Climate change is no longer just a theory
Hurricane Florence has drenched eastern North Carolina with more than 30 inches of rain, an all-time record for the state. Last year, Hurricane Harvey stalled over Houston and dumped more than 60 inches of rain, an all-time record for the whole country. Also last year, Hurricane Maria ravaged the island of Puerto Rico and caused, according to an independent study, nearly 3,000 deaths. Welcome to the new normal. Tropical cyclones are nothing new, of course. But climate scientists say that global warming should make such storms wetter, slower and more intense — which is exactly what seems to be happening. And if we fail to act, these kinds of devastating weather events will likely become even more frequent and more severe.
Climate change is a global phe- nomenon. Authorities in the Philippines are still trying to assess the damage and death toll from Super Typhoon Mangkhut, a rare Category 5-equivalent storm that struck the archipelago on Saturday with sustained winds of 165 miles per hour. Mangkhut went on to batter Hong Kong, and now, as it weakens, is plowing across southern China.
Every human being on the planet has a stake in what governments do to limit and adapt to climate change, including those who, like President Trump, prefer to believe global warming is some kind of hoax. I doubt the citizens of Wilmington, North Carolina — a lovely resort town that Monday was turned into an island by widespread flooding — feel there is anything illusory about the hardship they’re going through.
As I noted last month, scientists are now cautiously making the first serious attempts to gauge the impact of climate change on specific weather events such as storms, monsoons, droughts and heat waves.
The most ambitious attempt to quantify the link between climate and weather — a blue-chip international consortium called World Weather Attribution — has not yet made an attempt to estimate any possible effect global warming may have had on Florence or Mangkhut. But another group of researchers, the Climate Extremes Modeling Group at the Stony Brook University School of Marine and Atmospheric Sciences, estimated Sept. 12 that Florence would produce 50 percent more rainfall than if human-induced global warming had not occurred.
You don’t have to be a scientist to understand why that makes sense. We know from direct measurement that the concentration of carbon dioxide in the atmosphere has increased by more than 40 percent since the beginning of the Industrial Revolution, when humans started burning fossil fuels on a large scale. We know from di- rect observation that carbon dioxide traps heat. We know from direct measurement that both atmospheric and ocean temperatures have been rising sharply. We know from direct measurement that warmer water takes up more space than cooler water, which is the main reason why ocean levels are rising.
We know that warmer water is more easily evaporated, which means there is more moisture available to fuel a storm like Florence or Harvey — and to be released by such storms as rainfall.
If humankind suddenly stopped burning fossil fuels tomorrow, we would still have to adapt to the climatic changes we have already set in motion. The excess carbon dioxide we have pumped into the atmosphere will remain there for thousands of years. We will be coping with massive tropical storms, tragic coastal and riverine flooding, deadly heat waves and unprecedented wildfires for the rest of our lives.
At the very least, we should be trying to reduce carbon emissions and keep global warming to a manageable level. With the landmark Paris Agreement, the nations of the world agreed to try. But Trump foolishly pulled the United States — the world’s second-biggest emitter of carbon dioxide, behind only China — out of the deal.
The administration has already proposed weakening restrictions on carbon emissions from automobiles and coal-fired power plants. And last week, there were reports that the administration also wants to loosen rules governing the release of methane, which traps even more heat than carbon dioxide.
Another news item from earlier this month should be instructive: A cargo ship is presently making the journey from Vladivostok, on Russia’s Pacific coast, to the German port of Bremerhaven via the Arctic Ocean, rather than taking the usual southern route through the Suez Canal and the Strait of Gibraltar. Until now, the northern route has always been impassible because it was blocked by polar ice. But because of climate change, a lot of the ice has melted.
Climate change is no longer theoretical. It is real, it is all around us, and it is going to get much worse.