- Global warming and threats of extinction of species are two different issues. They may be connected, but let’s not confuse them.
- There is ample justification for moving away from fossil fuels. This is important to do not only because of the potential threats of global warming, but also because petroleum is going to become harder to get and more expensive, because our need for it poses threats to national security, and because petroleum causes pollution of various kinds in additional to production of greenhouse gases.
- Contrary to many popular assertions in the media, we already have the technology to obtain more than ample energy from solar and wind, and, subsidies aside, the technology is economically viable.
- Biological diversity is of clear importance and we should do whatever we can to conserve endangered species.
- Experts on the fossil record and causes of past extinctions have long argued about likely causes of extinctions. As the famous anthropologist Paul S. Martin has written, “The popular answer, ‘the climate did it,’ is unsatisfactory” for extinctions of large animals during the past 2.5 million years. Martin argues that hunting by people during the past 10,000 years caused extinctions of some of the biggest, fiercest, and most famous land mammals — the hairy mammoth, the saber-toothed cat, among others. Other experts suggest that new diseases may have done it.
- Whatever the causes, the percentages of animal and plant species that are known to have gone extinct during the past 2 ½ million years --- a period that saw the evolutionary origin of Homo sapiens and some of our humanoid ancestors --- are much smaller than what is forecast by the new report of the United Nations Intergovernment Panel on Climate Change and the new “Bali Climate Declaration by Scientists” (published December 6, 2007), as well as recent assertions by others.
- Today, human actions that pose major threats to endangered species include
- destruction of habitats of these species, as a result of deforestation and human settlement;
- overharvesting, including poaching and international trade in endangered species;
- introductions of exotic species, including parasites and microbial diseases
of endangered species.
- Climate scientists appear to be calling primarily for large reductions in the release of greenhouse gases from human activities as a way to prevent extinctions. For example, a group of more than 200 leading climate scientists met in Bali, Indonesia, in December 2007 and concluded that the world must reduce emissions of greenhouse gases by 50% by 2050; otherwise, many animal and plant species will be “in serious danger of extinction.”
- Meanwhile, biological conservationists point to the need for better-protected areas, focusing on specific species that appear to be in danger of extinction, and whose habitats are threatened and are in areas where habitat conservation seems possible, so that actions could have desired results.
- For example, a recent scientific paper with Taylor Ricketts as the primary author identifies 794 species of mammals, birds, reptiles, amphibians, and conifers that are endangered but open to conservation. They write that “only one-third of the sites are legally protected, and most are surrounded by intense human development. These sites represent clear opportunities for urgent conservation action to prevent species loss.”
- The question is: Which way should we devote our resources, our time, money,
- Pointing to global warming as the primary problem for endangered species, and fearing a catastrophic die-off of species in the future, should we make biological conservation one of the justifications for actions needed to reduce greenhouse gas production?
- Or should we deal directly with species known now to be threatened, and work to preserve and improve habitats, prevent overharvesting and poaching, and reduce
introductions of exotic species?
- Can we do both?
- In any case, there are ample reasons other than biological diversity to move away from the use of fossil fuels. Those other reasons should be the primary focus of policies and actions to reduce greenhouse gases.
- Finally, for those who are interested, here are some important scientific references:
- Botkin, D. B., Henrik Saxe, Miguel B. Araújo, Richard Betts, Richard H.W. Bradshaw, Tomas Cedhagen, Peter Chesson, Margaret B. Davis, Terry P. Dawson, Julie Etterson, Daniel P. Faith, Simon Ferrier, Antoine Guisan, Anja Skjoldborg Hansen, David W. Hilbert, Craig Loehle, Chris Margules, Mark New, Matthew J. Sobel, and David R.B. Stockwell. (2007). "Forecasting Effects of Global Warming on Biodiversity." BioScience 57(3): 227-236.
- England, M., Richard Somerville, Andrew Pitman, Diana Liverman, Michael Molitor (2007). 2007 Bali Climate Declaration by Scientists.
- Lovejoy, T. E., Lee Hannah, editors. (2005). Climate Change and Biodiversity. New Haven, Yale University Press.
- MacPhee, R. D. E., editor. (1999), Extinctions in Near Time: Causes, Contexts, and Consequences. New York, KluwerAcademic/Plenum Pub. In particular, see
- Martin, P. S., D. W. Steadman (1999). Prehistoric Extinctions Chapter 2. Extinctions in Near Time: Causes, Contexts, and Consequences. R. D. E. editor. MacPhee. New York, KluwerAcademic/Plenum Pub.: 17-56.
- Martin, P. (1963). The last 10,000 Years. Tucson, AZ, University of Arizona Press.
- Ricketts Taylor H. Ricketts, E. D., Tim Boucher, Thomas M. Brooks, Stuart H. M. Butchart, Michael Hoffmann, and J. M. John F. Lamoreux, Mike Parr, John D. Pilgrim, Ana S. L. Rodrigues, Wes Sechrest, George E. Wallace, Ken Berlin, Jon Bielby, Neil D. Burgess, Don R. Church, Neil Cox, David Knox, Colby Loucks, Gary W. Luck, Lawrence L. Master, Robin Moore, Robin Naidoo, Robert Ridgely, George E. Schatz, Gavin Shire, Holly Strand, Wes Wettengel, and Eric Wikramanayak (2005). "Pinpointing and preventing imminent extinctions." Proceedings of the National Academy of Sciences of the United States of America 102(51): 18497-18501.
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