As Maine has struggled to build a 21st century economy, we’ve faced many challenges, most of them man-made and some geographic. We’ve been painfully slow to accept how the world is changing around us, and unwilling to hear the warnings from economists about how manufacturing, forestry, farming and fishing would change.

Instead, we’ve spent too much time locked in senseless battles based on region and political differences and whether we live in cities or the countryside. And we’ve watched as the state’s economy has lost momentum and energy and our young people have left.

Now we’re doing a similar thing with climate change. We’ve been reluctant to heed the warnings of scientists who study these things every day. We’ve ignored the signs that are appearing all around us. We’ve confused political views with facts. As a result, the challenges for Maine, and for our economy, are growing.

Now we’re not only cold, remote, expensive, disorganized, discouraged and disgruntled – we’re also ill-informed.

Climate change is going to alter much of what we now see in our minds when we think of Maine. Some familiar things will become rare, while others that we have little experience with will become commonplace. Think of ticks, peach trees, new plant diseases, possums, vultures and insect-borne diseases.

Some people still maintain that climate change isn’t real, and they’ve employed a string of senseless and sometimes dishonest arguments to make their point. They’ve ridiculed computer projections, derided scientists and blamed cow flatulence and dead trees – anything but the role that burning coal, gas and oil plays. Now they say that climate change is a conspiracy among all of the world’s scientists, engineered by China.

Losing ground in the public debate, climate deniers are now moving toward another strategy, led by the new president: silence science. Cut funding to agencies, like NASA and NOAA, that collect and publish temperature data from around the world. Book burning can’t be far behind.

The problem with gagging scientists, from an economic standpoint, is that it will leave American businesses flying blind against global competitors who aren’t. And while they’re building technologies for the future, we’ll be reopening coal mines.

Most common-sense people seem to understand that our climate is changing, and that burning fossil fuels over the last hundred years or so is the major culprit.

Here’s what the scientists – while they’re still free to speak – have been telling us.

• 2016 was the warmest year on record, beating out 2015, which beat out 2014. Sixteen of the last 17 years have produced global temperatures records.

• Alaska and New England are warming faster than the rest of the country.

• New England will feel the effects 20 years earlier than other places.

• Our average annual temperature will rise by 3.6 degrees Fahrenheit over historical levels within 20 years, making us more like southern New England than Maine.

• The Gulf of Maine is warming faster than almost any place on the planet.

• Sea levels in New England could rise by as much as 10.5 feet by 2100, or twice what was earlier predicted. That would put 30 percent of Boston and many parts of our coastline under water.

What does all of that mean for the Maine economy? Warming climates force everything to migrate north: plants, trees, animals, insects, diseases and people. Already, we’ve seen Maine’s iconic cod pushed further offshore and northward. That’s why you’re not buying much cod at the supermarket that was landed in Portland or Massachusetts. Most of it now comes from Iceland and Norway.

Next up will be lobsters and other shellfish. Lobstering is booming now, in part because southern lobsters have moved in. But they won’t stop moving. Connecticut, not so long ago, had 300 lobsterman. Today there are only about half a dozen. In Rhode Island, lobstering is virtually nonexistent.

In agriculture, forestry and recreation, we can expect longer growing seasons but more rainy, icy winters and far less snow. That will release and sustain both diseases and insects we’re not prepared for. Think about explosions of ticks, new flying insects, tree and plant diseases. Then add human diseases we have no experience with.

Humans also will migrate, with the possibility of waves of people seeking refuge in places like Maine to escape the heat and violent storms to the south. While Maine needs more skilled people to grow the economy, let’s face it, managing change has not been our strong suit.

The most immediate and compelling challenge we face is that our political leadership, in Maine and in the White House, just doesn’t get it.

Alan Caron is the owner of Caron Communications and the author of “Maine’s Next Economy” and “Reinventing Maine Government.” He can be contacted at:

alancaroninmaine@gmail.com