Weather Forecast


In response: Bloggers, not scientists, are politicized climate con artists

(Nate Beeler / Cagle Cartoons)

In a May 17 viewpoint in the News Tribune, blogger Amy Ridenour listed 10 reasons why Congress should ignore calls for responsive legislation on climate change. Some were policy narratives relating to job forecasts, energy consumption, cap-and-trade policies and the trustworthiness of political leaders.

Unfortunately, Ridenour, the chairwoman of the National Center for Public Policy Research, a conservative Washington, D.C., think tank, dumbed down the scientific evidence for our planet’s changing climate. Among her points, one simply was invalid, another demonstrated a gross misunderstanding of scientific methods, another branded scientists as “activists” resorting to polls and ignored the overwhelming peer-reviewed scientific literature supporting climate change, and another revealed Ridenour doesn’t seem to understand the distinction between short-term weather and long-term climate.

Hers were threadbare arguments typical of the climate-change-denial camp.

I would like to touch on a couple of points that relate to Antarctica, a keystone in the Earth’s climate system. Because it is geographically isolated from other continents and is bathed by circumpolar currents of the Southern Ocean, the marine and glacial systems in Antarctica are particularly sensitive to global climate patterns.

As a researcher, I have witnessed firsthand evidence of warming since my first field expedition to the Transantarctic Mountains in 1985. Recent changes include the appearance of inland meltwater lakes, rushing mountain streams, and snow so wet ski-equipped planes can no longer land. And this is just a few hundred kilometers from the South Pole.

But don’t take my word for it. From food-web disruptions due to reduced krill populations to glaciers melting at their grounding lines by warmer oceans to accelerating ice streams to the loss of ice in essentially all Antarctic glaciers, there are many established lines of evidence of warming.

On May 12, a NASA news conference highlighted satellite and ground-based measurements by two independent research teams confirming what climate models have been telling us, that the largest glaciers in West Antarctica are now melting past the “point of no return.” Our warming climate means nothing can stop the disintegration of these ice streams over the next couple of centuries. This should be cause for alarm.

Doubters like Ridenour cite isolated measurements from Antarctica as evidence that global warming is not occurring. Cherry-picked data do not provide the full story. For example, recent observations indicate increasing snowfall over Antarctica’s ice caps. True. Antarctica is a polar desert, so what little snow does fall is transformed to ice over thousands of years. Recent increases in snowfall do not, however, indicate lower temperatures. Rather, warmer oceans generate greater evaporation, and a warmer atmosphere can contain more moisture. When this moist air comes into contact with the Antarctic ice cap it precipitates as snow for a net gain in the accumulation zone but not Antarctica overall..

Ridenour also stated that, “While Arctic sea ice levels are below average, Antarctic sea ice levels are above average.” This is another misrepresentation. Indeed, land-locked Arctic sea ice is diminishing because of ocean and atmosphere warming. In Antarctica, the annual sea ice that builds out from the continental margin is spreading farther, but there is not more of it. The greater sea ice coverage is due to a familiar oceanographic process called Ekman transport, in which surface winds coupled with Coriolis forces cause offshore surface currents that carry sea ice farther from the coast. Our warming atmosphere contributes more energy to wind speed, thereby pushing sea ice farther away. The same process dredges warm bottom water up along the coastline and is the main cause of melting in the ice sheets.

Ridenour might stimulate useful discussion by focusing her activism on climate-change policy rather than fallacious interpretation of the scientific record regarding climate change. The scientific evidence for climate warming is irrefutable, even if we don’t fully understand it. Rather than waste time on this,

wouldn’t it be better to start addressing how we will deal with it? Smart politicians from the left and right already are addressing the inevitable changes we face. Shouldn’t we all?

John Goodge is a professor of geological sciences at the University of Minnesota Duluth (