If renewable energy really were capable of reducing greenhouse gas (GHG) emissions on a large scale and creating the “millions of green jobs” their proponents claim, there would be no need, from the U.S. point of view, for a comprehensive international climate agreement. The U.S. could simply proceed with creating the millions of green jobs and then watching GHGs drop. As he tried to spin the Copenhagen non-event into something meaningful, this reality seemed to dawn on the U.S. president. He seemed to finally realize that renewable energy, his most touted solution to climate change, is not even remotely capable of solving the problem.

Unlike his predecessor, Obama has invested a large amount of his political capital in climate change. And for what result? The world media is today chock full of video clips of the president barging into high level Copenhagen meetings and sternly admonishing his colleagues—juxtaposed with his halting and incoherent wrap-up speech, which even his most fawning admirers admit was a disappointment.

Nobody is born an expert in all things. To be a good president, you have to follow good advice. Obama can be forgiven for listening to the mainstream green movement on the way forward on climate change: they supported him wholeheartedly during the election, and to his credit he is trying to live up to the promises he made to them.

But there comes a time when you have to accept that you’ve been given the wrong advice. Obama is learning the hard way that the greens are good at lobbying and not so good at offering solutions. I repeat: if renewable energy were the solution, then what’s stopping the U.S. from plowing ahead and creating the “millions of green jobs” and cutting GHGs? What’s stopping it is the tacit knowledge that renewable energy cannot hope to do either of these things on any appreciable scale. A massive shift to renewables will jeopardize the U.S. electricity supply, jack up the price of natural gas and hence electricity prices, and make living more expensive for everyone.

The only way to economically reduce GHGs from U.S. electricity generation—which at over 2.3 billion tonnes represents nearly 38 percent of America’s 6.1 billion tonne annual total—is to shift more power generation to nuclear. That is exactly what the greens don’t want. They are more anti-nuclear than anti-carbon.

Well, sooner or later the president is going to have to decide. He has sung from the mainstream green songbook, and embarrassed himself. Will the debacle at Copenhagen jolt Obama into seeking better advice on energy and environment? For his sake I hope so. In playing to accolades from an adoring international celebrity class and a fawning world media, Obama has undercut his own precious political capital—which is the source of a president’s power to persuade. He has other items on his agenda, healthcare chief among them. Suddenly, he cannot afford another defeat.

Obama’s response to the embarrassment of Copenhagen could well define the rest of his presidency.