Delegates from nearly 190 nations are in Bali this week hammering out the groundwork for a new global warming treaty beyond 2012 when the Kyoto Protocol's first phase expires.  Cutting greenhouse gas emissions, particularly carbon dioxide emissions, is considered critical to avoiding the worst effects of climate change. 

In determining how to do that, delegates are focusing on several policy options, including taxes on carbon fuels, limiting the expansion of new coal-fired electrical plants, and the ntroduction of a global cap-and-trade carbon trading system affecting utilities and manufacturers.

The issue of population is largely absent from these discussions.  Population growth, however, has played a significant role in boosting greenhouse gas emissions and will continue to do so for decades to come. Frederick A. Meyerson, an ecologist at the University of Rhode Island, wrote an analysis recently for the Bulletin of the Atomic Scientists.  Here’s a portion of what he had to say:

Human population continues to grow by more than 75 million people annually. Since the first Earth Day in 1970, global population and annual carbon dioxide emissions have both increased by about 70 percent. As a result, per capita emission rates remain steady at about 1.2 metric tons (mt) of carbon per person per year.

Unfortunately, the 1997 Kyoto Protocol has had little measurable effect on per capita emissions, even in the countries that have agreed to national targets. Emissions in Western Europe reached 2 mt per person back in 1970 and have fluctuated just above that level ever since. The same plateau phenomenon, which appears to be related to stages in development, happened in the early 1970s in "centrally planned Europe," which includes Russia and the former Soviet republics. 

Per capita carbon emissions in the United States also leveled off around 1970 at a much higher rate--above 5.5 mt per person--and have barely budged since, through recessions, economic booms, and swings in energy markets. From 1970 to 2004, U.S. population and emissions both rose by 43 percent.

More than any another factor, population growth drives rising carbon emissions, and the U.S. Census Bureau and United Nations both project that global population, currently 6.6 billion, will surpass 9 billion before 2050.

While the vast bulk of that anticipated population growth will take place in developing nations, some of it is concentrated in developing nations, most notably India, that are experiencing rapid economic growth and corresponding increases in carbon emissions. 

In the short term, of course, an expansion of international family planning assistance would do little to reduce emissions.  But global warming is not a short-term problem.  The threat of global warming is not going away. Even if industrial nations are successful in slashing their per capita carbon emissions by 50 percent or more by 2050, the danger won’t magically vanish. As Myerson points out, there will be 2.5 billion more people on the planet who will want to use their fair share of fossil fuels.

Many of the delegates from the developing nations at the Bali conference are insisting that combating poverty is a higher priority for them than reducing their already low rates of carbon emissions.  Rapidly developing nations like India, in fact, view sharply increased consumption of coal and oil as being essential to meeting the needs of their expanding population.

That’s what makes the expansion of voluntary, non-coercive family planning services a potential win-win solution. The prevention of unwanted pregnancies has helped to lift millions of families in developing nations out of poverty; it might also help to reduce future demand for fossil fuels.  In many countries where population pressures and the fight for survival is leading to deforestation, a reduction in unwanted pregnancies might also fight global warming by preserving tropical and semi-tropical forests as carbon sinks.

Increased support for international family planning assistance will not negate the need for carbon taxes or a global cap-and-trade program, but it could make the long-term job of combating global warming a lot easier.