You probably watched the presidential campaign debate Monday night.
So did Andrew Revkin, who writes the Dot Earth blog on The New York Times' website. When he talked to a group at the Missouri School of Journalism the next day, he noted that what might be the most important issue of all wasn’t even mentioned, again.
That's the issue of climate change – or rather, because climate change is a scientific fact, the issue of what to do to combat it or at least ameliorate its effects.
The vast majority of scientists agree that the climate is changing, the world is warming and that human activity is largely to blame. The consequences, some sooner than later, are likely to be mainly unpleasant for us and fatal for a good many of the creatures that share the earth with us.
Already, the polar ice caps are melting, the sea is rising and becoming more acidic, the weather is becoming more variable and more extreme. Meanwhile, we continue burning fossil fuels and dumping carbon dioxide and other greenhouse gases into the atmosphere. (You can find the facts at the NASA website.)
So you might think somebody would mention all that when the two men who would lead us take the stage.
Mr. Revkin, a veteran science journalist and author of books on the Arctic and on global warming, wasn't surprised that nobody did. After all, he reminded his audience, it's not near the top of the list of things that worry the public. He showed us a poll taken last month, which had the economy as the leading problem, followed by social issues and values, Social Security and health care. "None" and "Unsure" made the list, but not climate change.
We shouldn't have expected the journalists who moderate these debates to bring it up, he said. "Political reporters see climate change as a niche issue, like organic gardening."
It's not as though this is an issue like the Middle East or Afghanistan, whereMitt Romney seems to have adopted President Barack Obama's policies. Instead, as Mr. Revkin wrote in his blog, the president actually "has moved pretty aggressively, if quietly, to roll out restrictions on greenhouse gas emissions through regulations, tighter standards for energy use and vehicle fuel economy and pursue policies fostering a shift from coal to gas."
On this issue as on others, it's harder to know just what Mr. Romney thinks.
The nonpartisan fact-checking organization Politifact reported last year on two statements he made four months apart. In June 2011, he said he believed "the world is getting warmer" and that "humans contribute to that." In October 2011, speaking to a different audience, he said, "My view is that we don't know what's causing climate change on this planet."
He has been consistent in opposing any effective action, such as the cap-and-trade legislation President Obama proposed or the gas mileage standards he has imposed.
Mr. Revkin suggested that it might be a good thing for climate change not to become an overtly partisan issue. He even speculated that Mr. Romney, should he be elected, would be more progressive on at least this issue than his campaign comments have implied.
"Is a little climate silence golden?" he wrote.
I'm guessing not. What reason do we have to believe that Mr. Romney, in office, would turn his back on the science-denying zealots who dominate his party in the House of Representatives and have blocked President Obama's proposals in the Senate? I don't see any that are persuasive.
The president's silence isn't that hard to understand, either.
Let's remember, first, just which state is widely considered the key to victory Nov. 6. That would be Ohio. Now let's consider what are two of Ohio's important but struggling industries. Those would be coal mining and steel making.
If you were in such a tight, high-stakes race in such a state, what would you do? If you were the pragmatist Mr. Obama has shown himself to be, you'd talk about energy independence and saving the auto industry, wouldn't you? You'd mention the elusive dream of "clean coal," but not coal's huge contribution to the greenhouse effect.
The president's climate silence might be regrettable, but this is one case in which the actions he has taken speak louder than the words he doesn't say.
George Kennedy is a former managing editor at the Missourian and professor emeritus at the Missouri School of Journalism. Questions? Contact Opinion editor Elizabeth Conner.