The sub-prime crisis in the early summer of 2007 developed first into a financial crisis and ultimately into a recession. New economic problems soon rushed in to add to the existing ones: energy and food prices rose and then fell like a yo-yo; the dangers of climate change became ever more clear; and the mal-distribution of global political power demanded action.
一切都起源于2007年夏天爆发的次贷危机，先是衍变为金融危机，而后导致经济萧条。老的问题还没有解决，新的问题接踵而至。食品能源的价格先涨后跌，仿佛是在坐过山车。全球气候变暖的问题日益突现。各国政局的不稳定也令人担忧。