Launch HN: Wren (YC S19) – Offset Your Carbon Footprint - <AUTHOR> Hi HN,
We're Mimi, Ben, and Landon, founders of Wren (https://projectwren.com). Wren lets you offset your carbon footprint by funding projects that prevent or sequester greenhouse gas emissions. It works by calculating your carbon footprint and then funding a project of your choice through a monthly subscription. Some of the projects we have right now involve planting forests in East Africa, providing more efficient cookstoves to Ugandan refugees, and preventing deforestation in the Amazon.
We met in college, and worked together on numerous side projects and class projects. After a while we decided to try finding a meaningful project that we could work on after graduation. At the time, we didn't know much about the science or emerging technologies for mitigating climate change, but we saw carbon offsets and asked ourselves "why isn't everyone doing this?" Then we got to work on Wren.
Carbon offsets have been around for a while, and with some googling, research, and phone calls anyone can find reliable and transparent projects. Our goal is to make it as easy and enjoyable as possible to offset your footprint. We only work with projects that have good evidence suggesting they're long lasting and reliable. We also only work with projects that wouldn't happen without support from Wren users. In addition to climate benefits, we prefer projects with strong social impact. Projects listed on Wren reduce lung cancer risk for refugees, provide millions of dollars of economic benefit to subsistence farmers, and protect biodiversity.
We see climate change as the most important problem we can work on. Despite growing evidence of the damage it will cause, governments are not taking necessary action. Wren is a way for an individual to have impact today.
Most in this space are nonprofits but we are a business. We take a 20% fee on each subscription. This allows us to hire talented engineers, invest in marketing, and raise capital. This way we can build tools that make our projects more transparent and reliable—daily satellite images of forest projects, data visualizations of tree trunk diameters, and other ways we can build more trust for these projects.
I've seen a lot of posts on HN recently about climate change and potential solutions so I'm looking forward to a good discussion :) <comment><USER2> Part of me says this is great because we need every single action towards reducing carbon in the atmosphere - big and small - we can get if we want to even get close to where we need to avoid catastrophe.

Another part of me wonders why would anyone chose Wren over COTAP[0] (for example) - a non-profit (501c3) where 90.9% of funds go toward their projects, you get a tax deduction and you can check in on their finances via their non- profit filings to ensure they are actually allocating funds how they say they are.

[0] [https://cotap.org](https://cotap.org)

edit: grammar

<comment><USER3> Hi Justin! Ben here, co-founder of Wren. COTAP is a great organization, and the non-profit filings are a good, fundamental way to verify that they exist and are doing what they say. In response to why Wren, our philosophy is that most individuals—perhaps most of you on HN excluded—don't spend the time to figure how to contribute to stopping climate change, let alone carbon reduction projects, and certainly don't spend additional time following up on the additionality and usage of their donations. On top of that, there is a great opportunity to stitch this community together and create a place where ideas can be shared around climate reduction, projects can be supported in tandem, and ideas can be brought forward for how to reduce your carbon footprint. We're only a few weeks old and a lot of this is ambition, but our goal is to expand upon an individual's initial excitement around doing _something_ about climate change.

<comment><USER4> This is a really good point. The goal of both Wren and COTAP is to have the most impact solving climate change. Having the most impact doesn't have to mean you charge the lowest fee - but it does mean removing the most amount of CO2. If charging a higher fee gives Wren a change to reach millions and get them to pay more where COTAP is still tiny and have one-time donations that is a strong argument for why a different model is needed here

<comment><USER5> COTAP here... Thanks to thisjustinm for getting us into the conversation : )

Not to rain on the parade here, just a cautionary tale that is intended to be helpful...

I would say take a look at Cool Effect which launched in early 2016. Charity at a glance, but it's also a bottomless-pocketed family from Marin. It cuts itself checks from the Overlook Intl Foundation, run by the same people. Both orgs have same CEO. All fine...

But look at the 990s... They have thrown the kitchen sink at this and have probably dumped $10+ million by now. $800K+ in PR and marketing before they even launched.

Yet they've only sold well under 1 million tonnes over 3 years. In other words, back of the envelope they've lost $9 per tonne, even when being a charitable donation.

Also, divide their 838,715 cumulative tonnes noted on their home page by their 533,115 cumulative members. 1.57 tonnes/member over 3 years, or a half tonne per member per year. Not anywhere close to the average US footprint.

Half the country doesn't believe in climate change, or it's not a priority, or is living paycheck to paycheck, or all of the above. Offsetting is not anywhere on the horizon of their hierarchy of needs. Offsetting is complex, misunderstood, and controversial (see our op-ed's n TheHill.com for a taste).

When you finally get beyond those nesting subsets, there's enough market size to go around in theory but it's extremely competitive.

<comment><USER6> Sorry, I'm not very familiar with charities, can you clarify what your point is here? I'm not sure what Cool Effect is or what you're talking about.

<comment><USER5> They're a 501(c)3 private foundation, similar to a 501(c)3 public charity like COTAP. This makes offsetting contributions tax-deductible. The point is by making it tax-deductible, along with other things like helping folks offset monthly, they've already tried to make it as compelling and easy as possible to offset, but no dice relative to time/effort/$ put in. Similar to StandforTrees.org. I'm basically saying I don't think Wren is different enough, other than charging higher margins, something not in their favor. It is good they're transparent about margins, but that's not unique either.

<comment><USER6> I see, thank you. What would you recommend I donate to, if I wanted to maximize my environmental impact per dollar?

</comment></comment></comment></comment></comment></comment></comment><comment><USER7> I'm bias because I prefer YC companies, but I just signed up and started donating to offset me and my family's carbon impact. When I ran through the calculator and saw how much damage we were doing (the "if everyone lived like you the planet would have X months" was VERY effective) that really pushed me over the edge. Now that I've donated I feel great. I just have to pay a little bit more (relative to my income/standard of living) and I can live guilt free?? Sign me up!

And I note that this sounds pretty shilly, but seriously, if you don't donate to wren go donate to some other reputable climate change mitigating org. Just donate to something, even for the selfish feeling of smugness and guilt- removal it brings.

<comment><AUTHOR> Happy to hear it. One thing to mention though: We don't think offsetting is a license to live guilt free. We still have to do more! Hopefully the carbon footprint calculator will give you some ideas for how you can cut down your footprint pretty easily—often something as simple as cutting out red meat or using public transit more often can make a big difference. Also, progress from political action will likely be necessary.

That said, we need to pursue all solutions aggressively right now and we obviously think carbon offsets are a key part of the portfolio that will save humanity from climate change :)

<comment><USER7> Maybe you should expand your offering so that I can live guilt free. That's what I really want. To maintain my standard of living without harming the planet.

<comment><USER8> That's impossible unfortunately. Money alone won't "buy" a guilt free, business-as-usual lifestyle in the face of this emergency. I suggest doing a bit more research to see for yourself what I mean.

<comment><USER9> This is clearly false. Subsidizing the conversion of the the entire world to clean energy does more good than burning an ounce of coal does harm.

Conversely, planting one tree is insufficient to buy an SUV guilt-free.

There's inherently a crossover point somewhere.

<comment><AUTHOR> Yeah this is pretty interesting. There's some set of activities (getting everyone on renewables, making clean construction/ag/transportation cost effective, political action, etc) that would actually allow someone to be guilt free. It would be way more money than just offsetting the footprint but it could fully cover all externalities....

That's kind of theoretical still, but perhaps we could crack it

</comment></comment></comment></comment></comment></comment><comment><USER10> > We take a 20% fee on each subscription.

Why did you choose to charge with a percentage model instead of a flat fee? If I'm a "hero" and offset double my footprint why should I be charged double for doing that? Is the cost to you as a business relative to the dollar amount I donate?

<comment><AUTHOR> This is a great question. To be completely transparent, we are considering a flat fee because of the reason you stated.

We originally chose a percent fee because it was an industry standard model that many in the carbon offset space expect. However, we're learning that industry standard here does not mean it's the best possible option.

The big reason why a % fee is good is because for small donations (e.g. 25% of someone's footprint) it makes more sense to scale it. A $4 transaction cost on a $2 impact to the project is crazy.

The tricky thing about our cost structure is that currently we do not have enough revenue to cover our overhead expenses, so even if we're ignoring the per transaction cost we need to find a way to cover our overhead (e.g. a place for us to live so we can hack on this all day)

<comment><USER11> what about letting your users get a % of all the money from collected from users they invite?

They could either receive those as Stripe payouts, or further reinvest their earnings into curing global warming

i.e. cure global warming MLM style

This could also open up some nice customer acquisition strategies benefit from asymmetric motivation: teenagers/kids bunch of teenagers (who would spend hours persuading their rich parents /grandparents to donate $50/mo, such that in return the teenager earns $5/mo). This may be able to help mitigate the problem that older people are less likely to believe in the severity of global warming than younger people - in the same way that your grandma bought your magazine in 5th grade (so that you could win a prize, not because she actually cared about the magazine) as part of those gamified magazine fundraisers in elementary school

<comment><AUTHOR> This is very clever, we might try that. Thanks for sharing!

<comment><USER11> would love to schedule a call with you to see if there is any pro-bono help I could do. I've thought about a couple creative solutions w.r.t to donation psychology, and have actually pitched ideas similar to Wren before at events. I do full stack web dev and have a couple of ideas for visualizations/UX that may help increase donation/referral behavior

[http://calendly.com/johnsimerlink](http://calendly.com/johnsimerlink)

</comment></comment></comment></comment></comment><comment><USER12> Awesome to see new players in this space! I've been subscribing to [https://compensate.com/](https://compensate.com/) which seems somewhat similar to you guys.

Going the business route instead of non-profit sounds like something worth trying out. Ultimately this is about making the biggest impact on slowing down the climate change - not about who takes the smallest fees and has the lightest overhead.

<comment><USER3> Good local focus on Finland w/ Compensate! Like the team behind that product a lot. Thanks for sharing

</comment></comment><comment><USER13> > preventing deforestation in the Amazon

Could you say a bit more about how this works in practice? I'm asking because of vague memories that much of the logging in the Amazon is done illegally anyway. So presumably just saying "we buy up land and then it's ours and nobody will log it because it's forbidden" would not be effective.

Am I misremembering things and this is not really a problem? Or do you have some effective way to ensure that land not meant to be logged is really left alone?

<comment><AUTHOR> No you're spot on, historically this has been a huge problem. You can make it illegal to log an area, but people will log anyway.

What's different about the project we listed is that it uses satellite monitoring and drones to very quickly catch illegal logging. So instead of loggers taking out 100s of acres over a few weeks, they can be caught on day one and authorities can be sent to the area. This makes it very difficult to log at a large scale. They also send several patrols each month to walk through the area and inspect on the ground to make sure the forest is as expected.

</comment></comment><comment><USER14> Congrats on the launch guys! I am always excited to see green startups coming out of YC.

I'm not sure if you guys are looking for other projects to support, but one interesting project is Project Vesta[0]. Seems like there is some potential for a successful partnership.

[0]: [https://news.ycombinator.com/item?id=20403570](https://news.ycombinator.com/item?id=20403570)

<comment><AUTHOR> Project Vesta is super exciting! We've seen them on HN a couple times, they're still pretty early but it'd be cool to figure out how we could work together.

Thanks for mentioning them again

</comment></comment><comment><USER15> > Most in this space are nonprofits but we are a business. We take a 20% fee > on each subscription. This allows us to hire talented engineers, invest in > marketing, and raise capital.

Non-profits can do all of those things, too... Why not do them as a non- profit?

<comment><USER16> > Non-profits can do all of those things, too... Why not do them as a non- > profit?

We've already got nonprofits doing this stuff. Given the gravity of the situation, shouldn't we encourage a range of different approaches?

</comment></comment><comment><USER17> I'd love to see a further breakdown in options.

Like as someone who mostly bikes but does use a car a during the summer months there's a clear scale. I'm also a meat eater but have very little red meat. This would half the food emissions of an average American. Some sort of scale would make me feel like I'm getting a more accurate answer to nuanced questions (ones that I think a lot of people concern themselves with).

I was also suspicious when I put in vegetarian, car, and 2 flights a year < 3hrs resulted in having 11% lower than most Americans and then switching to electric car gave me another 10%. IIRC that's making some big assumptions (not considering electricity costs, lifetime emissions, state electric emissions).

I also find the "if everyone" part misleading (though I get why it's there, to show privilege), but I think it is also effective to promote competition within a country. I can be the best American but have a hard time beating someone from the third world. Maybe have both?

Also, if you're going to allow fake emails why don't you let people calculate first? Or maybe email required for a more nuanced position, if you're trying to harvest them (since that probably gives you a better set of people that you're looking for).

<comment><USER18> Have you tried editing your footprint further in the accordion below the first six questions? There are options there to edit your diet, transportation, electricity etc. at a much more granular level (i.e. I eat meat twice a week). The first six questions have the greatest deltas between you and your country's avg, which is why they're first, but I see how the setup makes it confusing that you can go more in depth underneath. Let me know if you were able to get that to work!

> switching to electric car gave me another 10%. IIRC that's making some big > assumptions (not considering electricity costs, lifetime emissions, state > electric emissions).

Are you talking about not considering electricity costs for manufacturing an electric vehicle or more generally for your personal footprint?

Might be helpful to note that our previous calculator set up was much more state specific (to postal code level) but we had to switch up the setup so it could accommodate for international users. Our breakdown is still based on the Berkeley Cool Climate model ([https://coolclimate.berkeley.edu/publications](https://coolclimate.berkeley.edu/publications)) but scaled by a country's per capita emissions (data from World Bank). Unfortunately that means there's less granularity on region specific data for the U.S. for now, but it should still be a pretty good estimate. That said — there's still plenty of improvements that we can make to the calculator, so thank you for the feedback.

Oh, I like the idea of competition on a country basis. Maybe showing your percentile in your country could work. Let me know if you have any other ideas here!

For the fake emails, from a product perspective it was more confusing for people to enter in their emails after calculating their footprint than right upfront. It might have been the way we had it set up or something but we can come back to explore what can be improved there. For now if folks want to calculate and leave without a way to get back to their footprint calculations or offset their footprint, it's fine to leave a fake email. If users make it to the create account page, they're able to confirm their email or change their fake email there. :)

Ideally we're going to make the calculator completely open to use, but for now it's still in our onboarding flow until we get around to spinning it out into a separate tool.

</comment></comment><comment><USER19> Why do I have to give you my email address before you'll let me figure out my carbon footprint, and how much this will cost?

<comment><AUTHOR> We use the email to save your progress, but if you'd like you can just use any fake email

<comment><USER19> But at the end you don't just show the footprint online, you only have the option to get it emailed to me.

<comment><AUTHOR> Your footprint should be available on that page—you should be able to see your annual total, your breakdowns by category, and how that compares to global averages. The "Email me my footprint" button just sends you a link so you can save it. I could see how you may want to change the email you entered once you get there though. We should add that!

Thanks for pointing that out

<comment><USER20> I just ran through the page _after_ seeing this comment and was also confused. To me the phrasing and styling of the "Email me my footprint" button makes it feel like the end of the process and that I need to click it. It didn't immediately occur to me that I should keep scrolling down. In my case I happened to scroll so that the "Step 3: Offset" was just out of view which made it feel even more like an "OK you're done!" button, but I think even if I saw there was more I would've wanted to click the button expecting that to be the way to see my results. Maybe the two of us are outliers but it might be worth it to explore some small design tweaks here. Love the concept!

<comment><AUTHOR> This is a great point, you're right. Thank you for that feedback, we can edit that soon.

</comment></comment></comment></comment></comment></comment><comment><USER21> Do you have any plans to expand to B2B? I'd imagine it might be a larger impact, along with the positive psychological effect of it not being an individual's money on the line.

<comment><AUTHOR> Great idea! We're actually piloting that right now. I think it would be promising especially since companies ask employees to travel and have otherwise larger footprints from work.

<comment><USER5> Beware b2b with large corporates, especially those that have already professed leadership and concern on climate change. Google, Disney, Microsoft, Apple, UPS, and... Interface. They will wear you out. Maybe they'll have a soft spot for your YCombinator gloss, but don't count on it. Most companies you would pursue are already partnered up w/Natural Capital Partners, NativeEnergy, Carbonfund, etc. It's very rare for them to switch. That gold rush happened long ago. There are of course exceptions and other pockets of opportunity. Don't think you're different, special, better... that "it's different this time" or that hey offsetting is a neat space where buyers can granularly allocate their buys across many different providers. Theoretically true, doesn't happen. Save your energy for companies with newly-announced neutrality commitments. Even then, in our experience, those dialogues move slowly (2+ years), usually involve RFI's and RFP's, and then you're up against 20+ incumbents who have been doing this for over a decade.

<comment><USER18> Hi! Thanks for putting in the time to respond to so many of the comments on this thread! You've all been in this space for so long and it's really valuable to hear your perspective.

>Beware b2b with large corporates

Just a note on b2b, we aren't going after large companies. Right now we are just responding to inbound interest from users who want to offer Wren as a benefit to their employees. We don't do offsets in scopes 1 through 3 because we're focused on individuals, and as you said there are 20+ incumbents who have been doing this for over a decade, and much better than we can right now.

>Don't think you're different, special, better... that "it's different this time"

I don't think we're under the illusion that we are special. We are only trying to build a good product to get individuals engaged who haven't been reached before. We are also not trying to put down any organizations that are already offering offsets to individuals by building Wren. I don't think we're going to get anywhere by competing internally when the vast majority of the world doesn't know what can be done on an individual basis to take action, whether that's lifestyle changes, political action, activism, offsets, etc. We are here to contribute, not take away from or hurt the space. Whether it's changing our organization structure, margin, projects we're working with, whatever it is, I'd love to hear from you about what you think we should be doing better. Please email me at email@example.com if you'd like to continue the conversation!

</comment></comment></comment></comment><comment><USER22> Here is part of what I told Paul Graham after he tweeted you last week:

"How about instead of directing people to pay a middle man to take 20% off the top to pay others to plant trees" which, correct me if I'm wrong, is exactly what you are doing, while some of may be going to non-tree planting activities - the most effective thing you can do with that money right now, unless you are sitting on a miraculous new technology, is to pay people to actively plant new trees and/or protect existing forest.

Per your website for those that haven't looked

>Wren takes 20% of each subscription and puts it toward growing the company.

Also like I told Paul, and Sam Altman,

"Planting trees isn't even a bandaid, it's like cutting your arm off and then gently blowing in the gaping wound. To offset our current CO2 production you need to add more than 31 million square miles, nearly 16% of the earth's land, of new forest assuming a healthy density of 40-60 trees per acre."

That figure above is actually really conservative. Add to that the fact we're losing forest at an estimated 28,125 square miles annually... do you realize how many customers you'll have to get to even combat 28,125 square miles annually? The best trees can manage about 48lbs of CO2 per year, and healthy forest is 40-60 trees per acre, that means you're going to need to plant a billion plus trees a year to even hope to combat current forest loss, a BILLION trees... and I'm not talking twigs, I'm talking 10ft+ trees, in healthy soil, with healthy fungal networks (the fungi that work in symbiosis with trees aid considerably in the carbon sequestration and overall tree health).

Seriously, do the math yourselves and then try and justify your business model. Not to me, but to each other.

I think you need to cease operations immediately, I think you need to do a lot more math, and then I think you need to come back with a strategy to help people personally minimize their carbon impact. You're selling people a fantasy, you're selling them nothing more than an uniformed "I'm helping save the world" feeling because they joined a subscription service while you take 20% off the top to hire more employees.

I honestly have no idea whatsoever why YC selected your company and chose to fund it, other than the 20% off the top of every subscription and perhaps banking on the fact that people will feel guilty about climate change and happily fork over money on a subscription model.

<comment><AUTHOR> You're right, we have to be critical of what we're doing because this is such an important challenge for humanity. This is why we're doing it:

People who sign up for Wren usually were not previously considering offsetting their carbon footprint. In 1 month ~200 people have offset their footprint through Wren. We anticipate this number to grow exponentially, and think several million people offsetting their carbon footprint is a reasonable goal for the short term. This is nontrivial—it will be as impactful as the U.S. agreeing to go on track for the paris climate accord again. This would not happen if we did not take a fee.

Planting trees is one of many solutions we're focused on. Project Drawdown has 99 more: [https://www.drawdown.org/](https://www.drawdown.org/) and if we were able to enact all of them we'd be carbon neutral as a planet.

We will certainly be doing more math and developing a better strategy. However we think that by launching Wren we have already learned more than months spent strategizing could have taught us—this is at its core a consumer behavior problem so we have to spend our time understanding people.

Keep us posted on more ideas and feedback for maximizing our impact

<comment><USER22> > Project Drawdown has 99 more: > [https://www.drawdown.org/](https://www.drawdown.org/)

You keep mentioning Project Drawdown in this thread.

Why should people pay you 20% instead of just donating to Project Drawdown.

Will you continue to take 20% when you reach those 'several million people' subscribing? I mean, at 5$ a month each that's 'several million' dollars a month for what, web hosting and 3 salaries?

I see on LinkedIn you're listed as a software company and keep mentioning engineers. What engineers do you need? What exactly are you doing other than acting as a middle-man for funds by hosting a simple calculator and merchant portal?

As my downvotes would suggest, I'm apparently coming across as quite harsh but I've yet to see anything remotely actionable other than "see the ideas so and so has" "engineers" "millions".

I'm not a venture capitalist, I have no use for projections and buzzwords. I'm not even a CS type so I don't immediately think "we need engineers!" for every problem that comes along in some subconscious way of justifying my career/creating job security.

"we prefer projects with strong social impact" what does this even mean. Global warming isn't something that's going to be solved by 'social impact'. China is building HUNDREDS of coal power plants right now and adding millions of new drivers to the road annually (in fact, China has more licensed drivers now than the United States does citizens). The methane produced by 1.3-1.5 billion cattle worldwide are responsible for roughly 2 gigatons CO2-equivalent.

Drawdown, as you keep linking, most of their proposed ideas/areas of interest are laughable

\- Electric bikes (going to largely be powered by, fossil fuels)

\- Electric cars (going to largely be powered by, fossil fuels, and will remain cost prohibitive for 95% of the world's population, if not more)

\- Mass transit takes years or decades to roll out, when funding can even be secured and all zoning challenges can be met

\- Alternative cement, this will be great if someone can make a breakthrough but there has been next to zero progress made on anything that is remotely feasible or even scalable

\- Bioplastic, while this takes petrochemicals out of the equation it is still pretty energy demanding and is still not good for the environment, biodegradable does not inherently mean safe.

\- Recycled paper, or how about doing away with paper. Instead of making recycled paper (which requires obscene amounts of toxic chemicals) why not get legislation passed to outlaw mass mailing, do you know how much mail I throw away each week that is advertisements and solicitations that I never even look at?

\- Industrial recycling, aside from aluminium and CLEANED glass recycling is mostly a farce. Don't believe me, do your homework, planet money even had an episode on this recently. Plastic is largely just taken to landfills, even if sent to recycling, because unless it is cleaned it is considered contaminated and China will no longer buy it to recycle it because of a loss of cheap labor and the pollution recycling it causes.

\- Autonomous vehicles, mutli-national companies are having trouble with this and even if they do pass it you likely have years of legal hurdles to get them legal and a decade or more to get people to even begin to accept and adopt them in numbers sufficient enough to make them more efficient than human driving as you'll have to remove the bulk of human drivers from the road.

\- Building with wood is already happening, but it adds considerable cost and still has considerable height limits which still require more land to be turned from green spaces to tarmac and building. Not to mention this wood isn't always sustainably farmed.

\- Direct air capture, this is almost certainly never going to happen barring multiple miraculous inventions. The closest person to doing this is Dr. Klaus Lackner and even his research has it not being viable, even if you capture in a method like his (a polymer that you then 'wash' it you still have to sequester it somehow).

\- Hyperloop, pure fantasy. Never going to happen for travelling large distances. Travelling large distances is one of the problems anyway. Commercial aviation fuel usage has gone up 33% in 9 years.

\- Refrigerant management, this will help with new appliances but the billion plus refrigeration/freezer units out there already...

\- Industrial hemp, will just require more land to be planted as farmland won't be sacrificed it and cotton will be farmed until at least the current generation of farmers dies, farmers don't like change.

\- Living buildings, they look great in concept art but aren't practical and won't have any meaningful impact. They'll likely take decades just to offset the CO2 emissions from manufacturing the concrete that went into the building's foundations.

\- Ocean farming and marine permaculture, coastal waters absolutely need kelp and seaweed 'forests' re-established. There are some women in/around the Bay Area working on this - Tessa Emmer, Catherine O'Hare, and Avery Resor and what they are doing needs to be done up and down every last square mile of water with proper depth in the entire world.

Smart grids, if you mean in the United States good luck. This isn't something you are going to be able to have any influence on whatsoever. You'll have to get every single power company in the United States and Canada to voluntarily replace perfectly functioning, very expensive, equipment over a decade or more and even if you did they'll pass the cost on tot eh customer.

\- Solid-state wave energy, at any scale this is likely to have any number of unforeseen consequences for marine life (probably sound-induced stress for starters) and be quite costly due to the corrosive nature of oceans.

<comment><USER23> There's a lot to be negative about wrt our climate crisis for sure.

However overwhelmingly negative messages I believe can contribute to inaction through people moving straight from the denial phase to the "what's the point, we're all doomed" phase.

Just to pick the first of your points to rebut:

> Electric bikes (going to largely be powered by, fossil fuels)

1) in my country the grid uses 70+ renewable energy (mainly hydro), so EVs are extremely promising.

2) progress made on EVs will pay off in the future, when/if the grid becomes greener. How crap would it be to make big success at one end of the equation, e.g widespread deployment of nuclear to green the grid, and then find that all the vehicles had no way to use that clean power?

Of course it makes sense to develop technologies like electric bike, EVs generally.

Yet your comment is written as if it makes no sense. It conveys a strong sense of doom and pointlessness.

If your intention is just to spread doom, then perhaps keep it to yourself.

If it's to shock people into action then there are better ways to communicate.

<comment><USER22> >1) in my country the grid uses 70+ renewable energy (mainly hydro), so EVs are extremely promising.

Sadly that's not the case for most of the world. Petroleum, natural gas, and coal—combined accounted for about 77.6% of the U.S. primary energy production in 2017. Fossil fuel energy consumption in China was reported at 87.48% in 2014.

> progress made on EVs will pay off in the future, when/if the grid becomes > greener.

Only if new battery technologies are created that can be manufactured quicker, in a greater capacity, than lithium batteries are now.

>There's little risk of lithium supplies running low in any absolute sense; the next decade will probably see less than one percent of the world's lithium reserves depleted. The real danger is that lithium won't be recovered and made available quickly enough to meet the rising demand.

>There are two sources of lithium: brine and mineral deposits. Brine is recovered through a process known as brine mining in which dissolved lithium (and other useful elements) are extracted through a long, energy-intensive, and costly process. Recovering lithium from mines is more straightforward, but most of the world's lithium is in brine pools in South America. About half of the 35,000 metric tons produced in 2016 came from brine operations in Chile and Argentina.

[https://blog.energybrainpool.com/en/is-there-enough- lithium-...](https://blog.energybrainpool.com/en/is-there-enough-lithium-to- feed-the-need-for-batteries/)

From the same article we also have to factor in how rapidly lithium prices are increasing:

>Anxiety about lithium's availability has caused its price to spike. In 2010, lithium sold for $5,180 per metric ton. By 2012, the cost was over $6,000 per metric ton, and by the end of 2017, a metric ton was going for about $14,000 – a 270 percent increase over 2010 levels.

So what happens when you start churning out EVs 10x faster than Tesla is, 100x faster?

And how much more fossil fuels will need to be burnt in power plants (it's worth noting that roughly 6% of power generated at a power plant is lost in transmission before it arrives, then more will be lost changing voltage at a charging location, then more as it feeds into the battery) instead of as gasoline as more and more cars come online? And all of the infrastructure that will have to be created to support them? 17% of Americans live in an apartment or a condo, they can't just pay to install a plug in their garage as in most cases they do not have a garage or even a dedicated parking spot and businesses, you're going to have to convince businesses to spend large sums of money to install charging infrastructure in their parking lots for tens or hundreds of parking spots, and likely to support that new lines will have to be run to the area, widespread adoption of electric vehicles in a country like the United States suddenly means tens of billions of dollars in just power lines and substations, wiring and charging stations.And adding a bunch of EVs will mean you'll need to add a bunch of grid storage or bring more fossil fuel plants online to meet the demand of all of the cars getting plugged in at 8-9am in each time zone as people arrive at work... renewable energy doesn't work well for spooling up to meet demand.

Plus with widespread EV adoption in a given country you have to basically retool every firehouse in that country to also be able to handle EV accidents, pierce a cell on an EV and you have a fire situation that can last DAYS as cells rupture one by one in a worst-case scenario (like when Richard Hammon crashed that Rimac Concept One supercar).

>Yet your comment is written as if it makes no sense. It conveys a strong sense of doom and pointlessness.

No my comment points out that the organization Wren keeps listing, has a bunch of whimsical fantasy ideas that are not remotely viable and I don't see why I should give Wren my hard-earned money to take 20% for themselves before they hand 80% over to organizations, or individuals, that are chasing fantasy technologies that won't be viable for decades, if ever.

</comment></comment></comment></comment></comment><comment><USER24> Why did you decide to pursue this strategy to help fight the climate crisis? As opposed to other strategies such as carbon removal technologies or supporting / electing public officials that understand the climate crisis?

<comment><AUTHOR> 2 big reasons: 1) There are a lot of solutions to climate change that we could enact today if they had funding. Project Drawdown ([https://www.drawdown.org/](https://www.drawdown.org/)) may be of interest—it lists all the solutions to climate change we can enact today. It's quite surprising—we don't need CRT, we just need action today. With electing officials, we think that would be the best solution but it's relatively high risk—if we fail to do it, climate change gets worse. (that said electing officials is still super important, more on why we didn't choose that route in (2))

2) We thought this is something we'd be good at relative to our other options.

It would be really cool to work on CRT or clean energy breakthroughs, but we have no science background and it would be years before we ramped up to start making an impact on those technologies.

For policy, we think we can be good active members of our communities and vote etc, but we could not see ourselves spending all of our time lobbying or campaigning or otherwise pulling levers in the political space.

But what we do love doing is building products. We are content doing this all day, and hope that will allow us to make more and more useful products to reverse climate change.

</comment></comment><comment><USER25> Great idea. I've signed up and I think your execution is pretty slick.

I'm still noodling on a somewhat similar project with treespree.io but had some of the same concerns raised in your thread that I still need to think through.

I think one of the core value adds of these approaches is that they convert people who are inactive out of fear or uncertainty into people who are at least starting to do something and possibly discuss the issues with people they are close to.

Still not sure how to best ensure ongoing engagement for the long haul.

All the best to you guys though - really want to see your project succeed.

</comment><comment><USER13> Some notes on the calculator:

\- Asking only for the size of my home but nothing else seems bogus. Surely apartments in a densely populated city have different footprints than single- family homes in suburbia or the countryside? Part of my housing's footprint will be modeled by transport considerations and heating costs, but apparently not all, otherwise you wouldn't ask.

\- District heating ([https://en.wikipedia.org/wiki/District_heating](https://en.wikipedia.org/wiki/District_heating)) is a big thing where I live, and it's impossible to quantify for individuals what their footprint is when they have that instead of gas.

\- My final result came back as 10% less than my country's average (yay) but I see no way to figure out why. Probably because I don't drive, but it would be cool to see a more detailed breakdown of all the data I entered, how they factor into the calculation, and how they relate to my country's (and the worldwide) average.

Nice job and certainly not trivial to set up!

Edit: Oh, and I'd like a less clumsy way to see in the footprint overview (the link mailed to me) how much it would cost to offset my footprint, and what projects are available. I had to re-enter all the data! It would be _awesome_ if I had a link that I could mail to friends and family saying "look, here is my impact, and this is how unexpectedly cheap it is to fix it".

<comment><USER18> Mimi from Wren here:

1\. You can change info about your transportation habits + electricity usage in the footprint breakdown below the first six questions. Those top level questions have the largest impact on the delta between your country's avg and your footprint, but you can go more in depth below to account for diff between if you live in an urban, suburb, or rural area.

Does that answer your q? I'm not sure if you are asking for more specificity on your footprint overall or just the housing section.

2\. Good point. We're improving the electricity section of our calculator to account for renewables and other specific energy setups. Will keep you posted when that's up.

3\. (Yay indeed!) All of the initial values pre-populated in the accordion below the first six questions are actually averages from your country. It might not be clear right now since the values appear somewhat random and also disappear as soon as you enter in your own information, but we can have those values persist and show specific deltas between you and your country / world for each question if that's helpful.

4\. We're setting up those links so it's easier to get back to your information in the calculator! Also, we have the cost to offset your footprint appear a page later once you choose your project. Wasn't sure if you hadn't made it to that step or just want that information in the footprint overview link as well.

Hope that's helpful, thanks for the feedback.

<comment><USER13> Thanks. For question 1, I guess the question has two parts: why you ask for the size of my home, i.e., how does it factor into the calculation; and why the density of the area it is in does not seem to factor directly into the calculation.

As for 3 and 4, yes, the more information I can get in the overview the better. And always with a link to the service you are actually providing for money :-)

</comment></comment></comment><comment><USER26> I'm more interested in setting up consumer/hobbyist level carbon capture processes (if thermodynamically possible).

Rough outline from Rod Fitzsimmons:

\- capture of CO2 from the atmosphere using a variety of techniques, usually adsorbtion ([https://en.wikipedia.org/wiki/Carbon_capture_and_storage](https://en.wikipedia.org/wiki/Carbon_capture_and_storage)). This takes quite a bit of energy.

\- Conversion of the dissolved CO2 into alcohols. Reaction is 2CO2 + 9H2O + 12e- → C2H5OH + 12OH- so it's energy-uphill and needs an energy input. Maybe solar cells or a wind turbine. Requires a catalyst, often a variety of copper matrix. Catalysts are the major subject of research. To figure out whether you could do this in your garage you'd probably need to go to the literature.

\- Distillation of the alcohols - usually done with heat, requires 800-900 deg C. Possible but hard and energy intensive. This is where Prometheus sits, they have a nanoscale membrane that does room-temperature separation of the alcohols using electricity input (more energy in!)

\- Conversion of the alcohols into gasoline, diesel, kerosene etc. This is a pretty well-known process that uses a catalyst called ZSM-5 plus heat (mo' mo' energy!). I haven't looked into the chemistry or the availability of the catalyst.

This seems like a better startup idea than a project funding aggregator.

<comment><USER27> \- plant a tree

It solar powered and even self-replicating!

<comment><USER28> Let ivy grow on your walls. The kind with glue pads will not harm walls, and the leaves provide shade in the summer and fall off in the winter.

<comment><USER18> Ivy walls are very beautiful. Might be hard to do at scale + also apparently difficult to maintain but I wouldn't know

<comment><USER28> Why hard at scale?

The only maintenance I've found you needed to do is clear the windows - do it at least monthly during the growing season. And also don't let it grow on to gutters.

Basically push the ivy off of the windows so it hangs down. Hanging down like that seems to send the plant a signal to stop growing in the area. (If you cut it it seems to grow even faster there.)

If the plant dies, which does happen, you need to wait a while for the glue pads to degrade before removing the old plant from the walls.

It's not really any harder than dealing with gardening in general.

</comment></comment></comment></comment></comment><comment><USER29> Not sure how you will provide updates but I think satellite imagery over time would be really neat for reforested areas.

<comment><USER18> Satellite imagery is definitely very powerful, and we're including it in updates for the rainforest protection projects. We'll look into providing that when we have reforestation projects :)

Here's a tweet from a user with a satellite image update from the Tech-enabled rainforest protection project we're working with: [https://twitter.com/crabbyafrica/status/1144332819969105920](https://twitter.com/crabbyafrica/status/1144332819969105920)

</comment></comment><comment><USER30> Congrats on the launch! Curious about your thoughts on the carbon impact of carbon offsets vs investing in green bonds that fund energy efficiency projects (e.g. [https://copower.me/en/](https://copower.me/en/)) vs investing in public companies that fund sustainable development (e.g. [https://www.hannonarmstrong.com/](https://www.hannonarmstrong.com/)) vs investing in green energy companies directly (e.g. vivint solar or first solar).

I recognize that the direct dollar-to-CO2 carbon impact might be lower, but green investments might enable higher retail & institutional spend (since it's an investment instead of a donation) and therefore might have more impact on reducing CO2.

<comment><AUTHOR> This sort of investment is very cool! I hope to see it becoming more common.

We're focusing on direct offsets because we think long term we'll need a great market for carbon offsets and reduction. We already have too much CO2 in the atmosphere, so everything we can do to literally pull it out is necessary. Clean energy is great but I think we'll need something like carbon offsets/reduction in addition to it.

</comment></comment><comment><USER31> This is pretty unfair. People who put money into these projects should be able to make money from them as well. Why should climate-conscious people have to donate money to offset the carbon footprint while investors get to earn?

<comment><AUTHOR> Treating this more as investing is very promising and maybe something we'd consider. Currently most of these solutions do not generate a profit that could be an ROI for investors on Wren or a similar platform, but some projects will have an ROI and it would be interesting if we (or someone else) could offer an easy way for anyone to invest in profitable ideas that are good for the climate.

</comment></comment><comment><USER32> Super neat! One note that I found odd: km/L is a weird way to talk about fuel efficiency for metric. Everywhere that I've seen typically uses L/100km rather than just doing a MPG equivalent conversion.

<comment><USER18> Oh great to know. We recently added in support for metric conversion and weren't familiar with the standard for mpg to metric. We'll change that!

<comment><USER6> Yes, that was very confusing for me because nobody here uses km/L. It's always L/100km.

</comment></comment></comment><comment><USER33> How do you work to avoid monoculture ecosystems when planting forests as carbon capture? Also, how do you ensure that the wood isn't subsequently harvested and burnt, releasing the carbon into the atmosphere again.

<comment><AUTHOR> Great questions.

Monoculture ecosystems are fairly easy to avoid, you just have to plant different types of trees that will thrive. This is easy for the Community Tree Planting project on our site because the farmers are the ones planting the trees and they usually want to incorporate agroforestry techniques as part of their farm, so it's a fairly diverse ecosystem already—they aren't just going out and planting 100s of pine trees.

There's a few strategies to ensure wood isn't harvested. The first one is by making the trees valuable in the ground to farmers—focusing on fruit and nut trees that the farmers benefit from day to day.

Next reason is simple: they're paid to keep them in the ground.

The next is that there's social pressure. These farmers plant trees with a group of other farmers, and if anyone cuts down their trees the whole group loses some of the benefits.

It's a promising model which is why we like this partner.

</comment></comment><comment><USER34> I don't believe in "offsetting personal footprint". This idea appeals to personal guilt, while aims at filling the pockets of the founders. The solution should be going after companies who make products that break by design after certain time of use, thus forcing the customers to buy new items. If done right, this will be painful for both companies (many will have to close the shop) and for the people who are used to cheap shiny stuff, but the result will be a cleaner planet and healthier business model.

<comment><USER5> Not guilt. Not sin. Your logic is specious parroted re-hash from George Monbiot's failed thought leadership from the mid-2000's. Carbon dioxide is pollution and waste just like household garbage, recycling, and compost. When you offset you're cleaning up after yourself.

As with more tangible-seeming waste, it's always better to avoid and reduce before paying another party to deal with it. Yet CO2 is demonized because global warming is a collective externality. Because it's invisible doesn't make it intangible. Because the reductions can be counteracted by an entity that's in another location doesn't make a difference, either!

</comment></comment><comment><USER35> Did you consider the ability for one to offset their carbon footprint on their own? I know there is probably less money involved, but it would be cool if I could determine my footprint and then be given tasks to try to offset it on my own.

EDIT: cool project btw :)

<comment><AUTHOR> Oh that's a great point. You can absolutely use our carbon calculator and then find another project to support. We want to make a really good carbon calculator that's useful to everyone, not just Wren subscribers. Let us know if you have ideas or feedback there.

<comment><USER35> Could you provide an API for the carbon calculator? Or is that relatively easy to build?

<comment><USER18> Here's the info on how we built it — Landon posted about this a few hours ago:

> We use data + research from Berkeley's cool climate lab > ([https://coolclimate.berkeley.edu/publications](https://coolclimate.berkeley.edu/publications)) > The main model is maintained by them, and is based on linear regression from > a bunch of lifestyle variables that you input into the calculator. Our > version is slightly different because we base it on country instead of zip > code, so we scale most input variables by the country's per capita emissions > to get a good estimate.

Some of the data might be a little tricker to find but most of it is based off of Cool Climate's model + World Bank per capita emissions data. Let us know if we can help with anything here!

</comment></comment></comment></comment><comment><USER36> Does this compete with Pachama? I don't understand this space well so I'm not entirely sure, but if I remember well Pachama is also trying to sell, carbon offsets by quantifying forest projects.

<comment><AUTHOR> We love Pachama! They have been helpful in shaping our understanding of the space and some of the big challenges with forest carbon projects. They are not a competitor though, they mostly work with bigger companies where as we focus on individuals.

</comment></comment><comment><USER37> Have you consulted any experts in this area to see if offsetting carbon footprint is an effective way? Perhaps that will provide more credibility to potential customers.

<comment><USER18> Yes, we've spoken to many (i.e. UC Berkeley's Cool Climate, Nori, and Pachama) who have deepened our understanding of the space and inspired us to keep building. As it turns out, the best solution to climate change is divesting from fossil fuels entirely, but we will need a whole host of solutions that includes carbon sequestration and carbon removal — projects and technologies that individuals can fund. If you have anyone you think we should talk to, please send them our way!

</comment></comment><comment><USER38> Can you share the methodology on how you calculate a carbon footprint/offset?

<comment><AUTHOR> For carbon offsets, it is pretty different depending on the type of project. We do not invent these methodologies, we use methodologies from groups like Verra Carbon Standard ([https://verra.org/project/vcs- program/methodologies/methodol...](https://verra.org/project/vcs- program/methodologies/methodology-catalog/)). [https://projectwren.com/methodologies](https://projectwren.com/methodologies) has more information about how we specifically choose projects.

It can be pretty down in the weeds to calculate the emissions from these projects and since it varies by type I can't summarize it all here. However if you have more specific questions I'd be happy to answer.

Re: carbon footprints, it's a little simpler. We use data + research from Berkeley's cool climate lab ([https://coolclimate.berkeley.edu/publications](https://coolclimate.berkeley.edu/publications)) The main model is maintained by them, and is based on linear regression from a bunch of lifestyle variables that you input into the calculator. Our version is slightly different because we base it on country instead of zip code, so we scale most input variables by the country's per capita emissions to get a good estimate.

</comment></comment><comment><USER39> see also: [http://www.carbonzero.ca/offset/?offset_tonnes=6.23423881733...](http://www.carbonzero.ca/offset/?offset_tonnes=6.2342388173333)

</comment><comment><USER40> Please add more payment methods, credit cards are kinda rare where I live.

<comment><USER18> Mimi, Wren co-founder here. What payment methods are most convenient / common for you?

<comment><USER40> Debit/IBAN or PayPal would work :)

<comment><USER18> Oh perfect. We're using Stripe and accept Debit Cards currently. The credit card wording we're using is pretty confusing, we'll change that!

<comment><USER40> I think that's a misunderstanding, sorry. I was talking about SEPA debit, via an IBAN. The checkout form doesn't appear to accept those atm.

<comment><USER18> Oh got it. Yes, we'll add in an ability to checkout with debit via an IBAN / Paypal soon. Will keep you posted!

</comment></comment></comment></comment></comment></comment><comment><USER41> Shameless plug: check out Cloverly.com for an API for Carbon Offsets.

<comment><USER18> Nice plug! Reminds me of this ask from Tobi Lütke at Shopify but with wind + solar credits: [https://twitter.com/tobi/status/1148376688423854080](https://twitter.com/tobi/status/1148376688423854080)

</comment></comment><comment><USER42> Hi! Jet-Set Offset here (www.jetsetoffset.com). This is an interesting approach for offsetting. We're a startup with a similar focus on air travel -- which is one of the largest contributors of carbon emissions in the US and around the world, with emissions rates that have been increasing 4% each year as more and more of us are flying. We've found that lack of awareness around this issue is almost as great as the difficulty of navigating the traditional carbon marketplace to "offset" your flight emissions. While flying less is the best thing each of us can do as individuals, it's not always possible or realistic.

Jet-Set Offset was founded with the belief that we can make better choices and do good when we fly. Jet-Set Offset is a platform that allows eco-conscious travelers to do something about the environmental impact of their air travel by automatically donating one-cent per mile to their choice of non-profit environmental organization - every time they fly. Rather than operate as another carbon market, we've developed a donation-based alternative. Our model allows members to give based on the exact air mileage of their flight (not an estimated subscription model), and give to nonprofits in a meaningful way without taking a 20% cut.

We share similar aims to Wren but our approach is different. Here's how: \- We provide a donation-based alternative to the traditional "purchase and sale" carbon offset market. Some of our nonprofit partners operate certified carbon offset projects, but Jet-Set Offset is not just another carbon marketplace. \- Jet-Set Offset operates as a business, but every donation made through the platform is 100% tax-deductible, as it's made directly to the organization of the flyer's choice. The organizations pay Jet-Set Offset a 3% fee of every donation made for use of the platform, in addition to credit card processing fees -- which means that the non-profit organizations are receiving 94% of each donation made. \- The work of many of our nonprofit partners moves beyond the direct mitigation of carbon emissions by also focusing on climate adaptation, resilience, energy transformation, and policy change. \- We've made choice a huge part of our model. Flyers can choose to give where they live and support a local organization with an environmental mission that resonates with them.

As public consciousness of this issue grows, we think that air travelers will seek viable options and alternatives to the traditional 1:1 carbon offset markets -- which can be challenging to navigate and bring up separate issues of resilience, additionality, permanence, and leakage (see Andy Newman's recent article in the NYT, "If Seeing the World Helps Ruin It…"). While certifying organizations go to great lengths to verify carbon offset projects, verification has limits.

To all the readers, check us out! We're interested in feedback to our approach and connection to more nonprofit partners doing amazing work that we can support. Is that an organization you'd want to give to when you fly? (Currently, any US-based 501c3 organization can request to become a Jet-Set Offset partner, provided that part of their mission is working to combat climate change and that they can provide measurable results of how donations made via the platform will be used.)</comment>