What are residual emissions?

Residual emissions are the part of a footprint you can’t yet get rid of. They are the reason carbon removal matters for net zero, and the right place for carbon credits in a climate plan: after the cuts, not instead of them.

This page is part of our carbon footprint section. For the bigger picture of where credits fit, see reduce vs offset.

What counts as residual?

The Oxford Offsetting Principles define residual emissions as greenhouse gas emissions that remain after taking all possible actions to implement emissions reductions given current resources and technology^{Source 2}. Two parts of that definition matter:

• “All possible actions”. Emissions you could cut but haven’t are not residual. They are a backlog.
• “Current resources and technology”. What counts as residual changes over time. The Principles say criteria should be revisited often, because emissions that were hard to reduce can become easier with new technology^{Source 2}.

Which emissions are hard to abate?

The IPCC gives agriculture, aviation, shipping and industrial processes as examples of hard-to-abate residual emissions^{Source 3}. It also finds that, even in pathways that limit warming to 1.5°C, transport likely doesn’t reach zero CO₂ by 2100, so negative emissions are likely needed to counterbalance its residual CO₂^{Source 3}.

The IPCC concludes that carbon dioxide removal to counterbalance hard-to-abate residual emissions is unavoidable if net zero CO₂ or greenhouse gas emissions are to be achieved^{Source 3}.

How big should residual emissions be?

For companies, the SBTi gives the clearest benchmark. It notes that most companies will reduce emissions by at least 90% through their long-term science-based targets, but that not every company can decarbonise completely^{Source 1}. Its cross-sector pathway cuts emissions by at least 90%, so long-term targets for many companies equal at least a 90% absolute reduction across scopes^{Source 1}.

In the SBTi’s own worked example, a company with 100 tonnes of base-year emissions excludes 1 tonne from its inventory and 1 tonne from its target boundary. After a 90% cut on the remaining 98 tonnes, 9.8 tonnes are left, and the company must neutralise 11.8 tonnes in total^{Source 1}.

From base year to residual emissions (SBTi example)swipe →

Scrolls sideways to show every column.

From base year to residual emissions (SBTi example), as of October 2026

Step	Amount (t CO₂e)
Base-year emissions	100
Covered by the long-term target	98
Residual after a 90% cut	9.8
Plus excluded emissions	2
To neutralise at net zero	11.8

As of Oct 2026 · Source: [1] SBTi Corporate Net-Zero Standard v1.3.1

How to balance what remains

At net zero, residual emissions must be neutralised: the SBTi requires companies to remove carbon from the atmosphere and store it permanently to counterbalance unabated emissions, from the target year onwards^{Source 1}. Emissions excluded from the inventory or the target boundary must be neutralised too^{Source 1}.

That rules out using avoidance credits for this job. The Oxford Principles explain why: if organisations kept emitting at net zero while paying others only to reduce their emissions, global emissions would never reach net zero^{Source 2}. They ask users to increase the share of removals over time, aiming for 100% removals by the global net-zero date, 2050 at the latest^{Source 2}. See removal vs avoidance credits for the difference.

Why storage time matters

Not every removal lasts equally long. The IPCC estimates storage time scales from decades to centuries for carbon held in vegetation and soils, and 10,000 years or more for carbon stored in geological formations^{Source 3}. Carbon in vegetation and soils can be reversed by human or natural disturbance and is exposed to climate change, while CO₂ stored in geological and ocean reservoirs, and carbon in biochar, is less prone to reversal^{Source 3}.

The Oxford Principles call for a shift to removals with low risk of reversal and durability over centuries to millennia, while recognising that high-integrity removals with a moderate risk of reversal play a valuable role in the short to medium term^{Source 2}.

Residual emissions for individuals

There is no formal standard for a personal residual footprint, but the idea is the same. It is what remains after the big changes you can make now. In a review of 53 studies, living car-free, switching to an electric car and taking one fewer long return flight each had median savings of more than 1.7 tonnes of CO₂e a year, renewable electricity 1.6 tonnes and a vegan diet 0.8 tonnes^{Source 4}. Start with how to reduce your carbon footprint, then size any credits on what is left.

1. 1

   Step 1: Measure

   Find your yearly footprint and its biggest sources.

2. 2

   Step 2: Cut what you can

   Make the large changes first, and set dates for the ones you can’t make yet.

3. 3

   Step 3: Size what remains

   Your residual footprint is the total after those cuts, not your original number.

4. 4

   Step 4: Balance it honestly

   Favour removal credits with durable storage, and describe them as a contribution.

The credits needed calculator turns your remaining tonnes into a number of credits. Measure again each year: as you make more changes, your residual footprint should shrink.