Some of the literature has pointed to difficulties in these kinds of assumptions. For instance, there may be aversion at any price towards losing particular species. It has also been suggested that low-probability, extreme outcomes are overweighted when making choices. This is related to climate change, since the possibility of future abrupt changes in the climate or the Earth system cannot be ruled out. For example, if the West Antarctic ice sheet was to disintegrate, it could result in a sea level rise of 4–6 meters over several centuries.