News stories about the Arctic always seem to say either that the Arctic is warming twice as fast as the global average, or that it’s warming nearly twice as fast as the global average. That’s not correct.
Arctic warming is more like three to four times as fast as global warming.
It’s already bad. But when will things get so bad that it is obviously — obviously — the worst problem in the world? How long until we go over the cliff? That depends on how much we’ve heated up already, and how fast we’re getting hotter.
We have already reached dangerous levels. The heat waves throughout the northern hemisphere this summer have cost plenty, to the economy, in human suffering, ill health, even lives lost. The wildfires in California this year were much worse than they would have been without global warming. Just last year we set a new record for the total cost (adjusted for inflation) of billion-dollar climate-related disasters. They cost the U.S. over $300 billion.
As bad as it is already, extremely bad is yet to come. Some say it’ll be when total warming since pre-industrial times reaches 2°C, others say — and I agree with them, given the costs we’ve already seen — that we’ll cross that threshhold at 1.5°C. That’s the level at which the costs, both economically and in terms of human life and suffering, will threaten our ability to cope.
Reader “Deltaeus” expressed his frustration about many aspects of the “debate” about climate change, including the fact that there are shallow arguments all over the place. I’d like to respond to some of his comments.
Some of my long-time readers have expressed an interest in a recent paper which attempts to predict how global temperature will change over the next few years, A novel probabilistic forecast system predicting anomalously warm 2018-2022 reinforcing the long-term global warming trend (Sevellec and Drijfhout 2018, Nature Communications). It has received quite a bit of publicity, featured in numerous newspaper articles, along the lines of “the next five years will be extra hot.”
It all started with Cliff Mass saying “… with huge transient peaks and troughs (see below). With such variability …” when talking about CalFire data of area burned by wildfire in California from 1987 through 2016. His comment led me to make a very serious mistake: I thought he might actually know what he was talking about.