Didn’t the National Academy of Sciences say greenhouse gases cause global warming?
• The National Academy of Sciences reported in 2001 that, “Because of the large and still uncertain level of natural variability inherent in the climate record and the uncertainties in the time histories of the various forcing agents…a causal linkage between the buildup of greenhouse gases in the atmosphere and the observed climate changes during the 20th century cannot be unequivocally established.” It also noted that 20 years’ worth of data is not long enough to estimate long-term trends.
