Beyond emissions The call to pull carbon out of the atmosphere

The Swedish scientist Kenneth Möllersten was at a conference in Cairns back in 2000 when an idea came to him that has become woven into the very fabric of international climate change politics, an idea some see as dangerous, some as fanciful, and others as crucial to stabilising the world’s atmosphere.

Möllersten’s insight, built upon by other scientists over years, will be central to scenarios laid out in a key climate science report by the United Nations’ climate body, the Intergovernmental Panel on Climate Change (IPCC), on Monday evening Australian time. That report will be central to world climate negotiations to be held in November in Glasgow.

Swedish researcher Kenneth Moellersten.

At the Cairns conference two decades ago, the then relatively new notion of Carbon Capture and Storage was discussed. This is the idea that carbon pollution from energy production and industry could somehow be captured and permanently stored in stable geological structures underground.

Speaking this week from Sweden, Möllersten said he was fascinated by the idea but concerned that at the time it was being considered only as a means of extending the global use of fossil fuels that the world needed to abandon.

What if, he thought, the material burnt in furnaces to produce industrial heat or energy was not coal or gas, but biological material like agricultural waste?

In that case the plant matter would suck carbon dioxide from the sky as it grew, and then be buried after it produced energy. It would not just be carbon-neutral, but carbon-negative.

By 2000 scientists had been warning for decades that the world needed to drastically reduce greenhouse gas emissions or risk dangerous global warming. Small steps, like the signing of the Kyoto Protocol in 1997, had been taken.

The problem was that scientists were finding it harder and harder to model a future in which dangerous climate change was not a near-certainty by just factoring in future emissions cuts.

There was too much of the stuff already in the atmosphere and millions of tonnes more was - is - being pumped out by the day.

Even as politicians argued over emissions cuts, scientists realised the window for cuts to work was closing. Soon we’d need both cuts in emissions and a drawdown in carbon dioxide already released.

By 2005 Möllersten had refined his idea, collaborating with the Austrian scientist Michael Obersteiner on a paper that was published in the journal Science. Other scientists who had been exploring the notion published work on negative emissions technologies too.

Unable to come up with forecasts that reliably showed a world avoiding dangerous climate change, the IPCC began including Bio-Energy with Carbon Capture and Storage - or BECCS for short - into its models for climate action.

Soon BECCS became what the UK online journal Carbon Brief has described as a “saviour technology”, championed in climate models even though it had yet to be proven.

Now all the IPCC models that see the world managing to keep warming to within 1.5 degrees incorporate the use of BECCS, even though it is still unproven at scale. The IPCC’s embrace of carbon capture in this context has been used as evidence by governments such as Australia that Carbon Capture and Storage has value as a tool against global warming.

Faith in a technological solution to climate change rather than in massive, costly and immediate cuts to emissions is central not only to the Australian government’s climate response, but to the far more ambitious goals of the United States government.

“You don’t have to give up quality of life to achieve some of the things we want to achieve,” US President Joe Biden’s climate envoy John Kerry told the BBC in May.

“I’m told by scientists that 50 per cent of the reductions we have to make (to get to near-zero emissions) by 2050 or 2045 are going to come from technologies we don’t yet have.”

This optimism perplexes Möllersten, who only ever envisaged BECCS as a last-chance emergency tool.

Australian environmentalist Tim Flannery says it is as though we took off in an aeroplane before landing gear had been designed, let alone built, and expected the job to somehow be done before we ran out of fuel.

The big report card

The findings of the IPCC’s working group into the physical science of climate change, to be released on Monday, form the first of three reports in what is known as the IPCC’s sixth assessment cycle. The last cycle was in 2014.

The significance of these assessments is impossible to exaggerate. An early assessment helped lead the world to the 1997 Kyoto Protocol. More recently another was central to Paris Agreement negotiations.

The report of the first working group will be the product of billions of dollars in scientific investment and millions of hours of research by thousands of scientists around the world.

Its 234 authors have read and synthesised 14,000 scientific papers published since 2014, and responded to 75,000 review comments on their work.

At the time of writing, representatives of the 195 nations that are members of the IPCC were going through the report’s 40-page summary line by line, negotiating a form of words that all could agree upon but that also reflected the truth of the science.

The IPCC itself has noted that this gruelling process has taken place as extreme weather has wreaked havoc across the Northern Hemisphere. Record-breaking heatwaves have fuelled fires in the United States and Canada as well as across southern Europe. Sudden deluges killed 196 people in Germany and Belgium.

“The German language can barely describe the devastation,” said German Chancellor Angela Merkel.

World Meteorological Organisation Secretary-General Petteri Taalas told a UN meeting that climate change was already visible. “We don’t have to tell people that it exists. We are seeing more extreme events,” he said. “Heatwaves, drought and the flooding events in Europe and China.”

Destroyed houses, roads and a bridge at Rech in Germany’s Ahr Valley.Credit:Getty Images

UN Climate Change executive secretary Patricia Espinosa said decisions taken this year will decide whether or not it will be possible to limit global warming to 1.5°C above the pre-industrial era by the end of the century.

“The world is currently on the opposite track, heading for a 3°C rise,” she said. “We need to change course urgently.”

Indeed many observers expect the report to say that warming beyond 1.5 degrees is already locked in due to the amount of carbon dioxide in the atmosphere.

“Australia at the end of last year had already warmed 1.44 degrees since 1910, when records began,” said the Climate Council’s Lesley Hughes, a former IPCC lead author.

“Temperatures in Australia have been at the very upper limit of model predictions,” she said, predicting that on our current trajectory lethal 50-degree days could be relatively commonplace in Sydney and Melbourne by 2050.

“There’s a lot of talk at the moment, and there will be after this report comes out, as to whether we are going to overshoot the 1.5-degree target,” she said.

“There is a lot of evidence … that this is likely, but that does not mean that the Paris Climate Agreement is lost. It is embedded in the Paris Climate Agreement that if we overshoot 1.5 degrees, then we need to work very hard to bring us back to a safer climate and stay well below two degrees.”

Three years ago the IPCC itself issued a report saying that limiting warming would require “rapid and far-reaching” transitions in land, energy, industry, buildings, transport and cities.

“Limiting warming to 1.5°C is possible within the laws of chemistry and physics but doing so would require unprecedented changes,” the IPCC’s Jim Skea said at the time.

Since then even more carbon has been released and the computer modelling relied upon by scientists to predict the impact of greenhouse gases on warming has improved.

One of the IPCC’s lead authors, CSIRO chief research scientist Pep Canadell, said this week that the new report would lay out the probability of temperatures exceeding 1.5 degrees of warming, and the time frames in which it may happen, under different scenarios of climate action.

Central to most of those scenarios will be the notion that the world will not only begin to reduce carbon emissions at an utterly unprecedented rate, but that we rapidly develop and deploy technologies to remove carbon from the atmosphere.

Flannery says he began to fear that emissions reductions alone would not be enough to save the world from dangerous warming when world leaders failed to map out a solution to the problem at the Copenhagen climate summit in 2009.

Demonstrators in front of the White House ahead of the 2009 UN climate conference in Copenhagen.Credit:AP

By the time the Paris Agreement was hammered out five years later, it was clear that emissions drawdowns would be needed alongside massive reductions. Today he estimates that we must soon start extracting 10 billion tonnes of carbon dioxide from the atmosphere each year and maintain that effort until the end of the century.

A once live debate over concerns that negative emissions technology might just give politicians and fossil fuel champions an excuse to keep emitting with the promise of future fixes has been overwhelmed by the sheer amount of greenhouse pollution already emitted, he says.

Möllersten agrees. “It would have been much nicer if politicians or world leaders could have agreed on ambitious targets much sooner and worked much harder,” he told the Sydney Morning Herald and The Age this week.

“We now have a significant need for negative emissions. It is disturbing, but this is where we are.”

Nick O'Malley is National Environment and Climate Editor for The Sydney Morning Herald and The Age. He is also a senior writer and a former US correspondent.

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