A rolling “dead zone” off the Gulf of Mexico is killing sea life and destroying livelihoods. Recent estimates put the blob at nearly the size of New Jersey.

Alas, I’m not talking about the Deepwater Horizon oil spill. As terrible as that catastrophe is, such accidents have occurred in U.S. waters only about once every 40 years (and globally about once every 20 years). I’m talking about the dead zone largely caused by fertilizer runoff from American farms along the Mississippi and Atchafalaya river basins. Such pollutants cause huge algae plumes that result in oxygen starvation in the gulf’s richest waters, near the delta.

Because the dead zone is an annual occurrence, there’s no media feeding frenzy over it, even though the average annual size of these hypoxic zones has been about 6,600 square miles over the last five years, and they are driven by bipartisan federal agriculture, trade and energy policies.

Indeed, As Steven Hayward notes in the current Weekly Standard, if policymakers continue to pursue biofuels in response to the current anti-fossil-fuel craze, these dead zones will get a lot bigger every year. A 2008 study by the National Academy of Sciences found that adhering to corn-based ethanol targets will increase the size of the dead zone by as much as 34 percent.

Of course, that’s just one of the headaches “independence” from oil and coal would bring. If we stop drilling offshore, we could lose up to $1 trillion in economic benefits, according to economist Peter Passell. And, absent the utopian dream of oil-free living, every barrel we don’t produce at home, we buy overseas. That sends dollars to bad regimes (though more to Canada and Mexico). It may also increase the chances of disaster because tanker accidents are more common than rig accidents.

But wait a minute – isn’t that precisely why we’re investing in “renewables,” to free ourselves from this vicious petro-cycle? Don’t the Billy Sundays of the Church of Green promise that they are the path to salvation?

This is infuriating and dangerous nonsense, as Matt Ridley demonstrates in his mesmerizing new book, “The Rational Optimist.” Let’s start with biofuels. Ethanol production steals precious land to produce inefficient fuel inefficiently (making food more scarce and expensive for the poor). If all of our transport fuel came from biofuel, we would need 30 percent more land than all of the existing food-growing farmland we have today.

In Brazil and Malaysia, biofuels are more economically viable (thanks in part to really cheap labor), but at the insane price of losing rainforest while failing to reduce the CO2 emissions that allegedly justify ethanol in the first place. According to Ridley, the Nature Conservancy’s Joseph Fargione estimates rainforest clear-cutting for biofuels releases 17 to 420 times more CO2 than it offsets by displacing petroleum or coal.

As for wind and solar, even if such technologies were wildly more successful than they have been, so what? You could quintuple and then quintuple again the output of wind and solar and it wouldn’t reduce our dependence on oil. Why? Because we use oil for transportation, not for electricity. We would offset coal, but again at an enormous price. If we tried to meet the average amount of energy typically used in America, we would need wind farms the size of Kazakhstan or solar panels the size of Spain.

If you remove the argument over climate change from the equation (as even European governments are starting to do), one thing becomes incandescently clear: Fossil fuels have been one of the great boons both to humanity and the environment, allowing forests to regrow (now that we don’t use wood for heating fuel or grow fuel for horses anymore) and liberating billions from backbreaking toil. The great and permanent shortage is usable surface land and fresh water. The more land we use to produce energy, the less we have for vulnerable species, watersheds, agriculture, recreation, etc.

“If you like wilderness, as I do,” Ridley writes, “the last thing you want is to go back to the medieval habit of using the landscape surrounding us to make power.”

The calamity in the gulf is heartrending and tragic. A thorough review of government oversight and industry safety procedures is more than warranted. But as counterintuitive as it may be to say so, oil is a green fuel, while “green” fuels aren’t. And this spill doesn’t change that fact.

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