Economic damages from carbon emissions could be up to four times higher than previously estimated, while global sea level rise is already locked in for centuries, according to a new report.
The report, 10 New Insights in Climate Science 2026/2027 by Future Earth, The Earth League and the World Climate Research Programme (WCRP), also finds that 2025 was about 1.43°C warmer than the pre-industrial baseline, while human activities released a record 38.1 billion tonnes of CO2 from fossil fuels and cement production.
The report draws on scientific evidence published between January 2025 and June 2026 and identifies 10 developments spanning physical climate change, water security, food systems, carbon economics, climate accountability, trade and geopolitics. It noted that the 2015 to 2025 period constituted the 11 warmest years on record, according to the World Meteorological Organization (WMO). Global atmospheric CO2 concentration reached approximately 425.6 parts per million (ppm) in 2025, 53 per cent above its pre-industrial level. The latest nationally determined contributions imply only a 12 per cent reduction in global emissions by 2035 from 2019 levels, compared with the approximately 55 per cent required for a pathway consistent with limiting warming to 1.5°C.
“The evidence is unequivocal: 1.5°C is a limit that we cross at our own risk. Beyond it, the risks of cascading and potentially irreversible climate impacts increase, with every additional tenth of a degree making them more severe,” said Johan Rockström, director of the Potsdam Institute for Climate Impact Research, co-chair of The Earth League and a member of the report’s editorial board.
The report said ocean heat content reached a record for the ninth consecutive year in 2025, with about one third of the global ocean ranking among its three warmest states on record. More than 90 per cent of the excess heat accumulated in the Earth system is absorbed by oceans, while heat takes about 25 years to penetrate from the surface to depths of 2,000 metres. This means part of the warming associated with the current energy imbalance is already committed.
The rate of global mean sea level rise has doubled over the past 30 years. The report estimates that emissions through 2050 under a continuation of current climate policies could lock in an additional 300 millimetres of global mean sea level rise by 2300. Extending that policy trajectory to 2090 raises the commitment to 800 millimetres. A stringent mitigation pathway consistent with the Paris Agreement could avoid around 600 millimetres of that 800 millimetres.
The report estimates that global glaciers could lose up to 39 per cent of their mass, adding roughly 113 millimetres to global sea level in the long term even without further warming. With continued warming, the contribution could rise to 230 millimetres. Around one billion people live in coastal areas less than 10 metres above sea level.
The report identifies continental drying as another accelerating climate risk. Roughly three quarters of the global population lives in 101 countries that have been losing freshwater since 2002.
A global assessment cited in the report found that human water consumption already exceeds sustainable availability by 458 cubic kilometres a year, roughly equivalent to the total annual water withdrawals of the United States or India. The gap is projected to increase by around 6 per cent at 1.5°C warming and 15 per cent at 3°C.
South Asia is identified as a major hotspot for unsustainable irrigation, with the Ganges, Sabarmati and Indus among the regions where groundwater depletion and water demand are already creating significant pressure.
One of the report’s major findings is that the social cost of carbon (SCC), which measures the economic damage caused by emitting an additional tonne of CO₂, has been substantially underestimated.
Recent research cited in the report found that projected economic losses under high warming scenarios by 2100 rose from around 11 per cent to around 40 per cent of gross domestic product when global average temperature was incorporated into economic models alongside local weather conditions. Another assessment found that using more realistic climate models could change SCC estimates by up to four times. One model puts the 2025 global SCC at about $194 per tonne of CO2 under an efficient and coordinated climate policy scenario, rising to about $437 per tonne under business as usual.
At the same time, advances in attribution science are making it possible to connect specific emissions to specific climate impacts. The report says emissions from large fossil fuel and cement producers, known as Carbon Majors, can be linked to 24 to 37 per cent of sea level rise to date, based on their activities between 1854 and 2020. Research cited by the report also links these producers collectively to around 50 per cent of the increase in heatwave intensity since the pre-industrial era.
The report further finds that the wealthiest 10 per cent contributed seven times more to extreme heat than the average individual, while the resulting impacts fall disproportionately on lower-income tropical regions.
“Attribution science is moving from ‘climate change is happening’ to ‘this emitter contributed to this harm," said Timothy Naish, WCRP Chair and a member of the report’s editorial board. “This changes the conversation on accountability, liability and who should pay for the damages we are already seeing.”
The report also examines the growing intersection between climate policy and trade. It says climate clubs and measures such as carbon border adjustment mechanisms (CBAMs) can help limit carbon leakage and incentivise cleaner industrial production but warns that their design can impose disproportionate adjustment costs on developing country exporters.
It recommends that CBAM implementing jurisdictions assess trade exposure, compliance costs, employment effects and institutional capacity, and says a defined share of CBAM revenues should be directed towards affected countries or multilateral funds to support emissions measurement, clean energy and industrial upgrading.
Geopolitical instability is identified as another threat to a just energy transition. While energy shocks can encourage some countries to accelerate domestic renewable energy investment, the report finds that geopolitical risk overall tends to hinder the global transition by increasing market volatility, disrupting critical mineral supply chains and redirecting policy priorities towards immediate security concerns.
The report also identifies a shift in climate obstruction, from outright science denial towards delay, dilution, greenwashing, misleading solutions and digital disinformation. It says such efforts can prevent effective climate policy even where the scientific evidence and technological options are increasingly clear.
The report concludes that the window for action is narrowing but remains open. Its recommendations for climate diplomacy include strengthening 2035 climate targets, scaling climate finance from the $300 billion annual goal towards at least $1.3 trillion by 2035, operationalising adaptation and just transition mechanisms, and addressing the distributional impacts of climate-related trade measures.