"Advocates of aggressive government intervention in the name of fighting climate change have posed as the defenders of “consensus science,” labeling any who dissent from their agenda as “deniers” with all of the baggage that term entails. And yet, as I’ve been pointing out for years, the peer-reviewed economics literature does not support the popular United Nations’ policy goals, of limiting global warming to either 2.0°C or the even more stringent ceiling of 1.5°C. Back in 2014, I used the latest issue of the UN’s own authoritative report—the Intergovernmental Panel on Climate Change (IPCC)—to make my case, and last fall I explained that the new Nobel laureate, William Nordhaus, had a career in climate modeling that did not come anywhere close to supporting the aggressive UN goals.

In the present post I’ll make my point with yet another striking example. I will show that one of the lead authors from the UN’s “Special Report” on the 1.5°C target is a co-author of a 2018 paper that admits the goal is difficult to justify. This should be shocking to naïve citizens and those who assumed that “the science” must all support the UN’s temperature goals. Yet as this example demonstrates, the UN’s new goal is so extreme that it’s difficult for even sympathizers to come up with a way to try justifying it using conventional economic analysis.

Rachel Warren’s Credentials

To set the context: Last fall, the United Nation’s IPCC released a Special Report telling policymakers various ways to (attempt to) hit the goal of limiting cumulative global warming to 1.5°C. The third chapter of the report summarized the recent economic research that had been published since the previous IPCC report (the Fifth Assessment Report or AR5). Rachel Warren of the Tyndall Centre for Climate Change Research (located at the University of East Anglia in the UK) is one of the lead authors of the chapter. Furthermore, Warren was author or co-author on at least four of the publications cited in the chapter. Here is an excerpt from her bio:
Rachel Warren is Professor of Global Change and Environmental Biology at the Tyndall Centre for Climate Change Research, University of East Anglia, UK. Her research focuses on the production of policy relevant science related to climate change and sustainability. A particular recent focus has been the quantification of the climate change impacts that can be avoided by timely mitigation of greenhouse gas emissions, in particular in relation to risks to biodiversity. She was a coordinating lead author of the 5th (2014) assessment of the Intergovernmental Panel on Climate Change (IPCC), and lead author of the 4th assessment which was awarded the Nobel Peace prize on 2007. Presently she is a lead author of the IPCC’s Special Report on 1.5°C warming. She has produced over 70 peer reviewed publications and over 40 scientific reports to government departments.
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Her academic background and training is in physics and the natural sciences at Cambridge University. After completion of her PhD she pursued an interest in atmospheric sciences and rapidly became involved in policy relevant research, a purpose to which she remains committed today. She has assisted in national, European and international policy development relating to combating stratospheric ozone depletion, acid deposition, eutrophication, and (since 2002) climate change. In particular, her former work at the NOAA Environmental Research Laboratories provided evidence on the environmental acceptability of CFC substitutes, leading to inclusion of fluorocarbons in the Kyoto Protocol, winning the NOAA Aeronomy Laboratories Outstanding Scientific Paper Award.
As the above description makes clear, we are not dealing with a “denier” or a “stooge for Big Oil” here. Warren is a leader among scientists who are advising governments on various policies through which they can intervene in the market to reduce emissions from businesses.

Rachel Warren’s (Co-Authored) Paper on the Economics of the UN Climate Goal

Given her background, it is extremely revealing to see that Warren (and co-authors) have a 2018 paper entitled, “The Economics of 1.5°C Climate Change.” Now because I know just how ludicrous (given standard modeling assumptions) this latest UN target is, I was curious to see how Warren and her co-authors could possibly try to justify it.

The reader can hopefully appreciate my shock when I read the first two sentences from the Abstract of their paper: “The economic case for limiting warming to 1.5°C is unclear, due to manifold uncertainties. However, it cannot be ruled out that the 1.5°C target passes a cost-benefit test.”

The skeptical reader should go ahead and click through to read the quote in context; I’m being completely fair. Believe it or not, the authors—including a Lead Author on the UN Special Report which advises governments on how to hit the 1.5°C limit—are arguing that because we understand this area so poorly, for all we know the UN target makes economic sense.

Is that the slam-dunk “consensus science” that citizens have been assured undergirds the suggested power grabs? Hardly. As I have been warning readers for years, the case for a carbon tax is far weaker than they’ve been led to believe.

Conclusion

One of the standard talking points among progressives is that the right-wing obfuscation machine will hide behind “uncertainty” in order to stall necessary action on climate change. And yet in this latest episode, the tables have turned. As Rachel Warren—a Lead Author on several important IPCC reports—and her co-authors argued in a 2018 paper, the uncertainty in our understanding keeps alive the possibility that the latest UN climate goal might pass a cost/benefit test after all."