In their book, Healing the Planet, Paul and Anne Ehrlich proposed an equation I=PAT. It's a heuristic, or cognitive short cut, to represent environmental impact.
Impact = Population x Affluence x TechnologyLike any heuristic, it has some shortcomings, but it's useful because it gets us to glimpse the unseen. Impact can be expected to increase if there is a net increase of P, A, and T. If affluence and technology remained steady but more people use them, impacts increase. If the population and technology remained steady but affluence increased, then more purchased stuff by the population increases impact. If population and affluence remained steady but technological impacts went up because of proliferation or size, then impact increases.
Today, we have all three. There are more people with more purchasing power buying more pieces of technology that net more material and energy use than ever before. Today's I=PAT is much larger than 1950's I=PAT even though we have had so much progress in that time.
So when we get to an issue like climate change, it's been easy to talk about energy efficiency or renewable energy. Environmentalists in the United States generally laud wind power and eschew coal. In a world with lots of poor people it's been important to laud global development efforts that afford people the ability to meet their daily necessities of food, water, shelter, community, and healthy environments. Beyond that, most people hope that people can meet more than the necessities but be comfortable and happy. There's the rub.
What's a necessity, or as the Brundtland Commission called it in their report Our Common Future, a "need"? If we all "need" to have heated or cooled housing, cars, and electronic gadgets, how can we expect to stop a problem like climate change if development mandates increased affluence and technological dispersion for 7 billion people later this year and 9 billion by 2044? With no appreciable reduction in fossil fuel demand by efficiency, are we on a collision course with the climate?
Get some insights on it from Lester Brown and Robert Engelman on Hard Ball. This is a hard nut to crack and it's impressive that MSNBC took it on at all.