Slashdot Mirror
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.'"
Wonder how many hypocrites who previously excoriate all climatologists who caution about global warming as corrupt and biased instantly trumpeting that these brilliant, honest, decent climatologists have to be right because the end result is one that they want.
It's hard to get funding for an experiment that takes two identical planets and changes the global CO2 concentration on one.
Climatology is an observational science like geology or astronomy. Models can be checked. It's not just curve fitting to the temperature record: climatologists figure they're on the right track when their models predict phenomena like El Nino.
Unfortunately, the effects from the ice age will not be apparent for another 1,500 years, while, on the other hand, the ice caps are already starting to melt. Though a small amount of global warming might be beneficial in the future for preventing an ice age (who knows what environmental impact THAT would have), it is very likely to be seriously detrimental for the next few centuries until then.
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.
Hating ice ages doesn't mean liking global warming. If you want to prevent the planet from cooling into an ice age, you don't need to warm it up above present temperatures. You just have to keep it from cooling below present temperatures.
Human civilization has adapted itself to a relatively stable range of climate over the last 10,000 years. Large warming or large cooling pushes us outside of that range. It may be costly to adapt our civilization to a completely different climate, particularly if it happens "fast" (century time scale). Thus, it's possible to hate both global warming and "ice ages".
If you want to use the greenhouse effect to prevent the planet from falling into a glacial period, then you should want to save fossil fuels for when we need them, rather than using them up now, when we don't. That is, dole them out slowly over thousands of years to keep the interglacial climate stable, as the next glacial period gradually deepens, instead of our current course of using them up rapidly and elevating temperatures well above the Holocene climate range.
Besides which, this study is controversial. Everyone agrees that we will see another glacial period someday, barring human intervention. The question is when. This study suggests 1500 years; a number of others have suggested that the next glacial period isn't due for as long as 50,000 years. Which is even less of an argument for global warming.