TADEAS:

Last week’s SPM report makes stronger statements than previous IPCC assessment summaries, but then again the situation is now much worse. Thousands of scientists have spent hundreds of thousands of hours developing the six full reports on which the SPM is based. Much of what was done is lost or downplayed in the SPM, though some strong messages survived, including that more than 3.3 to 3.6 billion people are living in places “highly vulnerable” to climate impacts and new extremes.

But there is a tendency to put into future tense what should be present tense. The SPM says that warming of more than 1.5 degrees would be devastating for Earth’s people and ecosystems, but that is already the case because a number of crucial climate systems have already passed their tipping points at the current level of warming of 1.2 degrees. A search of key words relating to system tipping points and their consequences in the SPM is instructive: “feedback” appears once, “cascade” and “hothouse” not at all, “tipping” gets one mention, as does “Antarctic”.

There is no admission that limiting warming of 1.5 degrees is not a desirable outcome and would involve, amongst many outcomes, eventual sea-level rises measured in many metres and likely in the tens of metres.

And again, the SPM says that beyond the 1.5 degrees threshold, scientists have found that climate disasters will become so extreme that people will not be able to adapt. But that is already happening. People are already fleeing from desertification of the dry subtropics, from unprecedented drought, and from the salination of their land, today.

In the report and the media commentary, there has been confusion about the feasibility of keeping warming below 1.5 degrees. Given the projected increases in emissions in the short term, which may not plateau till this decade’s end, and then remain high, the world is not within co-ee of keeping warming to 1.5 degrees (or even 2 degrees), and talk of 1.5 degrees is really about scenarios that involve significant overshoot and then trying to cool back to 1.5 degrees by century’s end.

Climate Code Red: IPCC: Separating the science from the politics?
https://www.climatecodered.org/2023/03/ipcc-separating-science-from-politics.html

A key feature of IPCC reports on the physical science has been to elevate climate models to the centre of the process, whilst relegating the bigger picture understandings that come from climate history (paleoclimatology) to a secondary position. Paleoclimatology teaches that in the long run each one degree of warming will raise the oceans by 10-20 metres. Models, unable to properly include cryosphere processes, suggest sea-rises to 2100 so small that the projections are not credible, a process of scientific reticence highlighted by NASA science chief James Hansen as far back as 2007.

Current climate models are not capturing all the risks, such as the stalling of the Gulf Stream, polar ice melt and the uptick in extreme weather events. Prof. Michael Mann says that “when it comes to certain important consequences of the warming, including ice sheet collapse, sea level rise, and the rise in extreme weather events, the [IPCC] reports in my view have been overly conservative, in substantial part because of processes that are imperfectly represented in the models.”

Another fundamental problem is the approach to risk. IPCC carbon budgets regularly include risks of failure (overshooting the target) of 33% or 50%, that is, a one-in-two or one-in-three risk of failure. Thus a 2-degree carbon budget with a 50% chance actually has a 10% risk of ending up with 4 degrees of warming, which is incompatible with the maintenance of human civilisation.

These are risks of failure that no government or person would agree to in any other aspect of life — whether it be buildings and bridges, safety fences or car seats — where acceptable failure rates are tiny fractions of one per cent

OMNIHASH: pri takovym otepleni hraje zasadni roli zmena vodniho rezimu a na ten je ryze dost citliva

TADEAS: tomuhle upřímně moc nevěřím. Až na extrémní podnebí ( typicky oblasti, který projdou velkou desertifikací) by mělo "akorát " dojít k tomu, že se začnou vyplácet jiný druhý plodin.

DZODZO: Vytopensky rezim pri vyuziti prepracovaneho paliva se urcite vyplaci a nedela se z bezpecnostnich duvodu. Kogeneracni nevim..