Let's make Devcon6 carbon neutral! A step towards implementing DIP-1/DIP-12

We’d love to make Devcon6 carbon neutral and take a step towards implementing DIP-1 and DIP-12!

This DIP would allow event participants to make a voluntary contribution to offsetting Devcon6 via external tooling. This would provide us with feedback for the subsequent implementation within Devcon’s ticketing system as proposed in DIP-1 (Accepted, @raphabenoi) and allow us to explore the community’s appetite to participate in the choice of carbon offset project to use (DIP-12, Draft, @raphabenoi, @lightclient).

Here’s the previous forum discussion.

We’re looking forward to your input!
danceratopz and haurog (Dan and Roger)


Hi @danceratopz
Thanks for the clarification on Github!

We’d love you to bring this idea further. :slight_smile:

We will find a good way to promote this amongst the Devcon attendees (for example, at the entrance when they receive their wristbands). And/or with a stand where you can explain details about the offsetting.

Do you need anything at the moment from the Devcon team?
Don’t hesitate to ask if you face impediments or have questions.


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Hey @Rose, wow great news, thanks, we’re really happy to have your support. Generally, I think we’re all set to go, we’ve been working on generic emission offset tooling and will start implementing the Devcon specific parts soon.

I just wanted to clarify if Devcon (or perhaps the EF?) are willing to potentially provide the funds that could not be sourced from the community in order to make the whole event carbon neutral? This is our current suggestion in the DIP :sweat_smile:. During initial chats with @wslyvh, we briefly discussed that Devcon could potentially match attendee contributions, but we didn’t talk about this option (currently outlined in the DIP). We don’t need to decide this upfront, of course, but just before any communication to attendees about the process is made.

Best, Dan

Hi @danceratopz

Cool! good to hear you’re all set to go.

It would be great to know beforehand how you will estimate the carbon footprint and the offsetting amount. And also, what the offsetting will look like.
Please feel free to share more info here in the Forum :slight_smile:


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Hmmm… I’m not sure how this works. The DIPs were interesting, though I just read them. We also have event footprint calculators that issue carbon offsetting NFTs. They can be configured and installed in a matter of minutes. We also have carbon offset projects in Colombia (Pacific Coast REDD+ and Cartagena Mangrove Restoration). We’d love to make these great projects available.

We can also provide a calculator for flights so all attendees can measure their footprint for their flight and hotel at the event and offset that too. It can all be tracked so we see the total offsets for all the DEVCON participants.

Finally, I can bring a sponsor to offset the event portion of the carbon (i.e. not the flights of people attending).

To calculate the event footprint we need a bit of data:
Venue Size (mt2)
Number of meals served
Food Types (i.e. what % of food is vegetarian)
Number of attendees

We can then set up a unique DEVCON Carbon NFT that people can collect each of which represents their contribution to offsetting the events footprint.

Tom (Tom@meta-carbon.com)

Tom, great that you want to help make this happen! Your tools and experience could be very helpful.

With regards to the infrastructure and tooling, DIP-17 proposes:

  1. To use NCT or BCT tokens for carbon retirement.
  2. To implement public goods that: Perform carbon emission offset calculations; allow attendees to use these tools and make a contribution to the event offset; and for the Devcon organizers to perform the actual credit retirement.
  3. To issue contributors with POAPs that also act as a voting token for choice of the offset project to retire the tokens from.

Apart from trying to stay as close to DIP-1 (approved by the community) as possible, our reasoning for this is as following:

  1. We want to tap into transparent, verifiable on-chain carbon markets with large liquidity. At the moment only BCT and the more nature focused NCT pools fulfill this. The Toucan Bridge allows anyone to tokenize carbon credits and makes them fully available on-chain. The bridged carbon credits from various projects are then pooled by type into the BCT and NCT pools allowing a liquid fungible on-chain market for carbon credits. During the retirement of the carbon credit one can then choose which project to support.
  2. We are developing open source offsetting tools that build on these on-chain carbon credits. As public goods, these tools will be available to subsequent Devcon events. As these tools use on-chain carbon credits, participation is also tracked on-chain. There’s more clarification on the scope of this tooling in DIP-17’s PR discussion.
  3. POAP is also a public good and a common way within the community to acknowledge event participation (they’re being used for the experimental Devcon6 ticket raffle, for example). They will also serve as a prerequisite to participate in the subsequent Snapshot vote to vote on the exact choice carbon offset project.

With regards to a flight emission calculator, we recently deployed an emissions estimator where Polygon users can offset their flights fully on-chain. You can find our beta version here:

The frontend is open source and uses the methodology from myclimate.org. We’ve cross-checked the results against other estimation methodologies but would be very happy for any input you have Currently, it “auto”-redeems NCT pool tokens, meaning it takes the oldest nature-based project from Toucan’s NCT pool. At the moment this is a REDD+ project in Congo. In the future, users will be able to pick exactly which offset project to retire credits from.

Tom, your projects look good! The Toucan NCT pool does have many projects in the pool. One project is from Colombia:

so the community can already choose from a wide range of projects. Once Verra have decided on their process for on-chain carbon credits, it will be possible to bridge even more Colombian projects.

Sponsorship for the event part of the emissions could be nice, but I think that’s rather a topic for the Devcon team to give their thoughts on.

Your advice for the event estimation is welcome! As @Rose mentioned, it would be good to provide an estimate before the event up front, using, for example, the input event parameters that you mentioned. Then I think there should be two aspects:

  1. Trying to adjust event parameters in order to reduce emissions generated by the event (if still possible, but definitely for future events).
  2. Offsetting what can not be further reduced.

DIP-1 already has a rough estimation of the carbon emission. It looks a bit low to me, but is definitely a good starting point for a more detailed analysis.

Looking forward to hearing your input, Tom, and the input from the rest of the community.

haurog and Dan

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your flight calculator looks good. Thanks for sharing. I’d love to talk further. Where are you located? Can we connect on linkedin? www.linkedin.com/in/tomherman


Hi @Rose

Thanks for the support. As one of the DIP-17 authors I will try to clarify the steps needed for the calculation and offsetting:

As soon as the parameters for the event are known by the Devcon team, we can provide you with a detailed list of of needed inputs (number of participants, available space etc.) you can forward them to us and any interested party and we will estimate the carbon emission for the conference itself. This is by far not an accurate science and we are therefore very happy for other experienced people to also chime in so we can converge on a number.
The total emission is then divided by the number of attendees to get the pure event emission per participant (per day).

The offsetting itself comprises of the following steps:

  1. Each attendee is directed to a dapp (website) where they can fill in their departure location to calculate the additional emission from their air travel. Together with the emission for the conference for each attendee (calculated above) times the number of days they attend they will get a price to offset their emission.
  2. They then initiate an on-chain transaction on the polygon chain to buy the necessary NCT token, each representing 1 ton of carbon, which then get forwarded to an account controlled by the Devcon team on the polygon chain (Gnosis Multisig?).
  3. Each offset participant can vote on which carbon capture project should be supported. There are a wide variety of projects from around the world in the NCT pool to choose from.
  4. At the end of the vote, the Devcon team can go to another dapp and initiate a transaction on polygon to offset the Devcon event. This results in an transparent verifiable on-chain transaction to prove to anyone that Devcon did offset a given amount of carbon.

The only parties involved in the transactions are the attendees and the devcon team otherwise it is purely smart contract based. This whole process is also an experiment to gauge the interest for each attendee to participate in such a offset pooling event. In parallel we can do an internal calculation to estimate the offsets by knowing how many participants come from which country to also see if we actually reached the goal of offsetting Devcon6.

The Devcon organizer can also choose for example to add a certain amount of NCT tokens to then reach the offsetting goal or even go further and add more tokens to offset even previous events.

We expect the cost for most participant to be in the range of 10-20 USD as the current on chain market price is between 3 and 4 USD per ton of carbon and they will have to offset about 3-5 tons. Participants from southeast Asia will have to offset the most (5-8 tons of carbon) and are therefore expected to have to pay in the range of 20-30 USD.

I want to emphasize, that we (Dan and me) are not adding any fee to any of these transactions for offsetting this event. We have applied for a developer grant (still pending) from Toucan which built the carbon bridge, but we are otherwise not associated with them. Our goal is to provide public goods for crypto natives to access carbon credits at market price and therefore reducing friction. This will hopefully encourage more people to use transparent, verifiable on-chain carbon retirements in their everyday life.

If there are more points which need clarification please feel free to ask as I might have overlooked some of the finer points in my answer.


Glad you like the flight offsetter, Tom. Feel free to DM either of us through the forum or just chime in here with any input you have for the DIP!

Hi @haurog and @danceratopz

Thank you so much for the detailed explanation!

We are curious about the NTC token. Can you maybe explain a bit more about its usage and what it means that each represents 1 ton of carbon?

We really like the idea of ​verifiable on-chain carbon offsetting, and we think it’s great to give this option to the attendees. Nonetheless, we think it’s important that it remains a voluntary option for everyone. :slight_smile:

Devcon can help to promote this possibility, but unfortunately cannot commit to offsetting the remaining amount of carbon at the moment.

Please feel free to send us the list of needed inputs!


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Hi @Rose

Thanks for reading our rather long posts :slight_smile:

We will prepare the list of the needed event emission estimation parameters and post them here next week.

Regarding the NCT token: In short, one NCT token represents 1 tonne of carbon dioxide removed from or not emitted into the atmosphere. As they represent removed or mitigated C02 these tokens can be used to offset ones own carbon emissions. NCT tokens are part of Toucan Protocol’s smart contract infrastructure. The tokens originate from the main off-chain carbon credit registry (the Verra Registry, in which approximately 75% of the world’s carbon credits are created and tracked) and are moved on-chain (to Polygon) via the Toucan Bridge.

To go into more detail (to the best of our understanding): In the traditional (off-chain) voluntary carbon market, a carbon offset project has to go through a rigourous measurement, verification and reporting (MRV) process in order to qualify for entry to carbon certificate registries (and create new carbon certificates). This process incurs quite some overhead which only makes it worthwhile for larger projects to complete. The certificates that get issued are specific to a project and year (vintage) and in this sense are non-funglible; some carbon offset projects are perceived as more desirable or credible than others (e.g. certificates issued due to emission reduction from a newly installed factory scrubber compared to certificates from emission mitigation from a forestry preservation project that can demonstrate that it supports biodiversity and the local community).

One disadvantage of the existing off-chain system, is that not everyone can easily trade certificates as no global, liquid market exists and only verified (Verra) registry account holders can own or retire carbon certificates; it is a closed system which involves an application process and fee.

These carbon certificates can now be bridged by the owner of the certificate in the originating off-chain registry using Toucan infrastructure (if your certificate fulfills certain requirements) to the bridger’s on-chain account. Once on-chain, the non-fungibility of these certificates is respected. However, in order to create a healthy on-chain market with adequate liquidity for these certificates, Toucan has created “pools” where certificates of similar types are pooled together and can be traded against each other (and thus become fungible). One of these pools, NCT (Nature Carbon Tonne), is dedicated to nature-based carbon offset projects, such as forestry preservation projects. The original certificate bridger can then swap their non-fungibile carbon certificate tokens for NCT as they need and, if they wish, choose to sell their NCT at market price on Sushiswap. Toucan’s documentation goes into more detail for the bridging and pooling of certificates.

This infrastructure has enabled the first liquid and fungible carbon certificate market that allows end users to buy small and relatively large quantities of certificates alike at approximately 3 to 10 lower prices than in the traditional off-chain carbon markets. We think this demonstrates how effective blockchain has been in “removing the middlemen” and brings large benefits for the end user and will in time lead to more value accruing to the originating carbon offset projects.

When an end-user comes to the point of actually offsetting their emissions, they must retire carbon certificates from a concrete carbon offset project of their choice. In our case, this will involve purchasing NCT, redeeming the NCT pool token for tokens from a specific carbon offset project (that the community will choose via Snapshot vote) and afterwards “retiring” them (i.e., sending them to the null address). You can find a transaction containing the swap, redemption and retirement actions here; in this example, the Verra Project with ID 1052 and Vintage 2012 was chosen as the carbon offset project and you can verify that TCO2-VCS-1052-2012 tokens were retired by sending them to the null address.

We propose to choose the NCT pool tokens as it has strict requirements that ensure that only high quality forest preservation and nature-based projects may be part of the pool. The pool contains about 30 projects from which we can choose to retire carbon certificates from as part of the governance decision at the end of Devcon 6. The NCT pool also has enough on-chain liquidity: 232,000 NCT liquidity on sushiswap and a total supply of approximately 1.85 million NCT. This should insure that we can offset Devcon 6 without having a huge impact on the token price.

haurog and danceratopz

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Dear @Rose

We’ve compiled a list of parameters to estimate the carbon emission from Devcon VI. The more detailed you can provide the information, the better the estimate will be that we can provide.

The total emission is dominated by the accommodation of the attendees, the catering and the general energy use for the conference. These dominant contributions can be estimated from the important parameters alone. These important parameters are the same as @tokenizerofcarbon mentioned 3 weeks ago.

The medium and less important ones will just help us to fine tune the estimated emission value without influencing the outcome more than 10-20%. The important parameters are the ones needed to make a good estimation, the less important ones would help if you have them available, but it’s necessary to spend days on end to determine them.

Important parameters

  • Duration (We would count 5 days, Mon-Fri, and exclude the co-working space provided on the weekend)
  • Number of attendees
  • Number of employees
  • Floor space (in m²)
  • Number of meals served and percentage of vegetarian/vegan meals
  • Number of drinks provided in liters. We assume only non-alcoholic drinks are provided?

Medium importance parameters

  • Number of snacks provided (e.g., number of packets of chips, snack bars, etc)
  • Area of stands for companies (in m²)
  • What percentage of the floor space is heated and cooled?

Less important parameters

  • Print material ordered (in kg)
  • Expected amount of plastic waste (kg)
  • Expected amount of recyclable waste (kg)
  • Expected amount of general waste (kg)
  • Estimation of electricity use (indicate if heating or cooling is included in this number)

Best regards,

danceratopz and haurog

Thanks for sending the parameters!
We’ll have a look at them and come back to you asap.

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Hi @James
What do you think about joining forces here and collaborating to achieve some first steps towards the initial idea of DIP1? :slight_smile:

Hi @haurog @danceratopz and everyone else involved!

We had a call with the people from DIP 1 from Toucan.
They like your approach and the thought you put into the calculation and said they would be open to collaborating and combining approaches. I pinged James here above.

We don’t have answers to all the requested parameters yet.
What do you think is the most important thing to offset or at least a good start? The flights maybe?

We need to get an MVP out for this idea.
We talked that we can email the attendees the opportunity to offset their part.
Would the offsetting happen on the Toucan website?
Do you have an example offsetting that I could go through to see how it exactly works?


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Thanks Rose, we spoke with Toucan last Friday and aligned our efforts regarding DIP-1/DIP-17 and also discussed our “Climate Impact” Community Hub Proposal.

Absolutely. @haurog and I have created a tentative list of deliverables and a summary of the current plan. The TLDR is:

  • Demo version/MVP available latest 9th Sept.
  • Full/finished version 30th Sept.

We’re also happy to share dev versions before 9th Sept.

Does that suit you? Any input is welcome!

After speaking to @beth_toucan and @James, we realized that we should create 2 estimates:

  • An “initial event emission estimate” to use in the dapp (by 30th Sept),
  • A more accurate estimate with parameters more easily determined post-event that we can use for the official offset.

This is also described in the deliverables doc.

The main contribution comes from the flight. The next are likely to be accommodation and catering, so the most important numbers you could provide are the total expected number of attendees (for accommodation) and the number of meals that will be served.

Perfect, we should just align that the dapp is live before the mail goes out :slight_smile:

In the spirit of neutrality and community effort, our preference would be a Devcon subdomain, would that be possible from your side?

The closest experience at the moment to the Dapp would be our flight offsetter. We will base the Devcon VI offsetter on it, with a fixed destination (Bogota) and add the initial event emission estimate per attendee to this value. Flight offsetting will be optional, however, in order to receive the participation POAP and participate in the community vote on the offset project.

Please note, that the flight offsetter directly retires the carbon tokens whereas the Devcon VI offsetter would send them to the pool address, controlled by the Devcon Team, and retired after the governance vote by the participants.

danceratopz and haurog


The flight offsetter is great already! Maybe UX wise it would be nice if it is integrated with WindingTree flight booking when it is ready.

So in the end the user journey takes a stroll to windingtree flight booking and then offsetting this exact flight in the flow of the ticketing process (after buying a ticket get the option to book your flight)

Just one thing in the current version - would be great to show the offset price even without the asset needed or even without a connected wallet. Just to lower the barrier to play around with it.

Thanks for pushing this forward - merged your PR and we will discuss it today - really hope it goes through. The only contentious thing I currently see is the usage of polygon - a L2 would be preferable - but I think this should not be a deal-breaker.


Thanks, this is a great suggestion.WindingTree was new to us, but we’ll take a closer look and follow-up once we’ve added more improvements to the flight offsetter.

We aim to add this for the Devcon VI Offset page. We’d also like to support more wallets.

Thanks! :pray: We’d also prefer to use a true L2, but unfortunately the offsetting infrastructure is currently only available on Polygon (respectively, NCT is not available yet on any L2s). We could collect funds for the event offset pool on an L2 (just not as NCT), but this approach has two disadvantages:

  1. It requires a manual bridge to Polygon by the Devcon Team.
  2. It requires manual token swap(s) of a larger value to NCT on Polygon - the relatively low liquidity of the USDC-NCT pool on Sushiswap could influence these larger swaps.
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Hi @danceratopz and @haurog

I have the feeling it would be great to have a dedicated Discord chat to have all communication around DIP 1 and 17 in one place. With all the teams involved.

Can you please share your emails with me so I can send an invite to the Discord chat?

Thanks @Rose, great idea. Just DM’d via the forum.