What is net zero? A plain-English explanation
Net zero has become one of the most used — and most misused — phrases in sustainability. This guide explains what it actually means, how it differs from carbon neutral, and how to tell the difference between a serious commitment and a marketing claim.
Net zero has become one of the most used — and most misused — phrases in sustainability. This guide explains what it actually means, how it differs from carbon neutral, and how to tell the difference between a serious commitment and a marketing claim.
The core definition
Net zero means reaching a state where the greenhouse gases you put into the atmosphere are balanced by the amount you remove. At a global level, net zero emissions would halt the accumulation of greenhouse gases and — if sustained — eventually stabilise temperatures.
For an individual company or country, net zero means eliminating as much of its emissions as possible and using high-quality carbon removals to balance whatever remains. The key emphasis is on elimination first, then removal of residuals.
The distinction matters because some organisations have claimed "net zero" while maintaining near-current emission levels and simply buying cheap offset credits to cancel them out. Under any rigorous definition of net zero, that is not net zero — it is a bookkeeping exercise.
Net zero versus carbon neutral versus carbon negative
These terms are often used interchangeably, but they have distinct meanings — and the distinctions matter if you are making or evaluating sustainability claims.
| Term | What it means | Key requirement |
|---|---|---|
| Carbon neutral | CO₂ emissions are balanced by offsets or removals | Balancing only — no required reduction target |
| Net zero (operational) | All operational GHGs (Scope 1 & 2) eliminated/balanced | Deep reductions first, high-quality offsets for residuals |
| Net zero (full value chain) | All GHGs including Scope 3 eliminated/balanced | The SBTi Net-Zero Standard definition |
| Carbon negative | More carbon removed than emitted | Removals exceed emissions — a net carbon sink |
| Climate positive | Often used synonymously with carbon negative | No standard definition — treat with caution |
The most rigorous definition is the SBTi Net-Zero Standard: companies must reduce their emissions by at least 90% across all scopes before neutralising the remaining 10% with permanent carbon removals. No avoidance offsets for the final 10% — only genuine removals.
What does a credible net zero target look like?
A credible corporate net zero commitment should include: a science-based near-term target (typically 50% reduction by 2030 from a baseline year), a long-term net zero target with a defined scope (all three scopes), a clear methodology for measuring Scope 3 emissions, and transparency about what role offsets will play.
Red flags include: no defined baseline year, no Scope 3 target, vague language about "offsetting" without specifying credit quality, and net zero targets set for 2050 with no near-term milestones.
The timeline question: when does net zero need to happen?
The IPCC has stated that global net zero CO₂ emissions need to be reached by around 2050 to limit warming to 1.5°C. For individual countries and companies, the timeline depends on their starting point and the pace of feasible reduction.
The UK has a legally binding net zero target for 2050 set under the Climate Change Act. The EU's net zero target is also 2050, with a binding 55% reduction target for 2030 as an interim milestone. Many large corporates have set net zero targets ranging from 2030 to 2050.
Net zero claims in practice: what to check
| Claim type | What it should include | Common gap |
|---|---|---|
| Net zero by [year] | Scope 1, 2 and 3 coverage, science-based pathway, interim targets | Scope 3 excluded or only partially included |
| Carbon neutral now | Emissions measured and offset with verified credits | No reduction plan — only offsetting current level |
| Net zero operations | Scope 1 and 2 covered with credible reduction plan | Excludes supply chain (Scope 3) which is usually the majority |
| Science Based Target | Validated by SBTi, covering required scopes with verified methodology | Committed not validated — SBTi validation pending |
Key takeaway
Net zero means deep emissions reductions plus high-quality removals for residuals — not current emissions minus cheap offset credits. The SBTi Net-Zero Standard requires at least 90% absolute reduction before any offsetting is applied. A company claiming net zero without a science-based reduction pathway is not net zero under any rigorous definition.