A well-known problem of our modern society is emitting large amounts of GHGs into the atmosphere which are changing the planet’s climate. According to Bill Gates’ latest book, people create 51 billion tons of emissions every year. These levels caused by human activities have never been experienced before in history.
As a result, scientists have recorded rapid melting of ice sheets, contributing to rising seas, and extreme weather events like hurricanes and droughts getting more severe over the last few decades. Reforestation and new emerging technologies for reducing accumulated CO2 emissions like carbon capture and storage are seen as a way to help mitigate climate change.
Planting more trees has surely been supported by scientists and nations across the world as one of the most efficient ways of reducing man-made emissions. In the UK, Boris Johnson has pledged to plant 30 million trees a year. Other countries have taken bolder measures: in 2016 one Indian state planted 50 million trees in one day, while in July 2019 Ethiopia said to have planted 350 million in a day.
Scientists have been saying that deforestation is actually one of the biggest emitters of CO2, because when trees are cut down much of the carbon stored within them escapes into the air. That case is much stronger when the wood is burned.
It is estimated that in 2017 land use changes, particularly deforestation, contributed four billion tonnes of CO2 emissions to the global total of 41 billion tonnes of CO2. Therefore, if the world stops cutting down trees, the total annual emissions will fall by around 10%. Currently deforestation costs the planet around 15 billion trees each year.
Reforestation is also part of the so-called “natural climate solutions”. They include restoring wetlands and other ecosystems, and minimising emissions from farmland, preserving existing forests and reforesting degraded areas. In a 2017 study, researchers estimated the natural climate solutions could lock up the equivalent of 23.8 billion tonnes of CO2 per year.
That is almost half global annual emissions. However, many of those solutions are estimated to be cost-ineffective. The more realistic figure comes to 11-15 billion tonnes of CO2 sequestered per year by natural climate solutions. That means they can take care of about 30% of the CO2 we need to deal with every year.
Reforestation alone has the potential to soak between 3 to 18 billion tonnes of CO2 per year as estimated by The UK’s Royal Society in a 2018 report on greenhouse gas removal technologies.
Issues With Reforestation
However, there are also some setbacks regarding reforestation that need to be mentioned. As trees are dark, planting more trees would make the land darker. Dark surfaces absorb more heat and warm the local climate.
Therefore, reforestation needs to be handled carefully as there is a delicate balance between trees’ ability to take in CO2 which mitigates climate change, and their tendency to trap additional heat and thus create warming. According to a 2007 study that has been repeatedly confirmed, the best place to plant new trees is the tropics as there they grow fastest and thus trap the most CO2.
Another pitfall is that tree-planting requires lots of fresh water which is scarce in drier areas. Tree capabilities to remove CO2 are also limited by nutrient availability of the soil, fire hazards and droughts expected to increase in the coming decades. Fires are especially worrisome as they can release the stored carbon dioxide in the trees and flip the forest to another type of landscape.
Carbon Capture Benefits
Trees are an obvious contributor. The world has emitted so much CO2 emissions so far that finding new ways to actively remove them is not a matter of choice. It needs to be done in order to achieve the world targets of limiting warming to 1.5C or 2C.
“Addressing climate change will require investment in technologies that help to limit future emissions, such as electric vehicles, and also the drawdown of carbon from the atmosphere. Nature-based solutions can help with both of these, but we will need thousands of solutions in combination,” says Tom Crowther, a tenure-track professor of Global Ecosystem Ecology at ETH Zürich and the chief scientific advisor to the United Nation’s Trillion Tree Campaign.
Elon Musk who has recently offered $100 million for the best carbon capture technology, addressed a query regarding using this money for planting trees: “trees are part of the solution, but require lots of fresh water & land. We may need something that’s ultra-large-scale industrial in 10 to 20 years.”
According to the Global CCS Institute’s report – 2020 Global Status on CCS, there are 26 commercial CCS facilities currently in operation around the world that capture almost 40 million tonnes of CO2 annually. That is equivalent to around 1,6 billion trees according to Carbon Engineering’s math. Therefore, carbon capture is a more efficient way of sequestering CO2 in the near term.
Carbon Capture Companies
Direct air capture companies like Carbon Engineering are working on sucking carbon from the air and thus reduce its concentration in the atmosphere. The company says it and its partners are working to build DAC facilities to capture a million tons of carbon dioxide a year. According to them, that is “equivalent to the work of 40 million trees.”
Climeworks, a Swiss direct air carbon capture company, says it is the first to extract carbon from nature permanently and bury it underground. The company is partnering with Carbfix in Iceland that turns the captured CO2 from its facility, turns it into rock and stores it underground. Carbfix aims to reach 1 billion metric tons of permanently stored CO2 in 2030.
Besides its plant in Iceland, Climeworks participates in the Northern Lights Project in Norway, with an expected capacity of up to 1.5 million tonnes of carbon storage per year. It also operates a facility in Switzerland that captures up to 1,000 tonnes of CO2 a year from the air. The gas is then sold to local greenhouses to boost plant growth.
Challenges Disrupting Widespread Reforestation
There are some challenges associated both with reforestation and carbon capture technologies when applied as CO2 reduction solutions. Cost and economies of scale are standing in front of utilization. Reforestation costs would vary depending on location, plans for monitoring, and intended outcomes.
The cost would vary between a dollar and $20 per tree. In many locations, co-blended financing between organizations and governments is essential for a reforestation project to take off and smaller projects are at a disadvantage due to economies of scale.
Organizations that have a long history of work in specific landscapes and communities are best suited to define the right trees in the right places for the right reasons with local leadership.
Trillion Trees is an example for such an approach. It is a project aiming to conserve, restore and grow 1 trillion trees by 2030, part of the World Economic Forum’s work to accelerate nature-based solutions. It carefully supports restoration initiatives with strong community backing and also prioritizes forest protection.
One challenge worth keeping in mind is that trees would also take 50-100 years to have their full effect of removing the CO2. Despite that, according to professor Crowther tree planting is “a climate change solution that doesn’t require President Trump to immediately start believing in climate change, or scientists to come up with technological solutions to draw carbon dioxide out of the atmosphere…It is available now, it is the cheapest one possible and every one of us can get involved.”
Challenges Preventing Carbon Capture Scalability
Carbon capture and storage widespread deployment is faced by some cost and technical issues. According to a study from the University of California, most carbon capture projects lack unconditional incentives upfront to provide a safe financial footing. That is also why they are mostly used for enhanced oil recovery. That is also the main reason why 149 CCS projects have been terminated or placed on indefinite hold so far.
Extracting emissions is also a very energy-intensive process. Therefore, a facility equipped with CCS can require more energy to operate as one without it. Another challenge preventing wide adoption is what to do with the extracted CO2. Usually, it can either be stored underground or sold to buyers to support revenue streams.
Government incentives like a carbon tax or carbon tax credits are needed to drive development and innovation. In the case of solar and wind power widespread adoption, subsidies played the biggest part as they created a marketplace for capitalism to take off the industry.
Both reforestation and carbon capture and storage are seen as viable solutions to reversing climate change. On their own, they can fill in the gaps in an overall effort to decarbonize the economy. However, alone they will never reach a scale that would remove all excess emissions humanity produces every year. The combination of natural climate solutions with carbon removal technologies like CCS on a massive scale in the next 10 to 20 years is considered to provide a great opportunity for near-term climate benefits.