To the Editor:

Re “Middle Stance Emerges in Debate Over Climate” (news article, Jan. 1):

Do we know for certain when and how much Greenland and the West Antarctic Ice Sheet will melt with global warming, and the exact amount the sea level will rise as a result? Or how intense heat waves, droughts, floods and storms will become?

The answer is no, it is not possible to make exact predictions about such complex systems.

But there is no uncertainty among the world’s leading scientists that if we do not significantly reduce our current levels of burning fossil fuels, our world will experience profound changes, many of them irreversible, in its physical, chemical and biological composition.

And there is absolutely no question that these changes will severely threaten life, including human life, on this planet. It would be shamefully ignorant and morally inexcusable if we did not do everything in our power to prevent these changes from occurring.

Political leaders, policy makers and the public should not be misled by the few scientists who persistently emphasize the uncertainties of climate science, as if these uncertainties guaranteed that global warming consequences would not be catastrophic.

Eric Chivian, M.D.
Boston, Jan. 2, 2007
The writer is director of the Center for Health and the Global Environment, Harvard Medical School.

Note from KBJ: Scientists can inform us of how things are (including how they were and will be). They cannot direct our behavior. What we as a society do about climate change, if anything, is up to us. It is not up to scientists. Perhaps if science hadn’t gotten so politicized, scientists would have more credibility on this issue. These days, it’s hard to disentangle the science from the progressive politics.