THE BLOG
04/17/2010 05:12 am ET | Updated May 25, 2011

Let It Snow

As the East digs its way out of another massive snow storm, some are led to wonder how so much snow is possible when we're supposed to be having global warming. Some people just don't want to believe in global warming. Others are just struck by the seeming incongruity. To see how it works, try this little catechism:

What is snow? Frozen water falling from the sky.

How does water get into the sky? It evaporates, mostly from the ocean.

What makes water evaporate from the ocean? Heat from the sun.

What is global warming? More heat from the sun is trapped near the Earth's surface.

Would global warming cause more or less water to evaporate from the ocean? More, obviously.

And that, in short, is why global warming causes more snow, as long as there is enough cold Arctic air to freeze the water. Otherwise, it would be flooding rain.

Climate scientists love to discuss their theories, observations, and models, which give more richness and detail to a terribly complex subject. But this little catechism is, as they say, "good enough for government work." At least, it's good enough for voters to understand which politicians espouse policy based on how the real world works, and which are talking from what they would like to believe, true or not.