[摘要]整个交通行业当前的温室气体排放将近占世界总排放的14%，在电力和土地利用部门的后面，但是和农业活动排放有着相同的排放比例。此外，交通业排放在世界经合组织里是增长最快的（1990-2002），在非经合组织增长第二快，增速分别是25% and 36%。交通排放的大头在公路交通（76%），航空业次之（12%）。
航空业占全球二氧化碳总排放的比例在不同来源有不同的数字，例如IPCC(1999)的计算结果是2%，WRI(2005)的报告称是2%，在2050要增至3%。但是如果考虑进去非二氧化碳效应，这个数字要翻2-4倍。虽然现在航空排放远低于电力能源行业和汽车排放，但是考虑到航空业的增长速度以及技术瓶颈，它的排放在所有交通行业是增长最快的，在过去的二十年中年增长速度是9%，据估计在2010年后，这个增长速度还会维持甚至继续扩大。到2050航空业的排放会是2005年的3倍，而公路交通为2倍。意味着如果现在不采取行动，一味的扩大民用航空器的数量，整个行业的排放将会占越来越大的比例。同时，象中国这样的崛起发展中国家，增长速度甚至会更快，现在的年平均增幅在14%左右，而且在未来的二十年增速也会维持在10%以上，尤其是国际航线方面增幅更快。
此外，在不同的情景分析中（senario analysis)中，现实情况不容乐观，英国，德国，以及澳大利亚的分析表明，如果按中等增速，最可能的情景，航空排放在2050年会占英国和德国总排放的40%左右，会占澳大利亚的10%。
因此，了解中国的现在排放和未来的情景分析应该是很有意义的，尤其是在西方的压力以及自身节能目标下，它对国家的气候变化方案的制定以及在国际谈判中的博弈都很必要。
Contribution of aviation sector to CO2 emissions
Transport sector accounts for around 14 % of total human-induced GHGs emissions in the world, behind power generation and land use sectors, with the same ratio as the agriculture sector. Transport was the fastest growth sector of GHGs emissions between 1990 and 2002 in OECD countries and the second fastest in non-OECD countries, with the increase of 25% and 36%, respectively (Stern, 2006). The major contributions to transport are from road transport (76%) and aviation (12%), and the carbon dioxide emissions from aviation are 0.7 billion tonnes per year, accounting for 1.6 percent of GHGs emissions (WRI, 2005). While according to IPCC (1999), aviation contributes 2% of the global CO2 emissions and it would increase to 3% by 2050; if taking into account the non-CO2 effects of aviation , this figure would account for around 5% of total warming in 2050 (IPCC, 1999).
Although the emissions are not that extensive as those from power generation or vehicles, enough attention should be paid to avoid the over-expansion of aviation sector, because civil aviation traffic has increased dramatically with an average annual growth rate of 9% in the past decades. From 2010, it is expected to expand further by 5% per year, among all modes of transportation, aviation has been considered as the fastest growing sources of GHGs both in the developed and developing world; between 2005 and 2050, the CO2 emissions are expected to triple over the period, in comparison to the double of road transport emissions (Stern, 2006). If taken into account the non-CO2 effects associated with aviation, the aviation emissions will be 2 to 4 times larger as mentioned.
