{"id":7987,"date":"2021-08-11T15:16:37","date_gmt":"2021-08-11T13:16:37","guid":{"rendered":"https:\/\/blog.mr-int.ch\/?p=7987"},"modified":"2021-08-11T16:11:46","modified_gmt":"2021-08-11T14:11:46","slug":"ipcc-latest-report-on-climate-change-are-we-caught-like-rats-in-a-trap","status":"publish","type":"post","link":"https:\/\/blog.mr-int.ch\/?p=7987&lang=en","title":{"rendered":"IPCC latest report on climate change: are we caught like rats in a trap?"},"content":{"rendered":"\n

The latest IPCC Report on \u201cThe Physical Science Basis\u201d of Climate Change in 2021 has just been published. The downloaded document weighs 3949 pages and contains a \u201cSummary for policymakers\u201d (SPM) with 41 pages. Aside of the summary, the rest, including a 150 page \u201cTechnical Summary\u201d, is marked \u201cDo Not Cite, Quote or Distribute\u201d. A 148 page \u201cCorrigenda\u201d can also be downloaded. If the summary is already approved, why is the bulk still in a correcting mode? Impatience and concern for communication should not be part of the climate scientists’ toolbox.<\/p>\n\n\n\n

These monstrous dimensions suggest that no one can claim to master the subject, not even the hundreds of authors who have shared the task of reviewing and drawing conclusions from thousands of scientific works of varying quality. This is an ideal basis for imposing whatever interpretation one may find serving her or his purpose.<\/p>\n\n\n\n

Flying over the not that easy-to-understand SPM, I\u2019ve noted that the observed warming is deemed almost exclusively anthropogenic. A best estimate was assessed for the climate sensitivity to CO2<\/sub> at \u201c3\u00b0C with a likely<\/em> range of 2.5\u00b0C to 4\u00b0C (high confidence<\/em>), compared to 1.5\u00b0C to 4.5\u00b0C in AR5, which did not provide a best estimate.\u201d<\/spam><\/p>\n\n\n\n

Such sentence reminds us of the eternal use of \u00a0\u00bb expert \u00a0\u00bb judgements, even though they only have one laboratory and only one experiment at their disposition. Imagine psychiatrists or astronomists founding their knowledge on one only patient or one only star system. The long footnote 4 on page 4 should be the object of cognitive studies and group dynamic evaluation:<\/p>\n\n\n\n

\u201cEach finding is grounded in an evaluation of underlying evidence and agreement. A level of confidence is expressed using five qualifiers: very low, low, medium, high and very high, and typeset in italics, for example, medium confidence<\/em>. The following terms have been used to indicate the assessed likelihood of an outcome or a result: virtually certain<\/em> 99\u2013100% probability, very likely<\/em> 90\u2013 100%, likely<\/em> 66\u2013100%, about as likely as not<\/em> 33\u201366%, unlikely<\/em> 0\u201333%, very unlikely<\/em> 0\u201310%, exceptionally unlikely<\/em> 0\u20131%. Additional terms (extremely likely<\/em> 95\u2013100%, more likely than not<\/em> >50\u2013100%, and extremely unlikely<\/em> 0\u20135%) may also be used when appropriate. Assessed likelihood is typeset in italics, for example, very likely<\/em>. This is consistent with AR5. In this Report, unless stated otherwise, square brackets [x to y] are used to provide the assessed very likely<\/em> range, or 90% interval. \u201c<\/p>\n\n\n\n

If this method can be valid for retrospective studies, it is probably about as likely<\/em> as not<\/em> (33%\u201366%) that prospective judgements have no basis other than intimate sentiments reinforced by confirmation biases among peers.<\/p>\n\n\n\n

So, I will need to study how theses scientific assessments have been reached, with a particular interest on how models have been validated as fit for making projections into the future. It is more likely than not<\/em> that my curiosity will not be satisfied (see https:\/\/blog.mr-int.ch\/?p=6696<\/a>).<\/p>\n\n\n\n

The bulk of the SPM is prospective: it deals with estimates of future emission scenarios and their potential impacts on temperature, frequency and intensity of meteorological events, precipitations and soil moisture, sea level and acidity. Climatic impact-drivers (CID, physical climate system conditions that affect an element of society or ecosystems) are addressed at global, regional, and local scale.<\/p>\n\n\n\n

Thus, all conceivable extrapolations have been made possible, including the worst case being taken as a kind of \u2018business as usual\u2019, albeit the IPCC reckons that its likelihood is low. But the contrary is already spelled in printed press headlines and media breaking news: if the worst could happen, it will and the sooner the better for the prophecies of doom to be confirmed. However, as the social cost of warming may be acceptable for a temperature higher than the arbitrary limit of 1.5\u00b0C or 2\u00b0C, a more sober assessment of the figures as presented does not provide an argument for a state of emergency. This is important because it leaves room for an ordered decarbonization instead of panic.<\/p>\n\n\n\n

Let\u2019s recall that such prospective studies are in no way a scientific job, but mere speculation driven by the choice of interplaying parameters. Doing so has its merits\u2026 as long as conclusions are not drawn in such a biased way as the knee jerk reactions of the media and political circles already show.<\/p>\n\n\n\n

Finally, carbon budgets are calculated. These are the remaining quantities of anthropogenic greenhouse gases to be emitted before trespassing a given global temperature threshold (1.5 \u00b0C, 2 \u00b0C, or more). Not unexpected, a low emission scenario leaves more time to attain such limits. Nevertheless, \u201cdiscernible differences in trends of global surface temperature would begin to emerge from natural variability within around 20 years<\/spam>\u201d. This means that all efforts undertaken now, even the strongest and fastest decarbonization actions if successful, would not produce any result before the next generation will be in charge. For the time being, this will be a pill hard to swallow for developing and emerging countries, which are home to the vast majority of the World’s population and have a great many other priorities than the threat of a too warm climate. The COP26 (next November in Glasgow?) will not be a smooth and flowery ride; rationality could at last be brought back to the agenda in a much less consensual spirit.<\/p>\n\n\n\n

This will have been my last grain of salt in that matter, the penultimate as always. At first glance, this new report does not bring new insights. Its speculative orientation will contribute to fostering the current alarmist dogma.<\/p>\n\n\n\n

A plea to readers and email correspondents: As no breaking news is brought forward, please refrain from sending me links or copies of long videos, boring articles, ‘in-depth’ reports, or meaningful and meaningless reviews. I don’t need to waste my time pointing out misuses and prejudices surrounding this matter, because I know well enough that this is abundantly the case.<\/p>\n\n\n\n

What really becomes urgent is to savour and enjoy anything else that is more joyful.<\/p>\n","protected":false},"excerpt":{"rendered":"

The latest IPCC report: nothing new under the sun but a confirmation that science and its uncertainties as well as the extrapolations made from it open the floodgates to alarmist interpretations. We are already swamped with them.<\/p>\n","protected":false},"author":2,"featured_media":7973,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"iawp_total_views":4,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[1,37,5],"tags":[],"class_list":["post-7987","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-uncategorized","category-climate","category-politics"],"_links":{"self":[{"href":"https:\/\/blog.mr-int.ch\/index.php?rest_route=\/wp\/v2\/posts\/7987","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.mr-int.ch\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.mr-int.ch\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.mr-int.ch\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.mr-int.ch\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=7987"}],"version-history":[{"count":0,"href":"https:\/\/blog.mr-int.ch\/index.php?rest_route=\/wp\/v2\/posts\/7987\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blog.mr-int.ch\/index.php?rest_route=\/wp\/v2\/media\/7973"}],"wp:attachment":[{"href":"https:\/\/blog.mr-int.ch\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=7987"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.mr-int.ch\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=7987"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.mr-int.ch\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=7987"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}