The climate crisis is a major issue requiring immediate and far-reaching action. This action cannot be limited to individual action, and requires major political changes, e.g., to give more people the means to act. However, I believe that individual action, while not a complete solution, is a necessity despite its small marginal impact: it is psychologically more satisfying than inaction, it helps proving to oneself and others that you are taking the problem seriously, and it can inspire others to act.

Of course, the climate crisis isn't the only environmental problem requiring widespread action. There are other environmental issues, e.g., biodiversity. I mostly focus on the climate crisis, for several reasons: it is a worldwide problem (so cannot be fixed by local solutions), with specific consequences (that have been estimated in detail), a very definite timeframe, and clear trajectories for action. Further, there are other important causes, e.g., fighting poverty and inequalities; I also take action for these, but do not cover this on this page.

I document on this page my individual actions against the climate crisis. My main reason to list them publicly is to encourage others to act, e.g., so that other people who would like to take action do not feel isolated. I hope it also helps giving a sense of urgency to the issue.

Commitments

I list here the current actions that I am taking to address the climate crisis. I distinguish:

This list describes what I currently do: I may end up changing it, or maybe giving up on some of these.

Firm changes

These are changes with a clear description, as opposed to more gradual change (e.g., "buying less clothes"). I believe that firm changes are important for several reasons:

I try to prioritize these commitments by their numerical impact, i.e., what actually matters in terms of my emissions. My point is not to say that smaller steps (e.g., turning off the lights) do not have value. However, I think it is important to distinguish large changes vs marginal changes in numerical terms, and focus on the large ones in possible (i.e., do not be penny-wise but pound-foolish with respect to emissions).

No plane travel for short trips (since 2020)

Since 2020, I refuse to use plane travel for short trips (less than 2 weeks). In particular, I do not fly to academic conferences or short research visits.

I list below the plane trips that I have nevertheless taken since 2020, for professional or leisure reasons:

Instead of plane travel, I travel by other means of transportation when possible (e.g., by train); or give up on travel altogether.

This commitment will allow me to meet the TCS4F goal of reducing my professional emissions by 50% relative to pre-2020 levels. Indeed, compared to my pre-2019 travel habits (in particular professional travel), this probably saves several tons of CO2-equivalent emissions per year, see this post.

No reviewing for conferences with formal proceedings that require in-person travel (since 2023)

Since 2023, I refuse to review (or be otherwise involved in the organization) for conferences with formal proceedings that require authors to attend in-person. When conferences have formal proceedings (in which it is prestigious to publish), then I believe submission to these proceedings must be explicitly open to everyone, no matter whether they can or want to attend the conference. (I think the simplest option is to simply not require absent authors to give a presentation, but another option is to involve them with remote talks, prerecorded talks, etc.) Further, the selection of accepted papers should not depend on whether authors intend to present in-person or not, in particular the information should not be available to reviewers.

Rationale: I think that conferences with formal proceedings are an awkward mix between a publishing venue and a way for researchers to network. (And, in practice, the publication process in many prestigious conferences already works a lot like a journal.) Further, I suspect that many if not most conference authors submit because they want to publish their work and not really attend the conference. Indeed: if authors had to choose between attending the conference and getting their paper formally published in the proceedings, I'm sure the second option would be more popular. (This is also illustrated by the comparatively small number of people who attend conferences without having a paper, contrasted with the success of events without proceedings such as Highlights.)

I think the common practice of requiring in-person attendance to conferences is problematic for two reasons: because it excludes some potential authors, and also because it encourages plane travel (which is the relevant point for this page). See here for more information about my position on mandatory attendance. In any case, as a reviewer, I am not interested in evaluating submissions from a pool from which some authors have been excluded in advance for non-scientific reasons, i.e., because in-person attendance was required (or not explicitly advertised as optional).

I realize that mandatory in-person attendance can have some indirect benefits: ensuring a critical mass for the in-person event, making it easier for researchers to ask for funding to attend, making it easier for people with childcare responsibilities (i.e., mostly women) to justify their trip, etc. Still, I think that the harms of mandatory attendance outweigh its benefits.

This point does not apply to in-person events with no proceedings attached (e.g., Highlights, invitation-only meetings without proceedings, etc.). While such meetings still encourage plane travel, I think that some balance must be found here between their scientific value and their carbon footprint. This is a separate question from the no-brainer point that people who want to publish a paper in conference proceedings should only travel if they actually want to attend.

This point is similar to my reviewing boycott on closed-access venues and the same FAQ applies. In particular, I do not think it is problematic to submit papers to conferences for which I refuse to review (especially at the insistence of collaborators). I also do not think that it matters whether I can personally attend the conference in-person or not, i.e., I think mandatory travel is a problem even if I can travel to the conference without flying.

(Ovo/Lacto)-vegetarianism (since 2022)

Since 2022, I refuse to eat meat and fish1.

This saves hundreds of kilograms of CO2-equivalent emissions per year (source).

No car ownership (since forever)

I do not own a car, or drive cars. (This is a non-issue as I currently live in a large European city with a good public transport offer.)

Compared to a baseline, e.g., of driving to work daily, this saves hundreds of kilograms of CO2-equivalent emissions per year, not counting the emissions of producing the car.

Here are soft ways in which I am trying to reduce my environmental impact:

Efforts

I list here things that I am concretely doing to help fight the climate crisis by moving things in the right direction:

Signatures

Here are some pledges run by other people that I have signed to express support:

Other researchers with visible involvement

Some other academic researchers also visibly display their commitments; some of them were an inspiration for this page:

  1. Of course I have eaten meat accidentally on some occasions, i.e., food prepared/served by other people which later turned out to contain meat. I also neglect hidden ingredients, e.g., rennet in some cheeses, isinglass in some drinks, gelatin in some desserts, fries that may be fried in animal fat; and other traces, e.g., food cooked together with meat, etc. ↩

  2. A word of warning: the notion of individual carbon footprint is not politically neutral, and can legitimately be described as a way to ascribe the responsibility of carbon emissions to individuals, as opposed to collectives, e.g., large companies, states, etc. It is not obvious that emissions should be ascribed to consumers: they could also be allocated to the people owning the stock of companies that produce the goods, or to the companies that are extracting the fossil fuels that are burned. I believe that these means of action are complementary, and limiting your individual footprint is a good step (and at least one that you can actually take); but again this should not mean that this is the right solution. ↩

  3. Vinted is not an especially virtuous company, and it is for-profit; but I am not aware of a well-known alternative. I would be happy to switch to one if I found one. ↩

  4. It is debatable whether organic food is in itself a step in the right direction for the climate crisis or for the environment in general: see for instance this Youtube video. What is more important for me is the fair trade certification (although not directly related to the climate crisis), and/or buying from small brands or shops, if possible run as a cooperative. Regarding organic food, my impression is that it is helpful to encourage food producers who are trying to adapt their practices to be friendlier to the environment (in particular biodiversity) instead of maximizing profit, even though I do not agree so much with the specific adjustments that they are making. ↩

  5. To me the main appeal of Enercoop is that it is a cooperative, and trying to fund and encourage renewable electricity producers. The market for "green electricity" is dubious in many ways (see this video by "Le Réveilleur" (in French)) but financing a cooperative who is trying to directly fund renewable producers seems like a good idea. ↩