Nature has endowed the earth with several giant “mushrooms”, or carbon sinks, that can help humans fight climate change. These natural fungi, as well as human, can sweep up carbon and effectively remove it from the atmosphere.
But what does this sci-fi-like act really mean? And how much does it actually cost – and cost – to make a difference and slow down climate change?
Sabine Fuss has been looking for these answers for the past two years. Fuss is an economist in Berlin and leads a research group at the Mercator Research Institute on Global Commons and Climate Change and was part of the original Intergovernmental Panel on Climate Change (IPCC) – set up by the UN to assess the science, risks and effects of Global Warming. After the panel’s report from 2018 and the new Paris Agreement’s goal of keeping global warming to 2.7 degrees Fahrenheit (1.5 degrees Celsius) or less, Fuss was commissioned to find out which charcoal removal strategies were most promising and feasible.
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Afforestation and replanting – planting or replanting of forests – are well-known natural carbon sinks. A large number of trees can bind greenhouse gases carbon dioxide (CO2) from the atmosphere for photosynthesis, a chemical reaction that uses the sun’s energy to convert carbon dioxide and water into sugar and oxygen. According to a study from 2019 in the journal Science, planting 1 trillion trees could store about 225 billion tons (205 billion tons) of carbon, or about two-thirds of the carbon that humans emitted into the atmosphere since the industrial revolution began.
Agricultural soil management is another natural carbon dioxide removal that is relatively low risk and has already been tested, according to Jane Zelikova, soil scientist and chief scientist at Carbon180, a non-profit organization that advocates carbon removal strategies in US practice such as rotary grazing, reduced tillage and crop rotation. , and that carbon is eventually stored in root tissues that break down in the soil. The National Academy of Sciences found that carbon storage in soil was sufficient to compensate for as much as 10% of US annual net emissions – or about 632 million tonnes (574 million tonnes) carbon dioxide – at a low cost.
But nature-based carbon dioxide removal, such as planting and replanting forests, could run counter to other policy goals, such as food production, Fuss said. Upscale, these strategies require a lot of land, often land that is already in use.
That is why more technically based methods of carbon dioxide removal are crucial. With direct air uptake and carbon storage, for example, a chemical process takes carbon dioxide out of the air and binds it to filters. When the filter is heated, CO2 can be captured and then injected underground. There are currently 15 direct air capture facilities worldwide, according to International Energy Agency. There is also bioenergy with carbon capture. With this method, plants and trees are grown, which creates a carbon sink and then burns the organic material to produce heat or fuel called bioenergy. During combustion, carbon dioxide emissions are captured and stored underground. Another carbon capture trick involves mineralization; in this process, stones are ground up to increase the available surfaces to chemically react with and crystallize CO2. The mineralized carbon dioxide is then stored underground.
However, none of these techniques have been implemented on a large scale. They are extreme expensive, with estimates as high as $ 400 per ton of carbon dioxide that has been removed, and each still requires a lot of research and support before it is distributed. But the United States is a good example of how a mix of carbon removal solutions can work together, says Zelikova: Land management can be used in the agricultural west; basalt rocks in the northwestern Pacific are excellent for mineralization; and the oil fields in the southwest are already founded with the right technology and skilled workers for underground coal storage, she said.
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Ultimately, each country will need to put together its own unique portfolio of carbon dioxide removal strategies as no single intervention will succeed on its own. “If we exclusively scaled up any of them, it would be a disaster,” Fuss said. “It would use a lot of land or be too expensive.” Her research has shown that afforestation and reforestation will be most productive in tropical regions, while solar radiation differences in the northern latitudes with more albedo (reflection of light back into space) mean that these countries are likely to be more fortunate to invest in the more technical interventions, such as carbon capture and biomass extraction.
The need to distribute these solutions is imminent. The global carbon budget, the amount of carbon dioxide that humans can emit before global temperatures rise 2.7 F (1.5 C) above pre-industrial levels, is about 300 gigatons of carbon dioxide, says Fuss.
“In recent years, we have released 40 gigatons,” she said. In other words, there are only a few years left in that budget. A new study in the journal Scientific reports suggests that it may be too late to wait even a few years to come if we are to reach the goal of the Paris Agreement. Based on their climate model, the authors predict that even if we stop emitting greenhouse gases completely, “global temperatures will be 3 ° C. [5.4 F] warmer and sea levels 3 meters [10 feet] higher than 2,500 than they were in 1850. “To reverse the effects of climate change, 33 gigatons of existing greenhouse gases must be removed this year and every year going forward,” the researchers say.
The reality, however, is that these approaches are not complete and there is no agreement on how to pay for them. There is agreement among researchers on the next step: We must stop further emissions immediately. But “because emissions are embedded in our daily lives and infrastructure,” Fuss said, “[carbon] removal comes more at the forefront. “
Originally published on WordsSideKick.com.