Record-high greenhouse gas emissions and diminishing air pollution have caused an unparalleled acceleration in global warming, 50 top scientists warned on Thursday in a sweeping climate science update. From 2013 to 2022, "human-induced warming has been increasing at an unprecedented rate of over 0.2 degrees Celsius per decade," they reported in a peer-reviewed study aimed at policymakers. Average annual emissions over the same period hit an all-time high of 54 billion tonnes of CO2 or its equivalent in other gases – about 1,700 tonnes every second.

World leaders will be confronted with the new data at the critical COP28 climate summit later this year in Dubai, where a "Global Stocktake" at the UN talks will assess progress toward the 2015 Paris Agreement's temperature goals. The findings would appear to close the door on capping global warming under the Paris treaty's more ambitious 1.5C target, long identified as a guard rail for a relatively climate-safe world, albeit one still roiled by severe impacts.

"Even though we are not yet at 1.5C warming, the carbon budget" – the amount of greenhouse gases humanity can emit without exceeding that limit – "will likely be exhausted in only a few years," said lead author Piers Forster, a physics professor at the University of Leeds. That budget has shrunk by half since the UN's climate science advisory body, the Intergovernmental Panel on Climate Change (IPCC), gathered data for its most recent benchmark report in 2021, according to the Forster and colleagues, many of whom were core IPCC contributors.

To have even a coin-toss chance of staying under the 1.5C threshold, emissions of carbon dioxide, methane and other drivers of warming generated mostly by burning fossil fuels must not exceed 250 billion tonnes (Gt), they reported. Bettering the odds to two-thirds or four-fifths would reduce that carbon allowance to only 150 Gt and 100 Gt, respectively – a two- or three-year lifeline at the current rate of emissions. Keeping the Paris temperature targets in play would require slashing CO2 pollution at least 40 percent by 2030, and eliminating it entirely by mid-century, the IPCC has calculated. Ironically, one of the big climate success stories of the last decade has inadvertently hastened the pace of global warming, the new data reveal.

Credit: Independent News Pakistan-INP