The world is not on track to meet its international climate targets, more than seven years since participants in the Paris Agreement pledged to keep global warming well below 2 degrees Celsius and under 1.5 C if at all possible. Both targets are swiftly approaching, and humanity could blow past the 1.5 C threshold within a decade or so.

That’s mainly because world nations aren’t cutting their carbon emissions fast enough. But there’s another problem, too — they're not sucking enough carbon dioxide out of the air.

new report, led by the University of Oxford’s Smith School of Enterprise and the Environment, found that the amount of carbon removal currently planned or deployed around the world isn’t consistent with what’s needed to meet the Paris Agreement targets.

It’s the first report of its kind to make a global assessment of the current state of carbon removal.

“Carbon removal looks a lot like renewables did like 25 years ago,” said Gregory Nemet, an environmental policy expert at the University of Wisconsin and one of the report’s co-authors. “Interesting technology: [It] could be really helpful for climate change, but [it's] still small and not taken very seriously — in part because there wasn’t a lot of data about how much these technologies cost, how much we would need or how much there even was.”

Carbon dioxide removal, or CDR, is a critical strategy for meeting the Paris climate targets. Stabilizing the Earth’s temperatures requires the world to achieve net-zero emissions within a few decades — which means any greenhouse gases going into the atmosphere must be balanced by any equal amount coming back out.

And because some sectors of the economy are difficult or impossible to decarbonize in time to meet the Paris climate goals, at least some level of carbon removal is necessary to cancel out the extra emissions.

CDR also can help reduce net emissions faster in the short term, as countries work to get to net zero. Studies suggest that emissions must fall by nearly half between now and 2030 in order to meet the 1.5 C target. And they must hit net zero around 2050.

In the distant future, after net zero is achieved, additional CDR could help tip the world into negative emissions — that means sucking more carbon out of the atmosphere than the world is putting in. Negative emissions could gradually bring global temperatures back down again.

There are a variety of potential carbon removal strategies. Today, most CDR is achieved through conventional land-based methods, such as planting new forests, which naturally soak up carbon dioxide from the air. But scientists are investigating a number of other possibilities, such as sprinkling special carbon-guzzling minerals in the ocean and sucking carbon straight out of the air with machines.

CDR isn’t a substitute for other forms of climate action, experts warn. Cutting emissions is still the first and most important strategy for addressing climate change. It’s impossible to meet the Paris targets without rapid and aggressive efforts to reduce the greenhouse gases human societies are pouring into the atmosphere.

But it’s also impossible to meet the Paris goals without at least some CDR.

Scientists use special models to explore the kinds of societal changes the world must make in order to meet its climate targets. They simulate changes in the global population, economy, energy landscape and land use patterns and produce a range of different scenarios that could allow for a 1.5 C or 2 C world.

Every pathway consistent with either target requires at least some level of CDR.

Scientists have known this fact for years. But it’s been slower to register in mainstream public discussions around climate action.

The Paris Agreement helped get the conversation started, according to Oliver Geden, a climate policy expert at the German Institute for International and Security Affairs and a co-author of the new report. The agreement explicitly notes a need for the world to balance its carbon sources and sinks — in other words, to find a way to cancel out any leftover emissions.

The recent explosion of net zero targets has shifted the conversation into a higher gear. Within the last few years, dozens of nations around the world have set net-zero targets for themselves — the United States included. These goals were largely spurred by a 2018 special report from the Intergovernmental Panel on Climate Change, warning that the 1.5 C target requires global net emissions to hit zero by midcentury.

The net-zero frenzy has helped make the world aware “that the ‘net’ part means CDR,” Geden said. “Otherwise it would just be ‘zero emissions,’ not ‘net-zero emissions.’” Achieving net zero means balancing out any residual emissions with carbon removal.

The IPCC recently has become more explicit on the necessity of carbon removal. Its most recent assessment report, released last year, declared that carbon removal is “unavoidable” if the world is to meet its climate goals (Climatewire, April 5, 2022).

The CDR 'gap'

The new report explores the progress the world has made so far on CDR. It investigates the current global investment in CDR research and development, tracks the amount of CDR already planned or deployed around the world and compares those efforts with what’s needed to achieve a 1.5 C or 2 C world.

The main takeaway is that today’s efforts aren’t enough. The findings echo the conclusions of the United Nations’ annual Emissions Gap report, which consistently finds that global emissions reductions efforts aren’t on track to meet the Paris targets.

The report estimates that the world is currently removing around 2 billion metric tons of carbon dioxide from the atmosphere each year, almost entirely through conventional land-based strategies such as afforestation.

The amount of future CDR required to meet the Paris targets depends heavily on how quickly the world reduces its emissions over the next few decades. Deeper emissions cuts will require less CDR.

Still, the report warns, pathways consistent with the Paris targets still will require carbon removal to rapidly expand in the coming decades.

Even meeting the 2 C target would require nearly an additional billion tons of carbon removal each year by 2030, compared with the present. But so far, the climate action plans that nations have submitted to the Paris Agreement encompass roughly a tenth of that. And even bigger increases in carbon removal would be needed in the decades ahead, especially from midcentury on.

Scenarios consistent with a 1.5 C or 2 C world likely will require a minimum total of about 450 billion metric tons of carbon dioxide removal between now and the end of this century.

And a significant portion of that removal needs to come from novel technologies, such as special minerals or direct air capture, another term for carbon-sucking machines. It all can’t come from forests, either — there simply aren’t enough global land resources available for that to work as a sustainable solution.

“It seems really helpful to have a diverse portfolio of carbon removal options because any of them at scale are going to generate issues,” Nemet said. “By limiting the scale of any individual technology, you make the whole system less vulnerable to any side effects.”

That means the world needs to see far greater investment in research and development of carbon removal technologies in the immediate future.

The report estimates that global public investment in CDR research, development and demonstration was around $4.1 billion between 2010 and 2022. About $3.5 billion has gone to direct air capture demonstration projects in the United States.

Between 2020 and 2022, the report finds that global investment in new CDR capacity totaled about $200 million, most of which went to direct air capture and carbon storage projects.

Interest is growing steadily, the report notes. CDR patenting activity has increased over the last 15 years, particularly in China. And while scientific literature on CDR accounts for a small fraction of the total number of climate-related studies in the world, it’s growing faster than research on climate change as a whole.

Still, most countries have not outlined carbon removal goals and strategies. While more than a 100 nations have set net-zero targets, just a few have explicitly incorporated CDR into their climate policies.

In general, the world needs more research and more demonstrations to get CDR on track, Nemet said. And it needs to establish markets for carbon dioxide removal services.

While this is happening, the world also needs to double down on reducing emissions as quickly as possible. The faster that happens, the less CDR will be needed in the future.

“We always have to work on both ends,” Geden said. “The CDR will only grow with every year without global aggressive emissions reductions.”

Reprinted from E&E News with permission from POLITICO, LLC. Copyright 2023. E&E News provides essential news for energy and environment professionals.