Air travel accounts for about 4 percent of human-induced global warming, and the United Nations warns that airplane emissions are set to triple by 2050. Planes are becoming more efficient, but our appetite for air travel is outpacing the industry's environmental gains.

Aviation is responsible for approximately 2.5% of global carbon dioxide (CO2​) emissions, but its total contribution to global warming is estimated to be significantly higher—around 3.5% to 5%—when "non-CO2​ effects" are considered. These additional factors include the release of nitrogen oxides (NOx​), soot, and the formation of contrails (condensation trails). At high altitudes, contrails can turn into cirrus clouds that trap heat radiating from the Earth's surface, a phenomenon known as "effective radiative forcing." Because these emissions are released directly into the upper atmosphere, their warming impact is intensified compared to ground-level emissions. While the industry has made planes more fuel-efficient, the rapid growth in passenger demand has historically outpaced these technological gains. To combat this, the sector is pivoting toward Sustainable Aviation Fuel (SAF), which can reduce lifecycle emissions by up to 80%, and exploring hydrogen and electric propulsion for short-haul flights. As other sectors like energy and ground transport decarbonize faster, aviation’s share of global emissions is projected to grow, making it one of the "hard-to-abate" sectors in the global effort to reach net-zero by 2050.