"Correction - The figure ‘Too close for comfort’ in this Comment incorrectly synthesized and interpreted information from the IPCC. The graph labelled the temperatures as absolute, rather than rises; misrepresented the levels of risk; misinterpreted information as coming from a 2007 IPCC report; extrapolated the focus of a 2018 report; and was not clear about the specific sources of the information. The graphic has been extensively modified online to correct these errors."
This is a top level publication, an article by the leading scientists in the field of climate change. It is so frustrating to see these errors happening on that level. One such little error generates more damage than 100 fake reports produced by the oil industry. Very sad.
(2019) "Climate tipping points — too risky to bet against"
https://www.nature.com/articles/d41586-019-03595-0
> "The palaeo-record shows global tipping, such as the entry into ice-age cycles 2.6 million years ago and their switch in amplitude and frequency around one million years ago, which models are only just capable of simulating... Now we are strongly forcing the system, with atmospheric CO2 concentration and global temperature increasing at rates that are an order of magnitude higher than those during the most recent deglaciation."
The central issue for human civilization is just how fast these changes are going to happen. Currently it takes about ten years for the warming signal to overrule the natural variability, for example a running 5-year average shows clear warming if you center each average ten years apart, i.e. 2008-2012 is clearly warmer than 1998-2002 and so on. Can humans adapt to this rate of warming over the next 100 years without enduring some degree of civilizational collapse, population reduction, etc.? Who knows. That's what's in the pipeline though, no longer any doubt about it. The real uncertainties are whether there might be any radical spikes in extreme weather or warming rates along this trajectory.
> "Atmospheric CO2 is already at levels last seen around four million years ago, in the Pliocene epoch. It is rapidly heading towards levels last seen some 50 million years ago — in the Eocene — when temperatures were up to 14 °C higher than they were in pre-industrial times. It is challenging for climate models to simulate such past ‘hothouse’ Earth states."
The rational thing to do, given our current state of knowledge, would be to institute a crash program to replace 3% of global fossil fuel use per year with a similar production of renewable energy capacity per year, which would require global coordinated industrial production at a truly massive scale, but humans are not rational actors, as economists have demonstrated.