© Jennifer Kay
11/17/2014 6:21:50 AM
Polar Bears and Students in the Infrared
What do polar bears look like in the infrared? We’ve been finding out this past week on Tundra Buggy® One.
One of our infrared pictures is above. The colors show the amount of thermal infrared radiation, or heat, that polar bear emit. Compared to the cold tundra surface—which shows up in purples and pinks—the polar bear appears in oranges and yellows.
Why? The polar bear is warmer than the cold tundra surface below him, and thus emits more radiation. But even though the bear is warm, his skin temperature is much lower than his internal temperature. A relatively low skin temperature demonstrates that the polar bear is retaining heat, even though he is not wearing a coat. Sounds like a pretty smart strategy given the cold winters on Hudson Bay!
Looking at these thermal infrared images of polar bears reminds me of earlier this fall, when we photographed students in my Climate 101 course at the University of Colorado in the infrared.
Like polar bears, students are relatively warm when compared to their background classroom environment. Unlike polar bears, who have warm noses, some students have cold noses, as you can see in the photo below.
It’s been exciting to share the tundra, polar bears, and polar climate science with my students today via a live webcast. Over the past semester, we’ve talked a lot about greenhouse gases and thermal infrared radiation. Greenhouse gases such as carbon dioxide and methane are important for explaining variations in Earth’s climate over time scales of hundreds of thousands to a million or even a billion years. But humans are responsible for greatly increasing the greenhouse gases in our atmosphere over a very short time scale—roughly the last 100 years—and thus causing the global warming we’re observing now.
The basic physics of the greenhouse effect are as well established as gravity, yet are hard for us to conceptualize. Our eyes detect light at visible wavelengths, not at infrared wavelengths. Our experience of looking at the world with visible radiation does not give us a good perspective on the infrared, so maybe seeing more photos in the infrared will help? The greenhouse effect depends on infrared radiation that we cannot see. But even though we cannot see it, evidence of our warming planet is everywhere.
It was great being on the tundra this week, teaching kids and adults about the reality of climate warming and its impact on polar bears. If people can take action to help polar bears, they will also be helping all the other species in the world, including humans!