How can climate scientists project what the climate might be like decades from now when it’s impossible to predict the weather for more than a week out?
Weather forecasting and climate projections are very different. For predicting weather, meteorologists must consider many variables that come into play and can change rapidly. With the complex interplay of variables, small differences in initial conditions can lead to widely different outcomes that cannot be predicted more than a week or so out. That’s why no weather forecaster could make a credible prediction of what the high temperature in a given city will be six months from now. Over long periods of time, however, the many variables that affect weather tend to smooth out and long-term trends can be discerned. Such trends can be used to make reliable projections about what the weather is likely to be in a given locale months in advance. You could plan an outdoor picnic in San Diego for the next Fourth of July with confidence that the day is likely to be warm and dry. You also know that if you decide to hold that outdoor picnic in Seattle on New Year’s Day, the event is likely to be
