings of £29bn per year, with the annual cost in total averaging £15bn. This excludes wider GDP impacts: the CCC said that the size of the economy, the number of jobs and real disposable incomes would all grow under a net-zero pathway. The CCC’s monetary estimates also exclude the cost of climate impacts, the sizeable health benefits of improved air quality and other externalities. The IEA recently concluded that accelerating climate action towards net-zero “could lead to major reductions in household energy bills”, again purely looking at economic costs and benefits. According to the OBR, the UK government spent £51bn on energy bill support during 2022-23, after gas prices rocketed.
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FALSE
£2tn
“The UK cost of net-zero has been estimated by the National Grid and others at some £2tn or more. It is so big that no one really knows.”
– Draft Reform manifesto – 19 March 2024
Where it comes from
In 2020, National Grid Electricity System Operator (ESO) estimated the cost of building and operating a net-zero energy system at a cumulative total of £2.8-3tn by 2050. This is the total cost of building and operating the country’s energy system for 30 years.
What it excludes
The Reform statement is false. The same National Grid ESO report said: “Scenarios where we hit net-zero in 2050…incur broadly the same costs as the scenario where we miss our net-zero target.” As such, based on the National Grid ESO analysis, there would not be any additional cost to hitting net-zero relative to running an energy system that does not meet the target. Moreover, in 2021, the Treasury stated: “The costs of global [climate] inaction significantly outweigh the costs of action.”
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FALSE
£2.8-3tn
“National Grid ESO, the company which manages our electricity supply, has estimated decarbonising Britain’s entire energy system will cost between £2.8tn and £3tn between now and 2050, working out at between £108bn and £115bn a year.”
– Sun comment by Ross Clark – 23 June 2024
Where it comes from
In 2020, National Grid Electricity System Operator (ESO) estimated the cost of the country’s energy system at a cumulative total of £2.8-3tn by 2050. This is the total cost of building and operating the energy system for 30 years.
What it excludes
The climate-sceptic columnist’s statement is false. The same National Grid report said: “Scenarios where we hit net-zero in 2050…incur broadly the same costs as the scenario where we miss our net-zero target.” As such, based on the National Grid ESO analysis, there would not be any additional cost to hitting net-zero, relative to running an energy system that does not meet the target. Furthermore, the £108-115bn annual cost cited by Clark can be compared with the £265bn spent by UK consumers on energy in 2022 – when fossil fuel costs spiked due to Russia’s invasion of Ukraine – including more than £100bn on imported oil and gas alone. These 2022 figures did not include investment in new infrastructure.
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FALSE
£1,000
“[R]estoring the 2030 ban on the sale of new petrol and diesel cars will cost an estimated extra £1,000 per household per year from 2022 until 2050.”
– Sunday Telegraph article and editorial – 15 June 2024
Where it comes from
The Sunday Telegraph article and accompanying editorial are based on a dossier compiled by free-market thinktank the Institute of Economic Affairs, which, in turn, cites a 2022 report published by consultancy the Centre for Economic and Business Research (CEBR). The CEBR work was funded by Fair Fuel UK, the motoring lobby group run by climate-sceptic Reform candidate for London mayor Howard Cox. The newspaper omits this detail from its article.
What it excludes
The Sunday Telegraph claim is false, because the underlying report from CEBR makes the “simply perverse” assumption that the relative cost of petrol and electric vehicles (EVs) is unchanged for the next 30 years. The assumption that EVs will continue to face a purchase price premium over petrol cars is directly contradicted by the evidence of falling costs, including recent data showing that EVs are now close to up-front price parity in the UK. The Climate Change Committee (CCC) concluded that an earlier combustion-engine car ban would deliver £6bn in cost savings, because EVs have much lower running costs than petrol cars, again directly contradicting the CEBR and Sunday Telegraph claims. When Sunak delayed the combustion-car ban from 2030 to 2035, the CCC said this was “likely to increase…motoring costs for households”, adding that EVs were “significantly cheaper than petrol or diesel vehicles to own and operate”.
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TRUE
£265bn
“The UK spent a staggering £265bn on energy in 2022 – the most recent data available – including more than £100bn on imported oil and gas alone”
– Tweet by Carbon Brief’s Simon Evans – 8 February 2024
Where it comes from
This is the cost of energy – the majority of it being fossil fuels – bought in the UK in 2022 at market prices, reflecting the cost to consumers of heat, power and transport fuel. The data was the most recently available at time of publication and covers the first year of Russia’s invasion of Ukraine, when Russia restricted gas supplies to Europe and sent fossil fuel prices rocketing. In the pre-crisis year of 2021, the UK spent £184bn on energy.
What it excludes
These figures do not include investment in energy-related infrastructure, such as power plants, pylons, boilers, cars or heat pumps. Many conversations about the cost of reaching net-zero ignore the substantial costs of the status quo, which is heavily reliant on volatile fossil fuels.
The post Factcheck: How ‘scary-sounding numbers’ are being used to mislead the UK about net-zero appeared first on Carbon Brief.
Factcheck: How ‘scary-sounding numbers’ are being used to mislead the UK about net-zero
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 go