Knowledge Base


Carbon offsets that would not have occurred if the offset project had not been implemented. (This is one of four factors to consider when acquiring carbon offsets.)

Planting of new woods on places that had previously been devoid of trees.

Caused by humans. The current scientific consensus states that global warming is a direct result of the sharp rise in anthropogenic emissions of greenhouse gases.


A biomass-derived fuel, usually in liquid form. Bioethanol from sugarcane or maize, biodiesel from canola, soybeans etc.

Organic material from living or recently dead plants or animals.

Blue carbon is the carbon absorbed and deposited in biomass and sediments by living organisms in coastal (e.g., mangroves, salt marshes, seagrasses) and marine environments.


The California Cap and Trade Program is administered by the Western Climate Initiative (WCI) and controlled by the California Air Resources Board. This program began in 2012 with California and subsequently was linked to similar emissions programs from the Canadian provinces of Quebec, and briefly, Ontario as well. Both jurisdictions' allowances can be used for compliance. The cap and trade scheme includes major electric power plants, large industrial plants, and gasoline distributors, among other sectors. Visit the California Air Resources Board's summary of their cap-and-trade programhere.

A regulatory procedure that puts a "cap" on the amount of greenhouse gas emissions that companies are permitted to emit. Firms that come in under their limitations have the option to "trade" (sell) their excess emission permits to other companies that have exceeded their limit.

Permissions (credits) to release greenhouse gases for participants in a controlled carbon market.

Middlemen who do not hold offsets but enable transactions between project developers and end-users, merchants, and/or retailers.

The maximum amount of CO2 that the world can release while still having a good probability of keeping warming below the 2°C goal laid out in the Paris Agreement.

A process that separates (captures) a reasonably pure stream of carbon dioxide (CO2) from industrial and energy-related sources, conditions it, compresses it, and transports it to a storage site for long-term isolation from the atmosphere (sequestration). Carbon capture and storage is another term for it.

A method of capturing CO2 and then using it to create a new product. Carbon capture, utilization, and storage occurs when CO2 is stored in a product for a climate-relevant time horizon. Only when coupled with CO2 that has recently been removed from the atmosphere does CCUS lead to carbon dioxide removal.

Equal to the offsetting of one tonne of carbon dioxide or carbon dioxide equivalent. A monetary value is ascribed to the reduction or offset of greenhouse gas emissions; this is a general term for any tradable certificate or permit reflecting emissions reductions.

For as far back as geological evidence shows – at least 650,000 years – the Earth's natural carbon cycle has maintained a steady equilibrium of carbon dioxide in the atmosphere - around 275 parts per million (ppm). We discovered this by examining the contents of Antarctic ice cores. As a result of the natural carbon cycle: People and animals (source) use respiration to turn oxygen into carbon dioxide. Plants (sinks) absorb CO2 and release it back into the atmosphere. Over the seas, oceans both produce (source) and absorb (sink) carbon dioxide. Dead organic matter traps carbon underground in various forms such as fossil fuels (sink), while volcanic eruptions (source) can release CO2 from carbonate rocks deep inside the Earth.

A heat-trapping gas composed of one part carbon and two parts oxygen. Too much CO2 in our atmosphere causes the Earth to retain too much of the sun's heat, leading to global warming. And excessive global warming eventually leads to various complications that are detrimental to our planet and its inhabitants, such as rising sea levels or certain areas becoming too hot for humans to live in.

The quantity of carbon dioxide emitted into the atmosphere as a result of any given entity’s actions. Individuals, corporations, and even nations can have a carbon footprint.

A marketplace that treats emissions reductions as a commodity, where participating members can buy and sell carbon credits

Often known as having a net zero carbon footprint, this is achieved by either reducing carbon emissions to zero, or by balancing a measurable quantity of carbon emitted with an equivalent amount offset..

Good to Know

It’s the impact created on the climate as we go about our daily lives and comes from the greenhouse gases emitted from each decision we make throughout the day – either directly or indirectly. It’s a way of representing your personal contribution to the polluting gases that cause climate change. These gases are often referred to as ‘greenhouse gases’ due to their effect on the planet’s climate.

From the type of car you drive to the construction materials of your new wardrobe – it all leaves a footprint. You can find out more in our article explaining exactly what a carbon footprint is.

The biggest stakeholders are society as a whole.

Climate preservation is a big, urgent task that will likely take trillions of dollars invested in reversing climate change before we are on track and balanced..

As GeorgeKenny finds a sustainable business model to champion, we find it will be much easier to raise the funding necessary to complete the large infrastructure projects that are necessary to balance out climate change by inspiring you with art and fashion.

Carbon neutrality is when you have a net-zero carbon footprint, which can only be achieved by carbon offsetting. Through offsetting, individuals and organisations can become carbon neutral by taking action to remove as much carbon dioxide equivalent from the atmosphere that they put into it.

‍Offsetting is a way to compensate for your carbon emissions by funding an equivalent carbon dioxide saving elsewhere. Offsetting projects could be native restoration or renewable energy projects, for example, and can be either domestic or international. 

Wren is a Public Benefit Corporation (PBC), not a non-profit. A PBC is a new legal structure for companies that balance mission and profits by being mission-driven.

How does their business model work?

80% of your subscription is sent straight to climate projects that plant trees, protect rainforest, and suck carbon out of the sky. The rest is spent keeping Wren running: paying salaries, sourcing the best climate projects, and paying for marketing to help as many people as possible take climate action.

The best minds of our generation are optimizing Ads at Google and Facebook. We will only be able to hire those people if we can pay them.

Fund 4 types of climate solutions.

1. Technology

Carbon removal technologies like biochar and mineral weathering turn atmospheric CO2 into solid rock—locking up carbon for thousands of years.

2. Tree Planting

Trees are nature’s soldiers in the fight against climate change, and Wren members help plant millions of native species every year.

3. Policy

Wren members support leading policy groups that push for changes to our economies, agriculture, infrastructure, power grid—every system that influences our planet’s climate.

4. Conservation

Natural ecosystems like old growth forest, peat bogs, and mangrove swamps are the lungs of the earth. Wren members help protect them.

The model is grounded in research from UC Berkeley's CoolClimate Network and data from the World Bank to estimate your carbon footprint, based on the lifestyle factors you enter.

Here's how it works:

  1. pull in typical baseline carbon footprint values from Berkeley's Cool Climate project.
  2. We calculate your country's average carbon footprint using data from World Bank, then scale the baseline carbon footprint values by your country's average.
  3. As you input your own details into your carbon footprint, we run that information through Berkeley's Cool Climate model.

Climate change is hard to get your head around– and we've found that contextualising it in terms of an individual's lifestyle helps people understand how they can make a difference.

1 kg of CO2e is equivalent to a (large) beach ball with a diameter of slightly over 1m (3 feet).

‍This is the same amount of CO2e produced by driving an average car 3.56 miles. It's the same as half a litre of petrol, or 128 smartphone charges.

Greenwashing is like the modern-day equivalent of cigarette companies claiming smoking is good for you. We eventually saw past the lies from tobacco companies and we need to decouple ourselves from dirty fossil fuels as soon as possible.

Although it is great for any company to fund climate solutions, fossil fuel companies and other big emitters should not be let off the hook just for buying carbon offsets. To end the climate crisis, every oil and gas company will either have to shut down or completely transform their business. Carbon offsets are not a viable longterm solution for these companies to keep polluting.

We spread the word. Collective action refers to the collaborative efforts of a group of people working together towards a common goal. At GeorgeKenny, we believe in the power of collective action. We have built our business off the belief that millions of small changes made by millions of individuals can have a significant impact and help us solve the climate crisis.

The Climate Crisis

To end the climate crisis, we broadly need to do 4 things: produce way more clean energy (and stop burning fossil fuels), decarbonize all of our greenhouse gas emitting infrastructure (everything from cars and stoves to steel and cement factories), save our forests and other natural ecosystems that are currently storing gigatons of carbon, and transform our food system to stop emitting so much greenhouse gases. To avoid the worst effects of the climate crisis, we need to do all of this in the next 10 years. Since it's almost impossible to get these four giant tasks done in 10 years, we also need to get to work removing carbon from the atmosphere through planting and restoring more forests, practicing carbon-sequestering agriculture, and likely even building machines to suck carbon directly from the air.

That gives us a total of 5 big priorities: make tons of clean energy, decarbonize our infrastructure, protect our carbon sinks, transform our food system, and remove carbon from the atmosphere. At Wren we think we'll one day be helping with all of these, but at the moment are focused on protecting our existing carbon sinks like the Amazon Rainforest, and on removing more carbon from the atmosphere through tree plantingbiochar production, and other solutions.

While effects of climate change are already being felt worldwide (historic wildfires, flooding, and heatwaves to name a few), there is still time to avoid many of the worst case scenarios and end the climate crisis for good.

However, every day we wait makes the peak of the climate crisis a bit worse. Based off the IPCC's best estimates, our "carbon budget" to mitigate the worst of global warming is blowing by fast, with only around 10 years before we pass a threshold of 1.5° of warming. It's never too late to address the climate crisis, but every day we delay means more extreme weather, more climate refugees, and more people dying—we must act immediately.

Carbon Calculator

Climate change is hard to get your head around– and we've found that contextualising it in terms of an individual's lifestyle helps people understand how they can make a difference.

We use a model grounded in research from UC Berkeley's CoolClimate Network and data from the World Bank to estimate your carbon footprint, based on the lifestyle factors you enter.

Here's how it works:

  1. We pull in typical baseline carbon footprint values from Berkeley's Cool Climate project.
  2. We calculate your country's average carbon footprint using data from World Bank, then scale the baseline carbon footprint values by your country's average.
  3. As you input your own details into your carbon footprint, we run that information through Berkeley's CoolClimate model.

Carbon dioxide makes up 75% of total GHG emissions. CO₂e represents the global warming potential of CO₂ plus the remaining 25% of emissions from methane, nitrous oxide, hydrofluorocarbons, and other potent GHGs converted to carbon dioxide equivalents (CO₂e). CO₂e is measured in metric units, so when we say a ton of CO₂, we mean 1 metric tonne (~2204.6lbs) of CO₂e.

Carbon Offsets

Carbon offsets are the key funding mechanism for projects that are planting billions of trees, producing biochar, destroying refrigerants, protecting the Amazon rainforest, and much more.

Not all carbon offsets are created equal, though—historically, some projects funded by carbon offsets have failed to be transparent with their impact. Our focus at Wren is finding the most impactful, transparent projects for members to fund each month.

Everything you do in life– driving a car, flying a plane, even the food you eat and the things you buy, emits some amount of greenhouse gases into the atmosphere. All these things add up to your carbon footprint.

By funding climate solutions like tree planting, rainforest protection, and biochar, you can support the removal of greenhouse gases from the atmosphere– and offset your carbon footprint. This lets you effectively live carbon neutral.

We pick climate projects based on four primary criteria:

  1. Measurable results
  2. Lasting impact
  3. Wouldn’t happen without your funding
  4. No double counting

We have a whole page dedicated to this subject, and we recommend you read about our how we choose projects here.

When we choose to fund a project, we establish a direct relationship with the team behind the project, ensuring quality progress updates on a monthly cadence, plus access to financial and other key details about the project.

All of this is passed on to Wren members, and when a project under-delivers, we will keep you apprised and allocate funds toward other projects.

The Climate Portfolio

The Wren Climate Portfolio is a dynamic portfolio of the best solutions to climate change.

The projects reduce and remove CO₂ by planting trees, promoting sustainable agriculture, protecting rainforest, and more.

Wren members offset their carbon emissions each month by contributing to the Climate Fund.

You can learn more about the projects in the Fund here.

Yes. Occasionally, we'll onboard a new project (see: Biochar in California, our first U.S.-based climate project) to the Fund.

We regularly update the fund allocation to make sure our members are having the most impact they can. Often, this means sending more money to a particularly promising project. Occasionally, it means diverting funds from a project that isn't going according to plan.