The aviation industry's growing contribution to global greenhouse gas emissions necessitates urgent and decisive government action. While the industry has made commitments to reduce its carbon footprint, achieving substantial and sustainable change requires strong policy frameworks, investment, and regulations from governments worldwide.

Aviation emissions are a significant and rapidly increasing problem. In 2023, the aviation sector accounted for 2.5% of global energy-related CO2 emissions, growing faster between 2000 and 2019 than rail, road, or shipping. As international travel demand recovers post-pandemic, aviation emissions reached almost 950 Mt CO2, over 90% of pre-pandemic levels. Without intervention, these emissions are projected to triple by 2050 compared to 2015 levels. Besides CO2, aviation's climate impact includes nitrous oxide (NOx) and contrail formation, further amplifying its warming effect.

International organizations and industry bodies have set aspirational goals, but these lack the teeth needed for real change. The International Civil Aviation Organization (ICAO) aims for "carbon neutral growth from 2020" and "net-zero carbon emissions by 2050," but its plans are often unsubstantiated and rely heavily on offsetting rather than direct emission reductions. Similarly, the International Air Transport Association (IATA) commits to net-zero carbon from aviation by 2050, but this target also depends on offsetting for approximately 20% of reductions and doesn't address non-CO2 emissions.

Governments must implement a range of measures to decarbonize the aviation sector effectively. One crucial step is promoting and mandating the use of Sustainable Aviation Fuels (SAF). These fuels, produced from renewable sources, can significantly reduce CO2 emissions compared to traditional jet fuel. Governments can incentivize SAF production through fiscal support, tax credits, and blending mandates. For instance, the US provides up to $1.75 per gallon of SAF produced through the Inflation Reduction Act (IRA). The EU's ReFuelEU Aviation mandates minimum SAF blend-in shares, including sub-targets for synthetic fuels, through 2050.

Another area for government action is investing in research and development of alternative propulsion technologies. While electric batteries and hydrogen fuel may be viable for short-haul flights, technological breakthroughs are needed for long-haul operations. The development of batteries with energy densities of at least 800 Wh/kg is crucial for passenger flights of 1,000 km or beyond. Governments can support these efforts through funding research grants, public-private partnerships, and establishing testing facilities.

Improving air traffic management and operational efficiency is also essential. Optimizing flight routes, minimizing flight distances, and modernizing air traffic control systems can reduce fuel consumption and emissions. Governments can invest in these improvements and work with airlines and air navigation service providers to implement them.

Furthermore, governments should consider demand management measures. Encouraging a shift to less emission-intensive modes of transport, such as rail, and reducing the need for travel through strategies like videoconferencing can help curb aviation emissions. The Environmental Audit Committee in the UK has recommended a frequent flyer levy to discourage excessive flying.

International cooperation is vital for addressing aviation emissions. The EU Emissions Trading System (ETS) covers CO2 emissions from flights within the European Economic Area (EEA) and departing flights to Switzerland and the UK. ICAO's Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) aims to offset international aviation emissions above a baseline year. Governments should actively participate in these international initiatives and work towards strengthening them.

Finally, transparency and accountability are crucial. Governments should require airlines to monitor and report their emissions and set clear, measurable targets for emission reductions. They should also regularly review and update their aviation climate action plans to ensure they are aligned with the latest scientific evidence and technological developments. The EU ETS Directive requires aircraft operators to report on non-CO2 effects from aviation, starting in 2025, a positive step towards a more comprehensive understanding of aviation's climate impact. By taking strong and coordinated action, governments can steer the aviation industry towards a sustainable future and mitigate its impact on the global climate.