ManusJustus said:
Ice caps have melted and grown before humans weren't around, but man is able to change his environment and is capable of doing such things. And humans aren't the first living thing to have that claim, I'm thinking of ancient bacteria and photosynthesis. Besides, mosquitos with three foot wingspans that were around in previous hot periods doesn't sound too appealing to me. I dont see why you mentioned your second point. What matters is how much overall effect something has. Methane is obviosly another greenhouse gas that has more of an effect per unit mass but there a lot less of it. Its the overall effect that we are concerned with, and yes methane is part of that equation. Again, I dont know how this pertains to the argument. We put CO2 into the air and the change leads to an increase in overall temperature, and that current increase is in terms of one or two degrees C, which isn't a lot in the grand scheme of things but can have major consequences as far as we are concerned. If we put more CO2 into the atmosphere than natures puts there we'd start to resemble Venus. The natural level of greenhouse gases results in our current climate, and I prefer to stay closer to our current norm. I dont want to put entire ecosystems on the brink and cause mass human migrations from global warming. We are going to run out of hydrocarbons soon anyway, so the quicker we try to switch to solar and/or nuclear forms of energy the better off we are. |
Whether it is theoretically possible that man could cause climate change, when you crunch the numbers it becomes clear that it is highly unlikely that man is causing dangerous climate change ...
While the IPCC predicts a temperature sensitivity to a doubling of CO2 at 3.6 degrees (Celsius) it has been observed at (roughly) 1.0 degree (Celsius). What this means is that humans’ production of CO2 has accounted for an increase in world temperature of (roughly) 0.6 degrees, and in order to stay below the 2 degree limit the IPCC has set we have to limit our CO2 output to (roughly) 6 times our current level.
