Lawrence Solomon, author of the book “The Denialists”, is a name that hits a nerve among global warming alarmists. No wonder, his article in “The Financial Post” earned some criticisms. Let’s go to the source of Solomon’s “praise of CO2″ resulting in a boom in the biosphere (net primary production NPP) and - big surprise - another name hits a nerve albeit in the opposite camp: Charles D. Keeling!

Solomon has taken a lot of his information from a paper as published in “Science”, volume 300, on June 6, 2003: Climate-Driven Increases in Global Terrestrial Net Primary Production from 1982 to 1999 (Ramakrishna R. Nemani, Charles D. Keeling, Hirofumi Hashimoto, William M. Jolly, Stephen C. Piper, Compton J. Tucker, Ranga B. Myneni, Steven W. Running)
What is the message all about? Is this booming biosphere really the result of CO2 fertilization? This is what the abstract says:

Recent climatic changes have enhanced plant growth in northern mid-latitudes and high latitudes. However, a comprehensive analysis of the impact of global climatic changes on vegetation productivity has not before been expressed in the context of variable limiting factors to plant growth. We present a global investigation of vegetation responses to climatic changes by analyzing 18 years
(1982 to 1999) of both climatic data and satellite observations of vegetation activity. Our results indicate that global changes in climate have eased several critical climatic constraints to plant growth, such that net primary production increased 6% (3.4 petagrams of carbon over 18 years) globally. The largest increase was in tropical ecosystems. Amazon rain forests accounted for 42% of the global increase in net primary production, owing mainly to decreased cloud cover and the resulting increase in solar radiation.

This is interesting in many ways. Let’s start with “eased critical climatic constraints to plant growth”. Various studies prior to the IPCC TAR report concentrated on both positive and negative effects of projected climate change scenarios, as well as the CO2-fertilization effects of various crops. In this context, it needs to be said that climate models and observations both agree on the following formula.

Warmer air holds more water. Satellite observations and climate models agree that each rise of 1 °C in global temperatures increases the amount of water vapour in the atmosphere by about 6.5%.

What models do not predict is increased precipitation along with a certain rate of increase in water vapor.

Models predict that worldwide precipitation — which must match the amount of evaporation — will increase by only 1-3% for each degree of future global warming.

However, this is what Frank Wentz and his colleagues at Remote Sensing Systems in Santa Rosa, California, reported in “Science” [Wentz F. J., Ricciardulli L., Hilburn K. & Mears C. Science, 10.1126/science.1140746 (2007)] after analysing data collected by US weather satellites from 1987 to 2006:

…the amount of water in the atmosphere, evaporation and precipitation all increased at the same rate, by about 1.3% per decade — or about 6.5% for every degree of warming.

This basicly tells us that the cooling rains increase just the same as the warming water vapor in the atmosphere does. Where is the net warming feedback? But this is yet another topic. Fact is that the assumed lack of increase in precipitation in a warmer world is predicted to put stress on the biosphere which could somehow offset the positive effect of CO2 fertilization. This however is inconsistent with what Ramakrishna R. Nemani et al., 2004, discovered. What surprised the scientists there is not the increase of 6.17% in NPP over 18 years or 0.2% per 1-ppm increase in CO2, but rather more precipitation and wind and yet more sunshine (less cloud) that led to enhanced plant growth in low latitudes, especially in the Amazone region. And emphasis in neither of the studies was given to the fact that the reason for the warming could have been explained at least partly by the decreased cloud cover and not by the rising CO2-level.

Two of somewhat hidden fact behind the global warming scare appear to be that

1) Satellite observations suggest climate models are wrong on rainfall and
2) The biosphere takes advantage of the benefits of global warming so far contrary to what many scenarios predict.

My suggestion is to stop condemming CO2 as a polluter. I’ll do some research on black carbon, ozone and other polluters versus “clean” CO2, whereby the latter should be emitted into the atmosphere rather than sequestered as far as I know by now. Bjorn Lomborg just had an interview at CNN on how to deal with the risks of climate change. Watch part of the interview here at Youtube.