Tropical cyclones that rapidly intensify when passing over marine heatwaves can become “supercharged”, increasing the likelihood of high economic losses, a new study finds.
Such storms also have higher rates of rainfall and higher maximum windspeeds, according to the research.
The study, published in Science Advances, looks at the economic damages caused by nearly 800 tropical cyclones that occurred around the world between 1981 and 2023.
It finds that rapidly intensifying tropical cyclones that pass near abnormally warm parts of the ocean produce nearly double – 93% – the economic damages as storms that do not, even when levels of coastal development are taken into account.
One researcher, who was not involved in the study, tells Carbon Brief that the new analysis is a “step forward in understanding how we can better refine our predictions of what might happen in the future” in an increasingly warm world.
As marine heatwaves are projected to become more frequent under future climate change, the authors say that the interactions between storms and these heatwaves “should be given greater consideration in future strategies for climate adaptation and climate preparedness”.
‘Rapid intensification’
Tropical cyclones are rapidly rotating storm systems that form over warm ocean waters, characterised by low pressure at their cores and sustained winds that can reach more than 120 kilometres per hour.
The term “tropical cyclones” encompasses hurricanes, cyclones and typhoons, which are named as such depending on which ocean basin they occur in.
When they make landfall, these storms can cause major damage. They accounted for six of the top 10 disasters between 1900 and 2024 in terms of economic loss, according to the insurance company Aon’s 2025 climate catastrophe insight report.
These economic losses are largely caused by high wind speeds, large amounts of rainfall and damaging storm surges.
Storms can become particularly dangerous through a process called “rapid intensification”.
Rapid intensification is when a storm strengthens considerably in a short period of time. It is defined as an increase in sustained wind speed of at least 30 knots (around 55 kilometres per hour) in a 24-hour period.
There are several factors that can lead to rapid intensification, including warm ocean temperatures, high humidity and low vertical “wind shear” – meaning that the wind speeds higher up in the atmosphere are very similar to the wind speeds near the surface.
Rapid intensification has become more common since the 1980s and is projected to become even more frequent in the future with continued warming. (Although there is uncertainty as to how climate change will impact the frequency of tropical cyclones, the increase in strength and intensification is more clear.)
Marine heatwaves are another type of extreme event that are becoming more frequent due to recent warming. Like their atmospheric counterparts, marine heatwaves are periods of abnormally high ocean temperatures.
Previous research has shown that these marine heatwaves can contribute to a cyclone undergoing rapid intensification. This is because the warm ocean water acts as a “fuel” for a storm, says Dr Hamed Moftakhari, an associate professor of civil engineering at the University of Alabama who was one of the authors of the new study. He explains:
“The entire strength of the tropical cyclone [depends on] how hot the [ocean] surface is. Marine heatwave means we have an abundance of hot water that is like a gas [petrol] station. As you move over that, it’s going to supercharge you.”
However, the authors say, there is no global assessment of how rapid intensification and marine heatwaves interact – or how they contribute to economic damages.
Using the International Best Track Archive for Climate Stewardship (IBTrACS) – a database of tropical cyclone paths and intensities – the researchers identify 1,600 storms that made landfall during the 1981-2023 period, out of a total of 3,464 events.
Of these 1,600 storms, they were able to match 789 individual, land-falling cyclones with economic loss data from the Emergency Events Database (EM-DAT) and other official sources.
Then, using the IBTrACS storm data and ocean-temperature data from the European Centre for Medium-Range Weather Forecasts, the researchers classify each cyclone by whether or not it underwent rapid intensification and if it passed near a recent marine heatwave event before making landfall.
The researchers find that there is a “modest” rise in the number of marine heatwave-influenced tropical cyclones globally since 1981, but with significant regional variations. In particular, they say, there are “clear” upward trends in the north Atlantic Ocean, the north Indian Ocean and the northern hemisphere basin of the eastern Pacific Ocean.
‘Storm characteristics’
The researchers find substantial differences in the characteristics of tropical cyclones that experience rapid intensification and those that do not, as well as between rapidly intensifying storms that occur with marine heatwaves and those that occur without them.
For example, tropical cyclones that do not experience rapid intensification have, on average, maximum wind speeds of around 40 knots (74km/hr), whereas storms that rapidly intensify have an average maximum wind speed of nearly 80 knots (148km/hr).
Of the rapidly intensifying storms, those that are influenced by marine heatwaves maintain higher wind speeds during the days leading up to landfall.
Although the wind speeds are very similar between the two groups once the storms make landfall, the pre-landfall difference still has an impact on a storm’s destructiveness, says Dr Soheil Radfar, a hurricane-hazard modeller at Princeton University. Radfar, who is the lead author of the new study, tells Carbon Brief:
“Hurricane damage starts days before the landfall…Four or five days before a hurricane making landfall, we expect to have high wind speeds and, because of that high wind speed, we expect to have storm surges that impact coastal communities.”
They also find that rapidly intensifying storms have higher peak rainfall than non-rapidly intensifying storms, with marine heatwave-influenced, rapidly intensifying storms exhibiting the highest average rainfall at landfall.
The charts below show the mean sustained wind speed in knots (top) and the mean rainfall in millimetres per hour (bottom) for the tropical cyclones analysed in the study in the five days leading up to and two days following a storm making landfall.
The four lines show storms that: rapidly intensified with the influence of marine heatwaves (red); those that rapidly intensified without marine heatwaves (purple); those that experienced marine heatwaves, but did not rapidly intensify (orange); and those that neither rapidly intensified nor experienced a marine heatwave (blue).
Dr Daneeja Mawren, an ocean and climate consultant at the Mauritius-based Mascarene Environmental Consulting who was not involved in the study, tells Carbon Brief that the new study “helps clarify how marine heatwaves amplify storm characteristics”, such as stronger winds and heavier rainfall. She notes that this “has not been done on a global scale before”.
However, Mawren adds that other factors not considered in the analysis can “make a huge difference” in the rapid intensification of tropical cyclones, including subsurface marine heatwaves and eddies – circular, spinning ocean currents that can trap warm water.
Dr Jonathan Lin, an atmospheric scientist at Cornell University who was also not involved in the study, tells Carbon Brief that, while the intensification found by the study “makes physical sense”, it is inherently limited by the relatively small number of storms that occur. He adds:
“There’s not that many storms, to tease out the physical mechanisms and observational data. So being able to reproduce this kind of work in a physical model would be really important.”
Economic costs
Storm intensity is not the only factor that determines how destructive a given cyclone can be – the economic damages also depend strongly on the population density and the amount of infrastructure development where a storm hits. The study explains:
“A high storm surge in a sparsely populated area may cause less economic damage than a smaller surge in a densely populated, economically important region.”
To account for the differences in development, the researchers use a type of data called “built-up volume”, from the Global Human Settlement Layer. Built-up volume is a quantity derived from satellite data and other high-resolution imagery that combines measurements of building area and average building height in a given area. This can be used as a proxy for the level of development, the authors explain.
By comparing different cyclones that impacted areas with similar built-up volumes, the researchers can analyse how rapid intensification and marine heatwaves contribute to the overall economic damages of a storm.
They find that, even when controlling for levels of coastal development, storms that pass through a marine heatwave during their rapid intensification cause 93% higher economic damages than storms that do not.
They identify 71 marine heatwave-influenced storms that cause more than $1bn (inflation-adjusted across the dataset) in damages, compared to 45 storms that cause those levels of damage without the influence of marine heatwaves.
This quantification of the cyclones’ economic impact is one of the study’s most “important contributions”, says Mawren.
The authors also note that the continued development in coastal regions may increase the likelihood of tropical cyclone damages over time.
Towards forecasting
The study notes that the increased damages caused by marine heatwave-influenced tropical cyclones, along with the projected increases in marine heatwaves, means such storms “should be given greater consideration” in planning for future climate change.
For Radfar and Moftakhari, the new study emphasises the importance of understanding the interactions between extreme events, such as tropical cyclones and marine heatwaves.
Moftakhari notes that extreme events in the future are expected to become both more intense and more complex. This becomes a problem for climate resilience because “we basically design in the future based on what we’ve observed in the past”, he says. This may lead to underestimating potential hazards, he adds.
Mawren agrees, telling Carbon Brief that, in order to “fully capture the intensification potential”, future forecasts and risk assessments must account for marine heatwaves and other ocean phenomena, such as subsurface heat.
Lin adds that the actions needed to reduce storm damages “take on the order of decades to do right”. He tells Carbon Brief:
“All these [planning] decisions have to come by understanding the future uncertainty and so this research is a step forward in understanding how we can better refine our predictions of what might happen in the future.”
The post Marine heatwaves ‘nearly double’ the economic damage caused by tropical cyclones appeared first on Carbon Brief.
Marine heatwaves ‘nearly double’ the economic damage caused by tropical cyclones
The launch of the Africa Energy Bank (AEB) has been put back yet again, raising doubts about the institution’s future ability to finance fossil fuel projects – its main objective – as global lenders retreat from such investments over climate concerns, experts told Climate Home News.
The bank, which had been billed to launch in September after a series of delays, is now scheduled to begin operations in November, according to the head of the African Energy Chamber, an advocacy body for the continent’s oil and gas sector.
Even as the world aims to transition away from fossil fuels, many African leaders have made clear they want to continue exploring and extracting the continent’s large oil and gas deposits – estimated at around 125 billion barrels of crude and over 600 trillion cubic feet of gas – to boost economic development.
As a group, Africa sided with a number of powerful oil-and-gas producing nations in blocking progress on negotiations to craft a global roadmap to transition away from fossil fuels at last year’s UN COP30 climate talks, although some countries did individually support the proposal.
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Meanwhile, major projects under development across the continent – including the 1,443-km East African Crude Oil Pipeline (EACOP) and Dangote’s 700,000-barrel-per-day Kenyan refinery – show that African governments see oil and gas as playing a significant role in meeting their energy and economic needs for many years to come.
In 2022, at a gathering of the African Petroleum Producers’ Organization (APPO) in oil-rich Angola, ministers from its member states adopted a resolution to create the Africa Energy Bank to finance projects for the production, use and trade of oil, gas and broader energy sources.
African control over energy resources
An article on the APPO website explains that the bank was conceived as a way to overcome “disenchantment” with fossil fuels among “the international community” which it said had crystallised around the “energy transition” concept.
“If Western countries, after having long taken advantage of the energy sources they now revile to develop, can afford the luxury of abandoning them, this is not the case in Africa,” it adds, noting that many of the continent’s economies are still largely dependent on oil and gas revenues.
A separate web page about the bank, also hosted on APPO’s website, says its objectives include financing the exploration, production and refining of oil and gas, as well as supporting member states in transitioning from fossil fuels to cleaner energy sources “while ensuring energy security”.
Said Addi, a former executive with Shell and energy commodities trading house Gunvor, said the new bank was judged necessary because financing for hydrocarbons from many traditional international lenders has become constrained.
In trying to fill this financing gap, Africa is not simply setting up another fund to support oil and gas, he added. “It is also an attempt to give African countries greater control over how their energy resources and infrastructure are financed,” he explained.
Nigeria to host the AEB
The energy bank – a joint initiative of APPO and the African Export–Import Bank (Afreximbank) – has so far suffered several delays and is almost two years behind schedule. The initial plan was to start operations in January 2025, with Nigeria as the host country, but the bank’s opening was delayed to June of that year to allow Nigeria time to finalise the construction of the bank’s headquarters in Abuja.
After the government announced the completion of the offices in late November 2025, a new launch date was set for January 2026, which was moved back to April, June and then September. Now it has shifted again to November, raising concerns that the institution may be losing momentum.
Former Shell executive Addi said that if the capital is eventually paid in, the bank becomes operational and its first projects are commercially credible, then the delays will be regarded as normal teething troubles in setting up a multilateral institution. But, he added, scepticism will be justified if it continues to stall.
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Baron Lamarré, an oil and gas expert and former Petronas oil trader, said that missing “three deadlines in a row is not normal”, and warned that if the timeline slips again, “the story flips from ‘ambitious institution finding its footing’ to ‘good idea that lost momentum before it found any’.”
The Nigerian government, APPO and Afreximbank did not respond to requests for comment by the time of publication.
The funding challenge
The Africa Energy Bank is targeting base capital of $5 billion, with plans to scale up to $120 billion within five years by mobilising private-sector funds. However, it is expected to start operations with initial seed capital of $500 million.
The funding plan is to have the 18 member countries of the APPO contribute $83 million each to the bank as equity for a combined $1.5 billion. Afreximbank, other non-APPO African countries and investors outside the continent are expected to provide the remaining $3.5 billion.
But even the initial $500 million has not been easy to mobilise. In May, APPO Secretary-General Farid Ghezali called on members to deliver on their pledges towards the startup goal before the end of June. But the delays suggest this may not have been met, with experts saying Africa may be finding it difficult to self-fund its oil and gas projects in the absence of international capital.
Lamarré said every extension of the deadline points to the fact that “raising fossil fuel capital in Africa without the majors and their financing networks is brutally hard”.
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Since 2020, Western lenders, export credit agencies and insurers have been in steady retreat from African hydrocarbons, he said, while oil majors are divesting their African assets, handing over fields to smaller local operators whose credit ratings are not high enough to borrow cheaply.
Even capital from China and the Gulf, which has partially filled the gap, cannot match the volume, tenor or pricing that Western investors once offered, Lamarré argued.
“If mobilising the first $500 million of seed capital [for the AEB] has taken this long, that’s the clearest signal yet of how steep the climb to $120 billion looks,” he said, noting that the continent’s energy financing gap is as large as $30 billion-$45 billion per year.
Africa’s investment landscape, meanwhile, has been shifting. While foreign direct investment dropped from a 2024 peak, inflows remained roughly one-third above the continent’s long-term average in 2025, according to the 2026 World Investment Report from UN Trade and Development (UNCTAD). They are concentrated in a few sectors including critical minerals needed for renewable energy technologies, battery manufacturing and advanced industrial production.
At the same time, data on global energy investment from the International Energy Agency (IEA) shows that fossil fuel investment in Africa has declined over the last decade.
“Trojan horse” for fossil fuels
While the Africa Energy Bank struggles to get off the ground, climate campaigners have criticised its primary aim of financing oil and gas on the continent at a time when the world is starting to move away from high-carbon fuels to cleaner alternatives.
Bhekumuzi Dean Bhebhe, founder of Africa Change Lab, described the bank as a “Trojan horse”, arguing that its focus on fossil fuel financing runs counter to the global energy transition and the African Union’s Agenda 2063 goals of sustainable development and inclusive growth.
The energy bank, he warned, “risks locking Africa into a new cycle of debt, dependency and fossil fuel entrenchment”, adding that its financing blueprint does not pave the way for a climate-resilient future. “In truth, it is to deepen the same extractive, carbon-heavy pathways that the continent should be moving away from,” he added.
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Kenya-based climate and energy expert Joab Okanda said the AEB’s plan to finance oil and gas is “a misplaced priority” and it should instead back clean energy in line with the policies of some of Africa’s major export markets like Europe.
In addition, the new bank could struggle to mobilise enough resources to advance large-scale oil and gas projects, he added, noting that its proposed $5-billion initial capital is equivalent to the cost of the East African Crude Oil Pipeline alone.
The AEB’s aim of backing more fossil fuels should be flipped “to support countries that are oil-dependent to start working on their transition plans”, Okanda said.
The post Launch of Africa Energy Bank delayed again in blow to oil and gas hopes appeared first on Climate Home News.
Launch of Africa Energy Bank delayed again in blow to oil and gas hopes
A booklet published by the UK’s opposition Conservative party includes a “cost of net-zero” that appears to have been doubled by a spreadsheet error.
The “common sense” policy document argues that “what people ultimately want is a government competent enough to solve the problems for which it takes responsibility”.
In a section that says “sophisticat[ed]…modelling” should not be a substitute for “political judgement”, the “Right Way” document disparages various estimates of the cost of net-zero.
The Conservative document then claims – incorrectly – that the government’s official adviser, the Climate Change Committee (CCC), had put the cost of net-zero at close to £1tn. It says:
“In 2020, the CCC estimated that its route to net-zero would cost £957bn.”
In fact, the CCC’s 2020 estimate was exactly half this amount – £478bn – and last year it published a revised figure of £108bn, largely as a result of the falling cost of electric vehicles (EVs).
Spreadsheet error
The Conservative party’s erroneous claim appears to stem from another report that had accidentally added up numbers twice, using a spreadsheet published by the CCC in 2020.
The 2020 spreadsheet contains a table listing the additional investments that would be needed to build a net-zero economy, from low-carbon electricity generation through to heat pumps and EVs.
These extra capital expenditures, listed as “CAPEX”, add up to a total of £1.38tn over the 30 years of 2020-50. They are set against operational savings, listed as “OPEX”, of £0.90tn.
Added up over 2020-50, the combined CAPEX and OPEX figures come to a total of £478bn.
In addition to the annual sectoral CAPEX and OPEX figures, the CCC’s 2020 spreadsheet also has a line giving combined totals for each year. It appears that someone has added all of these numbers together, resulting in the savings and costs being counted twice.
This double-counted total for the cost of net-zero amounts to £957bn – as shown in the image below – and it appears to be the source of the claim in the Conservative booklet.
At the time of publication in 2020, the CCC said that the £478bn net cost of net-zero amounted to less than 1% of GDP over 30 years – and that the large investment needed would not only result in savings due to lower fossil-fuel imports, but that it would boost GDP overall, by around 2%.
In 2025, the CCC revised its estimates for investment costs and operating savings to £670bn and £562bn respectively, giving a net total of £108bn over 2025-50, or less than 0.2% of GDP.
Earlier this year, the committee said that cutting emissions to net-zero would cost less than a single fossil-fuel price shock and that doing so would have benefits worth £110bn per year.
Paper trail
The erroneous claim in the Conservative document is referenced to the CCC’s 2020 advice on the UK’s sixth “carbon budget”, which, as explained, does not contain the £957bn figure.
The earliest online use of the £957bn figure found by Carbon Brief is a 12 January 2026 article in the Spectator, by retired engineer and self-described “accidental energy analyst” David Turver.
A day later, Turver repeated the mistaken number in a report for the free-market Institute of Economic Affairs. His report cites figure 5.3 of the CCC’s 2020 advice.
However, as set out above, the CCC spreadsheet containing the data for figure 5.3 only adds up to £478bn, half the figure claimed by Turver.
It appears that Turver accidentally added up all of the numbers in the CCC spreadsheet, without noting that it already included a line for the annual total. This results in double-counting the cost.
(Turver’s report also triggered a slew of inaccurate headlines stating that net-zero would cost £7.6tn – or even £9tn. These figures, which came from Turver’s report, were based, among other things, on the implicit assumption that fossil fuels and the cars, boilers and power plants that use them are all free.)
After Turver’s report and article in January 2026, the erroneous £957bn figure was repeated in March by the Great British Think Tank. The organisation has the tagline “data, not vibes” and says of its work: “Every figure [is] sourced from official public bodies.”
The £957bn figure then appeared in the Conservative “Right Way” document in October 2026.
