U.N. Climate Panel Says We Need to Switch to Clean Energy Right Now

The U.N. Intergovernmental Panel on Climate Change released a new report on Sunday, just two weeks after the last one. It's not pretty. Emissions of greenhouse gases, according to the report, rose more than twice as quickly between 2000 and 2010 than in any of the three previous decades. Humans need to cut those emissions between 40 and 70 percent by the middle of the century, and almost completely by its end, in order to avoid catastrophic global warming. And even that might not be enough.

"We cannot afford to lose another decade," said IPCC co-chairman Ottmar Edenhofer, explaining that the bulk of the push to cut emissions needs to happen within the next 15 years. "If we lose another decade, it becomes extremely costly to achieve climate stabilization." The report doesn't advise governments on how to tackle the problem, but it does point out that countries' reluctance to drastically change their current approaches to energy will lead to disaster.

The authors acknowledge that a "massive" shift to sustainable energy will take "heroic efforts" – but if we start now, we just might make it. "It is up to the public and up to decision makers to decide if it is affordable or not," Dr. Edenhofer said. Affordability, in fact, was the key to the report's seemingly only bright point. The costs of renewable energies like wind and solar power are finally falling quickly enough to make their use on a large scale more practical. Policy solutions are expected to be discussed when a new treaty is negotiated next year.

Meanwhile, another study out of McGill University has confirmed once more that, yeah, climate change is all our fault. Physicist Shaun Lovejoy, reacting against criticism that evidence for global warming dates only to the Industrial Revolution and might simply reflect natural trends, tracked temperatures back to the 1500s. Instead of using models, which are often critiqued by deniers, Lovejoy used atmospheric data from NASA and the NOAA as well as geological temperature data taken from samples of lake sediments and tree rings.

His findings are good news for scientists and crusaders for truth, but bad news for humanity: they pretty much reflect the human-made climate change what the computer models have been telling us for years. "Even if you allow for very, very extreme natural fluctuations, the worst you can do is reject the hypothesis [of natural variation] with 99.8 percent certainty," Lovejoy said. All right, people. We don't have any excuses now. Let's get to work.