Weather Lesson

Do I hear a call for help in Mike Miller’s letter (12/12)?  He wrote, “If they’re so smart, why can’t expert climate people predict the weather correctly for even a week?”

OK, Mike, here’s the scoop: Weather and climate are related but not the same. 

The weather is what you see outside. It’s forecast by balloons, satellites, radar and weather stations located in space and all over the country. Its main purpose is to help us plan our day or week and alert us to coming heat waves or approaching storms.

Climate is weather over a long period of time — decades and even millennia. We know that climate, but not necessarily specific weather events, is affected by changes in the sun’s energy and even more so by the accumulation of gases like CO2 and methane (CH4) that are trapped in the atmosphere, similar to what happens to air and water vapor inside a greenhouse. 

These gases have increased dramatically in the last 200 years because of human activities like burning fossil fuels, cutting down trees (which absorb CO2), and raising large numbers of cattle and pigs. To accurately predict this ever-quickening change in climate, scientists use computer models to project average temperatures, rainfall and their consequences for the earth by looking at past geological records and recent trends related to the sun, land masses, oceans and greenhouse gases.

I hope this helps, Mike.

Frank Keim