10 myths about net zero targets and carbon offsetting, busted

Source: 10 myths about net zero targets and carbon offsetting, busted

By 41 scientists

The idea of carbon offsetting, which underpins so-called net zero targets, is founded on a number of myths.

In many cases, offsetting relies on capturing carbon in vegetation and soils. Such capacity is however limited and is needed to store carbon dioxide that we have already emitted.

Assumptions of future technologies and targets decades ahead delay immediate action. Countries and corporations must shift focus from distant net zero targets to real emissions reductions now.

The impacts of the climate crisis are becoming increasingly severe, everywhere. We are experiencing heat waves, floods, droughts, forest fires and sea level rise as a result of global heating. The average global temperature is rising at an unprecedented rate, rapidly diminishing the prospect of keeping global warming below 1.5C and with increasing risks of crossing irreversible tipping points.

In the face of growing demands for action, many countries and companies are making promises and setting targets to reach “net zero” emissions or “carbon neutrality”. These often sound ambitious and may even give the impression that the world is awakening and ready to take on the climate crisis.

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In practice, however, net zero targets several decades into the future shift our focus away from the immediate and unprecedented emissions reductions needed. Net zero targets are generally premised on the assumption that fossil fuel emissions can be compensated for by carbon offsetting and unproven future technologies for removing carbon dioxide from the atmosphere. But offsetting does not cancel out our emissions – yet action to do so is immediately needed.

There are a number of myths about net zero targets and carbon offsetting that must be dispelled. By revealing them, we aim to empower people, so that they can pressure governments and companies to create real solutions, here and now:

Myth 1: Net zero by 2050 is sufficient to solve the climate crisis. Misleading.

Major and unprecedented reductions in emissions are needed now. Otherwise, our current high emissions will consume the small remaining global carbon budget within just a few years. Net zero targets typically assume that it will be possible to deliver vast amounts of “negative emissions”, meaning removal of carbon dioxide from the atmosphere through storage in vegetation, soils and rocks. However, deployment of the technologies needed for negative emissions at the required scale remains unproven, and should not replace real emissions reductions today.

Myth 2: We can compensate for fossil fuel emissions using so-called “nature-based solutions” (such as carbon sequestration in vegetation and soils). Misleading.

Fossil fuels are part of the slow carbon cycle (see fact box). Nature-based solutions are part of the fast, biological carbon cycle, meaning that carbon storage is not permanent. For example, carbon stored in trees can be released again by forest fires. Fossil emissions happen today, while their uptake in trees and soils takes much longer. The overall capacity of nature-based solutions is also limited, and is anyway needed to help remove the carbon dioxide that we have already released into the atmosphere.

The Carbon Cycle 

The carbon cycle has two parts: one fast cycle whereby carbon circulates between the atmosphere, land and seas, and one slow cycle whereby carbon circulates between the atmosphere and the rocks which make up Earth’s interior.

Fossil fuels (coal, oil and gas) come from rocks (part of the slow cycle). Carbon emissions from fossil fuel burning are today 80 times larger than the natural flow of carbon from Earth’s interior (via volcanoes). Since the return of carbon to Earth’s interior takes millions of years, about half of the emitted carbon remains in the atmosphere for a long time and contributes to global warming.

Myth 3: Net zero targets as well as carbon offsetting increase the incentives to reduce emissions because emissions are allocated a cost. Misleading.

The incentive decreases as long as it is financially more advantageous and socially acceptable to buy low-cost carbon offsets from abroad than it is to reduce emissions at home. Promises of future negative emissions also reduce the incentive to cut carbon emissions now, as their costs in decades to come are heavily discounted.

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