Kerby Anderson

When President Trump set forth his national security strategy, he omitted global climate change as a threat. Two years earlier, President Obama elevated climate change to the top “strategic risk” in his strategy. The ongoing debate about the significance of climate change will continue for years to come.

I contend that the debate is really about percentages. Consider people who are often labeled “climate change deniers.” Actually, even these people believe the climate changed in the past (we’ve had an ice age, a medieval warming period). They just don’t believe that human activity is the major driver for climate change. But they will usually admit that some small percentage of human activity might be influential.

On the other side are people who are deeply concerned about climate change. But I doubt any of them believe that human activity is responsible for 100 percent of the change in climate. We have had variations in the climate long before the industrial revolution. So really the debate is between percentages. Some believe the percentage is low, others believe it is higher.

Sometimes the discussion is framed as a debate between those who believe in science (climate change) and others who are anti-science (the deniers). But consider this recent quote from geologist Ian Plimer who believes in evolution and is anything but an anti-science proponent. “Climate change has taken place for thousands of millions of years. Climate change occurred before humans evolved on Earth.” He says he cannot find any correlation between temperature change and human emissions of carbon dioxide. Therefore, he concludes that “Without correlation, there can be no causation.”

Perhaps it is time to cool some of the rhetoric and consider what we know and don’t know about climate change.