Anfang April 2014 hatten wir an dieser Stelle über den angesehenen Klimawissenschaftler Richard Tol berichtet, der den IPCC verlassen hatte, da er die alarmistische Berichterstattung nicht mehr mittragen wollte. In seinem Blog beschrieb Insider Tol am 25. April 2014 die strukturellen Schwächen des IPCC. Richard Tols Bericht erlaubt einen seltenen Einblick in eine geheimnisvolle Organisation, die sich nach außen stets als vollkommen transpararent, integer und wissenschaftlich ergebnisoffen darstellt. Nach Lektüre der Zeilen wird hoffentlich auch der letzte Zweifler nachdenklich. Im Folgenden erlauben wir uns, Tols Text in voller Länger in englischer Originalversion wiederzugeben.
By Richard Tol
In September 2013, I stepped down from the team that prepared the draft of the Summary for Policy Makers to the Fifth Assessment Report (AR5) of Working Group II of the Intergovernmental Panel on Climate Change (IPCC). This attracted worldwide media attention in April 2014. Regrettably, the story of AR5 became the story of a man. I have been involved with the IPCC since 1994, fulfilling a variety of roles in all three working groups. After the debacle of AR4 – where the Himalayan glacier melt really was the least of the errors – I had criticized the IPCC for faulty quality control. Noblesse oblige – I am the 20th most-cited climate scholar in the world – so I volunteered for AR5. The Irish government put my name forward only to withdraw its financial commitment when I was indeed elected. The necessary funding could have easily been freed up if the Irish delegation to the international climate negotiations and the IPCC would trim its luxurious travel arrangements.
As a Convening Lead Author of one of the chapters, I was automatically on the team to draft the Summary for Policy Makers (SPM). AR5 is a literature review of 2,600 pages long. It assesses a large body of scholarly publication. In some places, the chapters are so condensed that there are a few words per article in the learned literature. The SPM then distills the key messages into 44 pages – but everyone knows that policy and media will only pick up a few sentences. This leads to a contest between chapters – my impact is worst, so I will get the headlines.
In the earlier drafts of the SPM, there was a key message that was new, snappy and relevant: Many of the more worrying impacts of climate change really are symptoms of mismanagement and underdevelopment. This message does not support the political agenda for greenhouse gas emission reduction. Later drafts put more and more emphasis on the reasons for concern about climate change, a concept I had helped to develop for AR3. Raising the alarm about climate change has been tried before, many times in fact, but it has not had an appreciable effect on greenhouse gas emissions. I reckoned that putting my name on such a document would not be credible – my opinions are well-known – and I withdrew.
The SPM, drafted by the scholars of the IPCC, is rewritten by delegates of the governments of the world, in this case in a week-long session in Yokohama. Some of these delegates are scholars, others are not. The Irish delegate, for instance, thinks that unmitigated climate change would put us on a highway to hell, referring, I believe, to an AC/DC song rather than a learned paper. Other delegations have a political agenda too. The international climate negotiations of 2013 in Warsaw concluded that poor countries might be entitled to compensation for the impacts of climate change. It stands to reason that the IPCC would be asked to assess the size of those impacts and hence the compensation package. This led to an undignified bidding war among delegations – my country is more vulnerable than yours – that descended into farce when landlocked countries vigorously protested that they too would suffer from sea level rise.
Many countries send a single person delegation. Some countries can afford to send many delegates. They work in shifts, exhausting the other delegations with endless discussions about trivia, so that all important decisions are made in the final night with only a few delegations left standing. The IPCC authors, who technically have the right to veto text that contradicts their chapter, suffer from tiredness too. This shows. The SPM omits that better cultivars and improved irrigation increase crop yields. It shows the impact of sea level rise on the most vulnerable country, but does not mention the average. It emphasize the impacts of increased heat stress but downplays reduced cold stress. It warns about poverty traps, violent conflict and mass migration without much support in the literature. The media, of course, exaggerated further.
Alarmism feeds polarization. Climate zealots want to burn heretics of global warming on a stick. Others only see incompetence and conspiracy in climate research, and nepotism in climate policy. A polarized debate is not conducive to enlightened policy in an area as complex as climate change – although we only need a carbon tax, and a carbon tax only, that applies to all emissions and gradually and predictably rises over time. The IPCC missed an opportunity to restore itself as a sober authority, accepted (perhaps only grudgingly) by most.
The IPCC does not guard itself against selection bias and group think. Academics who worry about climate change are more likely to publish about it, and more likely to get into the IPCC. Groups of like-minded people reinforce their beliefs. The environment agencies that comment on the draft IPCC report will not argue that their department is obsolete. The IPCC should therefore be taken out of the hands of the climate bureaucracy and transferred to the academic authorities.