Cause here, effect there: The climate disconnect

If total human population increases by one person—or by 10 people—it makes no real difference to the climate. But if you multiply those numbers by 1 billion, the difference can be enormous. This observation may seem self-evident. But it's not so evident to my roundtable colleague Wang Haibin, whose emphasis on good governance as an answer to climate change wholly ignores population's influence on climate.

Earlier in Round Three, Wang wrote that "[I]t's a mistake to exaggerate population's role in carbon dioxide emissions" because "The core of global problems such as climate change is actual human behavior." It's hard to disagree with the second of those two statements. Human behavior is indeed the single most important force driving environmental change. Behavior in the bedroom drives population growth. Behavior at the dinner table changes agricultural systems, which can drive land use changes and biodiversity loss. Behavior in commuting to work can increase people's carbon footprints. It is "normal" human behaviors that contribute to the 36 gigatons of carbon dioxide emissions generated each year. Human behaviors at all levels—from the individual to the global—are damaging the natural systems on which life depends. And as people seek solutions to the environmental mess they have created and continue to create, no level of human behavior should be ignored.

I acknowledge it would be naïve to think that family planning services, if made universally available and accessible, would be the magic-bullet solution to the climate challenge. But it's equally naïve to suppose that population size and rate of population growth do not matter for carbon emissions. If human activity is driving changes to Earth's natural systems—and it is—one cannot argue that the size of human population, and the rate of population increase, do not matter. A small increase in population size means nothing. But an increase on the order of billions? That's something else entirely.

Universal access to voluntary family planning services is important because its immediate benefit is the prevention of unintended pregnancies—and 40 percent of the world's 213 million pregnancies each year are unintended.

This is not just a problem in the developing world; if anything, rates of unintended pregnancy are higher in more developed economies. But abortion is generally safe and legal in such countries, so unintended pregnancies don't necessarily result in unintended births (or loss of women's lives). This, unfortunately, is not the case in many developing countries in Africa, Asia, and Latin America and the Caribbean.

In Africa, as I argued in Round One, development priorities must include not just enhanced access to family planning services but also expanded educational opportunities for girls, and efforts to delay marriage and childbearing. These interventions can slow the continent's rate of population growth and can do much to address its environmental challenges: land use changes, loss of tropical rainforest, biodiversity loss, and desertification. If the continent's population doubles over the next 35 years, however, Africa will find it very difficult to address these challenges effectively.

There is commensurate work to be done in countries with much heavier carbon footprints. They must demonstrate that the "good governance" of which Wang is such a proponent can work for the benefit of the environment too. Decisions made at the individual, corporate, and even societal levels often fail to account for the environmental harm that present-day economic gains can cause. The lion’s share of damage to the environment burdens the poor, the developing world—and future generations. Where the causes and effects of climate change are concerned, there's a disconnect both in time and in space. This disconnect frustrates efforts to achieve global consensus on environmental stewardship.

But human beings have only one planet. Disagree as they might, they share a common destiny.