We need to get carbon down – not just stop emitting it


But carbon removal has become a sensitive topic. There are real concerns that the increasing focus on reducing greenhouse gas emissions could encourage governments and businesses to delay or even avoid the most obvious and immediate way to tackle climate change: to prevent emissions from entering the atmosphere in the first place. .

The easy perception that in the future we may be able to continue pumping out large amounts of carbon dioxide and simply clean up the atmosphere is an example of what is known as a “moral hazard.” There is a risk that the use of fossil fuels will be maintained and that the costs of dealing with climate change will be passed on to future generations.

This is a legitimate concern† Some companies have wrongly suggested that carbon removal could allow us to continue emitting at nearly half current global levels. But that would require sucking up and storing carbon dioxide at levels that are almost certainly technically, environmentally or economically unfeasible, or possibly all of the above.

However, there is also a real risk that stigmatizing carbon removal over moral hazard poses an even greater danger: delaying much-needed investment and jeopardizing our ability to meet future climate goals. Unfortunately, after decades of delays, there are now simply few roads to meet our climate goals that don’t both reduce current emissions and build the capacity to imbibe massive amounts of carbon dioxide in the coming decades.

Emission reductions are not enough

Why is carbon removal necessary in the first place, and why can’t we just stop climate change by going to “absolute zero” emissions? The recent UN report identifies four distinct roles for carbon removal in climate modeling scenarios that limit warming to well below 2˚C relative to pre-industrial levels by 2100.

First, while fossil fuels can be replaced by clean energy alternatives in much of the economy, there will be some continued carbon dioxide emissions from sectors that difficult to completely decarbonise† These are big industries, such as aerospace, cement and steelmaking, where we simply don’t have affordable, scalable zero-carbon technologies. While more work needs to be done to understand how low our carbon emissions can get, these types of sectors are likely to continue producing a few billion tons per year to be neutralized by carbon removal.

Second, carbon dioxide is not the only greenhouse gas that is warming the planet. Others, including methane and nitrous oxide from sources such as livestock, animal waste and fertilizer use, are much more difficult to eliminate completely.

The recent UN report found that available technologies could likely reduce emissions of these gases by about 50%, with additional behavioral changes such as dietary changes pushing that up to 66%. However, carbon removal should counterbalance the significant amount remaining