Dr Art Robinson.

A review of the research literature concerning the environmental consequences of increased levels of atmospheric carbon dioxide leads to the conclusion that increases during the 20th Century have produced no deleterious effects upon global weather, climate, or temperature.
Increased carbon dioxide has, however, markedly increased plant growth rates.
Predictions of harmful climatic effects due to future increases in minor greenhouse gases like CO2 are in error and do not conform to current experimental knowledge.
Dr Art Robinson, University of Oregon.