The title of this article in Nature pretty much says it all. The authors make a case that the IPCC is underestimating the risk of a rapid deterioration in the climate situation. There are a couple counter-intuitive points here. First, there is good news about air pollution, particularly in China. This is good news for public health in the near term, but paradoxically the air pollution has actually been bad enough in recent years to measurably block sunlight. Second, there really is a non-manmade component to global warming, and it may be significant in the coming decades. This is not good news at all, because the manmade component is of course very real, and the two are additive.