evidence: How sensitive is the earth to carbon dioxide? It’s a question that’s at the heart of climate science. [...] Climate sensitivity is the warming we can expect when the concentration of carbon dioxide in the atmosphere reaches double what it was in preindustrial times. [...] Climate sensitivity estimates using climate models support the higher end of the IPCC’s likely range. Such estimates are rooted in the behaviour of known physical processes but contain large uncertainties, such as the interaction of aerosols with clouds.