Bruce,
you make a good point and I must admit that my call for immediate change comes in a feeling of desperation. True, it has been this hot before and the earth does what it wants over time, but I think there is enough evidence in not only in science but 70 degree weather in Boston in January that proves we are contributing plenty. Fossil fuels are known to be a large contributer to the problem, so we should start there right away, then plan some more researched attempts.
A recently failed theory was putting quantities of iron in the ocean which spurred plankton growth and helped remove CO2 from the air, but the results
weren't what we hoped. If something as desperate as chucking mass quantities of a metal into the ocean won't really work, then shouldn't we do what we can now?