I am writing to pre-empt the letter you are going to get next January. You know, the one that says, “It’s so cold today, how could anybody believe in global warming.” Well, it has been so hot this November, how could anybody not believe in global warming?
Global warming means the world’s present climate is going to evolve to a new climate where the temperature, averaged all over the world, is a few degrees hotter. It turns out that if the new climate is just a few degrees hotter, the ocean levels will rise dramatically, local weather will change a lot and agriculture will be drastically affected. Just a few average degrees!
It is impossible to tell, just by sitting in one spot like Chicago, how the world’s climate is changing. Scientists have to make measurements all over the world and combine the results to find this out. An occasional hot or cold day, or a hot summer or cold winter in one location means nothing.
Because global warming predicts the world’s climate is changing, a natural consequence is more unstable weather. Summers will become hotter; winters colder. More violent weather and storms will be expected. But summers will become a teensy bit hotter than the winters are colder, leading to an overall warmer climate.
