The latest findings of the Intergovernmental Panel on Climate Change conclude that we are quickly using up our carbon “budget” – the amount of carbon that we can afford to emit while still having a good chance of limiting global warming to 2º Celsius. According to the IPCC, keeping the global temperature increase from pre-industrial levels below this threshold – the recognized tipping point beyond which climate change is likely to get seriously out of control – requires that the world emit only about 1,000 gigatonnes of carbon (GtC).
政府间气候变化委员会（Intergovernmental Panel on Climate Change，IPCC）的最新发现表明，我们正在快速耗尽我们的碳“预算”——在仍有很大机会将全球变暖程度控制在2摄氏度以内的情况下可以排放的碳量。据IPCC的数据，将全球气温在前工业化水平基础上升高幅度限制在这一阈值之下意味着全世界只能排放大约1 000十亿吨碳（GtC）。超过这一阈值，气候变化就可能大大超过控制能力。到2011年，我们已经排放了一大半的碳量。除非我们很快减少碳密集行为，否则剩余预算将会在大约三十年内耗尽。