Chart: A Renewable Energy Reality Check
Along with making ecosystem-devastating blunders, BP also produces an annual global energy review. This year's review just came out (though the public has been justifiably focused on other BP-related news). At any rate, over at the excellent energy blog The Oil Drum, Euan Mearns used some of the data from that report to create the chart above, which shows the world's primary energy sources over time.
See that tiny sliver of red way over in the upper right-hand corner of the chart with the arrow pointing to it? That's the wind, solar, and geothermal energy we use combined. Hydroelectric is renewable, too, and nuclear is "clean," in a sense, but they are also a small slice of our primary energy. So, while it's great to applaud wind farms and solar plants—and I'll continue to do so—it's important to keep the challenge in perspective. We rely very heavily, as we always have, on gas, oil, and coal.
What's the solution? Well, as Mearns points out, wind energy has seen exponential growth over the past 15 years (and exponents are powerful things). There's also the prospect that some truly transformative technologies make distributed solar power, for example, viable. Those developments could go a long way towards quickly cleaning the energy we use for our houses and gadgets. A tax on carbon, or a cap-and-trade program, would help.
The real challenge, from my perspective, is transportation. Even if we started buying only electric cars tomorrow, and the electricity to power them were coming from renewables, it would still take us decades to get a meaningful percentage of the fleet off of fossil fuels. One way or another (trains? bikes? telecommuting?) we need to drive less.