Remember acid rain?

One of the top environmental crises of the 1980s, acid rain is now often considered a problem solved, or contained, at least.

For those too young to remember when R.E.M.'s song "Fall On Me" was a hit: Pollutants from power plants, vehicles and other sources react in the atmosphere and then settle back to earth as acidic dust or as acidic precipitation. The pollutants, and the amount of acid deposition, have been reduced dramatically in the past 20 years through a cap-and-trade system so successful it is now considered a model in the fight against global warming.

Well, better not cross acid rain off the to-do list yet.

A report to be presented today in Portland suggests that more than one-third of Maine’s forests are still at risk from continuing levels of acid rain that can change the soil chemistry and leach out nutrients. The study, conducted by Ecosystems Research Group of Norwich, Vt., is part of a regional mapping effort and based on computer deposition and sensitivity models rather than actual soil tests or signs of distress. The study is expected to focus more research back onto the issue, while also raising questions about how resilient the forests will be when faced with a changing climate.

We plan to examine the report and what it means in the Press Herald tomorrow. It’s posted online here. For information about the public presentation, look here

Whenever a professional think tank and common-sense Mainers come to the same conclusion, you've got to figure they're on to something.

The Washington, D.C.-based Brooking Institution, in its "Charting Maine's Future" report, declared that the state's scenic beauty and natural environment are its franchise.

Maine people could have spared them some think time on that point.

Imagine Maine without its rocky coast, its lakes and rivers and its mountains and forests. I'm getting North Dakota, with a different accent.

Even if we do take all that for granted sometimes, Mainers, deep down, appreciate what they've got.

"Mainers typically perceive themselves as environmentalist," said Curtis Mildner, president of Market Decisions, an opinion research firm in Portland. "Whether they are a hunter or wear Birkenstocks, the natural environment is very important to our way of life."

And not only are Mainers attuned to their environment, Mildner said, they're worried about sustaining it.

A poll by Market Decisions last fall found that 61 percent of Mainers believe the environment is in worse shape than it was 10 years ago. The poll, based on 403 interviews and with a 4.9 percent margin of error, also found that more than three-quarters of Mainers considered global warming an issue that's important to them personally.

Given all that it's no surprise that Maine is increasingly a leader in environmental protection policies nationwide, and one of a group of states that may soon follow Europe and Canada into the regulation of global warming pollution.

Which brings us here, a blog about what’s happening in, or to, the natural world around us. You’ll find tidbits, updates and news alerts from the environment beat. I’ll try to answer your questions. And maybe I’ll ask some of my own.

So, welcome to Down to Earth. We hope all of us end up more tuned in to our little corner of the globe, and the things that make our home what it is.

Hey, what’s wrong with North Dakota? Except that it’s not Maine, nothing, it seems.

Fargo, N.D., in fact, is the top-ranked U.S. city for environmental quality, according to a new report by the Earth Day Network.

Portland, the only Maine city to be ranked, fared well at number eight overall, after Seattle and ahead of Minneapolis.

The group ranked 72 cities as part of its new Urban Environment Report. The report evaluates such environmental and health indicators as toxics and waste; air and water quality, parks and recreation opportunities, public health and global warming actions.

Portland’s individual scores ranged from three for water quality to 27 for human and public health.

You can see the complete Urban Environment Report with methodology, interactive maps and city-by-city data here.