Posted April 7th, 2012 in Physics. Tags: Climate, Diagrams, Intermediate-Science, No Equations, Pedagogy, Physics, Quickie.
The overwhelming majority of scientists endorse this statement:
“Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations.” [IPCC Summary for Policymakers, 2007]
Here, “most” means at least 50% of the 0.55°C rise since 1950. Some mistakenly call this an “alarmist exaggeration” but it actually understates the human contribution because it’s easy to incorrectly conclude that the other 50% of the trend might be caused by natural forcing variations: (more…)