Airdate: Jul 12, 2004
Scientist: Lee Hannah
Climate Change and Extinction
Find out how global climate change will likely affect the distribution and survival of many plant and animal species.
ambience: Dawn chorus, Sierra
Many scientists now agree that the world's climate is slowly warming. The increased used of fossil fuels create gasses, such as carbon dioxide, which trap heat in our atmosphere, much like a greenhouse. The question is - how will this affect the survival of plants and animals worldwide? I'm Jim Metzner, and this is the Pulse of the Planet.
"Every species has its preferred climate, and as climate changes, they'll try and find that preferred climate by shifting their range, if necessary."
Lee Hannah is a senior researcher with Conservation International's Center for Applied Biodiversity Science. He and his colleagues have been working on computer models which predict the impacts of global climate change. Hannah's work is focused on species of plants found in South Africa.
"As climate warms, species will probably move upslope and towards the poles. In many cases, that may put species that are found on mountain tops at risk, also species with small ranges or lowland species that may not be able to get to mountain slopes and find equitable climate. Some species, that our study showed to be particularly sensitive to climate change, have already been observed declining in the field, due to the warming and drought in South Africa."
"Scientists believe that on average it takes about a million years for a species to evolve, so the sort of extinctions we're seeing in the study will take place on a very short time frame with respect to a million years, and for that reason, the species lost will not be replaced by natural processes and it's a very serious problem. Trying to assess what the actual impacts might be is the best way to avoid those impacts, because the future is in our control in terms of being able to control greenhouse gasses, and also in being able to design conservation strategies to respond to this problem."
Hannah's study suggests that as many as one million species of plants and animals worldwide could be facing extinction as a result of climate change.
Pulse of the Planet is made possible by the National Science Foundation.