Sunday, April 18, 2010
The Big Picture
So how does keeping trap of mice and voles, counting snowshoe hare scat, and mapping damaged tree bark help us understand climate change? Well, that is an interesting question with an interesting answer. Chris spent some time explaining his professional work and the science behind climate change. He did his best to put some very complicated data into terms that we could understand, since we haven't studied it before. First of all, it is important to call it climate change rather than global warming, since temperatures on the earth have always been changing throughout history. Actually, the average temperature at the moment is even a bit cooler than it has been in the past. What is alarming is the rate of change. Animals can be very good at adapting to their environment but they can't do it very quickly. When temperatures change faster than they can adapt, many of them will die off, especially the ones that have specific requirements for food and shelter. Let's take the snowshoe hare for example. It is an important source of food for birds of prey and large mammals such as coyote. Incredibly, when the days get short in the winter time, signals in their brain start to turn their fur from brown to white. This makes sense, since usually there will be snow in the winter and white fur will help it camouflage. But, if there is no snow and the hare turns white, it will be very easy for predators to see it. On the other hand, if it snows in the spring when the longer days trigger the fur to turn brown, the hare will be brown on a background of white and again very easy for predators to see. Winter weather here can change a lot anyways, and with increasing unpredictability due to rapid climate change, Chris and Christina are interested to see if this will eventually hurt their population. This is just one example, can you think of others? I should also explain what "rapid" means in terms of earth's history. Scientists have a way of measuring temperatures on earth even millions of years ago. Over a 20,000 year period of time, there was a 6ºC change. This caused a mass extinction of plants and animals. Humans have made a big impact in the last 200 years. Don't you think this must have some lasting effects?