A registered reviewer on the latest Intergovernmental Panel on Climate Change report has challenged the report’s findings on climate change’s economic effects.
Bob Ward, policy and communications director at the London School of Economics’ Grantham Research Institute on Climate Change and the Environment, said a number of data in the economic effects chapter remain unverifiable because journals have not yet secured agreement from a key researcher, Richard Tol, to make his calculations available.
In a 2013 paper University of Sussex economics professor Tol made several errors, including mistakenly plotting a 2006 study as finding a net benefit from global warming, Ward contends.
Ward says:
“I remain concerned about the following statement from the Summary for Policymakers from the report: ‘the incomplete estimates of global annual economic losses for additional temperature increases of ~2°C are between 0.2 and 2% of income (±1 standard deviation around the mean)’. These figures are drawn entirely from Professor Tol’s 2013 paper, and without independent verification of the data currently being possible, I do not regard them to have been proven robust.
“Furthermore, the version of Chapter 10 that has been published on the IPCC’s website is the draft that was distributed to governments in October 2013, and still contains at least three erroneous data points in Table 10.B.1 and Figure 10-1. The text of Section 10.9.2 remains a highly misleading description of the data: ‘Estimates agree on the size of the impact (small relative to economic growth) but disagree on the sign.’”
Richard Tol has generated widespread headlines after his decision to quit the IPCC writing team, branding its report “alarmist.” He said the report downplayed possible economic benefits from low-level climate change, such as better growing conditions for crops, the Guardian reports.
Takeaway: A reviewer has challenged the IPCC report for what he says are persistent mistakes overstating the economic benefits of climate change.
Tamar Wilner is Senior Editor at Environmental Leader PRO.