Richard S. Lindzen, Alfred P. Sloan Professor of Meteorology at MIT
USEPA Global Warming and Climate
As an environmental scientist there are many things that I believe we humans do to harm the planet. We create mounds of trash, bury it in the ground and hope that it doesn't come back to hurt us. We increase our use of pesticides every year because we're caught in a vicious cycle; pests build up tolerances to the pesticides, we make stronger pesticides and the pests build up more tolerances and on and on. The pesticides run off the fields into our drinking water and cause a myriad of problems. We've burned millions of tons of coal, in turn generating so much sulfur dioxide that it rains down acid on us, damaging our cars, our homes, our forests and even our health. We've produced chemical refrigerants that when released into the atmosphere, destroy the ozone layer that protects us from the sun. I am convinced that these problems and many others are a direct result of human activity.
Most scientists believe that the Earth's average temperature is increasing, this much is certain. What is less certain is whether or not humans have had a hand in its warming. More fossil fuel use means more carbon dioxide being pumped into the atmosphere. More carbon dioxide in the atmosphere leads to increased heat being trapped via the Greenhouse Effect. Imagine a bathtub (the atmosphere) filling with water (carbon dioxide) and simultaneously draining (carbon dioxide being absorbed by the ocean, plants, etc). If the rate of filling is equal to the rate of draining then the level of water (carbon dioxide) in the bathtub (atmosphere) remains constant. In a perfect world this is how the Earth's atmosphere is supposed to behave. The Greenhouse Effect, so called because of the manner in which the Earth's atmosphere acts like a greenhouse to trap heat, would be similar to opening the faucet more to let water enter the bathtub faster than it could drain out. In this case, the rate of filling is greater than the rate of draining and the level of water in the bathtub begins to rise. And it would seem that for the last 100 years, the human race has opened that faucet more and more, increasing atmospheric carbon dioxide levels and thus increasing the average global temperature. Additionally, human activity has added other heat-trapping gases to the atmosphere, thereby increasing the average global temperature. But are humans really responsible for the increase in global temperatures or is it just coincidence?
Probably the data that is most familiar to many of us are the measurements of atmospheric carbon dioxide levels at Mauna Loa Observatory, Hawaii starting in 1958. We've all seen the plot of the data showing an oscillating concentration of carbon dioxide that steadily increases with time. And if we look at a plot of average global temperature over the same time period, it too is increasing. It's extremely tempting to make a connection and say that because carbon dioxide is increasing, the temperature is increasing. But just because there is a correlation between two variables doesn't necessarily prove cause and effect. The data are certainly dramatic if we consider a change of 0.3°C dramatic. But if we widen our view to include temperatures from 1000 years ago we see that the current global average temperature is almost 1°C lower than it was during medieval times. If we continue to widen our view we'll see that there are other periods of history that were also much warmer than they are today and there was no industrialization (i.e. no human activity to add greenhouse gases) during those time periods.
Yes, average global temperatures are increasing. Yes, global climate is changing. Yes, we will be affected by these changes. Are we responsible for the supposed mess we're in? The jury is still out for some of us.
- What types of climate change have you noticed in your lifetime? Are they a result of global warming?
- If we assume that global warming is real, how will it affect our ability to sustainably feed ourselves?
- Based on what you've read here and at other sites, how much of a problem do you think global warming is?
- Should the United States sign the Kyoto Protocol, which calls for limiting the emissions of greenhouse gases? Why or why not?
- The Intergovernmental Panel on Climate Changehttp://www.ipcc.ch
From the website: " The role of the IPCC is to assess the scientific, technical and socio-economic information relevant for the understanding of the risk of human-induced climate change. It does not carry out research nor does it monitor climate related data or other relevant parameters. It bases its assessment mainly on peer reviewed and published scientific/technical literature".
- The Natural Environment Research Councilhttp://www.nerc.ac.uk/publications/climatechange/
Climate Change: Scientific Certainties and Uncertainties outlines facts and figures, global consequences and solutions to the climate change problem. This is a good starting point to learn the basics of climate change.
- Global Warminghttp://www.enn.com/indepth/warming/index.asp
The Environmental News Network has several sections of in-depth coverage of various topics including this one on global warming. Learn about methods of prevention, international impacts and then test your knowledge with the global warming I.Q. test.
- U.S. Department of Transportationhttp://climate.volpe.dot.gov/science.html
This is the official site of the U.S. Department of Transportation's Center for Climate Change and Environmental Forecasting. It is a very informative site with a large amount information.
- U.S. Environmental Protection Agency - Global Warminghttp://yosemite.epa.gov/oar/globalwarming.nsf/content/index.html
This is the official site for the U.S. Environmental Protection Agency's Global Warming section. There is a lot of good information here. Also realize that just because the government sponsors multiple sites, the information isn't always the same at each site and may even be contradictory.
- Global Warming: The Cooler Heads Coalitionhttp://www.globalwarming.org
From the website: "The Cooler Heads Coalition formed May 6, 1997 to dispel the myths of global warming by exposing flawed economic, scientific, and risk analysis. Coalition members will also follow the progress of the international Global Climate Change Treaty negotiations".
- The Goddard Institute for Space Studies: The Global Warming Debatehttp://www.giss.nasa.gov/edu/gwdebate/
James Hansen of NASA discusses the global warming debate and illustrates how data can be used or misused in the debate. Graphs and links to other material are included.
- The Goddard Institute for Space Studies: Global Warming in the 21st Centuryhttp://www.giss.nasa.gov/research/forcings/altscenario/
Here, James Hansen and his colleagues present alternate scenarios for the global warming that the planet will be facing. The article is a bit technical but very interesting.
- Global Warming: The Origin and Nature of the Alleged Scientific Consensushttp://www.cato.org/pubs/regulation/reg15n2g.html
This article, housed at the Cato Institute, is by Richard Lindzen (Alfred P. Sloan Professor of Meteorology at the Massachusetts Institute of Technology) and presents a compelling argument against anthropogenic global warming.
All material (except for some code and external links) © Jeffery A. Schneider, 2003