What if global warming isn as severe as predicted?
If models are wrong about the severity of global warming, it is because Earth’s climate is either more or less sensitive to change than we think it is. The biggest source of uncertainty in our understanding of climate sensitivity is climate feedbacks. Feedbacks are processes that either limit or amplify climate change once an external factor like a rise in greenhouse gases initiates change. Some argue that there may be as-yet-unidentified feedbacks in Earth’s climate system that will regulate global warming (negative feedbacks). If this is the case, they contend, then we should not waste money trying to mitigate global warming. However, most scientists believe that if there are hidden feedbacks, they are just as likely to amplify warming (positive feedbacks). In other words, there is just as much chance that the models are underestimating the severity of future warming as they are overestimating warming. Given the potentially catastrophic effects of global warming, uncertainty is not a
