Nature has equipped Earth with some giant “sponges” or carbon sinks that can help humans to fight climate change. These natural sponges, as well as man-made ones, can sop up carbon, effectively removing it from the atmosphere.
But what does this sci-fi-like act really entail? And how much it will take – and cost – to make a difference and slow Climate change?
Sabine Fuss has been looking for the latest answers for the last two years. Fus, an economist in Berlin, leads a research group at the Mercator Research Institute for Global Commons and Climate Change and was part of the original Intergovernmental Panel on Climate Change (IPCC) – established by the United Nations to assess science, Risks and impacts of global warming. After the 2018 report of the panel and the new Paris Agreement aim to keep global warming to 2.7 degrees Fahrenheit (1.5 degrees Celsius) or less, Fuss was tasked to find out why Carbon Removal strategies are most promising and feasible.
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Conservation and reformation – respectively planting or replanting of forests – are known natural carbon sinks. Vast number of trees can sequester the greenhouse gas carbon dioxide (CO2) from the atmosphere Photosynthesis, A chemical reaction that uses the sun’s energy to convert carbon dioxide and water into sugar and oxygen. According to a 2019 study in the journal Science, Planting 1 trillion trees Could store about 225 billion tons (205 billion metric tons) of carbon, or about two-thirds of the carbon released by humans into the atmosphere since the Industrial Revolution began.
Agriculture land management is another natural carbon removal approach that is relatively low risk and has been tested, according to Jane Zelikova, terrestrial ecologist and chief scientist at Carbon 180, a nonprofit that advocates for carbon removal strategies in the US. It. Practices such as rotational grazing, reduced tillage and crop rotation increase carbon intake through photosynthesis, and that carbon is eventually stored in root tissues that dissolve in the soil. The National Academy of Sciences found that carbon storage in soil is sufficient to offset as much as 10% of US. It. Annual net emissions – or about 632 million tons (574 million metric tons) of CO2 – At a low price.
But the nature-based carbon removal, like planting and replanting forests, can conflict with other policy goals, like food production. These strategies require a lot of land, often land that is already in use.
This is why more tech-based approaches to carbon removal are critical, they say. With direct air capture and carbon storage, for example, a chemical process removes carbon dioxide from the air and binds it to filters. When the filter is heated, the CO2 can be captured and injected underground. According to the, there are currently 15 direct air capture plants worldwide International Energy Agency. It’s too Bioenergy with carbon capture. With this method, plants plants and trees, creating a carbon sink, and the organic material is burned to produce heat or fuel, bioenergy. During combustion, the carbon emissions are captured and stored underground. Another carbon capture trick involves mineralization; In the process, rocks get ground up to increase the surfaces available to chemically react with and crystallize CO2. Then the mineralized CO2 is stored underground.
None of these technologies are implemented on a large scale. They are completely Dear, With estimates as high as $ 400 per ton Of CO2 removed, and each still requires a lot of research and support before deployed. Zelikova said however: a US. Is a good example of how a mix of solutions for carbon removal could be used: land management could be used in the agricultural Midwest. Basalt rocks in the Pacific Northwest are great for mineralization; And the oil fields in the Southwest are already primed with the right technology and skilled workers for underground carbon storage, she said.
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Ultimately each country will have to put together its own portfolio of CO2 removal strategies because no single intervention will succeed on its own. Leg said, if we were to exclude one of them exclusively. “It would use a lot of land or be prohibitively expensive.” Her research has shown that forestry and reforestation will be most productive in tropical regions, although solar radiation differences in the more northern latitudes with more albedo (reflection of light back into space) mean that countries will probably have better luck investing in the more Technological interventions. , Such as carbon capture and biomass extraction.
The need to deploy these solutions is imminent. FUS said that given the global carbon budget, the amount of CO2 humans can emit before global temperature rises 2.7 F (1.5 C) above pre-industrial levels.
“In recent years, we’ve released 40 gigatonnes,” she said. In a different way, only a few years are in the budget. A recent study in the journal Scientific reports Suggests that waiting even several years from now may be too late if we will achieve this goal in Paris Agreement. Based on their climate model, the authors predict that even if we stop completely emitting greenhouse gases, “global temperatures will be 3 C [5.4 F] Warmer and sea levels 3 meters [10 feet] Higher to 2500 than they were in 1850. “To reverse the effects of climate change, 33 gigatons of existing greenhouse gases must be removed this year and each year forward.
The fact, however, is that these approaches are not ready and there is not a consensus as to how to pay for them. There is a consensus among scientists about the next step: we need to stop further emissions immediately. However, “since emissions are embedded in our daily lives and infrastructure,” Leg said, “[carbon] Removal comes more to the forefront. “
Originally published on Live Science.