To the editor:
As I emerge from my winter’s cocoon I keep hearing more disbelief in global warming. “How can we have global warming when we have had two terrible winters in a row?!” This type of common wisdom snowballs, becomes fodder for political consultants and impedes what little we are doing to combat the real problem. In all the debate over statistics, observations and opinions, the basic physics of our earth system seems to be lost in the shuffle.
The climate all over the world is generated by the interaction of the air with the oceans that span the earth. Lakes, mountains and valleys modify it a bit locally, but it is created by the giant air-sea engine. The sun heats the oceans, which gently bubble water vapor and salt particles into the atmosphere.
This action also creates cells of circulation of the air, which carry the water vapor and particles to cooler heights where they form into clouds. You can see some of this on your stove top.
Put a pan of water on low heat and watch bubbles start to form and rise. You can feel the streams of slightly warmer air coming off the surface. If you put a pinch of salt into the water, you may be able to feel a few salt particles in the air streams above the pan. This warmer air is carrying a little bit of water as well, which you may be able to feel.
When we talk about global warming it is simply adding more heat to the air-sea engine, or your stove top pan. Add more heat to your pan and you get more energetic bubbling, which is exactly what is happening over millions of square miles of ocean.
Not as dramatic as the stove top but the principle is exactly the same, more heat equals more energetic creation of atmospheric cells. More energy means more energetic weather over the oceans, which then rolls over the land as the earth rotates.
We cannot change the seasons. They depend on the tilt of the earth as it makes its annual trip around the sun. Winter will always be cold, and summer will always be hot. What happens with global warming is that whatever weather we have for the season will be more violent than before we added the heat. Winters will be worse and summers will be worse, and everything in between will be more energetic.
If we don’t stop adding the heat, this planet will become uninhabitable except underground.
Donald A. Smith