Back in January, there was a huge debate in the comments here about “flora gains” – the suggestion by one of the regular commenters that we’d benefit from enhanced carbon dioxide because the plants on which we depend for food etc. would do better, with CO2 fertilization more than making up for any negative effects from climate change. It was one of those classic blog comment shouting matches, mostly heat and not much light, and I pretty much stayed out of it.
There are a couple of papers in tomorrow’s Science that add some light, and they suggest that the case for CO2 fertilization benefits has been overstated.
The problem, outlined by Stephen Long of the University of Illinois and colleagues is that the “enclosure studies” supporting flora gains were not terribly realistic. With better technologies that have allowed testing of enhanced CO2 in real-world settings, the benefits are far smaller.
I don’t know enough about the issue to understand where this fits in the broad sweep of research on this question. But I do know that this is a fair piece more interesting and important than hockey sticks, as this is the sort of stuff we actually need to understand in order to figure out what to do.
Food for Thought: Lower-Than-Expected Crop Yield Stimulation with Rising CO2 Concentrations, Long et. al, Science 30 June 2006: Vol. 312. no. 5782, pp. 1918 – 1921, DOI:10.1126/science.1114722
Climate Change and Crop Yields: Beyond Cassandra, Schimel, Science 30 June 2006: Vol. 312. no. 5782, pp. 1889 – 1890, DOI: 10.1126/science.1129913