Editorโs note: This commentary is by John McClaughry, the vice president of the Ethan Allen Institute.
[O]n Nov. 23 the U.S. government’s Global Climate Research Program delivered a congressionally mandated National Climate Assessment report. โGrimโ is too weak an adjective for the terrors that the report describes.
Hereโs an attempt to summarize the document: The earth is steadily getting hotter. โHuman activities, especially emissions of greenhouse gases, are the dominant cause of the observed climate changes in the industrial era, especially over the last six decades. Over the last century, there are no credible alternative explanations supported by the full extent of the observational evidence.โ
โWithout significant [greenhouse gas emission] reductions, annual average global temperatures could increase by 9ยฐF (5ยฐC) or more by the end of this century compared to preindustrial temperatures.โ The increasingly dire effects will be sea level rise, fires, floods, droughts, heat waves, ocean acidification, shrinking glaciers, disappearing Arctic sea ice, โgrowing challenges to human health and safety, quality of life, air quality, and the transmission of disease through insects and pests, food, and water and the rate of economic growth,โ and โchallenges to livestock health, declines in crop yields and quality, and changes in extreme events in the United States and abroad threaten rural livelihoods, sustainable food security, and price stability.โ In short, an unspeakable planetary calamity โcouldโ be coming.
The mainstream news mediaโs coverage of the report was predictably contrived to induce panic. The media featured the reportโs recurring statement that the dominant cause (Washington Post: โalmost entirelyโ) of its projected grim consequences is human action. Announced CBS News: โMass deaths and mayhem: National Climate Assessment’s most shocking warnings – billions of hours in productivity will be lost. Hundreds of billions of dollars will be wiped from the economy. Tens of thousands of people will die each year.โ
But whatโs new here? The report, relying on passive constructions such as โis projected to be,โ seems to collect all of the contentions made by climate alarmists over the past 30 years, and announce them again with a redoubled sense of urgency.
The โprojectionsโ are founded on computer models that, over the same period, have seriously overestimated the observed increase in global temperature. The report repeatedly tells us that somebody, unnamed, has โvery high confidenceโ in certain of their own projections.
One critic has described the output as โan assembly of prophecies,โ made by prophets whose careers in government-funded agencies will assuredly diminish if they donโt contribute to the correct planetary disaster narrative.
Equilibrium Climate Sensitivity is defined as the temperature increase that will result from a doubling of atmospheric carbon dioxide (now 410 ppmv). For 30 years the โofficialโ ECS has been estimated as 1.5 to 4.5ยฐ C, average 3.0, an extraordinarily broad range.
Climatologist Judith Curry (Georgia Tech) writes that โClimate sensitivity and estimates of its uncertainty are key inputs into the economic models that drive cost-benefit analyses and estimates of the social cost of carbon. Continuing to rely on climate-model warming projections based on high, model-derived values of climate sensitivity skews the cost-benefit analyses and estimates of the social cost of carbon.โ
At least four recent scientific papers, including hers, have concluded that the ECS is more like 1.6ยฐC. If so, even with continuing greenhouse gas emissions, warming will be gradual, comfortable and probably net beneficial.
The tangible benefits from a warming planet are not conceded in the report. Since the present warming โ not caused by humans โ began around 1850, living on Earth has become a much happier experience. We have longer growing seasons, fewer crop-destroying cold snaps, greater food production, fewer deaths from cold, less need for heating fuels, and less costly winter highway maintenance.
What of the reportโs supposed 4 percent (+/-2 percent) reduction in global GDP resulting from a purely conjectural 9ยฐF global average temperature increase by 2090? New York University physics professor Stephen Koonin, who was an Obama appointment as undersecretary of Energy for Science, puts that claim in perspective. Assuming a very conservative 2 percent annual global GDP growth rate, โthe U.S. economy in 2090 would be no more than two years behind where it would have been absent man-made climate change.โ (Wall Street Journal 11/27/18).
Yes, climate is changing, and human activity, notably land use changes and fossil fuel combustion, is in part responsible. Whether human activity is the โdominantโ cause remains debatable. Debatable, too, is whether the cost of reducing global fossil fuel combustion to non-threatening (to climate activists) levels demands too great a price in prosperity and human well-being.
Rational people are right to harbor serious doubts about this reportโs dire and highly speculative projections.
