Climate Change

* The discovery of the sudden, dramatic increase in global temperature 12,500 years ago (“Ice Age Ended Abruptly, New Study Shows,” Oct. 2) should come as no surprise to anyone familiar with the behavior of chaotic systems. Chaotic systems, such as the Earth’s climate, are characterized by abrupt, dramatic changes in behavior.

It is unrealistic to expect nations to curtail emissions of industry-related chemicals into the environment at this time. The force of economic imperatives is as implacable as gravity. This is not an indictment on modern technology. The geologic record is full of climactic upheavals that occurred without the help of humanity.

Research shows that at least some chaotic systems can be controlled in the laboratory. The question is, can we tune our emissions to keep the climate from changing to a new, more uncomfortable state? More importantly, is there time?

JOHN M. HOEY

San Diego