The Washington Post editorializes:
The IPCC admits that it doesn’t have a sure answer to a vexing question: Why has warming slowed a bit in the past decade or so? With medium confidence, the draft suggests that the explanation lies in a mix of natural variations and things such as the oceans absorbing more heat or more volcano debris reflecting sunlight back into space. It’s also possible, the scientists admit, that the planet’s sensitivity to greenhouse emissions is lower than middle-of-the-road projections.
Unless the IPCC’s report changes drastically between now and next month, the bottom-line message will be clear. Some uncertainties are inevitable when humans try to comprehend an incredibly complex climate system. Scientists might not be able to answer some questions for years, until they can look back at what changed after so much carbon dioxide entered the atmosphere so quickly. Those inevitable uncertainties are all the more reason for governments, starting with the United States’, to head off the ample risks of continuing to release huge amounts of greenhouse gases into the air and to set about it with speed and ambition.