I believe that the Kyoto Summit has some of the best global documentation and environmental scientists working on the Green House effect and carbon emissions. Direct involvement, intervention and adherence by the dominat countries worldwide to a set of emission reduction standards with achievable milestones over the next decade will dramatically help slow this devastating process to the earths atmosphere. Its unfortunate that the US has not participated as earnestly as some of our neighbors, as we are looked at by the rest of the world for being a benchmark regarding these standards.
Additionally, regarding man made pollutants within the environment, it is not the effects of a single source toxin or their half life which wreaks havoc, but the combination of them. Whole eco systems are showing signs of significant stress and entire species are being added to the endangered species list each year.