Scientists use climate computer models to compare these observed changes with natural climate drivers and human climate drivers. (ucsusa.org)
When climate models include only recorded natural climate drivers, the models can not accurately reproduce the observed warming of the past half century. (ucsusa.org)
As former NASA employees, we feel that NASA's advocacy of an extreme position, prior to a thorough study of the possible overwhelming impact of natural climate drivers is inappropriate. (cfact.org)