Robinson: In a world on fire, our president plays with matches

Answer: It’s here, it’s all around us and it’s getting worse.

Since the beginning of the 20th century, the report notes, global average temperature has increased by 1.8 degrees and global average sea level has risen by about 8 inches. These changes are accelerating. By the year 2100, if action is not taken to curb carbon emissions, the temperature rise could total 9 degrees and the sea level rise could exceed 4 feet.

Trump and other deniers can no longer claim with a straight face that no warming is taking place, since nine of the hottest 10 years on record have come since 2005. Instead, they try to blame some natural cycle. But the new climate assessment notes that “observational evidence does not support any credible natural explanations.”

Instead, “the evidence consistently points to human activities, especially emissions of greenhouse or heat-trapping gases, as the dominant cause.” As I have shouted until I am blue in the face, the atmospheric concentration of carbon dioxide has risen from around 280 parts per million at the beginning of the Industrial Revolution to more than 400 parts per million now. That is an astonishing 40 percent increase since humankind began burning fossil fuels on a massive scale.

Resist any temptation to write all this off as scientific gobbledygook. Pay attention to the numbers, which are important and not very hard to follow. Denialist officials and commentators who throw up their hands and say “I’m not a scientist” are being disingenuous. There is no real scientific debate about the existence of climate change or the fact that human activity is driving it.

Political debate

There is, however, a political debate about what to do. Trump is determined to accelerate climate change by boosting the production of coal — the “dirtiest” widely used fuel, in terms of carbon emissions — and keeping oil prices low. This is the dumbest, most short-sighted policy imaginable.

Trump visited California to see first-hand the destruction of the horrific Camp Fire, which killed at least 85 people and destroyed more than 14,000 homes. According to the new climate assessment, the cumulative forest area burned in the western United States by wildfires since 1984 is double what it would have been if climate change had not occurred.

No, wildfires are not getting worse because not enough raking is being done, as Trump weirdly insisted. They are getting worse because of climate change.

So are tropical storms, flash floods and heat waves. Trump claims to be all about economic growth. But the new report predicts “climate change is expected to cause growing losses to American infrastructure and property and impede the rate of economic growth over this century.”

The report sounds one more ominous note: Thus far, climate scientists’ dire predictions have proved to be conservative. The world is on fire. We have a president who plays with matches.