Old Rocks
Diamond Member
First, you state that there are natural cycles of warming and cooling. That is correct, they are called the Milankovic Cycles. And there are shorter cycles due to solar activity, and cycles of oceanic circulation. But these cycles have causes. In other words, they are responses to natural forcings.
Now if the response to a natural forcing of 100 ppm of CO2 takes us from continental glaciers to the mild interglacial, then what will an additional 110 ppm of CO2 do? We are already seeing part of what it does in the rapid thawing of the Arctic. For several hundred years, that Arctic has slowly been cooling. However, in the last century, it has started to warm rapidly, rapidly enough that the permafrost is melting and emitting both CO2 and CH4 into the atmosphere. There is the potential there for the amount emitted to exceed what mankind has already done. That is without even considering the clathrates in the Arctic Ocean. Clathrates that are already starting to emit CH4 in worrisome amounts.
The increasing heat in the atmosphere and oceans that we are seeing today is caused by the GHGs that mankind has put into the atmosphere in the last 150 years. We have created that forcing. And it will take thousands of years for the GHGs to be removed from the atmosphere by natural means. Not at all a wise gift to our descendents.
Now if the response to a natural forcing of 100 ppm of CO2 takes us from continental glaciers to the mild interglacial, then what will an additional 110 ppm of CO2 do? We are already seeing part of what it does in the rapid thawing of the Arctic. For several hundred years, that Arctic has slowly been cooling. However, in the last century, it has started to warm rapidly, rapidly enough that the permafrost is melting and emitting both CO2 and CH4 into the atmosphere. There is the potential there for the amount emitted to exceed what mankind has already done. That is without even considering the clathrates in the Arctic Ocean. Clathrates that are already starting to emit CH4 in worrisome amounts.
The increasing heat in the atmosphere and oceans that we are seeing today is caused by the GHGs that mankind has put into the atmosphere in the last 150 years. We have created that forcing. And it will take thousands of years for the GHGs to be removed from the atmosphere by natural means. Not at all a wise gift to our descendents.