Dear Tom,
Do you think that climate change could be due to the Earth’s position with the sun instead of man-made actions?
Michael Reed, Chicago

Dear Michael,
The Earth’s orbit around the sun has not changed. The planet is still orbiting the sun in the same manner that it has been for a long, long time. The Earth’s orbit around the sun is not a factor in the Earth’s changing climate.

Climate change is a result of natural processes and especially the result of changes to the Earth wrought by man especially in the last 150 years. Mankind has brought about significant changes to the planet’s surface, over land and even over the oceans. Altering the Earth’s surface has affected the relationship between that surface and the overlying atmosphere, in ways that are known and probably in some ways that are unknown.

An obvious known factor, for example, is the development and growth of urban areas. The presence of cities affects the atmosphere locally and downwind as well, usually causing higher temperatures and producing air and water pollution.