Chapter Three of the Fourth National Climate Assessment published by the US Global Change Research Program is entitled Detection and Attribution of Climate Change.
I’ll post the key finding below, but what has struck me about this massive, insightful, intelligent and official report on the science of global warming and climate change is the very temperate considered nature of the language used in it. These aren’t tabloid players by any stretch of the imagination.
Key Finding 1 of Chapter Three reads thus:
“The likely range of the human contribution to the global mean temperature increase over the period 1951–2010 is 1.1° to 1.4°F (0.6° to 0.8°C), and the central estimate of the observed warming of 1.2°F (0.65°C) lies within this range (high confidence). This translates to a likely human contribution of 93%–123% of the observed 1951–2010 change. It is extremely likely that more than half of the global mean temperature increase since 1951 was caused by human influence on climate (high confidence). The likely contributions of natural forcing and internal variability to global temperature change over that period are minor (high confidence).”
