"Right now, humans are well on pace to at least double carbon dioxide concentrations from preindustrial levels by the middle of the century. But given how complex the climate system is, how do we know that the IPCC’s sensitivity estimate holds true? There’s a lot at stake — if the scientists are overestimating the climate sensitivity then global warming might be less worrying. No wonder that climate “skeptics” have often cast doubt on the matter." - Todd Hoff