Leading scientists, numbering more than 60, have cautioned that indicators of climate change—ranging from carbon pollution and rising sea levels to global warming—are now in uncharted territory.
In 2024, emissions of greenhouse gases resulting from fossil fuel combustion and deforestation reached unprecedented levels, averaging a staggering 53.6 billion tonnes per year over the last decade. This translates to 100,000 tonnes per minute of CO2 or equivalent gases, according to their peer-reviewed findings.
Last year, Earth’s surface temperature surpassed 1.5 degrees Celsius for the first time, with projections indicating that humanity’s remaining carbon budget—allowing for a two-thirds chance of staying under this threshold long-term—will be depleted within a couple of years.
Notably, investments in clean energy surpassed those in oil, gas, and coal last year by a ratio of two-to-one. However, fossil fuels still represent over 80% of global energy consumption, and the growth of renewable energy sources has not kept pace with rising demand.
The agreed target for limiting global warming among nearly 200 nations is “well below” two degrees Celsius, typically interpreted as between 1.7C and 1.8C.
Co-author Joeri Rogelj, a professor of climate science and policy at Imperial College London, shared with journalists that “we are already in crunch time for these higher levels of warming.”
“The next three to four decades essentially mark the period during which we expect to see a peak in warming,” he added.
‘The wrong direction’
The accelerating pace of record heat and carbon emissions, along with other climate indicators, is equally concerning, as highlighted in the study published in Earth System Science Data.
Human-induced warming has accelerated over the last decade at a rate deemed “unprecedented in the instrumental record,” significantly surpassing the averages from 2010 to 2019 as reported in the UN’s latest Intergovernmental Panel on Climate Change (IPCC) assessment in 2021.
The new findings, conducted by the same team using similar methodologies, serve as an unofficial but authoritative update of the key IPCC reports integral to global climate diplomacy.
Policymakers should take these findings as a serious reality check, the authors emphasized.
“Though I’m generally an optimistic person,” noted lead author Piers Forster, head of the University of Leeds Priestley Centre for Climate Futures, “this year’s update clearly shows that things are moving in the wrong direction.”
The recent surge in sea level rise is also alarming, the scientists remarked.
After a steady rise of well under two millimeters per year from 1901 to 2018, global sea levels have accelerated to an annual increase of 4.3mm since 2019.
What happens next
An increase of 23cm in ocean levels—equivalent to the thickness of a letter-sized sheet of paper—over the last 125 years has jeopardized numerous small island nations and significantly intensified the destructive force of storm surges globally.
Research indicates that an additional rise of 20cm by 2050 could lead to one trillion dollars in flood damage each year across the 136 largest coastal cities worldwide.
Another critical indicator of climate change is Earth’s so-called energy imbalance, which signifies the difference between solar energy entering and leaving the atmosphere.
Currently, 91% of human-induced warming has been absorbed by oceans, thus preventing land life from experiencing an unbearable environment.
However, the planet’s energy imbalance has nearly doubled over the past two decades, and scientists remain uncertain about how long oceans will continue to absorb this excess heat.
Future climate impacts that are more severe than those already experienced are already set to unfold over the next decade or two.
Nonetheless, the future remains within our control, the researchers emphasized.
“We are on the fast track to reaching a global warming level of 1.5C, but the future hinges on the decisions made from here on out,” stated co-author and former IPCC co-chair Valerie Masson-Delmotte.
The Paris Agreement’s target of 1.5C allows for potential measures to reduce global temperatures below that threshold by the end of the century.
As the critical year-end climate summit in Brazil approaches, international collaboration has been weakened by the U.S. withdrawal from the Paris Agreement.
Experts express concern that U.S. President Donald Trump’s rollback of domestic climate policies may result in the U.S. failing to meet its emissions reduction targets, thereby undermining the commitment of other nations to enhance their own climate pledges.
