In response to the rapid growth in air transport CO2 emissions, International Civil Aviation Organization proposed the "Carbon Neutral Growth from 2020" strategy (CNG2020 strategy). The total CO2 emission reduction is investigated for 28 airlines during 2021-2023 under CNG2020 strategy based on the predicted data by BP neural network. A Network Weak Disposability DEA model is applied to calculate the airlines' maximum desirable outputs when the inputs are fixed and the undesirable outputs are weakly disposed. Then carbon trading is added into the model, which can obtain the maximum desirable outputs when taking into account of carbon trading. Firstly, the total max Total Revenue of these 28 airlines is much larger than the total original Total Revenue gotten by BP neural network. Secondly, for these 28 airlines, the maximum expandable Total Revenue and Greenhouse gases emission reduction can be achieved simultaneously under CNG2020 strategy, but the Greenhouse gases emission reduction proportion is too small to satisfy the requirements of CNG2020 strategy. (C) 2019 Elsevier Ltd. All rights reserved.