Planting trees helps remove carbon from the atmosphere, But are there other ways?

Planting a trillion trees could store two-thirds of the carbon released into the atmosphere since the (European) Industrial Revolution

God has blessed the Earth with many giant carbon sinks that can help humans fight climate change, as this natural sponge can effectively absorb and remove carbon from the atmosphere.

But what other man-made methods? And what does it take so that they can pull enough carbon from the atmosphere to make a difference and slow climate change? How long will it take? How much will it cost?

According to a report by Live Science, researcher Sabine Voss has been searching for an answer to these questions for the past two years. Voss, an economist in Berlin, leads a research group at the Mercator Institute for Research on the Global Commons and Climate Change (MCC), and was part of the Intergovernmental Panel on Climate Change (IPCC), set up by the United Nations to assess the science, risks and impacts of global warming.

Following the panel's 2018 report, and the new Paris Agreement target of keeping global warming at 1.5°C or less; Voss was tasked with studying the most promising and feasible decarbonization strategies.

Nature-based methods

Afforestation and reforestation - such as planting and replanting forests - are among the natural carbon sinks known in the world, where a large number of trees can sequester greenhouse gas "carbon dioxide" (CO2) from the atmosphere for photosynthesis, a chemical reaction that uses energy The sun to convert carbon dioxide and water into sugar and oxygen.

According to a 2019 study in the journal Science, planting a trillion trees could store about 225 billion tons of carbon, or about two-thirds of the carbon that humans have released into the atmosphere since the start of the industrial revolution. In addition to afforestation, "farmland management" is another method of natural carbon removal, which is relatively low risk and has already been tested.

According to Gene Zelikova, a terrestrial ecologist and chief scientist at Carbon 180 (a non-profit organization that advocates for decarbonization strategies in the United States), practices such as rotational grazing and crop rotation increase carbon uptake by photosynthesis, and that carbon is ultimately stored in Root tissues that decompose in the soil.

The National Academy of Sciences had found that storing carbon in the soil was enough to offset up to 10% of America's annual net emissions, or about 632 million tons of carbon dioxide at a low cost.

There are currently 15 plants to capture carbon dioxide from the air around the world (Getty Images)

Technology-based methods

But Voss says that nature-based decarbonization - such as planting and replanting forests - can conflict with other goals and policies, such as food production, because scaling up these strategies requires a lot of land, and in many cases that land is already in use.

These challenges are why technology-based methods for removing carbon from the air are critical, by capturing carbon directly from the air and storing it.

One technology-based chemical process takes carbon dioxide out of the air, then puts it in 'filters'. When these "filters" are heated, carbon dioxide can be captured and then injected underground. According to the International Energy Agency, there are currently 15 plants to capture carbon dioxide from the air worldwide.

Another "mineralization" trick is to sequester carbon. In this process, the rocks coalesce to increase the surfaces available for chemical reaction with carbon dioxide, after which the mineral carbon dioxide is stored underground.

According to Voss, none of these technologies have been implemented on a large scale, as they are extremely expensive, with estimates of up to $400 per tonne of carbon dioxide removed, and each still requires a lot of research and support before they can be generalized and published.

A special experience for each country

The United States is a good example of how a combination of decarbonization solutions can work together, Zelikova says. A land management solution can be used in the agricultural Midwest, and large basalt rocks in the Pacific Northwest can be used for mineralization, and the oil fields in the Southwest are already equipped with the right technology and skilled workers. Underground carbon storage.

Ultimately, each country will have to define its own unique set of CO2 removal strategies because no single solution will work on its own.

If we focus on one method and scale up one method to remove CO2 it will be a disaster, because it would use a lot of land or be too expensive, Voss says.

Voss' research showed that afforestation and reforestation would be more productive in the tropics, while differences in solar radiation at northern latitudes and with increased reflection of light into space meant those countries would have a better chance of investing in technological interventions to capture carbon.

Publish solutions

The need to deploy these solutions is imminent. Voss says the global carbon budget - the amount of carbon dioxide that humans can emit before the global temperature rises 1.5 degrees Celsius - is about 300 gigatons of carbon dioxide. And we've launched 40 gigatons in recent years already. In other words, there are only a few years left in that budget.

A recent study, published in Scientific Reports, suggests that waiting a few years from now may be too late if we are to achieve the goal set in the Paris Agreement. Based on their climate model, the researchers predict that even if we stopped emitting greenhouse gases completely, global temperatures would be 3 degrees Celsius warmer, and sea levels would rise 3 meters. To reverse the effects of climate change moving forward, 33 gigatons of current greenhouse gases must be removed each year.

However, the truth is that these methods are not ready and there is no consensus on how to pay for them. On the other hand, there is a consensus among scholars on the next step; And that is, we need to stop more emissions immediately. But Voss says, “As emissions are an integral part of our daily lives and infrastructure, decarbonization comes first.