Bjørn Lomborg is one of the most realistic environmentalists I've ever read. He goes beyond alleged benefits and looks at costs and feedback effects, and he pays attention to the impacts of changed/distorted incentives. In a recent piece in Slate, he takes on the folly of Earth Hour, scheduled for March 23rd.
[T]he reality is that Earth Hour teaches all the wrong lessens, and it actually increases CO2 emissions. Its vain symbolism reveals exactly what is wrong with today’s feel-good environmentalism.
... Hypothetically, switching off the lights for an hour would cut CO2 emissions from power plants around the world. But, even if everyone in the entire world cut all residential lighting, and this translated entirely into CO2 reduction, it would be the equivalent of China pausing its CO2 emissions for less than four minutes. In fact, Earth Hour will cause emissions to increase.
As the United Kingdom’s National Grid operators have found, a small decline in electricity consumption does not translate into less energy being pumped into the grid, and therefore will not reduce emissions. Moreover, during Earth Hour, any significant drop in electricity demand will entail a reduction in CO2 emissions during the hour, but it will be offset by the surge from firing up coal or gas stations to restore electricity supplies afterward.
And the cozy candles that many participants will light, which seem so natural and environmentally friendly, are still fossil fuels—and almost 100 times less efficient than incandescent light bulbs. Using one candle for each switched-off bulb cancels out even the theoretical CO2 reduction; using two candles means that you emit more CO2.[emphasis added].
... To green the world’s energy, we should abandon the old-fashioned policy of subsidizing unreliable solar and wind—a policy that has failed for 20 years, and that will fail for the next 22. Instead, we should focus on inventing new, more efficient green technologies to outcompete fossil fuels.
If we really want a sustainable future for all of humanity and our planet, we shouldn’t plunge ourselves back into darkness. Tackling climate change by turning off the lights and eating dinner by candlelight smacks of the “let them eat cake” approach to the world’s problems that appeals only to well-electrified, comfortable elites.