Net Zero’s carbon removal conundrum

To achieve net zero emissions, where emissions and removals of greenhouse gas pollution balance each other out, governments and corporations must do two things: reduce emissions as much as possible and remove any residual pollution from the atmosphere.

To measure how fast emissions must be reduced, analysts often use the so-called carbon budget, a well-established framework for calculating how much greenhouse gas can be emitted to stay at or below a certain level of global warming. (World leaders have committed to keeping the rise in global average temperature well below 2C above pre-industrial levels and ideally to 1.5C)

But quantifying the amount of carbon dioxide removal available to help meet such temperature goals is a less-penetrated area of ​​analytical focus. So researchers at the University of Oxford have just devised a ‘carbon removal budget’ to tackle the problem.

Think of carbon removals as the net zero “net”. CO2 can be removed in many ways, including through nature-based approaches such as forest or peatland restoration. There are also technologies such as direct air capture and storage, so-called biochar and bioenergy and carbon capture and storage (BECCS).

But much of this technology hasn’t reached its full potential – and time is running out. The planet is warming so fast that without swift and drastic action, the critical 1.5C threshold is almost certain to be exceeded. As such, the need to scale up technologies and projects that can reduce billions of tons of planet-warming gases to lower global temperatures becomes essential.

The Oxford academics who authored the paper, Ben Caldecott and Injy Johnstone, argue that while it is essential for this industry to grow, if we are to have any chance of reaching zero, removing CO2 will always be “a fundamentally finite resource”. which should be allocated responsibly.

“Carbon removals are not free and face some significant economic constraints,” Caldecott said in an interview. “So if a company that could easily reduce emissions decides to use some of its available carbon removal budget, what will that mean for other actors? There has to be equity in how this finite resource is distributed, and there will undoubtedly be trade-offs.”

In other words, industries that can most easily reduce emissions should maximize that effort, leaving more of the world’s limited capacity to remove carbon from the atmosphere to those that, by their very nature, are limited in their ability to do so. . Companies in so-called “hard-to-mitigate” sectors, such as steelmakers and airlines, may have a greater need for such write-offs in certain scenarios, the authors said.

The capacity to remove and store CO2 is generally constrained by physics as well as a number of economic, institutional and technological barriers. As such, Caldecott and Johnstone said, “who has the right to access already feasible CO2 removal, as well as who bears the burden of developing the additional potential,” remain important questions.

So how much carbon do we need to remove from the atmosphere and at what cost to meet our climate goals? And what is possible given the current state of carbon removal technology?

Assuming a minimum price per tonne of carbon removed of $100 and taking into account what is actually technically and economically feasible (not to mention policy variables), the authors estimate that between 2025 and 2100 the world will will face a carbon elimination. deficit of 49 gigatonnes of CO2 in a scenario where warming is kept at around 1.5C.

A shortfall implies that the need for carbon removal will exceed the intended implementation of such technologies.

Now, if humanity were to settle for 2C warming, which could be catastrophic from a climate change perspective, there is the potential for a small surplus of 12 gigatonnes of CO2 when it comes to the carbon removal budget.

Nature does not have an unlimited capacity to store carbon. And all natural carbon sinks could eventually release some of the stored CO2 back into the atmosphere. Meanwhile, new carbon removal techniques such as direct air capture, where cars suck CO2 from the atmosphere and bury it deep underground, have less risk of reversal. But they also come with costs of up to $1,610 per ton for the most complex technologies. And it can take a long time to develop the necessary infrastructure.

“Carbon removal is like the new gold,” Johnstone said. “They are very valuable, they are rare and should only be reserved for a select number of use cases.”

Robert Höglund, an expert in CO2 removal, has a different view. He says the main constraint on the amount of disposals is “not exhaustible resources – it’s willingness to pay”.

Where he agrees with Caldecott and Johnstone is that, while phase-outs must be expanded, the first priority of corporations and governments seeking to decarbonize should be to reduce emissions. “We should plan as if CO2 removal will be limited, but build for it to be abundant,” he said.

“There are large uncertainties about our ability to remove CO2 and the focus should be on conserving the original carbon budget,” Johnstone said. “Any conversation about getting rid of carbon has to start with the fact that it’s much easier to reduce emissions than it is to get them back out of the atmosphere.”

Sustainable finance in brief

Another Wall Street giant appears to be caving in to the far right’s anti-ESG crusade on behalf of Big Oil and others. The asset management unit of Goldman Sachs Group Inc. has pulled out of the world’s largest investor climate alliance, marking the latest in a string of similar defections amid continued Republican attacks on green finance. The departure feeds into a broader trend as financial firms are increasingly spooked by opponents of environmental, social and governance investment strategies.

• Climate groups are stepping up warnings about Project 2025, the plan by allies of Donald Trump to gut government regulations, including environmental protections, if he wins in November.
• The Biden administration is offering Qcells up to $1.45 billion in conditional financing to build the largest U.S. factory that makes silicon ingots and wafers, the building blocks of solar panels.
• Red-state Republicans who opposed President Joe Biden’s climate legislation are now warning Trump against defunding projects in their districts.

Photo: A direct air capture and storage facility operated by Climeworks AG in Iceland. Photographer: Bloomberg

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