There is no better Fourth of July movie for my money than Jaws. I would watch it at least twice every Independence Day weekend if that wouldn't bore and annoy my spouse. It was designed and filmed so carefully that time has transformed it into a beautifully accurate period piece, capturing the New England beaches of my 1970s childhood in loving detail. Time has also turned it into something else it was not originally meant to be: a parable about the dangers of denying climate change.

Jaws is the story of a community whose economy depends on its natural resources. That's true of every community and every economy, but in this story it's simple and obvious. The town has a beach. Its entire economy depends upon tourists coming to that beach during the summer. If the summer people don't come, everyone will go hungry. Clear enough.

Then the natural world throws up a problem; there's a shark in the water, and that shark kills a swimmer. The local police chief wants to close the beaches, but doing that at the height of the tourist season means financial ruin for the townsfolk, the danger that they will, as one character puts it "be on welfare all winter."

Watching the movie, the right thing to do is obvious. But that doesn't mean it's easy. Closing the beaches would cause real pain for many people. It isn't a cheap or easy solution.

The town authorities cave and do the wrong thing, trying to wish the shark away. They change the first victim's cause of death to "boating accident." When a second person is killed, they balk at the price of commissioning a serious shark hunt by a professional and instead countenance an amateurish bounty hunt that brings in "a shark, but not the shark." That gives them just enough apparent evidence to dismiss scientific advice and open the beach for Fourth of July weekend.

Then, as one of my friends likes to say during the shark sequences: nom nom nom nom nom.

The last act of the movie leaves the island behind to focus on the daring shark-hunters' interpersonal struggles and their fight with the monstrous fish. But the ending of the town's story is clear: they have destroyed their economy, not simply for a few crucial weeks but for the entire summer and probably for years to come. No summer people are coming to an island where three people have been killed. And tourists aren't going to magically forget the shark attacks next summer either. Trying to deny the problem in order to protect the beach economy leaves the beach economy in ruins.

So it is with us. Our economy depends on exploiting fossil fuels. And burning those fuels has begun to create major problems. Reducing emissions will not be cheap or easy. It will have painful costs, and there is no point in underestimating those costs. Nor is it helpful to expect that people who will bear heavier losses than the rest of us should simply take those losses. It's dysfunctional to let individual create massive social expenses, but it's also dysfunctional to make individuals shoulder massive social expenses themselves.

But here's the thing: avoiding the necessary economic sacrifice in the short term only makes the price of the eventual economic sacrifice higher. If we don't take the emissions-reduction hit now, we will incur all the costs of a changed climate AND eventually have to reduce our emissions even further. We will hold on to Fourth of July weekend and lose all of our summers. The character talking about "being on welfare all winter" isn't talking about closing the beaches for two weeks. He's talking about the cost of cheaping out and not killing the shark.

The Jaws parable is playing out in North Carolina right now, where the State Legislature has ordered experts to change a report on how rising sea levels will affect the Outer Banks. (At the same time, Virginia is taking steps to protect its endangered coastline.) North Carolina is afraid that the news of rising sea levels will be bad for the Outer Banks's beach-tourist industry, so (like the Mayor and medical examiner in Jaws), they have had the alarming report amended. The problem for the Outer Banks is that, as they say, This was no boating accident. And waiting until the sea level has already risen too high to ignore means waiting until it may be too late for the Outer Banks to be saved.

Denying climate risk is like ignoring a debt; it simply gets harder to pay off. I understand why people on the Outer Banks are afraid that their property will lose value if the state projects a thirty-nine-inch rise in the sea level by 2100. But if no steps are taken to deal with the rising sea, property on the Outer Banks will someday lose all its value. You can't sell a hotel to the fish.

And sooner or later, every climate denialist will have to hear the hardest news of all: "Summer is over. You're the Mayor of Shark City."

P.S. It has come to my attention since I started this post that the admired Historiann has also recently posted about Jaws, and that she has only recently seen the movie for the first time. Welcome to Amity Island, Historiann. Amity, as you know, means friendship.