Earlier estimates may have understated the extent by which world temperatures will rise by 2100 by up to 15%, according to a new study published in the journal Nature.
In other words, if the current goal of limiting climate warming to under 2° Celsius (3.6° Fahrenheit) above pre-industrial levels by 2100 (which is considered by many researchers to be insufficient to avoid civilizational collapse) is to be achieved, then the actions taken will need to be even more rapid and comprehensive then previously thought.
To explain that yet another way, greenhouse gas emissions would have to be curtailed completely within the very near term in order to avoid climate shifts, crop losses, and mass migrations.
“Our results suggest that achieving any given global temperature stabilization target will require steeper greenhouse gas emissions reductions than previously calculated,” as explained by study authors Patrick Brown and Ken Caldeira of the Carnegie Institution for Science.
Reuters provides more: “Average surface temperatures could increase up to 0.5° Celsius (0.9° Fahrenheit) more than previously projected by 2100 in the most gloomy scenarios for warming, according to a study based on a review of scientific models of how the climate system works. “The extra heat would make it harder to achieve targets set by almost 200 nations in 2015 to limit a rise in temperatures to ‘well below’ 2° Celsius (3.6° Fahrenheit) above pre-industrial times to restrict droughts, heat waves, and more powerful storms.
“The models that best represent the recent climate ‘tend to be the models that project the most global warming over the remainder of the twenty-first century,’ the scientists wrote. In one pessimistic scenario, under which greenhouse gas emissions continue to rise until 2100, temperatures could rise by 4.8° Celsius (8.6° Fahrenheit) against 4.3° Celsius (7.7° Fahrenheit) estimated by a UN panel of experts in 2014, they said.”
It should be remembered here that, even according to the UN (which is unrealistically optimistic about climate change mitigation in some regards), current pledges from governments around the world to reduce greenhouse gas emissions are far too limited to actually limit anthropogenic climate warming to under 2° Celsius. More accurately, current pledges put the world on track to experience 3–4° Celsius warming by 2100.