Can you hear it? That screeching sound ofenvironmentalists being torn apart? In my world, it’s ear-splitting. As green initiatives flounder, as concerns about climate change and the state of the planet slide down the list of public priorities, environmentalists are being blamed. Is this fair? Have we failed?

After the collapse of the climate talks in Copenhagen in 2009, governments began quietly to shuffle away from their green commitments. In Canada, you won’t have noticed much difference, as the Harper government was fiercely opposed to environmental restraints long before Copenhagen. The same can be said for the United States. But in the United Kingdom, the green consensus to which all the major parties have subscribed has started to fragment. Our government is now gutting the English town planning system, which is the envy of nations blighted by urban sprawl. Even as it starves essential services of money, it’s launching a new road-building program.

Senior ministers hint that they want to drop the U.K.’s carbon targets. They talk of using shale gas as a “bridge” to a low-carbon economy, which is like using chocolate fudge cake as a bridge to a low-calorie diet.

Is this because environmentalists have messed up? Have we alienated the public? Have we supported the wrong policies, promoted the wrong causes?

Plenty of people say so. One of our most prominent critics is the venture capitalist Vinod Khosla. In an interview with The Economist earlier this year, Khosla maintained that we “get in the way with silly stuff like asking people to walk more, drive less.… Environmentalists use artificial rates of return, buried assumptions and ‘what if’ assumptions about behaviour changes. It’s useless crap.” Instead, he suggests, only new, “black swan” technologies will deliver us from disaster.

There is truth in some of this. We have tended to overestimate both people’s willingness to change the way they live and the effectiveness of these changes when they do occur. We have been better at explaining what we don’t want than at explaining what we do want. We have engaged in magical thinking, particularly about energy technologies. We’ve supported useless projects we like the look of (solar power at high latitudes, for example), while rejecting useful sources (such as atomic energy) on unscientific grounds.