neither the rate nor the magnitude of the reported late twentieth century surface warming (1979–2000) lay outside normal natural variability.
neither the rate nor the magnitude of the reported late twentieth century surface warming (1979–2000) lay outside normal natural variability.
global warming:55
before the industrial revolution, naturally occurring amounts of greenhouse gases caused the air near the surface to be warmer by about 33 °c (59 °f) than it would be in their absence.