Global Warming

Does it Exist?

If so, is it Man- or Sun-made?

 Graph of solar activity versus climate 
From Friis-Christensen, E., and K. Lassen, "Length of the solar cycle: An indicator of solar activity closely associated with climate," Science, 254, 698-700, 1991.



Global warming -- the gradual increase in planet-wide temperatures -- seems to be accepted by many scientists and people now as fact. Generally, this warming is attributed to the increase of green-house gases in the Earth's upper atmosphere.

However, some solar scientists are considering whether the warming exists at all. And, if it does, might it be caused, wholely or in part, by a periodic but small increase in the Sun's energy output. An increase of just 0.2% in the solar output could have the same affect as doubling the carbon dioxide in the Earth's atmosphere.

What is the Problem?

What is the evidence for global warming? Certainly, there are considerably more green-house gases (e.g. carbon dioxide) in our atmosphere than in previous times. And there appears to be some evidence that global temperatures are rising. But, how accurate and correct are our global warming statistics? And, do we really know what role, if any, the Sun might play in any global warming patterns?

These issues are currently being debated, and may significantly affect you for the rest of your life. Would you like to do some research to find out more about global warming?

We suggest here some research topics and places to begin looking for information. But these are all controversial issues, and there are no definitive answers (yet). As an informed, and voting, citizen of the next millenium, you will need to keep listening, looking, and being alert to new research and evidence.

The following are key questions in your research on global warming:



Where Do I Start?

For information on global warming in general and student activities and research topics in particular, visit:

Now, to research whether or not global warming actually exists, and the affect the Sun may or may not be having on it, check out these:


For Teachers

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Copyright 1997 Stanford University. All rights reserved.
Created by Deborah Scherrer in October 1997
Last modified by DKS on 15 Dec 1997.