If you have been following the scientific research and its findings on the topic of global warming for the last 2 decades as I have, you will experience cognitive dissonance while engaging the trolls (aka deniers) as well as the authors of more mainstream publications as expressed in the media. With a few notable exceptions, everyone seems to be downplaying the severity of the issue, and not by a nose.
The truth of the matter is, humankind has no control over the climate system, and that’s about the only thing I share with the beliefs of the flat-earthers who seem to think that is all there is to it. This being said alongside arguments that express sentiments like: “the climate has always changed”. I guess they don’t want to persecute killers either, for death is natural.
We have no control over the climate system, because we have no control over our greenhouse gas emissions. Save for a return to bronze age living arrangements some 30 years ago, or an alien intervention, there is no way in Hell we are going to prevent an eventual global mean warming of under 8 degrees C.
The math underlying this is not even that complicated.
If we take the lower bound of every positive feedback in the climate system we already know will be triggered as the result of the path we are on right now, which we absolutely can’t curb and won’t even try to curb, the picture looks like this:
Current global warming measurements acknowledge about 1.1 degrees C of anomalous warming given a certain baseline. Estimates are that baseline should be corrected for by + 0.1 C because there is strong evidence that human activity prior to the industrial revolution, already caused 0.1 C of warming. That gives us 1.2.
But that 1.2 is just a global average. On land, warming is much higher than on the surface of the oceans because oceans are our natural heat sinks, and land is not. Obviously we live on the land, not the seas.
Furthermore, the global mean temperature as is it measured today, only gives a reflection of the warming caused by emissions up to 20 years ago, since there is a 20 year lag in measurement of warming and the eventual warming that will occur. In those twenty years, we have expelled more greenhouse gasses than the entire period before it. Actually, since the first serious talks about this subject in the early 90’s, emissions have gone up almost 60%.
So, if these emissions up to 20 years ago caused a 1.2 C degree of average warming, imagine where we would be 20 years from now even if all emissions stopped right now, which will not happen.
Then there is the phenomenon of global dimming. As we burn coal and oil, small particles get into the atmosphere blocking sun rays as they come in, actually providing a cooling effect on the energy system. The most dire estimates attribute way over 0.5 degrees C of cooling due to that effect. Pan evaporation measurements come to mind. Look it up.
Lest we forget the very real effects of positive climate feedbacks. The reduced albedo (the reflective potential of the earth’s surface) , the melting of permafrost and clathrates (dense pockets of ‘frozen’ methane that can become unstable and would be released into the atmosphere if surrounding water increased too much in temperature) and.. well, just take a stiff drink and consult Wikipedia if you want the full horror script of what these rebound effects entail.
There’s a lot more to this, but I think you get the gist of it by now..
To state there’s a chance to stay below 1.5 degrees Celsius of warming is like saying John F. Kennedy could be up for a second term in office next election.
And that is why the proposed warming targets make no sense..