Total Pageviews

Tuesday, March 1, 2022

On IPCC AR6 WG2 Release, by Roger Pielke Jr., Ph.D.

 FULL  ARTICLE  HERE:

" initial thread on the IPCC AR6 WG2 report released today

Whereas WG1 received a mixed review in my areas of expertise (specifically: poor on scenarios, solid on extremes), my initial reaction to the WG2 report is that it is an exceedingly poor assessment

The first observation is that the report is more heavily weighted to implausible scenarios than any previous IPCC assessment report

In particular, RCP8.5 represents ~57% of scenario mentions


This alone accounts for the apocalyptic tone and conclusions throughout the report

Remarkably, RCP8.5 is characterized in the report as a "business as usual" future, and RCP4.5 is a "low emissions future"

In actual reality, RCP4.5 is currently thought of as an upper bound trajectory under current or stated policies & RCP8.5 is implausible

WG2 is not ignorant of the debate over implausible scenarios, but they chose to ignore almost all of the relevant literature

Instead they quote the widely discredited & COIed Schwalm paper to justify emphasizing RCP8.5 & some hand-waving about C cycle feedbacks

Embarrassing

WG2 states, correctly: "Nonetheless, the likelihood of a climate outcome, and the overall distribution of climate outcomes, are a function of the emissions scenario’s likelihood"


And then cites NONE of the relevant literature on this point

None of it
That was a choice

On US hurricane damages the report cites 2 studies to counter our study on normalized US hurricane damages (which is cited!)

What is not stated is that there are 7 other studies in the literature, all of which point in the same direction

Blatant, obvious

I did the work for the IPCC, performing a literature review on normalization methodologies across the literature, reviewing > 50 studies

Unlike in past IPCC reports this literature was ignored
    https://doi.org/10.1080/17477891.2020.1800440

Like WG1 Grinsted appears to justify claims that economic losses from climate extremes are increasing due to climate change, despite almost all literature (and previous IPCC reports) coming to contrary results

On floods, WG2 completely misrepresents the conclusions of AR6 WG1

(L) WG2 says increased frequency & magnitude of river floods was given "high confidence" by WG1

Nope

(R) WG1 said the opposite: confidence is "low"

There are many indicators of decreasing vulnerability to weather and climate, one leading paper is Formetta and Feyen 2019, which WG2 casually dismisses deep in Chapter 16
    https://www.sciencedirect.com/science/article/pii/S0959378019300378

Formetta and Feyen 2019 contradicts much of the doom and gloom of this report

Even so, the good news of Formetta and Feyen 2019 sneaks in elsewhere

Interestingly, WG2 reports that globally, wildfire shows regional patterns but no overall global trend

WG2 states that reported flood deaths have increased but somehow fails to note that the paper cited to support that claim explains the increase is due to better reporting in the EM-DAT database (right)

In fact, Tanoue et al. 2016 report – as is widely found in the literature but not in this WG2 report – that flood mortality is dramatically down over decades

If the IPCC's job is to review the relevant literature, there are massive gaps in this report

    https://www.nature.com/articles/srep36021

No room in the report for assessing the substantial literature on economic damage associated with weather and climate, but somehow the NOAA billion-dollar disaster press releases make it in

The IPCC report outlines a bizzaro world in which up is down

This NYT article accurately reflects the IPCC report but not the reality of the world we live in

In actual fact, the world has made incredible progress on adaptation and vulnerability

Climate change is real (but that does not) justify science assessments built for headlines and political advocacy, which WG2 appears to be

Bottom line:
Disappointing."