A climate scientist responds

Regarding David Wordinger’s March 1 letter (“Science is never settled”), science is indeed never completely settled, and the Intergovernmental Panel on Climate Change reports are not completely accurate.

But as an accomplished climate scientist, I can say that our confidence in our conclusion regarding the dominant human influence on recent and future global warming is far greater than your confidence that your house will burn. You insure your house because there is a chance it will burn, and if it did it would be catastrophic.

Similarly, there is a chance that global warming will be catastrophic. Fortunately, we have the technology and effective policies available that can do something about it. A prudent response to the IPCC reports is to invest in climate policies that insure us against climate catastrophe.

Yes, the climate was changing long before humans started burning things. But the ice core records from Antarctica tell us that the greenhouse gas (carbon dioxide and methane) concentrations have changed in sync with temperature changes over the last 800,000 years of ice age cycles. Although the timing of the ice age cycles is governed by small changes in the Earth’s orbit, the magnitude is greatly amplified by the influence of the greenhouse gases on the Earth’s energy balance. Indeed, the dramatic ice age cycles cannot be explained without accounting for that influence. And the influence operates whether the greenhouse gas concentrations change in response to natural processes or human activities.

Steve Ghan

Richland