Despite chronic scandals that suggest it can’t clean up even its own offices, the United Nations wants to manage the weather of the entire planet. In the name of cooling global warming, the U.N. is steering toward a role as chief broker for assigning and trading national rights to emit carbon dioxide. The plan amounts to a tax on high per-capita carbon emitters, such as the United States, and subsidies for low emitters, such as Laos and Equatorial Guinea.

Unfortunately, a global carbon tax-cum-redistribution system would likely chill the productivity of free societies and subsidize some of the world’s worst regimes.

The worst carbon offenders, after all, tend to be the countries that are the freest, most democratic, and, as a result, the most vibrant, creative and productive. America, in all its freewheeling bounty, may exhale more than its share of greenhouse gases, but it also has given the world a disproportionately huge roster of inventions — telephone, airplane, computer, the Internet, leaps in modern medical technology — that enhance the quality of life. Given a chance, the States might yet invent ways of correcting the weather undreamt of in any U.N. bureaucrat’s philosophy.

By contrast, countries that emit the least carbon dioxide per person generally are saddled with the most repressive, corrupt and stifling governments — ruinous for their own people and damaging to a civilized world order. A prime example would be Zimbabwe (now chairing the U.N. Commission on Sustainable Development), which under the brutal rule of aging tyrant Robert Mugabe has gone from breadbasket of southern Africa to basket case.

The good news, presumably, is that Zimbabwe is a paragon of carbon thrift, giving off, per Zimbabwean, less than one-sixteenth of the U.S. average of carbon dioxide. The bad news is the Mugabe misrule. Babies born in Zimbabwe today have an average life expectancy of 37 years, or less than half the average 78-year span in America.

So it’s not impoverished children who are likely to benefit from climate-change subsidies. It’s their rulers, who control the toll gates.

My question is: Why stop with carbon offsets? We live in an interconnected world, teeming with behaviors and byproducts that might lend themselves to U.N.-brokered trading. Here are a couple:

Corruption offsets. When highly corrupt governments do business in world markets, they taint the business climate in ways that create incentives and avenues for others to become more corrupt. How about the U.N. levying a tax on the most corrupt regimes, and redistributing the revenues to countries that enhance the global business environment by enforcing financial integrity? No need to soak already impoverished peoples in corruption-fostering regimes. The U.N. could levy a direct personal tax on their rulers, and collect it when said potentates arrive for the annual U.N. General Assembly opening in New York — requiring simply that they dip into their private accounts, or maybe open their briefcases.

A glance at the annual country corruption index by Berlin-based Transparency International suggests, for example, that, under this scheme, governments of such graft-happy places as Burma and Belarus could buy corruption offsets from places such as Finland and New Zealand.

Despotism offsets. Much as financial corruption taints world markets, tyranny contaminates the integrity of global politics. How about a U.N.-brokered levy on tyrants, with the proceeds to be paid out as further incentive to the benevolent influence of democracies? Let Cuba’s Fidel Castro and Libya’s Moammar Gadhafi buy despotism offsets from countries such as Poland and Mongolia.

The possibilities are endless: Sex-discrimination offsets for the Saudi royals; bombast offsets for Venezuela’s Hugo Chavez; illicit-nuclear-bomb offsets for Iran’s mullahs and North Korea’s Kim Jong Il.

The only hitch I can see is if the U.N., in all fairness, imposed similar levies on itself. In that case, by the time the dignitaries of Turtle Bay got done paying for their own corruption offsets, incompetence offsets, self-aggrandizement offsets, cover-up offsets, and, most of all (lest we forget climate change), hot-air offsets, the U.N. would be out of business.