The sub-zero temperatures across the state of Michigan this morning do not mean that global warming isn't real.
Jeff Masters, Director of Meteorology for Weather Underground, is explaining this a lot these days. He says the long-term trend is clearly a warming planet. But global warming doesn't mean 'no more winter.'
"The earth is still tilted on its axis," says Masters, "which means we get unequal heating of the poles, and that causes the seasons, and the seasons haven't gone away. We still expect cold weather, just less of it."
Masters says people need to look beyond their own city's temperature ups and downs to understand global warming.
"And when you look at the entire globe, this year is going to be our third consecutive warmest year on record, averaged over earth's surface," says Masters.
This November was also the second warmest November on record.
Masters says 97% of earth scientists agree human activity is causing global warming. That's about the same number of medical researchers who are convinced smoking causes cancer.
The biggest contributor to global warming is the carbon emissions from the burning of coal, oil, and natural gas, along with industrial processes. That accounts for about 65% of greenhouse gases.
Deforestation, the use of fertilizers, and the burning of biomass are other large contributors of greenhouse gases.