Crisis is a buzzword, but does it actually mean? Many argue that multiple crises coexist, but how are they actually related? If crises are defining our time, why isn't there a proper socialist crisis policy? This book analyses economic and ecological crises, partly to understand the crisis itself, but, even more, to understand capitalism. Crises are not exceptions to an otherwise functioning capitalism, but integral parts of the system. Still, socialists often cling to the hope that crises are 'opportunities', and resort to Keynesianism as soon as they need concrete policies. In contrast, this book shows how capitalism produces crises and how crises reproduce capitalism. There are crucial similarities between the crises: rooted in capitalism and having similar class characters. But there are also differences. Economic crises are solved through creative destruction, and the ruling class will ensure that these crises are resolved at any cost. But neither the mechanisms of the system nor the ruling class will save us from the climate catastrophe; only we ourselves can do that. The tendency for crises to reproduce capitalism is, fortunately, not an iron law. Our historical mission in the face of the climate crisis is to create a historical exception to this rule. It is time for ecosocialism against crisis.