Forecasting the long-term future has never been easy, but in the coming decades it will get much harder. Although science and technology have greatly expanded the possibilities open to us, Earth is now approaching a number of resource and environmental limits. Technological fixes will thus become increasingly ineffective (because progress in solving one problem will often make others worse). Also trying to make sense of the long-term future is becoming more difficult. Not only might the palette of technical options for the future become smaller than we hope for, but as the politics of climate change has already shown, achieving consensus on a preferred future in one country, let alone the world as a whole, will become more complicated. The main change that we see occurring in the coming decades will be the end of economic growth, both global and national. This could result from a serious global financial meltdown, or from rising constraints on resource use and emissions. Alternatively, this could happen because we plan for it, as promoted by the proponents of degrowth. A global economic contraction would most probably entail radical changes to our economic system, perhaps with an end to the present reliance on markets.