It's due to many reasons, and Americans are cutting back. Our CO2 emissions have steadily been dropping for decades. the US and Europe have been solving environ

It's due to many reasons, and Americans are cutting back. Our CO2 emissions have steadily been dropping for decades. the US and Europe have been solving environmental problems. Since the US has started to lower global CO2 emissions have more than doubled. That's mostly due to Asia. Their per capita emissions continue to rise and rise and rise, that's even with their booms in population.