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Aviation accounts for 2.5% of global CO2 emissions. But it has contributed around 4% to global warming to date

Year-wise Global Aviation demand, Energy Efficiency, and CO2 emissions

CO2 Emissions: When jet fuel burns, it releases carbon dioxide (CO2) into the atmosphere, much like any other combustion process. CO2 as a greenhouse gas has contributed around 4% to global warming to date.
Non-CO2 effects: In addition to CO2, aircraft emissions also include other substances like nitrogen oxides, soot, water vapor, and sulfate aerosols. These substances interact with the atmosphere in various ways and can have different climate impacts. For example:
- Contrails: These are the visible trails of condensed water vapor and ice crystals that form behind aircraft in certain atmospheric conditions. Contrails can contribute to the formation of cirrus clouds, which can have a warming effect on the climate.
- Induced cirrus cloud formation: Aircraft can also induce the formation of cirrus clouds through their emissions, further contributing to warming.

India is a Party to the United Nations Framework Convention on Climate Change (UNFCCC), its Kyoto Protocol (KP) and the Paris Agreement (PA).
As a Party to the UNFCCC, India periodically submits its National Communications (NCs) and Biennial Update Reports (BURs) to the UNFCCC which includes national Greenhouse Gas (GHG) inventory.
The energy sector contributed 75%, Industrial Process and Product Use 8%, the agriculture sector 14%, and the waste sector contributed 3% of total greenhouse gas emissions in 2016.
The Land Use Land-Use Change and Forestry (LULUCF) sector was the net sink and absorbed about 15% of the carbon dioxide in 2016.

Transitioning to Alternative Fuels: Invest in Research and Development of sustainable aviation fuels (SAFs), such as biofuels, hydrogen, or synthetic fuels, which emit fewer CO2 emissions compared to conventional jet fuel.
Improving Aircraft Efficiency: Encourage the adoption of more fuel-efficient aircraft and technologies, including advanced aerodynamics, lightweight materials, and efficient engines.
Implementing Operational Improvements: Enhance air traffic management systems to optimize flight routes, reduce delays, and minimize fuel consumption during taxiing, takeoff, and landing.

Describe the major outcomes of the 26th session of the Conference of the Parties (COP) to the United Nations Framework Convention on Climate Change (UNFCCC). What are the commitments made by India in this conference? (2021)
Discuss in detail the photochemical smog emphasizing its formation, effects and mitigation. Explain the 1999 Gothenburg protocol. (2022)