The "inconvenient truth" overhanging the UN's Copenhagen conference is not that the climate is warming or cooling, but that humans are overpopulating the world.

A planetary law, such as China's one-child policy, is the only way to reverse the disastrous global birthrate currently, which is one million births every four days.

The world's other species, vegetation, resources, oceans, arable land, water supplies and atmosphere are being destroyed and pushed out of existence as a result of humanity's soaring reproduction rate.

Ironically, China, despite its dirty coal plants, is the world's leader in terms of fashioning policy to combat environmental degradation, thanks to its one-child-only edict.

The intelligence behind this is the following:

-If only one child per female was born as of now, the world's population would drop from its current 6.5 billion to 5.5 billion by 2050, according to a study done for scientific academy Vienna Institute of Demography.

-By 2075, there would be 3.43 billion humans on the planet. This would have immediate positive effects on the world's forests, other species, the oceans, atmospheric quality and living standards.

-Doing nothing, by contrast, will result in an unsustainable population of nine billion by 2050.

Humans are the only rational animals but have yet to prove it. Medical and other scientific advances have benefited by delivering lower infant mortality rates as well as longevity. Both are welcome, but humankind has not yet recalibrated its behavior to account for the fact that the world can only accommodate so many people, especially if billions get indoor plumbing and cars.

The fix is simple. It's dramatic. And yet the world's leaders don't even have this on their agenda in Copenhagen. Instead there will be photo ops, posturing, optics, blah-blah-blah about climate science and climate fraud, announcements of giant wind farms, then cap-and-trade subsidies.

None will work unless a China one-child policy is imposed. Unfortunately, there are powerful opponents. Leaders of the world's big fundamentalist religions preach in favor of procreation and fiercely oppose birth control. And most political leaders in emerging economies perpetuate a disastrous Catch-22: Many children (i. e. sons) stave off hardship in the absence of a social safety net or economic development, which, in turn, prevents protections or development.

China has proven that birth restriction is smart policy. Its middle class grows, all its citizens have housing, health care, education and food, and the one out of five human beings who live there are not overpopulating the planet.

For those who balk at the notion that governments should control family sizes, just wait until the growing human population turns twice as much pastureland into desert as is now the case, or when the Amazon is gone, the elephants disappear for good and wars erupt over water, scarce resources and spatial needs.

The point is that Copenhagen's talking points are beside the point.

The only fix is if all countries drastically reduce their populations, clean up their messes and impose mandatory conservation measures.

dfrancis@nationalpost.com