When important people become concerned or annoyed, they have several options.

They can stand for office. Or, failing that, they can write an open letter.

I'm not sure whether science has ever shown open letters to be effective. This hasn't, however, stopped 375 scientists from penning one to appeal to the minds of humans.

The letter published Tuesday by members of the National Academy of Scientists, Stephen Hawking among them, purports to be about climate change.

It's really a missive begging people not to vote for Donald Trump.

It speaks in stern tones.

"Human-caused climate change is not a belief, a hoax, or a conspiracy. It is a physical reality," reads the first line. The letter goes on to explain that human health, food production and even national security are at stake. It describes the matter as "basic science."

The real intent, though, appears half way down this academic piece of writing.

"It is of great concern that the Republican nominee for President has advocated U.S. withdrawal from the Paris Accord," the scientists say. The Paris Accord is an international agreement that commits the more than 195 signees to fight global warming and dedicate themselves to a low-carbon future.

If, as Trump has promised to do, the US withdraws from this agreement, the scientists would be aghast. It would, they say, signal that America "does not care about the global problem of human-caused climate change. You are on your own."

Many people are saying that much of Trump's "America First" platform necessitates for the country to stand alone and apart. He has repeated many times that he doesn't believe global warming is man-made.

I wonder, though, whom Hawking and his fellow scientists are trying to influence with this letter.

Do they believe it will move voters?

Hawking has already made his feelings about Trump quite clear. Earlier this year, he described him as "a demagogue who seems to appeal to the lowest common denominator."

Trump's whole platform exists to make enough people believe he is anti-establishment and, in some sense, essentially American. Sadly, I fear these scientists will appear to represent that very establishment.

It seems plausible that the more these scientists warn that Trump is dangerous, the more those tending toward Trump will vote for him.

The Trump campaign didn't immediately respond to a request for comment.

It's not hard to imagine, though, that an open letter from scientists is unlikely to move him.

After all, he already has the best words.