HEWITT, N.J. — A plague of science denialism is afflicting the United States. We are in danger of inundation by succeeding waves of wishful thinking and misinformation about scientific matters crucial to this country's welfare, and indeed the world's.

HEWITT, N.J. — A plague of science denialism is afflicting the United States. We are in danger of inundation by succeeding waves of wishful thinking and misinformation about scientific matters crucial to this country's welfare, and indeed the world's.

To be sure, other developed nations have science-denialism problems of their own. Parts of the United Kingdom are for the first time in decades suffering outbreaks of measles — including some fatalities — through unfounded fears that the MMR vaccine (measles, mumps, rubella) could be linked to autism. Christopher Monckton, a classics scholar who once served as a low-level economics wonk in one of Margaret Thatcher's think tanks, has carved out an international audience as an "expert" denier of climate science. The nation's leading pharmacy chain, Boots, carries a line of homeopathic "medicines" — despite facing public demonstrations of protest.

But there is no parallel to the situation in this country, where in many schools evolution is either ignored or denigrated, and where as much as half the population seems convinced that imminent climate change is either a hoax or doesn't matter.

It's easy enough to understand how our lack of action to counter or mitigate climate change is going to cause us gross economic damage and potentially millions of lives; just look at the size of the bill for a year's extreme weather events, or our shrinking share of the market for clean-energy devices such as solar panels in the face of competition from other countries that got there earlier and acted with firmer resolve. Just imagine the economic impact when large parts of the U.S. agricultural heartland can no longer sustain food crops. But evolution?

For decades under Stalin the U.S.S.R. rejected evolution. Although the doctrine involved, Lysenkoism, was scrapped in the U.S.S.R. from in the mid-1960s, it was decades before the country caught up with the rest of the world in fields such as genetics. That knowledge gap was not without significant economic consequences. Do we want to make same mistake here?

The two most damaging forms — by far — of science denialism facing us concern climate science and evolution, and both are generally identified with conservatives. To say that the vast majority of the damage we're suffering through science denialism is a problem born of the right is not in any way to be partisan: It's an observation of fact.

Yet this doesn't mean the left doesn't have its own embarrassments in connection with science denialism. It's not for nothing that the prominent medical blogger Orac habitually describes the center-left Huffington Post as "that wretched hive of scum and quackery." Although HuffPo has recently inaugurated a science section and may start to improve its ways, for years it has given a platform to a host of crank medical ideas, most notably the spurious vaccination/autism link. Among the webzine's consultants and regular contributors is Deepak Chopra, whose "quantum medicine" is just the tip of his personal iceberg of ideas that fly in the face of established science.

Matters are little better at the left-leaning activist site Care2, where anti-vaccination articles are fairly commonplace. Reading the comments appended to these is as depressing as reading those beneath any article published by, say, American Thinker on the subject of climate change. It's obvious that, in both instances, the arrogant determination to remain ignorant of science is deeply ingrained. On Care2 there's also a near omnipresent detestation of Big Pharma.

Of course, it's difficult not to detest Big Pharma, but in the Care2 community the antipathy often goes far beyond the rational. Recently Care2 mounted a campaign protesting the FDA's desire, for safety reasons, to make sure vitamin supplements are properly tested before they're put on the market. Not only is campaigning to reduce safety measures clearly foolish, but many of those supplements and "alternative" medicines are manufactured by ... Big Pharma.

But at least the left can claim to have elected an administration that takes science seriously, that corrects the egregious errors made over the eight Bush years, when we were told, falsely, that "the science was still out" on climate change, that Saddam Hussein had stockpiled high-tech weapons of mass destruction, and so forth.

Look closer, though. It's certainly true the Obama administration is not, for example, putting unqualified ideologues in administrative positions within the various science agencies in order to muzzle the science. There's no parallel to the Bush administration appointee who doctored the NASA site in case it upset creationists. Yet, on the ground, the situation within the science agencies seems not to have improved very markedly; in particular, almost nothing has been done to protect scientific whistle-blowers.

A few weeks ago we witnessed an especially cynical act by the current administration. A major medical crisis threatens because of the overuse of antibiotics in agriculture. The big drawback of overuse of antibiotics is that it's a surefire way to generate antibiotics-resistant strains of bacteria. Since we eat the treated meat, there's an ever-increasing chance that, next time your doctor prescribes an antibiotic for your possibly life-threatening disease, it won't work.

In the early 1970s the FDA recognized this problem, and in 1977 it announced proposals to curb some of the abuses. There then began an example of that tiresome political game whereby "our" representatives — in this instance "sponsored" by the agriculture industry — keep claiming that "more research is necessary" before anything should be done no matter how much research there's already been and no matter how conclusive its results. In the case of Big Ag's abuse of antibiotics, this game has been permitted to continue for 3 1/2; decades.

In 2010 the FDA finally declared itself ready to get tough. But the agriculture industry rallied its troops, and a lot of money changed hands in the House and Senate. Not fancying a major political fight in an election year, the administration caved. At the end of last year the FDA announced it was opting instead for a system of voluntary regulation. Since the agriculture industry is still pretending, in the teeth of the available science, that the use of antibiotics in livestock presents no medical problem at all, we can imagine how effective this voluntary regulation will be.

And how did the FDA's announcement of its capitulation go out? It was buried in the Federal Register for Dec. 22 — perfect placement and timing to ensure, fortunately unsuccessfully, that it would go completely unnoticed.

It would be silly to claim that, just because the Obama administration's record of science denialism is patchy — and the above case is only one example — the Bush administration's wasn't even worse. Similarly, just because the U.S. left has a problem with science denial doesn't mean the problem isn't vastly greater on the right — both quantitatively and, because of the sciences involved, qualitatively. But neither does it mean that the left's science denial can be safely ignored. In October 2010, because of irrational fears of vaccination fostered largely on the left, California suffered its worst whooping cough epidemic in over half a century, with 6,000 cases and 10 fatalities. Wherever its ideological origins, science denialism has its human cost.

John Grant is the author of 60 books, including, most recently, "Warm Words and Otherwise: A Blizzard of Book Reviews" (InfinityPlus Ebooks) and "Denying Science" (Prometheus Books).