Since January 2020, Elsevier has created a free COVID-19 resource centre with information in English and Mandarin. The centre is hosted on Elsevier Connect, providing access to research on the novel coronavirus. Elsevier grants permission to make all its COVID-19-related research immediately available in PubMed Central and other public repositories for unrestricted use. The article discusses aviation's contribution to climate change through radiative forcing (RF). Aviation emissions include CO₂, NOₓ, aerosols, and increased cloudiness from contrails and induced cirrus. The IPCC AR4 report quantified aviation's RF contribution for 2005 based on 2000 data. Aviation traffic grew significantly, with a 5.3% annual increase from 2000 to 2007, leading to a 38% increase in passenger traffic. Updated 2005 RF values show a 14% increase in total aviation RF (excluding induced cirrus) over 2000–2005. Aviation-induced cirrus RF increases the total RF to 78 mW m⁻², representing 4.9% of total anthropogenic forcing. Future scenarios for 2050 show aviation RF increasing by 3.0–4.0 times the 2000 value, representing 4–4.7% of total RF. Technological improvements could reduce fuel use, and incorporating aviation into emissions trading systems could reduce CO₂ emissions. However, no global agreement exists on such a system. The article reviews aviation's climate impacts, including contrails, cirrus clouds, and non-CO₂ emissions. Contrail RF was recalculated, showing a 10 mW m⁻² estimate, while aviation-induced cirrus RF was estimated at 30 mW m⁻². These values are used to assess aviation's contribution to climate change. The study highlights the complexity of quantifying aviation's RF, particularly due to limited observational data and model uncertainties. The 2005 aviation RF is 55 mW m⁻² (excluding AIC), an increase of 14% over 2000. This exceeds the IPCC's ±10% range. Non-CO₂ RF components, such as water vapour, sulphate, and soot, increased by 8.4%. Contrail RF increased by 18.2% due to changes in fuel and flight efficiency. The total aviation RF is 78 mW m⁻² (including AIC), representing 4.9% of total anthropogenic forcing. Uncertainties in aviation RF are high, with a LOSU (level of scientific understanding) of 'low' for most components. The study uses Monte Carlo simulations to estimate uncertainties, showing a 90% likelihood range for aviation RF. The Total NOₓ RF is estimated atSince January 2020, Elsevier has created a free COVID-19 resource centre with information in English and Mandarin. The centre is hosted on Elsevier Connect, providing access to research on the novel coronavirus. Elsevier grants permission to make all its COVID-19-related research immediately available in PubMed Central and other public repositories for unrestricted use. The article discusses aviation's contribution to climate change through radiative forcing (RF). Aviation emissions include CO₂, NOₓ, aerosols, and increased cloudiness from contrails and induced cirrus. The IPCC AR4 report quantified aviation's RF contribution for 2005 based on 2000 data. Aviation traffic grew significantly, with a 5.3% annual increase from 2000 to 2007, leading to a 38% increase in passenger traffic. Updated 2005 RF values show a 14% increase in total aviation RF (excluding induced cirrus) over 2000–2005. Aviation-induced cirrus RF increases the total RF to 78 mW m⁻², representing 4.9% of total anthropogenic forcing. Future scenarios for 2050 show aviation RF increasing by 3.0–4.0 times the 2000 value, representing 4–4.7% of total RF. Technological improvements could reduce fuel use, and incorporating aviation into emissions trading systems could reduce CO₂ emissions. However, no global agreement exists on such a system. The article reviews aviation's climate impacts, including contrails, cirrus clouds, and non-CO₂ emissions. Contrail RF was recalculated, showing a 10 mW m⁻² estimate, while aviation-induced cirrus RF was estimated at 30 mW m⁻². These values are used to assess aviation's contribution to climate change. The study highlights the complexity of quantifying aviation's RF, particularly due to limited observational data and model uncertainties. The 2005 aviation RF is 55 mW m⁻² (excluding AIC), an increase of 14% over 2000. This exceeds the IPCC's ±10% range. Non-CO₂ RF components, such as water vapour, sulphate, and soot, increased by 8.4%. Contrail RF increased by 18.2% due to changes in fuel and flight efficiency. The total aviation RF is 78 mW m⁻² (including AIC), representing 4.9% of total anthropogenic forcing. Uncertainties in aviation RF are high, with a LOSU (level of scientific understanding) of 'low' for most components. The study uses Monte Carlo simulations to estimate uncertainties, showing a 90% likelihood range for aviation RF. The Total NOₓ RF is estimated at