Hundreds of nations and corporations, some with GDPs larger than many nations, have pledged to achieve net zero carbon emissions by 2050. For that to be realistically achievable, the scientific consensus is that global net emissions of carbon dioxide (CO2) resulting from human activity need to fall by about 45% from 2010 levels by 2030.
That’s highly problematic when set against the reality that in 2023, with less than seven years until that interim 2030 emissions reduction deadline, carbon pollution is not yet believed to have peaked. In 2010 humans emitted an estimated 33.36 billion tonnes of carbon.
Source: Our World in Data
By 2021, the last year data has been published for, total global carbon emissions had reached 37.12 tonnes. That represents an increase of over 10%, meaning that a 45% reduction on 2010 levels means reaching 2030 on track to achieve the 2050 net zero commitments means reducing global emissions by over 50% in less than seven years.
2022/23 figures carbon emission levels will almost certainly rise on post-pandemic 2021. Use of coal, the most polluting fossil fuel to burn, in power stations has spiked again after looking like it was in terminal decline. Russia’s invasion of Ukraine in early 2022 sent oil and gas prices soaring and interrupted supply lines.
The war has also seen huge amounts of fossil fuels burned as a result of attacks on oil depots and energy infrastructure. In September 2022, the sabotage to the two Nord Stream pipelines led to the biggest ever single source release of methane – one of the gases that contributes most to global warming.
Despite positives elsewhere such as the start of the mass market migration towards the electrification of transport, especially cars, it looks increasingly likely humanity will fall well short of both the 2030 and 2050 net zero targets on carbon emissions.
Why the ‘net’ in net zero is key
If it now looks unrealistic that the international community will succeed in reducing its carbon emissions by 45% before 2030 and to zero twenty years after that, is the battle against climate change already lost?
Not necessarily. It will be extremely difficult but the key to the hope that does remain lies in the first word of the term “net zero” – “net”. The net offers a potential loophole for both the targets and Earth’s climate. If gross emissions can’t be reduced quickly enough to avert climate change, net emissions still might be.
Closing the gap between gross and net emissions logically implies that carbon pollution would have to be somehow ‘disappeared’ after it has been released. The term for that is carbon capture and billions are being invested in various technologies it is hoped will make it possible.
Carbon capture technology – how does it work?
Carbon capture technology can be divided into roughly two groups.
The first set of technologies is designed to capture harmful gases as they are emitted, such as from the chimneys of power plants or industrial facilities. These technologies require an upfront capital commitment from polluters but that can be incentivised using various mechanisms such as tax breaks and imposing costs for not doing so and exceeding emissions caps.
The second set of carbon capture technologies suck already emitted pollutants out of the air. Because they are in much smaller concentrations and mixed in with other gases that naturally comprise the Earth’s atmosphere, such as oxygen, this is a technologically greater challenge and more expensive. But making this kind of carbon capture technology work, and on an industrial scale, could be the only hope of hitting net zero targets.
For corporations with net zero targets, carbon capture offers a potentially convenient fix. If it works well in practice, paying for the removal of emissions would be a lot easier than the changes required to stop them in the first place. At least over the coming couple of decades as low carbon energy sources replace legacy fossil fuel infrastructure.
As such, companies such as banks, insurers and big tech are already lining up to provide upfront funding for major carbon capture projects yet to be built. A collection of major American corporations, including Alphabet, Meta, McKinsey and JPMorgan Chase, have collectively pledged to spend up to $1 billion to purchase carbon removals by 2030, though so far they have contracts for only about 9,000 tons.
That should, in turn, help with the development and roll out of new and increasingly effective carbon capture technologies.
The most promising carbon capture technologies
There are a wide variety of different carbon capture technologies being developed, or already in use but require scaling. Among the most promising categories of the technology include:
Carbon capture and storage (CCS)
Source: New York Times
The biggest carbon capture projects to-date rely by which carbon dioxide is liquefied and pumped into underground geological formations. CCS technologies are usually integrated into highly polluting industrial processes, such as steel and cement production, or from the burning of fossil fuels in power generation.
Advanced filters trap carbon as it is emitted, usually converting it into a liquid form before transporting it from where it was produced, via ship or in a pipeline, storing it deep underground in geological formations.
Direct Air Capture – “Scrubbers”
Scrubbers, tech that chemically removes carbon dioxide from the air long after it has been emitted, are still considered too expensive and to use too much energy to be effective. But the technology is advancing and could well be viable in the future.
Direct air capture technologies are less efficient than those that capture at the source of emissions because concentrations are much lower. For example, gas released from cement production is abut 15% carbon dioxide. In the atmosphere the concentration is about 0.04%, which means over one thousand tons of ordinary air would have to be processed in order to capture a single ton of CO2.
To be scaled, direct air capture would also require national or even international infrastructure to subsequently pressurise captured CO2 into liquid and transport it for sequestration or other uses.
Biochar
Source: Cornell University
One of the more promising carbon capture approaches attracting investment is biochar. Biochar plants create low carbon fertiliser from the burning of wood and other organic waste without oxygen.
Biochar plants are seen as a potentially effective way to significantly reduce the net emissions of farming operations, a major polluter.
Can the necessary scale be achieved for the “negative emissions” carbon capture technology promises?
Many scientists and climate change experts stress the dangers of relying heavily on carbon capture technologies in meeting 2030 and 2050 net emissions targets. They argue that these technologies are still too immature, and often too expensive, to be scaled quickly enough to have the desired impact.
There are also valid worries that corporations will use carbon capture as an excuse to carry on emitting dangerous gases.
However, there is also recognition that carbon capture technologies could be the only chance of hitting targets. The United Nations Intergovernmental Panel on Climate Change believes carbon capture is a necessary ingredient. It calculates the world will probably need to remove billions of tons of carbon dioxide from the air to limit warming to 1.5 degrees Celsius above the pre-industrial era.
The advance of technology created the carbon pollution problem. It might also be the only realistic solution to that problem, with carbon capture tech potentially almost as important as that which prevents emissions in the first place.
