By John Ikani
Global warming is unfolding more quickly than feared and humanity is almost entirely to blame, a report released on Monday by the UN Intergovernmental Panel on Climate Change (IPCC) first major scientific assessment since 2014, has stated.
A rundown of some of the key findings from the IPCC Working Group 1 report on physical science notes that Earth’s average surface temperature is projected to hit 1.5 or 1.6 degrees Celsius above preindustrial levels around 2030 in all five of the greenhouse gas emissions scenarios, ranging from highly optimistic to reckless.
By mid-century, the 1.5C threshold would have been breached across the board, by a tenth of a degree along the most ambitious pathway, and by nearly a full degree at the opposite extreme.
“There is a silver lining in the most ambitious if we do everything right scenario, global temperatures after overshooting the 1.5C target fall back to 1.4C by 2100,” it said.
Over the years, forests, soil and oceans have absorbed 56 percent of all the CO2 humanity has chucked into the atmosphere even as those emissions have increased by half. Without nature’s help, Earth would already be a much hotter and less hospitable place.
“But these allies in our fight against global heating known in this role as carbon sinks are showing signs of becoming saturated, and the percentage of human-induced carbon they soak up is likely to decline as the century unfolds,” the report added.
The report highlights the stunning progress of a new field, attribution science, in quantifying the extent to which human-induced global heating increases the intensity and/or likelihood of a specific extreme weather event such as a heatwave, a hurricane or a wildfire.
Within weeks, for example, scientists established that the record-shattering heatwave that devastated British Columbia in June would have been virtually impossible without the influence of climate change.
More generally, the 2021 IPCC report includes many more findings reached with “high confidence” than before.
