If "one" is the most lonely number, then "two" is the worst. Mankind should not allow global temperatures to rise by 2 degrees Celsius, according to the Paris climate agreement. The crossing of this line will mean a catastrophe. Uncertainty is a particular problem in the process of climate study.
We can not predict what will happen and when, because there are thousands of variables in this massive and intricate system. But this can change. The other day in the journal Nature, an article appeared in which researchers stated that they managed to reduce the uncertainty of the key metric of climate change by 60%, narrowing the range of possible warming from 3 to 1.2 degrees Celsius.
Over the past 25 years, the generally accepted range of potential warming has been between 1.5 and 4.5 degrees Celsius. This is a fairly large range, given that even one degree can change the world. This, for example, is 5-10% less than the precipitation during the dry season in the Mediterranean, in the south-west of North America and in southern Africa.
Of course, scientists know quite a lot about the classic greenhouse factors of climate change, carbon dioxide and methane. But humanity pumped other particles into this system, and they cooled the system.
