Basic carbon arithmetic illustrates the scale of the problem. According to the most recent assessment of the Intergovernmental Panel on Climate Change (IPCC), we are on a trajectory toward exhausting the twenty-first century’s entire carbon budget by 2030.
基本碳算术说明了问题的严重性。根据政府间气候变化委员会（IPCC）的最新评估，我们在2030年就将用完二十一世纪的全部碳预算。