The Kyoto Protocol2 to the United Nations Framework Convention on Climate Change3 requires signatories to reduce their yearly emissions to about 13 tons of C02 emissions per person by 2012, which seems achievable. This target would be coupled with declining rates of emissions increase in developing countries. To stay within the absolute CO concentration limit of 450 parts per million accepted by the Copenhagen Climate Change Summit, accelerated progress towards a renewable or green energy transformation will be needed, as this limit would entail cutting annual emissions gradually to 3 tons per person by 2050, or less for any more stringent limit set to stabilize the climate.