James Hansen Proves His Ability to Predict the Future

Now we return to the thrilling yesteryear of l981, when James Hansen and a team of scientists at the Godard Institute of Space Studies released a study called Climate Impact of Increasing Atmospheric Carbon Dioxide. Take a gander at the summary:

The global temperature rose by 0.2 degrees C between the middle 1960’s and l980, yielding a warming of 0.4C in the past century. The temperature increase is consistent with the calculated greenouse effect due to measured increases of atmospheric carbon dioxide. Variatons of volcanic aerosols and possibly solar luminosity appear to be primary causes of observed fluctuations about the mean trend of increasing temperature. It is shown that the anthropogenic carbon dioxide warming should emerge from the noise level of climate variability by the end of the century, and there is a high probability of warming in the l980’s. Potential effects on climate in the 21st century include the creation of drought-prone regions in North America and centra Asia as part of a shifting of climactic zones, erosion of the West Antarctica ice sheet with a consequent worldwide rise in sea level, and the opening of the fabled Northwest Passage.

In assessing the accuracy of his forecasting, we note that solar luminosity has declined somewhat, and volcanic aerosols now are much better understood as factors. Because in part due to the infamous hole in the ozone layer, Antarctica has proven to be less vulnerable to warming than originally thought. Otherwise, Hansen was precisely on target, and concluding with a reference to the opening of the Northwest Passage in the 21st century gave the writing a poetic touch that proved to be right on time.

In short, the mild-mannered James Hansen did remarkably well…especially considering what his fellow physicist Niels Bohr once said.

Prediction is very difficult, especially about the future.