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Plans to stabilize Earth's climate rely on emerging carbon removal technology—we need to get moving, say researchers

Global carbon emissions from fossil fuels continue to rise and 2024 is likely to be the .

It's becoming increasingly clear that limiting global warming to 1.5°C will require much more than existing efforts to reduce emissions and decarbonize industry. We also need to remove enormous amounts of carbon dioxide from the atmosphere, .

The Intergovernmental Panel on Climate Change (IPCC) says to achieve global and national net zero targets. In other words, there is no net zero without COâ‚‚-removal, because emissions of greenhouse gases are .

There will be trade-offs, as COâ‚‚-removal can be costly and often uses up . But Earth is hurtling towards a climate catastrophe, with more than under current global policies. We must do everything we can to avert disaster, which means slashing emissions as much as we possibly can, and removing what's left.

Within the , the debate about carbon dioxide removal has moved on from "could we, should we?" to "we must"—recognizing the urgency of the situation. So it's worth coming up to speed on the basics of carbon dioxide removal technology, both old and new, and the role we can expect it to play in Australia's net-zero future.

Why do we need carbon dioxide removal?

Carbon dioxide removal accelerates natural processes such as storing carbon in trees, rocks, soil and the ocean. It differs from carbon capture and storage, which seeks to remove carbon before it enters the atmosphere.

As Australia's Climate Change Authority , reaching the national goal of net-zero emissions by 2050 does not mean all emissions are eliminated across the economy. Some emissions are likely to remain—about 25% of Australia's 2005 emissions under the current plan—and they need to be dealt with.

So how much carbon dioxide are we talking about? Some 133 million tons a year by mid-century, according to the authority. This equates to billions of tons of additional carbon dioxide removal over the next 25 years.

Ways to remove and store carbon dioxide from the atmosphere are among the federal government's . So let's take a look at the technologies we are using now and what we might need.

What technologies do we need?

The international scientific community carbon dioxide removal technologies into "conventional" (nature-based) and "novel" (new) approaches.

The conventional technologies rely on biological processes, such as planting trees, boosting soil carbon levels and increasing carbon stores in coastal ecosystems such as mangroves. The carbon is typically stored over shorter timescales, from a decade to a century.

Unfortunately, many of these natural carbon stores or "" are already . They will also become increasingly vulnerable in a changing climate. For example, are releasing billions of tons of carbon dioxide back into the atmosphere annually.

To reach net zero emissions, the world will need to find more ways to remove COâ‚‚ at scale from the atmosphere. This is where the new technologies come in.

Examples include adding crushed carbonate or silicate rock to the ocean or farmland. Research suggests could be used for this purpose.

Concerningly, novel approaches currently comprise of total global carbon dioxide removal.

Avoiding potential pitfalls

Like all technologies, carbon dioxide removal comes with .

In a market worth as much as (A$1.7 trillion) by 2050, there's always a risk of overstating the benefits.

To counter this, the IPCC is to ensure the amounts of carbon removed can be verified and included in national accounts. This should promote transparency and or .

Carbon dioxide removal . For instance, some approaches such as tree planting may with agriculture or biodiversity conservation for water and land. This challenge is compounded by climate change.

Other , such as direct air capture and storage, currently face in extracting COâ‚‚ from air without consuming high amounts of energy.

The interests and rights of Australia's First Nations communities must also be considered. A in 30 countries around the world, including Australia, found positive attitudes to climate intervention technologies. However, this is only a starting point. Greater engagement is needed nationally concerning specific carbon dioxide removal approaches.

More work is needed to understand these challenges, including how to manage them and their impacts on Australian communities.

A new industry for Australia?

Australia's large land mass and vast oceans mean we have far greater physical capacity than other nations .

Australia also has access to renewable energy used to power the technologies, and a skilled workforce to develop and run them.

Much like solar and wind energy, tackling carbon dioxide removal in Australia at the scale required will require a new industry with its own infrastructure, institutions and processes.

and other organizations are advancing the technology, but more is needed. Australia requires a national dialogue and clear vision around how to deliver carbon dioxide removal responsibly and sustainably.

Of course, prevention is better than cure. It's always better to cut emissions and stop carbon dioxide entering the atmosphere in the first place, than to try to remove it afterwards. But time is running out, carbon dioxide levels are already too high and we need to reach net zero by 2050.

Carbon dioxide removal is now , along with deep and urgent emissions reduction. We must get moving on permanent carbon dioxide removal if we are to preserve the planet for future generations.