As a scientist and as an educator, I like to ask people the following question:
A digital billboard displays an unofficial temperature July 17 in downtown Phoenix. In July, Phoenix recorded the hottest month ever observed in a U.S. city: The average temperature was 102.7 degrees Fahrenheit. Matt York/Associated Press
“Do you understand the difference between global warming and climate change?”
Most of the time, I get a blank stare in response.
No, they are not the same.
Global warming is a direct result of putting carbon into the atmosphere. Think of the atmosphere like a blanket on the Earth, one that gets thicker and more insulating with more carbon. With the same amount of energy coming in from the sun, globally averaged, if we put more carbon into the air, of course the Earth will get warmer.
We have good models for global warming, given the amount of carbon we have added to the air. Both measurements and modeling are spot on at an increase of about 1.5 degrees Celsius, or about 3 degrees Fahrenheit, averaged worldwide. This might not sound like a lot, but it represents a huge amount of energy when one considers the entire planet and especially the volume of the oceans. We scientists understand global warming very well and our predictions tend to be spot on.
Climate change, on the other hand, is the result of global warming and all that extra energy in the system.
It is totally unpredictable just what will happen. For all we know, we will end up in an ice age if and when the Gulf Stream collapses. What we scientists can tell you is that there is much more energy in the system and that the extremes will get more extreme. More rain, more snow, more cold, more hot, more droughts and more wildfires. In July, Phoenix, Arizona, recorded the hottest month ever observed in a U.S. city. Catastrophic flooding devastated parts of Vermont. In Hawaii, wildfires have consumed a town on Maui. And we are just getting started. More and more property will be damaged. More and more lives will be lost.
Except for just saying the extremes are going to get more extreme – and certainly the evidence bears that out – scientists cannot well predict climate change. But again, we can say it is a direct result of global warming, and we can say global warming is the direct result of putting so much carbon in the air. We can say, absolutely, that if we want to slow down climate change, we must stop putting so much carbon into the air. It is as simple as that. And time is now of the essence, regardless of cost.
In the early industrial age here in New England, we dumped all the byproducts of the mills directly into the rivers. We killed everything. Then, in the latter half of the 20th century, we figured out that we should stop. Our rivers, for the most part, have recovered. Now we can look back at what we did, tap ourselves on the foreheads and go, “What were we thinking, dumping all that stuff into the rivers? What did we think was going to happen?”
I have faith that someday in the future, we will look back at this time period, tap ourselves on the foreheads and go, “What were we thinking dumping all that carbon into the atmosphere? What did we think was going to happen?”
The good people in Hawaii, who have lost so much, have certainly just found out.
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