This paper describes two mitigation scenarios leading to the stabilization of atmospheric CO<Subscript>2</Subscript> concentrations at 550 and 750ppm. These mitigation scenarios are developed from the A2-ASF baseline scenario, which characterizes a regionalized world with continuous population growth (to about 15...</subscript>

Learning-i.e. the acquisition of new information that leads to changes in our assessment of uncertainty-plays a prominent role in the international climate policy debate. For example, the view that we should postpone actions until we know more continues to be influential. The latest work on...