Residual Emissions
Residual emissions are carbon emissions that are difficult or impossible to (fully) eliminate due to technological or other limitations. These emissions are extremely important, because β given that we effectively cannot avoid them β they need to be compensated with various kinds of carbon removal technologies (mainly carbon capture and storage) to be able to reach net zero (or carbon-neutrality). Carbon removal is very energy intensive, however, and there are limits to how much carbon we can remove. Estimates of these limits vary, but the most optimistic ones are typically somewhere in the neighborhood of 25Gt/year, or roughly half our...
Tipping Points, Permafrost Thaw, and βFastβ Reduction
Last Thursday a new analysis of the main βtipping elementsβ in the Earth system was published in Science., The paper and its supplementary materials provide data on likely thresholds and effects of all the main tipping elements that have been discussed in the literature of the past two decades. Furthermore, the supplementary materials also discuss a number of other feedback effects that have been suggested as tipping elements before, but that turn out to be too gradual to be properly classified as such. These effects are at least as important, however, and tend not to be (fully) included in common...