By Professor Will Happer
One of the latest entries in the campaign to demonize atmospheric carbon dioxide gas, CO2, is the organization RepublicEn, based in Berkeley, California. They tout themselves as Climate Realists and Energy Optimists. Someone recently pointed out that the politically correct stance on CO2 by California’s two main parties is:
Democrats: CO2 is an unnecessary evil.
Republicans: CO2 is a necessary evil.
RepublicEn seems to have positioned itself somewhere between these two party lines. No doubt this will go down well in California. But CO2 is not at all evil, in spite of the political consensus in California.
RepublicEn would have you believe that it is simply reporting honest science about CO2. Not so: the claims are sugar-coated versions of those from the IPCC , the United Nations International Panel on Climate Change, an organization mired in scandal for compromising science to produce politically desired messages.
For example, on the RepublicEn website we read, “The effects of CO2 in the atmosphere were first established in 1850. Radiative physics shows us that a doubling of CO2 would raise global temperatures by at least 1.8 Celsius. More warming than this is possible but how much is uncertain.”
What are the facts? First, no one knows how much temperature increase would be produced by doubling CO2. The complete absence of surface warming over the past 15 years or so gives very little confidence in establishment models, which falsely predicted an easily measurable warming of order 0.3 C.
With no “feedbacks” from changes in water vapor, clouds and other factors, radiative physics predicts a warming of around 1 C from doubling CO2. Even this number may be too large perhaps by a few tens of percent because of uncertainties about the edges of the CO2 radiative absorption bands. To get as much as 1.8 C for CO2 doubling, substantial positive feedback must be invoked, for example from changes in the distribution of water vapor with altitude or cloud cover. It is entirely possible that the feedback could be negative and the warming from CO2 could be as little as 0.5 C.
It will take a long time to double CO2. The present atmospheric levels are about 400 CO2 molecules per million air molecules (ppm). CO2 levels are increasing at about 2.5 ppm per year. At this rate it would take 400 /2.5 =160 years to double the atmospheric concentration to 800 ppm. And observations indicate that the temperature rise for doubling is unlikely to differ much from the no-feedback value of about 1 C.
To get another 1C of temperature rise, one would have to double the CO2 concentration again, to 1600 ppm, which would take an additional 320 years at current emission rates. If the warming is small and slow, so will be any contribution to sea-level rise.
Given that appreciable warming from more CO2 will take centuries to develop, what is the harm of waiting another decade or two until the science is more certain, instead of immediately taking actions guaranteed to be economically ruinous? Proposals to “decarbonize” the world economy will enrich a favored few with good political connections, and will condemn many others to continued poverty and misery for lack of adequate supplies of energy.
But aside from poorly understood but almost certainly small warming from more CO2, there are very substantial benefits to agriculture. These benefits are very well understood theoretically and have been repeatedly verified in field experiments. The Earth is currently in a CO2 famine compared to the levels that have prevailed over much of geological history. Land plants are starved for CO2. There have been impressive increases in plant cover since about 1982, when satellite monitoring of chlorophyll began. This is especially striking in semi-arid regions of the Earth, where more CO2 allows plants to cope with what would have been inadequate rainfall at pre-industrial CO2 levels of about 280 ppm. About 15% of the impressive increase in agricultural yields since the start of the “green revolution” is estimated to have come from more CO2.
The CO2 released by burning fossil fuels over the next century or two will be good for the Earth. It should be welcomed since it will bring prosperity to many currently impoverished people in less fortunate parts of the world. It will also provide huge benefits to agricultural productivity. This is the real “climate realism.”