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Can emerging technologies undo our climate damage, or are they a deadly distraction? This week’s big global climate report should offer some answers, as Eloise Gibson and Olivia Wannan report.

Imagine if it turned out that a common mineral found in liberal quantities near Nelson could safely take 1,000 years’ worth of humanity’s greenhouse gas emissions and tuck them away forever.

If you thought it would work, would you relax and stop worrying about climate change?

Or imagine if you learned that scientists could shoot particles into the air to deflect some of the sun’s heat, countering the impacts of people-made warming with a process a bit like a huge, artificial volcanic eruption.

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If that last option doesn’t sound particularly relaxing to you, you’re far from alone.

The latest Intergovernmental Panel on Climate Change (IPCC) report said solar radiation modification – as the particle-shooting is known – was riddled with knowledge gaps and uncertainty and would “introduce a widespread range of new risks to people and ecosystems, which are not well understood.”

In other words, the cure could be worse than the problem.

But there’s a counterpoint. Having squandered almost all of our chances to pursue gentler climate solutions, we are running out of time.

Earth will likely tip above 1.5 degrees Celsius of heating caused by greenhouse gases not long after 2030, the IPCC says.

Thousands of studies show how this will bring extensive misery and cost, even if temperatures can be brought back down to a safer level.

The window is closing to avoid rapidly worsening floods, fires, droughts, and heat waves, concluded the planetary science body in August.

With that kind of warning now routine, some scientists argue they must pursue as many fixes as possible.

“It's a scary prospect, I will totally admit that,” Ben Kravitz, an assistant professor of earth and atmospheric sciences at Indiana University Bloomington​ in the U.S told Politico in an interview about geoengineering options last year. “But climate change is also scary.”

The already-fiery debate is about to get fierier.

As you read this, many of the world’s top scientists and representatives of almost every government could be wrangling over this very question.

Having set out in two previous chapters the perilous state of the planet and its deadly threats to people, the IPCC has turned its attention to a third topic: what to do about it.

Scientists and government diplomats have spent all week debating how to summarise years of global research on curbing the heating, spanning techno-fixes as well as better-known options like riding bikes and tree planting.

By now they’ll have modelled various social, technical, political and economic futures, pulling on various levers to see how fast or slow emissions could fall.

By today, the exhausted authors will either have just handed in the report (then collapsed or gone to the pub to unwind) or they’ll still be in their meeting, arguing.

One of things they’ll be grappling with how is much gas we can suck back in – versus how quickly we can stop emitting.

If addressing emissions fails, governments may have to confront at what point they’d turn to the more, ahem, volcanic options. There are remarkably few international rules covering solar geoengineering – which is somewhat alarming, given the potential for a rogue act to affect another country.

Stratospheric aerosol injection may prove tempting – it would be fairly cheap compared with the cost of climate catastrophe, and, as a feature by WIRED noted last year, there’s nothing stopping countries from unilaterally deciding to spray their airspace, even though the impacts would spread around the globe.

Just as left-wing voters tend to favour stronger climate action, there is evidence of a left-right split on attitudes to deploying these technologies, according to work by environment conflict researcher Rebecca Colvin and others at Canberra’s Australian National University.

Left-aligned people seem more likely to oppose geoengineering, because it’s seen as an excuse to delay other urgent action. Right-aligned people seem more likely to support it, because it could help justify the status quo, the research suggests.

That creates a danger that those making decisions will get bogged down in partisan arguing, just as they did with climate action, as both sides try to be proved “right”.

A steer from the IPCC could help take out the partisanship.

Different definitions

People use the word ‘geoengineering’ to mean both using technology to suck in carbon and store it, and tinkering directly with the climate, à la solar radiation modification.

But the two are not the same.

While both are still unproven at big-enough scales to turn the tide of climate change, tinkering with the climate directly is seen as the more dangerous and speculative option. For a start, the world’s climate wouldn’t cool evenly, leading to uneven effects and, possibly, droughts, storms, and crop failures.

And while removing carbon dioxide from the atmosphere undoes the root cause of climate damage, ideas like partly blocking the sun’s heat only attempt to tackle climate change’s worst symptoms. They don't affect other results of growing pollution, such as shellfish-killing ocean acidification.

As soon as people stopped doing it, the climate would rebound, with uncertain consequences.

Sucking and storing gases

Even carbon-sucking technologies don’t have an infinite ability to solve our problems.

The oldest carbon-sucking solution is growing trees – but even trees rely on finding enough land to plant new ones, and it needs to be land that is both suitable and won’t affect food crops. Restoring wetlands and tucking away carbon dioxide in marine species, such as kelp, are other helpful alternatives.

Other, more complex ideas – like fertilising the ocean with iron to boost growth of small floating plants, phytoplankton – have been tried with disappointing results.

Then there are the artificial alternatives. Massive machines have been built to suck in air and extract CO2, diverting it elsewhere.

The location of the machines matters. Some of these are attached to or nearby large polluting factories, such as a power plant in Canada or a number of industrial plants in the US.

This type of process is known as carbon capture or point source capture, says US researcher June Sekera.

But success was limited: most carbon capture projects at fossil-fuelled power stations had failed, and the Canadian facility still emitted more greenhouse gas than it captured.

The final destination of this CO2 also matters, Sekera says. Some is pumped underground, meaning it is removed permanently.

Other CO2 might be turned into products: including fuel for vehicles that will be combusted.

If that captured CO2 is displacing petrol and diesel that would have been extracted from fossil fuel reserves, then including carbon capture can make the overall product less carbon-intensive.

But the factory and the fuel must split the responsibility for the fossil fuels used in the first place. This fossil CO2 will end up in the atmosphere, even though it takes a longer route to get there.

In climate terms, an electric vehicle powered by renewable electricity still remains a cleaner option.

And most of the CO2 captured from large US factories is used by the oil and gas industry to help drill more oil, Sekera says.

“They compress it into a supercritical state, between a liquid and a gas. They pipe it to an oil field and inject it. CO2 in this state has the capability of squeezing out the remaining oil,” she says. “They’ve been doing this for a long time, and then said: oh, we can make it seem like it’s climate change mitigation.”

Carbon capture also locks in fossil fuel dependence, Sekera says.

“To have any climate-significant impact, you’re talking tens of thousands of miles of pipelines in the US… There are only certain locations that you can shove it underground.”

New Zealand has fewer large polluting factories than average, because our electricity is mainly from hydro dams, geothermal energy and wind. This means carbon capture is unlikely to be a major part of our green transition.

Because our sources of carbon tend to be diffuse – vehicles, boilers and peatlands – carbon removal from the air could be more promising.

Unlike capturing emissions from a factory, carbon dioxide removal is carbon-negative, actually absorbing CO2 from the atmosphere permanently.

One of the most famous current examples is in Iceland. Air is sucked into a machine, where it’s filtered and heated, separating out CO2. This CO2 is then mixed with water and, using a geothermal well, pumped deep underground. After a few years underground, the greenhouse gas should react with the basalt rock and mineralise, becoming permanently stored.

Climeworks – the company that built the air-sucking-and-filtration machine – estimates the process, including energy use, permanently stores about 90 per cent of the CO2 that enters the machine.

But Sekera warns, for all the hype, the plant captures “three seconds worth” of annual CO2 emissions.

And like many ground-breaking projects, this process isn’t cheap: it costs roughly US$600 (NZ$870) to capture one tonne of CO2.

Yet the International Energy Agency says the world will need 4 billion tonnes of carbon removal by 2035 and 7.6b tonnes by 2050, to reach net-zero mid-century. The race is on to improve this technology, including research to cut the costs.

In New Zealand, Allan Scott​ from the University of Canterbury and Christopher Oze​ from Occidental​ College, California are focused on finding a cheap source of a key material: magnesium hydroxide.

When this mineral encounters CO2, the two bond and produce magnesium carbonates.

Scott and Oze believe they’ve found a low-carbon, energy-efficient way of creating magnesium hydroxide out of olivine. Since there are huge amounts of olivine – including a 871 billion tonne deposit of the greenish rock in the Red Hills near Nelson – this could help bring down the costs.

As part of their research, the pair have created magnesium hydroxide and sequestered a few grams of CO2. But they’ll need to scale the process up before it’ll catch the attention of the carbon capture companies.

Their research is still early: only in the “pre-pilot development phase”.

Other groups are also looking at olivine.

British biologist Tom Green wants to use it with a weathering process to turn carbon dioxide into rocks, then drop them at bottom of ocean.

Despite the obstacles, geoengineering researchers often say we need to keep studying and funding these technologies, given how slowly emissions cuts are going.

But they almost always follow this up by stressing that we can’t use them as an excuse to stop rapidly slashing emissions.

For example Oze, the olivine researcher, has said that the simplest solution to global warming would be to reduce CO2 emissions.

If all we did was keep polluting and sucking the gases away again, “we would need an extra planet to store all the CO2”, another scientist told Reuters in August.

Not helping public trust in these technologies is the enthusiastic support from oil companies, some of which spent previous decades actively misleading the public on climate change. Climate campaigners accuse polluting companies of “predatory delay” – pretending to support climate action, while delaying meaningful emissions cuts for their own short-term profit.

In or out?

When it plotted a path to net-zero emissions, New Zealand’s Climate Change Commission left carbon removal technologies out of its roadmap, because its pathways are premised only on technologies well-proven today.

If the suite of proven technologies changes, however, the commission could update its advice.

Whether it’s foolish to put hope in these emerging technologies, or foolish not to, governments are going to have to grapple with them.

We’ll find out on Monday whether the IPCC helped them out.

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