EUGENE ROBINSON

July and August were the hottest months for the planet since record keeping began. Scientists are confident that 2016 will be the hottest year. Rising sea levels have made flooding commonplace in several major U.S. cities. And meanwhile, one of our leading presidential candidates says climate change is some kind of Chinese hoax.

Elections have consequences, and this is one of the most fateful: Anyone who takes climate change seriously had better do everything possible to keep Donald Trump out of the White House.

Believe it or not, there are issues more important than Trump’s latest offensive outburst or Hillary Clinton’s score on the likability scale. Clinton accepts the scientific consensus on climate change, which is increasingly supported by what we see and feel every day. She would build upon President Obama’s efforts to address the issue, which include the historic Paris agreement, seen by many experts as our last best hope to prevent catastrophe.

Trump, by contrast, is a bald-faced denier. “Obama’s talking about all of this with the global warming and … a lot of it’s a hoax,” he said at a December rally in South Carolina. “It’s a hoax. I mean, it’s a moneymaking industry, OK? It’s a hoax, a lot of it.”

He tweeted in 2012 that “the concept of global warming was created by and for the Chinese in order to make U.S. manufacturing noncompetitive.” He later said this was a joke, but during the campaign he has again said he does not believe in climate change and claimed that action to limit carbon emissions “is done for the benefit of China.”

The Paris pact represents the first time the world’s two biggest emitters, China and the United States, have formally agreed to hold down the amount of heat-trapping carbon they spew into the atmosphere. Trump would renounce the agreement – and also scrap Obama administration rules limiting emissions from coal-fired power plants. He has promised greater fossil-fuel production and scoffed at alternative energy sources such as wind power.

Clinton recognizes the potential economic benefits of developing the technology to lead the world toward a clean-energy economy. Trump would rather let China, Germany and other nations compete for that prize.

The differences could not be more stark. And the evidence for climate change has never been clearer.

According to the National Oceanic and Atmospheric Administration, 15 of the warmest 16 years on record have come since the turn of the century. By examining air bubbles preserved for centuries in polar ice, scientists know the concentration of heat-trapping carbon dioxide in the atmosphere has increased by 40 percent since the Industrial Revolution, when large-scale burning of fossil fuels began.

Global warming is affecting weather patterns worldwide. Deniers point out that it is not possible to conclusively blame any given storm or localized heat wave on climate change – and that, yes, it still gets cold in the winter. But the phenomenon is clearly visible in melting glaciers and ice caps, the opening of ice-free sea lanes through the Arctic and, most urgently, sea-level rise.

The oceans are rising because warmer water occupies a greater volume than cooler water and because so much land ice is melting. According to NOAA, average sea level is rising by about 1.2 inches per decade. That may not sound like much, but it has already been enough to at least triple the amount of “nuisance” flooding that coastal cities have to cope with when onshore winds coincide with high tide.

In Norfolk, Virginia, some low-lying intersections flood so often that officials have installed gauges so residents can tell when the water is too deep to drive through. In Miami Beach, some frequently flooded streets are being elevated. In New York, officials are debating how to prepare for the next storm that takes the path of Hurricane Sandy, which caused an estimated $75 billion in damage in 2012.

Last November, in Time magazine, Clinton wrote that “I won’t let anyone take us backward, deny our economy the benefits of harnessing a clean energy future, or force our children to endure the catastrophe that would result from unchecked climate change.”

Neither her policies nor Trump’s will reverse the climate effects we’re already seeing. But it is possible, and necessary, to keep the impacts from becoming completely unmanageable. Obama leaves behind a framework for coordinated international action, more than two decades in the making, that still could fail – but that might, just might, succeed. Trump boasts that he can’t wait to tear it all down.

The choice is ours.

Eugene Robinson’s email address is eugenerobinson@washpost.com.