I'm not a Democrat; I'm an anti-Republican.

That's how I recently described myself. Though truth be told, I focused mainly on the second half of that formulation, explaining why I — a former conservative — have broken strongly from the right over the past decade.

When it comes to the first half of my self-description, the explanation is a little more complicated. I nearly always vote for Democrats these days, though I don't feel much loyalty to the party or particularly intense devotion to the cluster of issues that most strongly inspire liberals.

Environmentalism is a good example.

I think it's important to work for clean land, air, and water. I support recycling. I love natural spaces and think America's system of national parks and other protected lands is one of our country's finest achievements.

But on each of these issues, as on nearly every other question of environmental policy, I firmly believe that judgments need to be singularly based on how proposed regulations will impact people — individuals as well as communities — and not other species or the planet's ecosystem considered apart from human beings.

By all means, let's protect land from development. But only if it's done for the sake of human enjoyment and appreciation. Let's keep our air and water clean, but only because doing so benefits human quality of life — and only if we decide the economic costs are worth it.

Which brings me to the Obama administration's proposed regulations on carbon emissions. When I try to evaluate them in terms of a human-centered — and properly American-centered — calculation of costs and benefits, I find myself baffled.

Now, before you bite my head off and throw it on the compost pile, let me lay a few more of my cards on the table.

Like any scientifically informed person, I accept that climate change is real and happening. And I presume that the scientific consensus is right that much of this change is anthropogenic (caused by human activity, especially carbon emissions).

But this is not a sin for which we need to pay penance. It's a process that's likely to produce significant negative externalities — as sea levels rise and flood coastal communities, weather patterns change and potentially become more severe and damaging, and so forth. We should try to avoid these externalities — if we can find a way to do so that doesn't involve paying even higher costs.

Which would be more costly, in terms of economic expense and disruption of American lives: doing little or nothing to cut back on emissions and adjusting to higher sea levels and changes in the weather? Or cutting back dramatically on emissions and contending with higher energy prices and significant job losses?

I don't know. And neither, really, does anyone else. Predictions about the costs of contending with climate change are guesses based on very little concrete information (because we don't yet know how far and how fast temperatures, or oceans, will rise). The same can be said about predictions of how much of an impact even very substantial cuts in emissions (like the ones Obama hopes to win from China and India in upcoming negotiations over a global climate treaty) will have on the severity of climate change, which is already well underway.

What is comparatively far more certain is that the Environmental Protection Agency's proposed regulations will have a significant negative impact on the industries of coal mining and coal-driven power production. How significant? We don't know that either. Resources for the Future (an environmental think tank) predicts the impact will be negligible. The Chamber of Commerce, on the other hand, estimates that the regulations will cost roughly $51 billion a year and lead to 224,000 fewer jobs a year through 2030.

Now it's true that the Chamber of Commerce is ideologically opposed to regulations on business, and that its study assumed that the EPA would seek to cut carbon emissions by 42 percent from 2005 levels. (The proposed regulations actually aim only for a 30 percent reduction by 2030.)

Another complicating factor: Coal-related industries have already gone into a tailspin, with an earlier round of EPA regulations and intense competition from cleaner-burning natural gas (thanks to the fracking boom) putting them under considerable pressure. A December 2013 study by the Union of Concerned Scientists calculated that out of dozens of coal plants that were in danger of retirement over the coming years, 77 percent would be forced out of business by the cost of compliance with regulations, while 23 percent would be shuttered because of competition.

So let's split the difference between the overly pessimistic Chamber of Commerce prediction and what is surely the overly optimistic estimate of Resources for the Future, and assume for the sake of argument that the new EPA regulations will cost something in the range of $25 billion a year and lead to roughly 112,000 fewer jobs a year through 2030.

That's a lot of money and a lot of jobs.

Especially when you consider that the pain will be narrowly confined to a small group of industries clustered in relatively few states. (I'm not even attempting to estimate costs from possible regionally based increases in energy prices as a result of the new regulations, since those costs might be partially offset by continued growth in natural gas production and the development of renewable energy sources.)

I can't think of another recent occasion when a president has actively and knowingly pursued a policy that would decimate an entire segment of the economy and the communities that depend on it. (The New York Times refers to experts who say the new regulations "could close hundreds of plants.")

Mind you, this isn't something to which I'm opposed on principle. Outflanking some Democrats on the left, I would have supported an effort by the president to give the U.S. a single-payer health-care system, even though it would have destroyed the health-insurance industry — because the social benefits would have been so overwhelmingly positive.

Will Obama's coal regulations prove to be equally salutary? I doubt it.

There is, first of all, the uncertainty I mentioned above. And then there's the map in this Vox story about the "tragedy of climate politics," showing that the U.S. is among the countries in the world "least vulnerable" to climate change.

Excuse me, but by what standard is that a tragedy? I would have thought it was outstanding news. Especially for the president of the United States, since it seems to mitigate the need for precisely the kind of tragic trade-off involved in the new coal regulations.

Things will be much worse elsewhere in the world, and that is morally troubling. But as I've argued on other occasions, politics and morality are not interchangeable, and nations are not normally in the habit of harming their own citizens for the benefit of people in other regions of the world.

Just as it's not every day that leading politicians and political parties commit unforced errors.

I suspect that June 2, 2014 — the day the Obama administration announced its new environmental regulations — will come to be seen as one of those days.