Statistics of Voluntary Carbon Offsets in 2020

What does the voluntary carbon offsets market really look like? Here are some key statistics of the voluntary carbon offsets in 2020 with The Open Offsets Directory, using data from the Berkeley Carbon Trading Project.

Offsets Issued and Retired by Year

First, let’s take a look at the big trends: total amount of voluntary offsets issued and retired each year:

Offsets Issued and Retired

The good news is that the market is growing. Compared to 2015, for example the total volume of offsets issued is nearly three times higher.

Overall, though, the market is still very small: About 250 million tons were issued in 2020, and a total of about 1.24 billion tons of voluntary carbon offsets have been issued ever. Meanwhile the annual global emissions are about 43 billion tons. To put this in perspective, the issued offsets in 2020 account for about 51 hours of the world’s emissions.

Furthermore, less than half of the offsets issued each year has actually been “retired,” or used by an organization to offset its emissions. The rest are either unsold or held by traders. The ratio of retired versus issued offsets has hovered at about 50% in the last few years:

Ratio of offsets retired vs issued by year

Offsets Issuance by Vintage Year

An important detail about voluntary offsets is that they may be issued years after the emissions reduction or removal took place, because of the lengthy process of issuing and verifying the offsets. “Vintage year” refers to the year when the emissions reduction/removal happened, while “issuance year” refers to the year when the offsets are actually issued. In calendar year 2020, offsets were issued with a weighted average vintage year of 2016:

Offsets Issued by Type

The voluntary offsets market supports an amazing variety of project types. Here is a breakdown for offsets issued in 2020:

Note this is different than the breakdown of offsets issued for vintage year 2020, which was featured in a related blog post.

Offsets Issued by Project Country

Offsets Issued by Standards/Registry

How big are the standards organizations and registries? Here’s a breakdown by volume of credits:

Here’s a breakdown by number of projects:

Biggest Developers of Offsets 2020

Now for something you’ve really wanted to know… Who makes these offsets?

Here are the top offsets developers based on credits issued in 2020:

Biggest Users of Carbon Offsets in 2020

Once offset credits are issued, they may be bought and sold several times before someone finally uses them to actually offset their emissions. When that happens, the offsets are “retired” and removed from circulation.

These are the top organizations that retired the offsets in 2020, for themselves and on behalf of their customers:

Want to See More?

You can take a look at the offsets yourself at

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If you’re involved in the offsets market, as a developer, broker, trader, retailer, or buyer, please join The Open Offsets Directory project to make offsets more transparent and trustworthy. Start by completing this questionnaire to let us know your role, your thoughts on the market, and if you’d be available for an interview.


Barbara Haya, Micah Elias, Ivy So. (2021, September). Voluntary Registry Offsets Database V2, Berkeley Carbon Trading Project, Center for Environmental Public Policy, University of California, Berkeley. Retrieved from: