MNN - Mother Nature Network

for about 85% of the last HALF BILLION years have been around 1,500 PPM, roughly 4 times current levels, with temperatures up to 10 Centigrade degrees higher than at present. If atmospheric CO2 were to increase about 10%, from the current 392 PPM to around 430 PPM, which seems to be the "critical mass" point at which some folks fear the planet would suffer a catastrophic runaway greenhouse effect, it would merely be a small step away from our current historically (in the context of geologic time scales) low global temperatures and CO2 concentrations back toward a "Normal" situation. It never destroyed the planet before, and it won't this time. A return to the historically normal situation would certainly wreak havoc on human populations with rising sea levels and unimaginable devastation of costal cities. It's a risk we take in developing trillions of dollars worth of real estate right down to current sea level. Climate change is not to blame for this; we are, for failing to learn from the examples set by previous civilizations whose sunken cities we can find in numerous places around the continents. There are three primary things we need to control in order to effectively control the climate of Planet Earth: 1) Control the energy output of the sun 2) Control the orbital path of the Earth around the sun 3) Control geologic activity on Earth, i.e. volcanism and plate tectonics There is virtually nothing we can presently do about any of these things so we focus vast resources on reducing anthropogenic CO2 from burning fossil fuels, a factor that does contribute to climate change but to such a small degree in comparison to the really big influences mentioned above as to be insignificant. By all means, we should strive to develop clean and renewable energy solutions because there is only a finite amount of fossil fuel for us to burn, and combustion of most materials releases a great deal more than CO2 to the atmosphere. We should do what we can to eliminate waste and pollution, but defining CO2, an essential atmospheric gas to life, as a "pollutant" borders on insanity. By that sort of reasoning, we probably have way too much water on Earth, too. Looking at recent climatic history – again, on the geologic time scale of the last few million years – a much more realistic fear is return of the glaciers to large areas of present human habitation. Our present misguided initiatives might simply hasten the end of the current Holocene Interglacial Period and subsequent re-glaciation of much of the northern hemisphere.