Simon Donner wrote: > Michael's basic argument makes sense. But, it is worth asking what > this year's cereal grain production would have been without, say, the > drought in Australia. In other words, should we be comparing grain > production to an old baseline or to "business as usual". Production is > increasing because of technology (genetics + industrialization of > agriculture) and the increase in croplands in S America. Maybe climate > limited that increase in the past year. The evidence from the US is > that grain yields have not just increased, but have become more > volatile, in part because of climate -
This paper discusses yield trends and variability: http://www.sage.wisc.edu/pubs/articles/F-L/Kucharik/Kuch2005EarthInt.pdf James will be pleased to know that the paper expresses yields in tonnes per hectare... Ray --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups Global Change ("globalchange") newsgroup. Global Change is a public, moderated venue for discussion of science, technology, economics and policy dimensions of global environmental change. Posts will be admitted to the list if and only if any moderator finds the submission to be constructive and/or interesting, on topic, and not gratuitously rude. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/globalchange -~----------~----~----~----~------~----~------~--~---
