Two new studies have found that squirrels and beavers contribute more to climate change than previously thought.
Arctic ground squirrels melt permafrost when they burrow. Permafrost preserves dead animals and vegetation underground for hundreds of years. The squirrels’ feces also fertilize the soil, which allows microbes to thrive. These microbes decompose dead plants and animals, which releases greenhouse gases. It is estimated that the Arctic permafrost contains twice the amount of carbon that is currently in the atmosphere. When permafrost melts, it can create a cycle of rising temperatures and further melting.
Another study discovered that beavers contribute to climate change. When beavers build dams, shallow pools of water collect. Biological material accumulates and is broken down into greenhouse gases, which contribute to climate change. Ponds formed by beaver dams have stagnant water, which has less oxygen than a flowing river and allows microbes to thrive. Methane does not dissolve in water. Instead, it enters the atmosphere.
Researchers at the University of Saskatchewan in Canada estimate that beavers produce 200 times more methane today than they did in 1900, when they were nearing extinction due to hunting. There are currently about 10 million beavers in Canada. They have created approximately 16,000 square miles of dammed ponds that release 882,000 tons of methane. That is 15 percent of the amount of methane produced by deer, antelope, and other cud-chewing animals. The beaver population has grown because of conservation efforts and their status as a protected species.
Cows are the largest contributors to climate change. One cow can produce 250 to 500 liters of methane. Other animals that chew the cud, such as sheep and goats, produce 18 percent of greenhouse gases, which is more than the amount released by transportation.