Carbon Capture & Storage
Carbon is a building block of life. A balanced carbon cycle sustains life by regulating the absorption and release of carbon as organic matter grows and decomposes. For example, dead plants release CO2, which then gets absorbed by living plants who use that carbon to perform photosynthesis. However, carbon emissions from human activity are threatening a driving factor of climate change.
Widespread development through industrialization and destruction of key ecosystems has released unprecedented amounts of carbon into the atmosphere and compromised natural carbon sinks such as peatlands and soil. As people realize the importance of sequestering carbon, there have been advancements in capturing and storing carbon emissions, but there is still a long way to go.
Globally, there are about 51 large-scale Carbon Capture and Storage (CCS) facilities responsible for mitigating about 40 million metric tons of CO2. To put this number in perspective, the United States alone produced over 5 billion metric tons of CO2 in 2018. What these numbers show is a pressing need to both reduce the amount of CO2 emissions being released while also scaling up carbon sequestration facilities and regenerating key ecosystems.
How Carbon Sequestration Works
Carbon capture can work in two ways – you can either capture the carbon at the source through an industrial plant or implement passive strategies to capture ambient carbon.
There are three major steps in industrial CSS. First, the CO2 must be captured, then transported, then stored. Industrial CSS plants work by capturing the emissions at the source and filtering any other elements. When it is just CO2 it can be compressed and transported via pipelines or ships. The final stage is injecting into storage reservoirs such as oceans, aquifers, or depleted oil wells.
Industrial CSS plants are popping up around the world to address specific points of high emissions (such as factories and manufacturing plants), but they are not the only strategy. These industrial plants are the most efficient way to go about carbon storage from specific points that emit high amounts of CO2 but are not very effective at capturing ambient carbon. Other strategies include forestation and regenerative farming practices (discussed in further detail here), ocean fertilization, and microalgae cultivation.
Landscapes are natural carbon sinks. Soil naturally retains carbon captured via plants and ecosystems such as peatlands and mangroves are particularly good at storing carbon. As we degrade landscapes with destructive agricultural practices or clear the way for development projects, we release carbon that has been stored for thousands of years and compromise the natural mechanisms to contain our increased emissions. These ecosystems, which are essential for a healthy planet, are systematically being destroyed and are difficult to regenerate. Regardless, we must protect and restore these natural carbon sinks parallel to evolving complementary strategies to increase the earth’s capacity to retain carbon. One promising way to do so is by cultivating microalgae.
Microalgae cultivation is a fascinating emerging strategy for capturing and storing carbon. Like with plants, it works by recycling the CO2 into biomass via photosynthesis. Microalgae is fascinating because they grow 10-50 times faster than plants and can be cultivated with much more ease than traditional plant stocks. They do not require fertile land and survive in places where plants cannot such as sewage wastewater. The biomass has the potential to be used to create biofuels and other value-added products. However, there are major hurdles in the supply chain and production to make microalgae viable and sustainable.
Challenges to CSS
The biggest challenge to CSS is financing. Sequestering carbon is vitally important for protecting the planet, but current regulations provide little incentive for the biggest offenders to spend the money to responsibly manage their emissions.
The second big issue to consider is that there is a limited capacity to store carbon. As we inject it back into these limited natural reservoirs, the carbon is sequestered but not eliminated. Once the reservoirs are exhausted there won’t be additional places to store carbon. So CSS is important, but it is not a solution to carbon emissions. Serious cuts in emissions must be implemented regardless of CSS capabilities.
Carbon sequestration is crucial for mitigating harmful emissions. However, it is not a long-term solution since the earth has a limited storage capacity. Additionally, it is important to consider that not only must we sequester emissions produced from industrialization, we must also understand the impact of destroying key ecosystems such as mangroves and peatlands which are important carbon sinks.
CCS shouldn’t be considered a solution to climate change. Thinking of it as a way to sequester emissions is dangerous if it gives the biggest polluters the sense that their emissions are acceptable since they are managing them. These strategies must be implemented to mitigate current emissions while actively reducing our yearly CO2 emissions.
Carbon Capture & Storage