Barring wayward asteroids, global warming, human population growth and nuclear proliferation are Earth's most immediate threats to life.

According to Eric Schlosser's Command and Control, the U.S. once had 32,000 nuclear warheads. Slightly less insane, our stockpile now numbers 8,500.

Comparable to Russia, roughly one-third are strategically operational. By conservative estimates, combined arsenals of other countries may add another 1,000 nuclear weapons worldwide. Two hundred fifty nuclear devices, less than France's and Israel's arsenals, are enough to exterminate our species.

Since the first of America's 1,054 nuclear weapons tests in 1945, scores of "broken arrow" mishaps and near misses have occurred.

The 'human' threat

While Bill Clinton was governor, a workman's socket wrench dropped 70 feet down a Titan II ICBM silo, rupturing the missile's fuel tank. But for heroic intervention, it would have incinerated Arkansas.

That hydrogen bomb's fallout would have tracked up the east coast making swaths between Richmond, VA and Bangor, ME uninhabitable. Warhead maintenance has improved, but human error is inevitable. Malevolent hackers are increasingly sophisticated and delivery systems, such as missiles and aircraft, are aging infrastructure perils. Our passivity suggests we've no appreciation of laws of averages and risk.

Voices of reason

Early notable opponents of nuclear armament -- Einstein, Bertrand Russell, Buckminster Fuller and Orwell -- are gone. Scientists and engineers, who developed and know the flaws in nuclear ordnance, disappear daily. We 1960s-types -- whose Saturday matinees gave us Dr. Strangelove, On the Beach, Failsafe and The Bedford Incident -- aren't running deep-outs any longer either.

That leaves only younger generations, no more afraid of nuclear winter than they are of Karloff and Lugosi.

Accidental warhead detonations, while not unheard of, become probable in America because of sheer numbers. When it happens, Hurricane Sandy will seem like a stroll in the park.

The U.N. must aggressively convene and oversee unilateral nuclear arms reduction aided by U.S. commitments to an arsenal of 300 warheads or less pending proportionate reductions by other nations.

If we want Iran to stay thermonuclear weapon-free, we must pressure Israel to lighten its atomic war chest as well.

Of course, Democrats and Republicans won't.

Be scared this Halloween, be very scared.
