To see Part 1 of the FlyingLess “Update in a Time of Coronavirus,” go here.

The COVID-19 pandemic has led to a significant downturn in global CO2 emissions. According to a study published earlier this month in Nature Climate Change, emissions in April 2020 were 17 percent less than they were in April 2019. At their peak, the decline averaged 26 percent in individual countries.

While the decrease shows what is possible, more importantly it illuminates the enormity of the challenges presented by climate change. As Corinne Le Quéré, a professor of climate change at East Anglia University and the study’s lead author, said in regard to the April numbers, “This is a really big fall, but at the same time, 83% of global emissions are left, which shows how difficult it is to reduce emissions with changes in behavior.” Similarly, Dave Reay, a professor of carbon management at Edinburgh University, characterized the findings as “sobering” in light of the small impact of what is a temporary decline will have on the climate system. “All those billions of lockdown sacrifices and privations have made just a small and likely transient dent in global greenhouse gas emissions.”

Rebuilding in the aftermath of the coronavirus and its economic disruption thus requires very different policy choices than those that have become standard fare. As Paul Morozzo, a senior climate campaigner at Greenpeace UK, told The Guardian, “We know how to do it. We have to rebuild our cities around walking, cycling and public transport. We’ve got to create hundreds of thousands of jobs upscaling renewable energy and insulating people’s homes. Let’s learn from this tragedy, build back better and not make the mistake of ignoring the next crisis [of climate breakdown] heading our way.”

Also central to the effort to “learn from this tragedy” and to “build back better” is scaling back on flying—and radically so.

An analysis of air traffic in the last week of March found a drop of over 50 percent in comparison to a typical March week in 2019, with the decrease particularly pronounced in international flights. By mid-April, eight of ten flights were cancelled worldwide, according to one report. In the United States, the Transportation Security Administration saw a 96 percent decrease in passenger volume. However, there was only a 50 percent drop in the number of flights with many airlines opting to fly nearly empty planes—a reflection of the act that it can be less expensive for an airline to fly a plane that to pay to park it somewhere.

Daniel Rutherford, aviation director at the International Council on Clean Transportation called the mismatch a “huge environmental waste.” What Rutherford characterizes as “the million-dollar question” is, once the pandemic passes, “whether we will curb flying to protect the climate, as we are now doing to protect public health.”

For myriad reasons, the near- and long-term future of aviation is unclear. What is certain is that, from the industry’s perspective, there are many worrisome signs—a small uptick in flying in the last weeks notwithstanding.

In China, for instance, the number of domestic flights began to rise in mid-February, but reached a plateau in early March of a little over 40 percent of pre-pandemic levels. In the United States, in response to a polling question of “If restrictions were lifted on the advice of public health officials to do the following, how likely would you be to fly on an airplane?” only 28 percent answered “definitely” or “probably.” And in early May, Warren Buffett, one of the world’s richest people and most important investors, sold his firm’s entire holdings in the four biggest U.S. airlines, explaining that the “world has changed” as a result of COVID-19.

Meanwhole, Germany’s state airline, Lufthansa, has reported that it will ground 300 of its 763 planes over the next year; by 2023, when the airline foresees that the coronavirus-related impacts on aviation will have passed, Lufthansa expects its fleet to be smaller by 100 planes. This is probably related, in part, to a decline in business travel predicted by some experts as companies experience the possibilities of videoconferencing and an economic downturn forces some to forego spending on flights.

Finally, in the days in which FlyingLess was putting together this update, Boeing, the world’s largest manufacturer of commercial aircraft, announced that it would layoff 10 percent of its workforce—over 12,000 employees—in a first round of cuts related to the coronavirus-related downturn. And American Airlines and Delta Airlines announced that they were offering buyouts to employees given their expectation that it will take years for the industry to reach its pre-coronavirus levels.

Regardless of what transpires in light of such developments, the necessity of working to ensure a massive, long-term decrease in flying is as urgent as ever. A new article in the Proceedings of the National Academy of Sciences is one manifestation as to why.

Published by a team of five scientists, the study finds that, if present trends in regard to greenhouse gas emissions continue, one third of the world’s population—about 3.5 billion people—could be residing in regions with temperatures inhospitable to human life in the next 50 years. The study foresees a mean annual temperature of 29 degrees celsius (84 F) in the affected regions, a “terrifying“ outcome according to Nathan Sayre, a geographer at the University of California, Berkeley, “Those places are more or less uninhabitable, let alone arable.”

In the face of such findings, flying markedly less is not a question for academia to debate, but a goal for the academy to achieve.

Of course, as writer George Monbiot points out, flying and, more broadly, traveling less are necessary in the face of the climate crisis, but not sufficient. Broader structural change is needed as well. So, to quote Monbiot, “let’s have what many people were calling for long before this disaster hit: a green new deal. But please let’s stop describing it as a stimulus package. We have stimulated consumption too much over the past century, which is why we face environmental disaster. Let us call it a survival package, whose purpose is to provide incomes, distribute wealth and avoid catastrophe, without stoking perpetual economic growth. Bail out the people, not the corporations. Bail out the living world, not its destroyers. Let’s not waste our second chance.”

Recent academic articles, reports, and essays

To remedy the gap between what academics know about the climate impacts of their professional flying and what they do in response, James Higham (University of Otago) and Xavier Font (University of Surrey) contend that scholars must call into question ““our own long-standing and deeply entrenched travel behaviours.” Academics find it difficult to do so, they say, because of a tendency to “morally disengage from the significance of our impacts and exonerate ourselves with worthy causes.” As a result, “we absolve ourselves from personal responsibility.” However, because “participation in the high-carbon air travel regime is a social convention,” individual sacrifice will not suffice. Thus, coordination among policymakers is needed. In the end, the authors suggest four steps for realizing “a different way of doing our jobs”: 1) auditing of carbon footprints within the academy, particularly at the departmental level; 2) raising consciousness regarding necessity of regulating academia’s climate impacts and setting up standards for determining when flying is appropriate; 3) public sharing of the resulting policy changes; and 4) developing systems to facilitate low-co2-emitting ways for academics to do their jobs effectively and efficiently. (See James Higham & Xavier Font (2020) Decarbonising academia: confronting our climate hypocrisy, Journal of Sustainable Tourism, 28:1, 1-9, DOI: 10.1080/09669582.2019.1695132)

Because Sweden has emerged as an epicenter of activity aimed at decreasing air travel, a quartet of researchers interviewed Swedish residents, largely those who have reduced their flying, to understand what brought about the shift in behavior. The team, led by Lisa Jacobson, finds that, while knowledge of climate change is essential, it must be coupled with an emotional internalization of such knowledge. However, given how “entangled in the knot of habits, norms and structures promoting air travel” many people are, large-scale change requires greater support from the political sphere (particularly the state). “This could be a combination of improving travel alternatives, e.g., better train infrastructure and economic and regulatory policy instruments promoting cleaner alternatives, as well as improved climate communication and education to change social norms.” What the authors call “moral entrepreneurs”—those who stop or reduce flying absent such political support—may play a significant role in bringing about the needed shift in norms and values. (See Lisa Jacobson, Jonas Ackerman, Matteo Giusti, and Avit K. Bhowmilk, “Tipping to Staying on the Ground: Internalized Knowledge of Climate Change Crucial for Transformed Air Travel Behavior,” Sustainability 2020, 12, 1994.)

A key tension at the heart of most universities in high-income countries is the effort to enhance sustainability—to reduce their ecological impact—and to increase internationalization (for reasons of prestige and financial income). Sanna Barrineau and Keri Facer of Uppsala University explore this tension “to identify inspirations and examples that might constitute gestures towards sustainable internationalisation.” The authors thus provide an overview of innovative efforts from various countries to deploy technology to “green” conference-going, to shift academic culture, and to “decolonize” curricula. Thereafter, the authors report on a workshop at their own institution focused on rethinking sustainability and internationalization so that they complement one another; the goal was to envision what an ideal Uppsala University would look like in 2030. Participants then engaged in an exercise of “backcasting” aimed at identifying concrete steps, which the report outlines, to achieve that vision. (See Sanna Barrineau and Keri Facer, “Sustainability & Internationalisation Agendas in the University: How can they support each other?” report for the Zennström Climate Change Leadership Initiative, November 2019, 10 pp.)

In April, a team of 17 researchers led by Alberto Sanz-Cobena (El Centro de Estudios e Investigación para la Gestión de Riesgos Agrarios y Medioambientales in Madrid) published an article titled “Research Meetings Must Be More Sustainable” in Nature Foods (Vol. 1, 187-189). Calling flying “the most contradictory choice that sustainability researchers make,” the authors point out that aviation has received the most scrutiny by scholars, which has facilitated the diversion of “attention away from other anthropogenic drivers of environmental degradation.” Of particular concern to the authors is the nitrogen “foodprint” of conferences. As such they call for the prioritization of plant-based meals. This is one of twelve points that make up the Cercedilla Manifesto, which aims to enhance the “sustainability dimensions’ of scientific meetings. The manifesto “starts with the definition of whether a physical, remote or hybrid meeting is most appropriate … and ends with an evaluation of the meeting’s environmental impact and lessons learned for the next Meeting.” To read and/or sign the manifesto, go here.

To defend the human rights of all people, Richard Parncutt (University of Graz) seeks to measure the relationship between fossil fuel consumption and future deaths attributable to the resulting greenhouse gas emissions. Given the socially uneven impacts of these emissions, the author characterizes emissions as ageist, racist, and sexist. To illuminate this, the author develops, via a thorough analysis that acknowledges statistical uncertainty, the “1,000 tonne rule”: the burning of roughly one thousand tons of carbon-based fuels (which creates about 3,700 tons of co2 emissions) leads to the death of one future human being. Among the concrete examples he offers is that involving four long flights by passenger aircraft, which together lead, on average, to the premature death of one person. For this reason, he states, “flying should be made more expensive (e.g. by carbon taxes) and reserved for emergencies and life-saving projects.” More broadly, the 1,000-ton rule illustrates the need to center human rights in discussions of climate change and the transition to a post-fossil-fuel world. (See Richard Parncutt, “The Human Cost of Anthropogenic Global Warming: Semi-Quantitative Prediction and the 1,000-Tonne Rule,” Frontiers in Psychology, 2019, doi: 10.3389/fpsyg.2019.02323)

Three researchers at the School of Earth and Environment at the University of Leeds have published a study which provides new insights into the inequities associated with income and energy consumption. Via a survey of the energy embodied in privatized goods and services consumed across income groups in 86 countries that centers intra- and international inequalities, the authors find that energy inequality exists in all consumption categories. The inequality is so pronounced that the bottom 50% or the world’s population consumes less than the top 5 percent. Transport, however, is among the most unequal. The top 10% of the world’s population consumes about 55% of mobility-related energy—187 times more than that consumed by the bottom 10%. This speaks to how, as people become wealthier, they spend more on transport—and energy-intensive goods more broadly (e.g. vacations abroad). As a result, the energy gap increases to a greater degree than the income gap. (See Yannick Oswald, Anne Owen, and Julia Steinberger, “Large inequality in international and intranational energy footprints between income groups and across consumption categories,” Nature Energy, Vol. 5, March 2020: 231-239.)

The impacts of air pollution, and from emissions associated with ground transportation in particular, on premature births and other adverse birth outcomes is well established. Newly published research fills a gap in the literature by focusing on the effects of aircraft emissions with a focus on nano- or ultrafine particles from jet engines. Through a study of the birth records of 174,186 mothers who gave birth between 2008 and 2016 residing within 15 kilometers of Los Angeles International Airport, a team of six researchers found the aircraft emissions play an “etiologic” or causal role in preterm births. (See Sam E. Wing, Timothy V. Larson, Neelakshi Hudda, Sarunporn Boonyarattaphan, Scott Fruin, and Beate Ritz, “Preterm Birth among Infants Exposed to in Utero Ultrafine Particles from Aircraft Emissions,” Environmental Health Perspectives, Vol. 128, No. 4, April 2020.)

With an intended audience of scientists and conservationists—”often among the most frequent of flyers”—a group of six researchers illustrate the co2 impact of flying on Arctic sea ice and polar bear habitat. Using the example of researchers flying from Copenhagen to Oslo for a polar bear meeting, the authors point out that each passenger is responsible for 1 m2 of Artic summer sea-ice melt resulting in several hundred square meters for all the attendees. With one metric ton of CO 2 emissions melting 3 square meters of Arctic summer sea-ice, the authors estimate that the world’s flight passengers together melt 5470 km2 sea-ice each year—a landmass equivalent to Trinidad and Tobago or 1.35 million soccer fields. Such melting explains why the world’s polar bear population is severely threatened. The authors call for webinars and videoconferences to replace gatherings involving flying and ask Artic researchers to “think twice about conducting fieldwork.” (See Christian Sonne, Aage K.O. Alstrup, Rune Dietz, Yong Sik Ok, Tomasz Maciej Ciesielski, Bjørn Munro Jenssen, “Aviation, melting sea-ice and polar bears,” Environment International, Vol. 133, Part B, December 2019, 105279.)

In an opinion piece for the blog of The BMJ, one of the world’s oldest and most important medical journals, former editor Richard Smith confesses to his frequent flying (which has included crossing the Atlantic some 300 times and travelling to Madrid for lunch). He also announces that, because of the climate emergency, he has stopped flying—except when he goes from London to Mexico to see his son, daughter in law, and grandchildren. In the end, he writes, “Those organising—and those funding—every meeting should ask if the meeting has to take place face to face. My assertion is that the majority could be conducted electronically without anybody needing to fly anywhere. We have to change how we think about meetings just as we have to change how we think about everything. Disaster is close.” (See Richard Smith, “Most Meetings Can Happen Electronically, Saving Tonnes of Carbon,” thebmjopinion, December 31, 2019.)

New Initiatives



In March, the Environmental Association for Universities and Colleges (EAUC)—the self-described “sustainability champion for universities and colleges” in the United Kingdom—launched the “Travel Better Package.” One of the initiative’s key aims is to reduce air travel in higher education, “specifically amongst academics and staff.” Another is to encourage individuals to be “more knowledgeable about sustainable travel, actively choose sustainable travel options and encourage others to do the same.” Developed by Sonya Peres, the package includes three documents: a “travel better” pledge for institutions and individuals; a question and answer tool for addressing concerns that individuals may have about reducing flying; and a decision tree to help guide reflections on attendance of a conference, meeting and/or event to which one can travel only by flying.