This week marks the 30th anniversary of the first public warning that global warming had started, and climate scientists are assessing where the predictions of the NASA scientist who sounded the alarm stand up now, thirty years later.
On June 23, 1988, NASA scientist James Hansen told the Senate Committee on Energy and Natural Resources in a testimony that he was highly certain that there was “a cause-and-effect relationship between the greenhouse effect and observed warming.”
Pat Michaels and Ryan Maue, the director and an adjunct scholar at the Cato Institute’s Center for the Study of Science, respectively, discussed in an opinion piece in The Wall Street Journal this week the three scenarios that Hansen developed in 1988 for the future global carbon dioxide emissions. In Scenario A—‘business as usual’—the prediction was that the earth would warm by 1 degree Celsius by 2018. Scenario B, which Hansen considered the “most plausible”, predicted lower emissions, rising at the same rate today as they did in 1988 and predicted that the warming would be 0.7 degree Celsius by 2018. In Scenario C—considered “highly unlikely” by Hansen—the projection was that emissions would flat-line after 2000.
According to Michaels and Maue’s piece in the WSJ, the scenario closest to today’s reality is Scenario C.