In 2014, before the Paris climate agreement, the world was on track to heat up nearly 4 degrees Celsius (7.2 degrees Fahrenheit) by the end of the century, an outcome widely seen as catastrophic. Today, thanks to rapid growth in clean energy, humanity has started to bend the emissions curve. Current policies put us on pace for roughly 3 degrees Celsius of warming by 2100 — a better result, but still devastating. Many countries have vowed to slash emissions even faster. So far those promises exist mostly on paper, but if nations follow through, the world could potentially limit total warming to around 2 to 2.4 degrees Celsius by 2100. Yet scientists and world leaders increasingly say even that much warming is too risky. To hold global temperature rise to a safer limit of 1.5 degrees Celsius, far more drastic action is needed. When the Paris agreement was signed, nations agreed that they should keep total global warming “well below” 2 degrees Celsius and make a good-faith effort to stay at 1.5 degrees. But in the years since, a slew of studies have found that 2 degrees of warming is vastly more harmful than 1.5 degrees.
By Brad Plumer and Nadja Popovich. New York Times. Oct. 25, 2021.
