What Is Net Zero?

Net zero means that the amount of greenhouse gases added to the atmosphere is balanced by an equivalent amount removed from it. Rather than requiring that no emissions occur at all, the concept accepts that some emissions will remain and insists that they be cancelled out by removals, so that the net contribution to atmospheric greenhouse gases is zero. It has become the central organising goal of international climate policy.

The idea behind the balance

Greenhouse gases, chiefly carbon dioxide, trap heat in the atmosphere and drive global warming through the greenhouse effect. Because carbon dioxide accumulates and persists for a long time, scientists have found that global temperatures are closely linked to the total amount emitted over time. Stabilising the climate therefore requires reducing net emissions to zero: as long as more is being added than removed, concentrations keep rising.

The Intergovernmental Panel on Climate Change (IPCC), the leading scientific authority on the subject, concluded in its special report on 1.5C of warming that limiting warming to that level implies reaching net zero carbon dioxide emissions globally at around the middle of this century, with deep reductions in other greenhouse gases as well. This finding underpins the targets that many governments and organisations have since adopted.

Cutting emissions comes first

A common misunderstanding is that net zero can be achieved mainly by offsetting or removing carbon rather than by reducing emissions. In the mainstream scientific and policy view, the priority is to cut emissions as far and as fast as possible — by shifting to low-carbon energy, improving efficiency, changing industrial processes, and altering land use. Removals are intended to deal only with the residual emissions that are genuinely hard to eliminate, such as some in aviation, heavy industry, and agriculture.

Removing carbon dioxide can happen in two broad ways: through natural processes, such as growing forests and restoring soils and wetlands, and through engineered methods that capture and store carbon. Both face limits of scale, cost, and permanence, which is why they are seen as a complement to deep emissions cuts rather than a substitute for them.

Net zero, carbon neutral, and gross zero

Several related terms are often used loosely, and it helps to distinguish them:

• Net zero usually refers to balancing emissions and removals across all greenhouse gases, or specifically carbon dioxide, for an entity or the whole world.
• Carbon neutral is a similar idea often applied to a specific product, organisation, or activity, and has historically relied more heavily on offsetting.
• Gross zero would mean eliminating emissions entirely, with no residual emissions to balance — a far more demanding standard that is not generally considered achievable across a whole economy.

Because these terms carry different implications, credible net-zero commitments increasingly specify which gases are covered, over what boundary, and how far they rely on removals or on carbon offsets, whose quality and permanence are the subject of ongoing scrutiny.

How progress is measured

Assessing progress towards net zero requires measuring both emissions and removals, which is more complex than it sounds. Countries report their emissions using internationally agreed methods under the UN Framework Convention on Climate Change (UNFCCC), and the Paris Agreement of 2015 established a framework in which nations set and update their own targets. For an organisation, credible measurement usually distinguishes between direct emissions, emissions from the energy it buys, and those across its wider value chain, since ignoring the last of these can understate the true total.

Independent scrutiny matters because the term net zero can be applied to very different levels of ambition. A pledge that depends heavily on distant future removals, or on offsets of uncertain quality, is weaker than one built on near-term cuts. Transparency about assumptions is therefore central to judging whether a net-zero claim is meaningful.

Why it matters

Net zero is the yardstick against which climate action is now widely judged, from national policies to corporate strategies. Understanding it correctly — as a balance achieved primarily through steep emissions cuts, with removals handling a limited remainder — helps separate substantive commitments from looser claims. It connects directly to related ideas such as an individual or organisation’s carbon footprint, and it frames much of the debate about how the world can limit further warming.