We are deeply concerned about how much flight traffic is caused by us - machine learners and, more generally, (data) scientists who should understand the dangers of climate change. Although we acknowledge that scientific exchange is difficult without traveling, we believe that video conferences - if set up properly - could become an increasingly important replacement. By streaming talks, some conferences already offer the opportunity to follow remotely. However, usually it is strictly required that authors present their work via physical attendance. Especially in machine learning, where conferences play an important role in scientific communication and careers, young scientists cannot realistically choose not to publish at the main venues, "just" because they are too far away.

We therefore ask all conferences, in particular all machine learning conferences (NeurIPS, ICML, AISTATS, ICLR, UAI, ...), to introduce the option of presenting papers or posters remotely, so that anyone be free to decide in his or her own conscience, whether the benefits of attending on site outweigh the negative consequences of the trip - both for climate and for family life. The implementation of these measures should ensure that presenting remotely actually does reduce conference emissions.

We understand that it is challenging to make remote presentations a positive experience for both the presenter and the audience, but we believe that this is possible with state-of-the-art technology. Posters could, for instance, get printed and hung up by the organizers, with a QR-code to log into a video session with the remote authors. In the long run, conferences should also promote more mature modes of tele-presence to address the other benefits that a researcher would be giving up by not attending in person (e.g. networking). If we, computer scientists, don't take the lead and show how modern communication systems can efficiently organize scientific exchange with less transportation, who will?

To stay below a 2 degree increase in temperature (the upper limit of the Paris agreement), world wide emissions must be steadily cut by roughly 3 in 30 years (i.e. 4% a year) [1,2] down to an average of 2-3 tCO2eq/person [3]. Today, one inter-continental round trip is typically once or twice that amount (2-5 tCO2eq [4]). We therefore support ongoing initiatives such as conferences offsetting their emissions by buying emission certificates or (better) organizing localized events on each continent to reduce travel distances and allow travel by train. We encourage all future conference organizers to follow these examples and actively develop, test and promote new incentives and strategies that both drastically reduce the overall CO2 impact of our conferences and remain fair to those living far from the typical conference locations.

C.-J. Simon-Gabriel, D. Janzing, N. Lawrence, B. Schölkopf, Y. Bengio, and the petitioners

[1] IPCC 2014, Summary for Policy Makers, SPM 3.4 & Table SPM.1.

[2] UN Emissions Gap Report 2019, Executive Summary, Figure ES.4.

[3] Assumes constant world population.

[4] See e.g. the flight emission calculator on atmosfair.de/en