This story by ESI Journalism Fellow Nora Hertel was originally published for The St. Cloud Times, where it appears with additional photos and resources.
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By Nora Hertel
Carbon cycles constantly through living organisms, and the Earth's crust, oceans and atmosphere.
Sometimes that carbon is part of the living trees and other plants, or locked in the chemical structure of rocks such a limestone. Other times it's in the form of carbon dioxide, a gas that spreads through the atmosphere and helps regulate the planet's temperature.
Today, there is an overabundance of carbon dioxide in the atmosphere, released through use of fossil fuels and other industrial practices, such as deforestation.
Instead of keeping the Earth's temperature steady, this freed carbon dioxide is heating our planet up. That has meant more disastrous weather events and changes to average temperature and rainfall across the globe.
Those effects are why many people are talking about carbon sequestration as a tool to slow or reverse climate change.
Carbon sequestration is the science of capturing and storing carbon dioxide from the atmosphere. It's converted from a gas into a liquid or solid form.
Why bother?
The last time carbon dioxide levels were as high as they are now was more than 3 million years ago, according to the National Oceanic and Atmospheric Administration. And the Earth looked different then — there were trees in Antarctica and sea levels were up to 30 feet higher than they are now.
Large companies use a lot of energy and cause emissions through their operations, such as through the use of vehicles that burn fossil fuels. Organizations face pressure from consumers and regulators to reduce that carbon footprint. And many are promising to do that.
Microsoft, for example, has promised to get all its energy from renewable sources like wind and solar by 2025, stop using fossil fuel-powered vehicles by 2030 and then remove the carbon it released throughout its history by 2050.
We also need to adapt to the climate change that has already occurred. This is a different challenge that can be addressed by shoring up infrastructure, preventing erosion on farm fields with cover crops and myriad other solutions.
How do we do it?
Luckily, plants sequester carbon naturally through photosynthesis. They take sunshine, water and carbon dioxide from the air and convert it into oxygen and sugars. Those sugars have carbon atoms and are used to grow the plant. Some carbon is also deposited into the soil.
Natural environments like forests can be big carbon sinks — storing carbon safely in a form that does not warm the planet. Protecting carbon sinks is a key way to reduce emissions.
And humans can help the process by growing more trees or helping crops deposit more carbon into the soil. Encouraging natural carbon sequestration in soils and trees can help draw down carbon already in the atmosphere.
Carbon markets and other incentives are popping up to encourage land managers like farmers and foresters to draw in more carbon to their soils and plants. And Minnesotans are involved in these projects.
These solutions are not a panacea. Reducing the use of fossil fuels is a big piece of the puzzle too.
But natural climate solutions, which include a lot of practices that sequester carbon, could manage 37% of carbon dioxide emissions reduction in the next nine years, according to a study published in the 2017 Proceedings of the National Academy of Sciences.
Those practices, paired with other aggressive emissions reductions, could put the planet on track to keep global average temperature rise below 2 degrees Celsius — the level experts say is needed to avoid the greatest risks from climate change.
