Hello John (McCormick), Sorry to be late getting back, I've been having a rest from this hole AGW issue prior to the release of AR4 Scientific Basis. Whether or not I decide to read it (as I did AR3 Sci Basis) will probably determine whether I carry on learning in this field.
I don't think that short term problems like recessions or depressions will change what I am saying. Take the world since the 1930s depression or WWII. Being British I reflect on the UK since the 1970s - back in the 70s many seemed to see the UK as down and almost out. We're quite able to pick ourselves up from such events. With regards crop yields, I really think that's too much of a resultant effect from the process we can have certainty in. We KNOW that as we continue to emit CO2 we'll warm the planet. We have very good reason to think that we will continue to emit at an increasing rate for some decades at least. But the more one extrapolates from such processes into other processes like agriculture, the less interested I am. Sorry but I think the issues around crop yields, as with the effects on people, are too complex for us to be sure. I'm prepared to tentatively accept many things as being processes that may continue and worsen - the Australian drought is but one. On the "Day After Tomorrow" DVD there's a documentary in which the former head of the WHOI talked worryingly about drought in continental interiors progressing. When I first saw it I was a sceptic and dismissed it, now I just don't know. I'm afraid that my answer to most of these questions is 'ask me in a decade'. However as Kooti Masuda indirectly points out re China, climate change is not the only factor. Didn't ploughing up and down slopes instead of with the contour contribute to the US' 'dustbowl' in the 1930s? There's a risk people concentrate of AGW and neglect issues like deforestation and land use changes (I've recently been reading about the Aral Sea http://enrin.grida.no/aral/aralsea/english/arsea/ arsea.htm ) Basically I look back at the challenges and technological changes of the last 100 years and don't think that a climate sensitivity of 3degC is likely to produce a response that will act as a negative feedback on our activities (unlike say a 10degC sensitivity). But throughout the technological changes 1) our numbers have increased as we have removed constraints (health-care etc), 2) fossil fuels have remained our best option for energy in terms of 'energy recovered for energy invested, 3) a greater absolute number of people have experienced an increasing standard of living (given China and India as examples it's reasonable to see this as leading to an proportionate increase). PS CobblyWorlds - the alternate dimensions discovered by the Dogs in Clifford Simak's "City" - a modernist fantasy that opens with the death of Cities due to nuclear power providing energy too cheap to meter. It seemed apt. Hank, >That's more likely that than we're as stupid as we appear to be acting >on our own. Surely we're acting like any animal does when you remove the constraints on it's population. Perhaps we're Cane Toads, not boiling frogs. ;) --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
