Behind the details of defining climate responsibility

This post originally appeared on CDRANet’s website.

Author: Glenn Hampson, Founder and Director at CDRANet

The term net zero is a cornerstone of modern climate policy, invoked by nearly every major country and corporation as a benchmark of responsibility. Yet behind this apparent consensus lies a wide array of definitions, accounting practices, and political choices that shape how genuine progress toward our climate goals is made and measured. Remedying these inconsistencies is essential if we are to keep building our climate policy future on this foundation.

Why net zero?

For most of the past 12,000 years—the period during which human civilization has developed—the Earth’s carbon cycle has kept our atmospheric carbon dioxide levels in rough balance. This equilibrium began to tilt after the start of the Industrial Revolution in the early 1800s, when fossil-fuel combustion and large-scale deforestation started adding carbon faster than our planet’s natural sinks could absorb it.

Today, the pace and scale of this carbon imbalance is alarming. Humans are adding over 37 billion tons of carbon dioxide to the earth’s atmosphere every year, and of this amount, only 2.1 billion tons are removed (almost entirely through reforestation and soil-carbon management). This imbalance is obviously not without consequences, causing rising surface temperatures (spiking to 1.55 °C above pre-industrial levels in 2024), melting Arctic ice, rising sea levels, increased ocean acidity, and increasingly violent weather patterns.

Achieving net zero is a necessary first step for arresting this destructive change. It is not, however, the final step. Even given the current concentration of CO₂ in our atmosphere, global temperatures will continue rising for centuries, which is why we also need to begin removing more carbon dioxide than we emit—that is, achieve net-negative emissions—as soon as possible, most likely through a combination of aggressive emissions reductions and accelerated scaling of our CDR capacity.

Net zero confusion and tensions

Under the 2015 Paris Agreement, signatories promised to limit global warming to well below 2°C above pre-industrial levels, aiming for 1.5°C, and to achieve “net zero” climate neutrality by the second half of the century by reducing greenhouse gas emissions. Countries also agreed to periodically submit Nationally Determined Contributions (NDCs) describing their specific emissions reduction goals.

Significant as this agreement has been in marking our global commitment to fight climate change, the outcome of this agreement over the years has been mixed. At least in part, this is because our approach to calculating net zero—our definitions, goals and accounting methods—have all varied widely. For instance, some NDCs cover only carbon dioxide, while others bundle all greenhouse gases or omit certain emissions (like imports or exports). Or, some pledges cover short-term actions, while others defer cuts and rely on massive removals after 2050. Modeling shows that deferring removals to decades in the future may be allowing 20-30 percent more carbon emissions by 2050 than pathways that constrain removals early.

Inconsistency in how CDR is mixed into NDCs has also opened the door to abuse. For one, not all carbon storage is permanent. Counting the carbon dioxide sequestered by forests works only if those forests don’t burn. Canada’s 2023 wildfires alone emitted more than half a billion tons of CO₂, wiping out years of national land-sink gains. Some countries even include CO₂ absorbed by oceans in their territorial waters—technically correct, but far from the intent of the Paris Agreement.

Deciding what counts is another loophole. For example, when an emissions-reduction or removal project generates a carbon credit, both the host country (where the project occurs) and the buyer (the country or company purchasing the credit) can claim the same ton of CO₂ toward their targets. How to treat avoided removals is also problematic; only around 16 percent of carbon credits issued are for actual carbon reductions. The global carbon offset market (which includes removals, reductions, and avoidance credits) lost 61 percent of its value in 2023 after investigations revealed widespread over-crediting of avoided-deforestation projects.

Beyond these technical and implementation issues, the absence of a unified definition for net zero has politicized the role of CDR in achieving net zero. Some environmental groups see CDR as a license for delay, while others view it as essential for balancing hard-to-abate sectors. This tension—between skepticism and pragmatism—has fragmented international cooperation, making it harder to develop consistent policy frameworks and shared rules.

Political and economic tensions have also resulted. Durable carbon removal is expensive, while claiming a forest or ocean sink is nearly free; not all emissions are equally easy to abate, nor are all natural or engineered CDR approaches feasible in every geography; and there are no rules prohibiting wealthy countries from funding carbon removal projects in developing countries, claiming the removals, and continue emitting—a dynamic often described as carbon colonialism.

There’s also the political and economic tension of realizing we’re running out of time. Our global temperatures are increasing, our Paris pledges aren’t being fulfilled, our planet’s natural carbon sinks are weakening, and the CDR market needs help scaling. The time for action is now or never. Our political and economic challenges need to be met with haste, not postponed until 2050.

A way forward

Restoring integrity and effectiveness to our net zero ambitions can begin with aligning our climate definitions and ambitions with reality. Five principles stand out here:

1. Use every tool available: Net zero must rely not only on emissions prevention and reduction, but also removal. Each leg of this triad is critically important for achieving net zero emissions as quickly as possible. Waiting until mid-century to reach net zero means waiting until global temperatures are well beyond our Paris targets.

2. Prioritize durability: CDR methods that can store carbon dioxide for a century or longer must be prioritized. Short-term biological storage can also contribute but should be heavily discounted in carbon accounting. One megaton of carbon emitted is not equivalent to one megaton of carbon stored in flammable forests.

3. Temporal integrity: Short-term reduction is imperative. While long term reduction is also important, we can’t play shell games with our commitments. Real reductions need to be happening today.

4. Transparency and verification: Developing stronger and more consistent monitoring, reporting, and verification (MRV) policies will be essential for maintaining confidence in the global carbon accounting system. Even adopting “geological net zero” definitions might help, where only deliberate, durable storage (for example, via mineralization or deep injection) offsets fossil carbon.

5. Equity and capacity: Global cooperation must ensure that developing nations gain access to durable-storage technologies and finance, not just serve as providers of land-based sinks.

These reforms are more than an academic exercise. They will determine whether capital flows into genuine decarbonization efforts, and whether the public retains trust that net zero reflects real decarbonization work and not statistical manipulation.

At its core, improving our net-zero efforts is about aligning our climate removal policies with climate reality. With better definitions and rules, and a renewed international commitment to keep climate change in check, net zero can evolve from a political slogan into a measurable framework for genuine climate responsibility and international cooperation on carbon removal.