We find CO2 effects increase global crop water productivity by the 2080s depending on crop types, with particularly large increases in arid regions. If realized in the fields, the effects of elevated [CO2] could considerably mitigate global yield losses whilst reducing agricultural consumptive water use (4–17%). We identify regional disparities driven by differences in growing conditions across agro-ecosystems that could have implications for increasing food production without compromising water security. (Great news, right? Good luck finding it in the New York Times.) “This is a huge global phenomenon, which is bringing enormous financial benefits to agriculture,” Ridley told me. “That means we have a genuine benefit to carbon dioxide that surely must be taken into account if you are calculating the social cost of carbon. Given that we are not seeing any clear impact on droughts, floods, or storms, it is very hard to argue that there have been net negatives to carbon from climate change so far. In fact, there have clearly been net benefits.” Grain production worldwide hit an all-time high in 2016, with global cereal production 5.5 million tons higher than the peak year of 2014, according to the United Nations. It seems like Ridley’s timing couldn’t be better for him and worse for the carbon-is-poison crowd. Last week, the scientific establishment had a bench-clearing brawl over a new climate study that suggests we have a much bigger “carbon budget” to burn before we reach the danger zone in global temperatures. Several climatologists authored a paper published in Nature Geosciences indicating that, despite the desperate warnings from the climate tribe that it’s too late to save the planet, we can continue to emit carbon at current levels for the next few decades and still remain within the Paris Climate Accord range of a 1.5°C increase in global temperatures from the late 1880s to 2100. The reason? Climate models projected that rising CO2 levels would result in warming about 0.3°C higher than it actually is. In other words, CO2 did not have the heat-inducing effect that climate scientists warned it would. Richard Millar, one of the paper’s co-authors, said at the website Carbon Brief that the models’ projections “don’t match exactly with how much warming we’ve seen — they display slightly more warming for slightly less cumulative CO2 than we’ve seen in the real world.” Ridley told me he welcomes the climb-down:

This is a long overdue public concession by mainstream climate scientists — though the IPCC [Intergovernmental Panel on Climate Change] has also admitted it in somewhat obscure language two years ago — that the models they rely upon have been running too hot, predicting too much warming. They now admit that the 2°C threshold, which is when climate change is expected to do net harm, will not be reached at this rate for 80 years, roughly the end of the century. I would be amazed if the much richer people of the later 21st century have not cracked fusion or some other efficient source of low-carbon energy by then.

Climate scientists, environmentalists, and politicians here and abroad could use a healthy dose of that kind of rational optimism. Instead, they will no doubt continue their scare tactics, push their unattainable and punitive zero-emissions goal, and bully any “denier” who doesn’t capitulate to their political agenda. Too bad we don’t have more Matt Ridleys on this side of the Atlantic. This article appeared on the National Review website at http://www.nationalreview.com/article/451889/matt-ridley-climate-change-rational-optimist]]>