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Carbon Emissions 'Will Defer Ice Age'
Sven-Erik writes "Due to subtle variations in the Earth's orbit, researchers have calculated that the next Ice Age is due within 1,500 years. However, a new study suggests greenhouse gas emissions mean it will not happen that soon (abstract). 'Dr Skinner's group ... calculates that the atmospheric concentration of CO2 would have to fall below about 240 parts per million (ppm) before the glaciation could begin. The current level is around 390ppm. Other research groups have shown that even if emissions were shut off instantly, concentrations would remain elevated for at least 1,000 years, with enough heat stored in the oceans potentially to cause significant melting of polar ice and sea level rise.'"
Except... that isn't quite how it works.
Global warming means that we're changing a massively complex system. And like all massively complex system, when you tweak the parameters beyond a certain point, the system as a whole can itself wind up altering other parameters drastically as it seeks a new stable state.
Or, to put it simply, global warming could potentially lead to a sudden and drastic cooling:
http://science.nasa.gov/science-news/science-at-nasa/2004/05mar_arctic/
Check your premises.
How do you know that? Some models predict increased desertification in the mid latitudes but then many show increasing crop productivity at more northern latitudes. What we do know is that during previous ice ages the human species went through some bottleneck events that reduced our numbers to what we would now considered near extinction for a large animal species.
Go visit the tundra, tell me what you think that place will smell like when it thaws.
Sure, in about 1000 years when the toxic rot has run its course, there will be productive land there able to grow crops, but it won't get there without a lot of pain during the transition.
Intrinsically, people are inconvenienced by change, change of this magnitude is inconvenient enough that people will go to war over it.