Pathway to zero emissions in global tourism: opportunities, challenges, and implications
研究通过系统动力学模型探索全球旅游业实现2050年净零排放的路径，分析了45种政策方案，发现强制使用合成燃料和投资氢能飞机、高铁是关键，但可再生能源供应有限会制约航空业增长。
Human emissions must reach zero by 2050 to avoid dangerous climate change. Most sectors have achieved a downward path for their greenhouse gas emissions, but tourism’s emissions have continued to grow. We explore scenarios to reduce global tourism emissions and find only a narrow pathway to zero emissions tourism that could lead to net zero by 2050 while not severely damaging the tourism economy. Our study uses a system dynamics model. We describe the business-as-usual scenario, including its consequences for emissions and for tourism’s share of the remaining global carbon budgets if the world is to limit global temperature rise to 1.5 or 2 °C. We explore 45 possible policy approaches, like taxes and subsidies, infrastructure investments, off-sets, technology, behavioural changes, and sustainable aviation fuels. Key measures appear to be a mandate for e-fuel mixing up to 100% by 2050, and a multi-trillion USD investment in hydrogen-powered electric aircraft and high-speed rail infrastructure. We find that a limited renewable energy supply will constrain the growth of aviation if it is to be zero emissions in 2050. A risk-analysis explores the robustness of the policies. Finally, we discuss the consequences of the zero emissions tourism (ZET) scenario we propose.