Although regular readers here understand that I am not a believer that humans are the sole, or even the major, cause of global warming, I understand that yes, there is some warming going on. It's small in global terms, but it's there. But today's Washington Post has a column about the subject that is a must read. Robert J. Samuelson asks the real important question. So what are you going to do about it?
From 2003 to 2050, the world's population is projected to grow from 6.4 billion people to 9.1 billion, a 42 percent increase. If energy use per person and technology remain the same, total energy use and greenhouse gas emissions (mainly, carbon dioxide) will be 42 percent higher in 2050. But that's too low, because societies that grow richer use more energy. Unless we condemn the world's poor to their present poverty — and freeze everyone else's living standards — we need economic growth. With modest growth, energy use and greenhouse emissions more than double by 2050.
Just keeping annual greenhouse gas emissions constant means that the world must somehow offset these huge increases. There are two ways: Improve energy efficiency, or shift to energy sources with lower (or no) greenhouse emissions. Intuitively, you sense this is tough. China, for example, builds about one coal-fired power plant a week. Now a new report from the International Energy Agency in Paris shows all the difficulties (the population, economic growth and energy projections cited above come from the report).
The IEA report assumes that existing technologies are rapidly improved and deployed. Vehicle fuel efficiency increases by 40 percent. In electricity generation, the share for coal (the fuel with the most greenhouse gases) shrinks from about 40 percent to about 25 percent — and much carbon dioxide is captured before going into the atmosphere. Little is captured today. Nuclear energy increases. So do "renewables" (wind, solar, biomass, geothermal); their share of global electricity output rises from 2 percent now to about 15 percent.
Some of these changes seem heroic. They would require tough government regulation, continued technological gains and public acceptance of higher fuel prices. Never mind. Having postulated a crash energy diet, the IEA simulates five scenarios with differing rates of technological change. In each, greenhouse emissions in 2050 are higher than today. The increases vary from 6 percent to 27 percent.
Since 1800 there's been modest global warming. I'm unqualified to judge between those scientists (the majority) who blame man-made greenhouse gases and those (a small minority) who finger natural variations in the global weather system. But if the majority are correct, the IEA report indicates we're now powerless. We can't end annual greenhouse emissions, and once in the atmosphere, the gases seem to linger for decades. So concentration levels rise. They're the villains; they presumably trap the world's heat. They're already about 36 percent higher than in 1800. Even with its program, the IEA says another 45 percent rise may be unavoidable. How much warming this might create is uncertain; so are the consequences.
This is a must read. Samuelson asks a simple question: what sacrifices are you willing to make? No lights? No computers? (There goes this blog). No heat in the winter or air conditioning in the summer? No more cars?
Is everyone else on earth willing to sacrifice?
The issue is an engineering problem. Stop trying to make it a moral crusade and we can progress.
Update: Donald Sensing at One Hand Clapping has links to Stephen Den Beste's series on power and engineering.