We don't choose to talk about it in the industrialized world when listing all the individual to-do things for the environment, like changing to CFL lighting or turning up the A/C a couple of degrees. Governments don't talk about it when debating cap-and-trade schemes, carbon taxes, and renewable energy, all directed toward reducing greenhouse gases, global warming and lessening the negative impact of climate change.
In the poorest nations on the planet it's frequently considered a meaningless abstraction--and distraction--from the "real" problems. Occasionally it rears its unwanted head and then disappears just as quickly. The lurking monster in the room is of course human population increase.
According to Population Connection, some 13 million additional humans will appear on planet Earth from July 1 of this year to early September. Depending on United Nations' population projections in 2006, we could go from the current 6.5 billion people to a low of 7.8 billion or as high as 10.8 billion by 2050. Only the most naive, blind or willfully ignorant (a vast number) will continue to harbor the delusion that the pressures on our finite natural resources will not be enormous, with a greater number of people chasing after those shrinking resources, from water to fertile land to a secure place to live.
A number of scientists and economists believe that even if we were actually committed enough worldwide to cut carbon emissions 40% by 2050, a 40% increase in human population (to 9.1 billion) would likely cancel out the corresponding CO2 reductions.
There have been projections that suggest our planet could sustain a population as high as 12 billion people. Of course these forecasts point out that some drastic changes are required in how we humans think and live, as well as some striking technological breakthroughs not yet discovered. We ought not to hold our breath for the 'reptilian" brain to wither away anytime soon.
Population pressure is not going away just because we don't want to bring it into climate change discussions. We are the one species that needs to talk about it openly and consistently and demonstrate some intestinal fortitude by doing so.