In a recent letter, John Dixell said that people who have watched PBS programs on the history of the earth will understand that climate change has been continuous since the earth was formed. Therefore, since climate change happens naturally, we should accept the inevitability of currently occurring global warming and concentrate on controlling immigration and refugees.
That’s a long leap in questionable logic. Climate change has, in fact, been occurring since the earth was formed around 4.5 billion years ago. Scientifically known causes of climate change include continental drift, changes in the sun, volcanic emissions, and variations in Earth’s orbit around the sun. These changes occur on the scale of many thousands to millions of years. Present global warming isn’t caused by these forces and is occurring on the scale of a few hundred years. Dixell apparently missed the PBS shows on this topic.
Current global warming is caused by rising levels of atmospheric carbon dioxide. The increase has been caused by human burning of fossil fuels. Those are scientific facts. Unless we reduce carbon emissions, by the end of this century we’ll reach levels of carbon dioxide that haven’t been seen on earth in tens of millions of years, when sea levels were much higher and no ice sheets remained.
The do-nothings of today, the science/climate change deniers, the willfully ignorant, and those who don’t care what they leave to their descendants will someday be held responsible for the results of their inaction.