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Opportunities for Microsoft’s Carbon Negative Plan lie in the Deep Oceans

Updated: Sep 6, 2021

Policy Pulse - Madhumita Varma - 29 January 2020

Last week, at the World Economic Forum in Davos, Microsoft pledged $1 billion in an Innovation Fund aimed to promote carbon removal technology. This fund is part of Microsoft’s climate action plan in which they would reduce their emissions by half before 2030 and draw out all of the carbon they have ever emitted by 2050.

Microsoft’s carbon negative plan points to a crucial element of climate action that is too often overlooked – carbon drawdown. Carbon drawdown – also known as carbon sequestration – refers to the removal of carbon dioxide from the atmosphere. While the focus of climate action has been to reduce emissions, which is an indispensable step, carbon drawdown has gained little attention though it has been just as essential as cutting emissions. This is due to the fact that greenhouse gases such as carbon dioxide have a long atmospheric life and trap heat for many years. Therefore, even if all greenhouse gas emissions are stopped right away, we are still committed to the rise in average temperature over the next few decades. Consequently, climate action can no longer stop at reducing emissions; carbon sequestration is now an obligation.

While Microsoft and the Intergovernmental Panel on Climate Change (IPCC) are considering carbon capture and storage technologies, the agriculture and forestry sector is not to be overlooked when considering carbon drawdown. When it comes to natural forms of carbon drawdown, trees and other land-based plantations gain most attention. Nonetheless, the oceans are impressively capable of capturing and storing atmospheric carbon. This can be done through seaweed. Certain species such as giant kelp, can grow up to two feet a day. Such growth requires intensive photosynthesis, which the entire body of the kelp plant is capable of. Once the kelp plant sinks about a kilometer deep into the ocean, the carbon it has captured stays in the ocean for centuries. It has been stipulated that a hundred square metres of seaweed can capture 16 tonnes of carbon a year. Thus, if approximately 9% of the world’s oceans can be covered in seaweed farms, climate change can be reversed.

This chart shows that seaweed is more efficient at absorbing CO2 than rainforests.

Source: “What is Marine Permaculture?,” Climate Foundation.

South Korea’s seaweed farms, which are some of the largest in the world, provide hope that carbon drawdown can be expanded to large scales. These farms produce seaweed, which are used for human consumption. While this method draws down atmospheric carbon, it does not sequester it in the deep oceans. Therefore, while Microsoft’s Innovation Fund can be used to scale-up land-based air capture and carbon storage technologies, it can also be used to fund initiatives that place seaweed in the deep oceans.

Dr Brian von Herzen and his team are working on a marine permaculture project, in which kelp is grown in the open ocean. With the help of wave- and solar-deep water pumps, nutrients are provided to the seaweed. The regeneration of kelp forests in ocean deserts attracts various species of fish. Both kelp and fish can then be used for human consumption. The kelp could be harvested to be used as biofuel, feedstock, superfood, to name a few. Investing into kelp forest regeneration would help provide food, fertilizer and fuel for 9 billion people who are likely to inhabit the planet by 2040. After high-value extraction, the kelp could be sunk into the deep ocean where it locks away 90% of the sequestered carbon for millennia. Dr Herzen estimates that with an initial investment of $5 million, yields of $1 million per year for the kelp and another million per year for the fish can be expected. Thus, opportunities for Microsoft to clean out its emissions lie not only on land, but also in the deep oceans. By contributing a part of its $1 billion fund to open ocean permaculture, Microsoft would not only be setting an example for other firms by cleaning up its emissions, it would also be investing into feeding the world.

About the author: Madhumita has research interests in climate, environment and conservation issues, as well as impact evaluation of policies and practices related to security and development.

About Veritas Global: Our vision is to have a positive impact on the world through truthful advice informed by robust analysis. We are a premier provider of tailored solutions on climate change, international conflict economics and infrastructure.

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