Dharmendra Kumar Singh and Donald J. Wuebbles
Department of Climate, Meteorology & Atmospheric Sciences (CliMAS), University of Illinois Urbana-Champaign, Urbana, IL 61802, Illinois, USA
Abstract
Contrails, the linear ice clouds formed by aircraft at high altitudes, are a critical yet often underappreciated component of the climate system. These clouds play a significant role in radiative forcing by trapping outgoing longwave radiation, thereby contributing to a net warming effect on the Earth's atmosphere. With the ongoing expansion of global aviation, the frequency and persistence of contrails are expected to increase, amplifying their climatic impact.
This study aims to project the aviation emissions for 2035 by analyzing the rise in fuel consumption since 2006, under the assumption that fuel use growth mirrors the increase in total aircraft distance traveled. By scaling the Aviation Environmental Design Tool (AEDT) data from 2006 to 2035, with a 9% annual growth rate post-2018, we determine a scaling factor of 1.58, supported by the increase in travel distances from 33.2 × 106 km in 2006 to 54.7 × 106 km in 2018. To evaluate the impact of contrails on Earth's energy balance and their potential contribution to the projected global temperature change in 2035, we utilize the CESM2/CAM6 model, incorporating meteorological data for 2035 from CMIP6/SSP245 to ensure accurate atmospheric representation. Our findings highlight the urgent need for an updated aviation emissions database and more current projections to refine these assessments. Furthermore, we explore mitigation strategies, such as adjustments in flight altitudes and fuel compositions, to reduce the climate impact of contrails. The results underscore the necessity for comprehensive policies to address the environmental consequences of aviation-induced cloudiness and provide a foundation for future research in this critical area of climate science.
Keywords: Contrails, radiative forcing, climate change, global temperature, aviation emissions, AEDT, CMIP6/SSP245, mitigation strategies
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