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Roadmap for carbon storage
With the Federal Climate Change Act, Germany has set itself more ambitious climate goals. This means that there is a greater need to remove carbon dioxide (CO2) from the atmosphere. For this reason, several experts are calling for a roadmap to negative emissions.
It's a formidable challenge. By 2045, Germany is aiming to become carbon-neutral and have a net-zero balance in terms of greenhouse gas emissions. To achieve this, all greenhouse gases need to be avoided or compensated – i.e. a present total of 739 million tons of CO2 emissions per year. According to estimates by experts, emissions cannot be entirely reduced to zero, as residual emissions from agriculture, waste treatment, and perhaps also from some industry sectors will likely remain.
The draft version of the Federal Climate Change Act projects that these residual emissions will amount to 37.5 million tons of CO2 in 2045. From 2050 onward, the EU’s goal is even more ambitious, a net-negative climate balance. The amount of greenhouse gases captured will need to exceed the amount still emitted. Consequently, proposals have been made in the past few weeks to create a roadmap as to how CO2 should be stored.
Recently, the German Energy Agency (dena) called for a strategy to store or use carbon. dena and its project partners from business and science argue that companies could avoid bad investments by using a roadmap for expanding the required technologies. A corresponding CCS strategy for “carbon capture and storage” is one of the 50 recommendations for the upcoming legislative period recently put forth by Agora Energiewende, Agora Verkehrswende, and the Climate Neutrality Foundation.
In addition, both institutions are also calling for a biomass strategy because the BECCS technology (bioenergy with carbon capture and storage) for storing CO2 requires large quantities of trees that grow quickly or residual materials from the timber industry. Sustainably produced biomass would need to be burned in power plants and the resulting CO2 captured and then stored underground. The three think tanks have written that the strategy would need to analyze the amount of sustainable biomass in Germany and account for competing alternative uses, such as the cultivation of food products or using forests to capture CO2.
Large swaths of forests could die off
Climate scientist Andreas Oschlies also considers it necessary to create a roadmap for CO2 extraction and storage. The earth system modeler from the GEOMAR Helmholtz Centre for Ocean Research Kiel co-heads the “Roadmap & Scenarios” project in the Helmholtz Climate Initiative. “According to our calculations, by 2050 Germany needs to capture about 70 million tons of CO2 from the atmosphere each year,” says Oschlies.
Of that amount nature can absorb approximately another 20 million tons of CO2 per year, according to scenarios run by the Helmholtz Climate Initiative, says Oschlies. Doing so would require rewetting peatlands, increasing the carbon content of soils, converting fallow land to grassland or forest, and planting seagrass meadows on the coasts. “That said, the potential of using near-natural means to store 20 million tons is quite optimistic. It also assumes that large areas of forests do not die out, which becomes more and more unlikely with the progression of climate change,” says the Helmholtz researcher.
Related Links
Helmholtz Climate Initiative projects
Technical carbon dioxide sinks
Climate Neutrality Foundation
5
million tonnes of CO2
Amount Northern Lights is to store per year.
It is also not yet clear whether the population will support the transformation of entire ecosystems, such as the restoration of bogs. “At present, the idea of using bogs to capture CO2 is seen as being positive. The question is whether this will continue to be the case when people no longer see well-drained green landscapes, but rather large areas of damp bogs. Even the natural means of storing CO2 do not guarantee sure-fire success,” says Oschlies.
The Helmholtz Climate Initiative has calculated that another 50 million tons of CO2 per year would have to be stored underground or extracted from the atmosphere using methods such as artificial weathering of rock, and as yet these methods have not been adequately researched, explains Oschlies. On land, there has been resistance to the initial attempts at storing CO2 underground, which has motivated several European countries to look into injecting CO2 into saltwater formations or natural gas reservoirs, which have been emptied out deep beneath the North Sea floor. “The biggest issues involve constructing pipelines and developing suitable leak-proof geological reservoirs,” says Oschlies. “The opposition to CO2 pipelines could be even greater than for power lines. And finding solutions for transport by ship would require careful consideration.”
CO2 storage already in 2030
The ocean researcher finds it necessary to develop a CO2 storage roadmap, given the immense scope of the task. The mammoth Northern Lights project off the Norwegian coast is expected to store up to 5 million tons of CO2 per year beneath the North Sea. Achieving the 50 million metric tons of Germany's target of net-zero emissions would thus require a whole host of similar large-scale projects in the North Sea. After 2050, projects on an even larger scale would be necessary if Europe wants to reach a negative emissions balance. “It would be wise to secure suitable CO2 reservoirs in advance and not at some later point when all the national economies get on board,” says Oschlies. “Germany needs to have the means to store several million tons of CO2 by as soon as 2030. In this way, the amounts that need to be reached each year to achieve the climate targets by 2050 could be stored in a manner that is fair to future generations.”
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