Climate Change Meme Change

Good News - It's Not As Bad As We Thought. Bad News - It's Worse Than We Thought

Climate cultists have, over the past decade or two, pivoted subtly from one pseudoscientific catastrophist position to another pseudoscientific catastrophist position.

It used to be the case that the main focus of ‘dangerous’, nay catastrophic, climate change was the projected rise in global mean surface temperature over the period from 1850 (pre-industrial) to 2100. Using ‘climit moddles’ and the preferred ‘business as usual’ greenhouse gas emissions scenario, called RCP8.5, climate scientists were able to project ‘truly alarming’ increases in global temperature of 4-5C by 2100. Seeing as the planet has only warmed about 1.1C since 1850, this would involve a very considerable acceleration in global warming over the next 80 years. This is now looking increasingly unlikely because, (a) RCP8.5 is totally implausible, (b) the ‘climit moddles’ all run way too hot (which even the ‘climit scientists’ themselves now admit), and (c) the significant influence of neglected natural climate cycles (on global warming and cooling) is starting to be recognised.

Judith Curry has an excellent article on this over at Climate etc. She says:

Summary:  The climate “catastrophe” isn’t what it used to be. Circa 2013 with publication of the IPCC AR5 Report, RCP8.5 was regarded as the business-as-usual emissions scenario, with expected warming of 4 to 5 oC by 2100. Now there is growing acceptance that RCP8.5 is implausible, and RCP4.5 is arguably the current business-as-usual emissions scenario. Only a few years ago, an emissions trajectory that followed RCP4.5 with 2 to 3 oC warming was regarded as climate policy success. As limiting warming to 2 oC seems to be in reach (now deemed to be the “threshold of catastrophe”),[i] the goal posts were moved in 2018 to reduce the warming target to 1.5 oC. Climate catastrophe rhetoric now seems linked to extreme weather events, most of which are difficult to identify any role for human-caused climate change in increasing either their intensity or frequency.

At the heart of this good news is abandonment of RCP8.5 from UNFCCC policy making. The hero of science behind this abandonment is Justin Ritchie, a recent Ph.D. graduate (whose work has been cited in previous RCP8.5 posts at Climate Etc).

The COP26 and now the COP27 have quietly dropped RCP8.5 (and SSP5-8.5) from their considerations, focusing on the envelope between RCP4.5 and RCP2.6. 

The second so-called scientific advance is lower values of climate sensitivity.  The so-called advance is associated with the IPCC AR6 decision NOT to include values derived from climate models (which have dominated previous IPCC reports). They implicitly acknowledge that climate models are running too hot and that you can pretty much get whatever value of climate sensitivity that you want from a climate model (this has been blindingly obvious to me and many others for over a decade).

Once you include alternative scenarios of natural variability, temperature change by 2100 could easily be below 2oC and even 1.5oC.  Recall that this warming is with reference to a baseline of 1850-1900; 1.1oC warming has already occurred. 

Basically, we are looking - maybe - at a further increase in global mean surface temperature over the next 80 years of 0.9C, perhaps even less. We might not see any increase and it’s quite possible that we will see some cooling take place. We’ve already seen a rise of 1.1C and we’re still not broiled and drowned, as predicted, so another less than 1C is just not scary enough! So you see what they did? They shifted the threshold of ‘dangerous’ global warming from 2C, which they had quoted for years, to 1.5C in 2018 and they started claiming that the impacts of 1.5C warming were bad and would get much worse the warmer the world became. The imaginary climate crisis therefore came into being and its most immediate manifestation in the here and now was allegedly bad weather or extreme weather as they like to call it.

The new and improved climate crisis catastrophists immediately set to work linking individual extreme weather events to global warming and thus was born the new pseudoscience of extreme weather attribution. The old pseudoscience of projecting huge rises in global mean surface temperature using ‘climit moddles’ is rapidly going out of fashion, so this new and exciting pseudoscience has been embraced by climate alarmists with open arms. The serial climate misinformers at the Guardian just can’t get enough of it! Every other day it seems they report on the latest evidence of the climate crisis as revealed to us by this ‘record-breaking’ heatwave, or that hurricane, or that ‘unprecedented’ flood or drought. Bad weather happens, somewhere, sometime, always. They can just take their pick, reference a dodgy attribution study from the Met Office or World Weather Attribution, plus dubious ‘homogenised’ weather data going back 50 or 100 years at most, and hey presto, it’s your fault - for driving a car, eating meat and dairy and having the nerve to heat your goddam house to a comfortable temperature in the middle of winter (you’ll need nerve and lots of cash this winter)!

The thing is, they can’t point to any convincing trends in extreme weather since 1850, with 1.1C of warming, excepting the fact that - naturally - warm spells have got a little warmer and some seasons have become wetter in accordance with generally warmer weather. So how can they say another 0.4C or 0.9C in the coming decades is going to be ‘catastrophic’? They can’t. It’s ridiculous.

With regard to extreme weather events and their causes, they can’t discriminate between and quantify the influence of significant changes in land use, increasing urbanisation, changes in local and global circulation patterns and a moderate observed increase in mean global surface temperature. But that doesn’t stop them claiming that they can and that ‘climate change’, aka global warming, made such and such an event more likely. They might as well be reading tea leaves or using chicken entrails to divine the hidden signal of the ‘climate crisis’ in bad weather!