Climate change past and present

Editor's note: This letter has been edited to correct some missing text.

A Jan. 25 article by the Associated Press cited Earth's 2018 average temperature at 58.93 degrees, 1.39 degrees warmer than the average from 1951 to 1980. Information from the 1981 Compton Encyclopedia states one theory of what caused the ice ages were large quantities of dust in the atmosphere, possibly from volcanic activity. Today, governments regulate industry and vehicles to reduce air pollution.

According to NASA, about half the light reaching our atmosphere passes through the air and clouds to the surface where it is absorbed and then radiated upward as infrared heat. About 90 percent of that heat is absorbed by greenhouse gases and radiated back toward the surface which is warmed to a life supporting average of 59 degrees. The industrial activities that our modern civilization depends upon have raised atmospheric carbon dioxide levels from 280 parts per million to 400 parts per million in the last 150 years. That is a 42.8 percent increase. Other sources estimate the current global population is over 7.3 billion people, compared to about 2 billion in 1920, a 265 percent increase. The population is projected to be almost 10 billion by 2050 with corresponding increased levels of carbon dioxide via respiration, livestock production, and basic life sustaining energy needs.

It is obviously easier to state a problem rather than identify all causes and solutions. It would be beneficial to see a factual examination of all possible elements concerning climate change, both past and present, when making future predictions.

DAVID SANDERS, Cape Girardeau