Even though 2021 will be virtual, let’s think of the future

While MobileHCI’21 will be held virtually, we are committed to make the conference as sustainable as possible. Based on the actions already taken during previous conferences, our goals are to go one step further. In this blog post, we summary our thoughts on a greener conference either virtual or physical.

Don’t be afraid but be aware…

Conferences are great to meet people but they obviously have an impact on the planet.

However the community is taking action! Since 2019, SIGCHI conferences include Sustainability Chairs into their program committee. We are thrilled to continue the trend with MobileHCI’21! We are not seeking perfection (yet 😉), but to do steps in the right direction. As a thought exercise we tried to estimate what a conference like MobileHCI held physically in Toulouse would look like. Based on MobileHCI 2018 attendance numbers in Barcelona (closest city that hosted MobileHCI in the last few years), and with an estimation of 300 attendees at MobileHCI 2021, the conference in Toulouse would yield around 575.000kg of CO2 emission just for the travels of its participants. Which is roughly equivalent to the electric consumption of 540 UK households in a year. Offsetting these carbon emissions would require planting around 3830 trees.

Numbers used for the calculation:

  • Based on MobileHCI’18 participation, we took the same country distribution. For each country we computed the carbon emission of a round-trip flight from the capital city to Toulouse using the following {carbon calculator}. We reached a total of 574,544.4 kg of CO2.
  • We used the following kg of CO2 to kWh {converter}, based on UK power stations (0.28307 kg of CO2 per kWh), and reached a total of 2,029,690.2 kWh.
  • The annual electric consumption of a household used is around 3760 kWh, based on the UK 2017 average, for a total of 539.8 households.
  • A tree stores roughly 150 kg of CO2 across a 30 years period. We used this figure for a total of 3,830.3 trees.

Whether held physically or virtually the carbon footprint of a conference is not limited to the days of the conference. There are other costs that enter the mix. For instance, the use of servers to store and process submissions to the conference. This year the cost was about 2100kg of CO2 emission. Which is roughly equivalent to the electric consumption of 2 UK households in a year. Offsetting these carbon emissions would require planting around 12 trees.

Numbers used for the calculation:

  • Based on PCS data for MobileHCI’21, the conference footprint on their server is 8.79Go.
  • A typical server uses two 500W power supplies to accommodate 16 storage bays of 500Go each. So for an hour of functioning, a server yields an electric consumption of 2x500kWh. Or a consumption of 0.125kWh / Go.
  • PCS servers are provided by OVH which has a Power Usage Effectiveness {PUE} of 1.2 or less. Which means that for every kWh required for the functioning of the server, 0.2kWh are used by the data center facility.
  • MobileHCI’21 submission deadline was on February 4th which is 236 days prior to the conference. So assuming all the PCS data was uploaded at once on February 4th and kept up to September 27th (which is highly underestimated), servers for MobileHCI’21 consumed 236 days x 24h x 8.79Go x 0.125kWh / Go x 1.2 (PUE) ≈ 7 468,0 kWh, or 1 741,1 kg of CO2 {converter}.
  • Which (using the previous CO2 and electric consumption data) is equivalent to the annual electric consumption of 2 households, or 12 trees.

Our approach

We built upon what UIST’19, IHM’19, CHI’19 and CHI’20 have done or intended to do. We are trying to be as transparent as possible by documenting what we do. All details are or will be provided. Our goal is that other conferences from the HCI community can benefit from it.

One last thing! Feel free to re-use this webpage and build upon. The text and the documents we use are or will be freely available. If you want to contribute, you are more than welcome to contact us. We hope this might help future conference chairs, or anyone that needs to take actions in event organization, for instance as a list of items to look at. We will use the following symbols when points apply to virtual (☁️) or physical conferences (🏫).

Contacting previous Sustainability Chairs (☁️ and 🏫)

Let’s start with the obvious. In order to prepare our plan, we started by looking at what previous conferences had done, as well as the sustainability statement written by our General Chairs for their conference proposal. We then contacted the different Sustainability Chairs of the past conferences for more details (CHI 2019, UIST 2019, IHM 2019 and UIST 2020).

Carbon footprint (☁️ and 🏫)

Our general goal is to reduce the carbon footprint of the conferences. However it should not be at the expense of the conference attendance. We therefore aim to undertake sustainable actions in order to balance out the carbon produce, by either directly cutting through the emissions or offsetting them through tree planting programs (such as local or more global ones), following CHI 2019 and IHM 2019 examples.

Fully virtual Program Committee meeting (☁️ and 🏫)

As CHI, our community flagship conference, the Mobile HCI 2021 general and paper chairs have decided to hold a fully virtual Program Committee. Although difficult to organize, this is a critical decision that greatly helps reduce carbon emissions. Less flights. Less is more.

Public Transport (🏫)

Going downtown from the airport can be done by taking public transport (tram). The city has two subway lines. For short distances, a bike rental service is also available (the first 30 minutes are free), more information can be found on the Toulouse official website. In general, most places are at walking distance and clustered within the downtown area (hotels, restaurants, conference center).

Food (🏫)

During the conference, we will aim at providing healthy, local and ethical food. We are aware this is a tricky subject and therefore with the will to satisfy all participants, from meat lovers to vegan lovers, we decided to compromise. We had the intention to propose a meat option with a low carbon footprint (meat produced locally) as well as vegetarian and vegan options. To reduce plastic bottles, water fountains should be available at the conference center and the caterer should reusable cutlery.

Badges (🏫)

To further reduce plastic waste, we can build upon UIST 2019’s idea to replace plastic badge holders into paper ones, and use a design inspired from the original template. Based on UIST team feedback, this design can be adapted and refined, and why not, manufactured as part of a “Maker” design course. Badges would have the same features as conventional badges but would be degradable and locally made from certified recycled paper.

Ideas and text adapted from UIST 2019 (Alexandra Ion, Nicholas Chen & Kristin Williams)

Bags and Goodies (🏫)

As many conferences before, we seek to drastically reduce and ideally eliminate promotional items, so-called “swag”. Virtual or not, you will not have received a conference bag at MobileHCI this year. The reasoning is simple: if there is no container for putting “stuff” in, there will be no “stuff”. Ask your sponsors, they may well be very supportive of this push towards sustainability. If you feel that you need a conference bag, consider packing one of the durable tote bags from past conferences. This can even serve as a good conversation starter.

Luckily a trend started in previous conferences moving away from objects and towards experiences. Experiences can include vouchers for local traditional food items, vouchers for local bike rental services, tickets to events like museums, etc. Similar to experiences, supporting a cause can be a valuable gift. This might include contributions to carbon offsetting, or to charity such as local homeless shelters, food banks, etc. Such sponsored experiences and charity might leave an even more memorable impression, compared to pens or flyers, while producing virtually no waste.

We could consider re-usable items such as eco cups, mugs or water bottles. Re-usable is often quickly better than disposable. However, multiplying these types of promotional items dilute their benefits. The best move? Not providing one, but instead providing glass containers at breaks that are brought by the caterer and that will be re-used for sure.

Although we do push for a reduction of promotional items, we do support sponsors in promoting their investment in our conference. The community has researched ideas and recommendations for sustainable promotion, including sources such as this guide.

Ideas and text adapted from UIST 2019 & 2020 (Ion Alexandra, Nicholas Chen, Kristin Williams & Christopher Clarke)

Conference centre (🏫)

Following CHI 2020, we will look at the use of AC in the conference building. We will be in control of the AC thermostat, which allows us to drop the conference room temperatures by a few degrees.

We will also avoid using conference center screens (which will therefore be turned off during the conference) and will prefer using a control number of printed papers and SV hours to help participants navigate between the rooms.

Reducing web traffic (☁️ and 🏫)

Loading a web page generates carbon emissions due to data exchanges happening between the server and the client. Using Website Carbon Calculator you can estimate your web page carbon footprint. In an attempt to minimize our footprint, our web chairs (kudos to Emeline Brulé & Katta Spiel) developed the MobileHCI 2021 website using Grav, a flat file lightweight CMS, and customize it to reduce the file size to only what’s needed, which results in pretty much no javascript. Another benefit is long term sustainability helping the maintenance from one organizing committee to the next.

To go further, when possible, images from the website are stored in a vectorial formal (svg) rather than bitmap formats (png, jpeg, …). When bitmaps are required, we downgraded image resolutions to the minimum resolution required. For instance, if images are displayed as 100px per 100px squares, we match the corresponding image file resolution to a 100px per 100px.

Numerous guides exist to help authors create video figures and/or video presentations of their work (for instance the CHI 2020 guide for video figures and the Medium SIGCHI guide for remote presentations). However we would like to complete those guidelines with a final step aiming at compressing the different videos. This step can collectively make a huge difference if all videos are compressed from (typically around) 200MB to few dozens of MB. It will play out at every re-upload but more importantly every download or youtube view! Here are some tools that can be used:

  • ffmpeg: to compress videos with with reasonable bitrates (around 1.5Mbps for the video chanel and 128kbps for the audio one), you can use the following command: ffmpeg -i originalvideo.mp4 -c:v libx264 -b:v 1.5M -c:a aac -b:a 128k outputvideo.mp4
  • Handbrake: free software that helps you convert and compress videos.

Symbolic gestures, we organizers, tried to follow (☁️ and 🏫)

We provided a list of symbolic gestures to the organizers. Our goal was not to have every member adopting them but rather encouraging them to give a shot at developing new habits that may stick. Feel free to make some of the following yours!

  1. Reducing our use of video stream during remote meetings.
  2. Favouring instant messages over emails for internal communication.
  3. Reducing the size of our emails (eg. deleting previous mails content while replying).
  4. Typing URLs directly instead of searching for them.