Mechanical Trees might sound like something out of a dystopian, sci-fi movie — but their ability to suck CO₂ out of the atmosphere 1,000 times faster than real trees could make them an important tool in the fight against climate change.
What Are Mechanical Trees?
Klaus Lackner’s Mechanical Trees stand at 10 metres tall, and instead of leaves, his ‘trees’ contain a stack of 150 discs that collect and store CO₂. Lackner is the director of the Center for Negative Carbon Emissions, and professor at the School of Sustainable Engineering at Arizona. Since the 1990’s, Lackner has been working on building a Mechanical Tree that functions in a similar manner to real trees!
He’s successfully built a Mechanical Tree that absorbs carbon dioxide (CO₂) 1,000 times faster than real trees. CO₂ is emitted when humans burn fossil fuels like coal, oil and gas, but it also comes from our oceans, volcanoes, and animals. An abundance of CO₂ in the atmosphere contributes to the ‘greenhouse effect’, where the trapped heat warms the average temperature of the planet.
Photograph: Carbon Collect
How Do Mechanical Trees Work?
Inside the Mechanical Trees are 150 circular discs, which separate the CO₂ from oxygen and store it away for later use. Klaus Lackner explains how the Mechanical Trees work.
“As the air blows through, the surfaces of the discs absorb CO₂. After 20 minutes or so, the discs are full, and they sink into a barrel below. We send in water and steam to release the CO₂ into a closed environment,” he said.
Recycled CO₂ can be used to harden cement, create fizzy drinks, or to turn it into insulation foam for housing. Or, the CO₂ can be mixed with minerals that are rich in calcium to form solid carbonates. In this solid form, carbon can be stored underground permanently. “The atmospheric carbon situation has become critical and we need to start taking action."
Photograph: Eelco Böhtlingk / Unsplash
Can Mechanical Trees Help In The Fight Against Climate Change?
Carbon Capture and Storage (CCS) technology has been hailed as a ‘solution’ to climate change. After many years of CCS research and billions poured into it all over the world, there is very little to show for it.
The biggest problem isn’t how to capture CO₂, it’s what to do with the massive amounts that are collected. Experts at the Climate Council believe that CCS technology gives the fossil fuel industry an excuse to keep burning fossil fuels — without actually doing anything to reduce emissions.
There may be, however, the need for this type of technology when the world is in a position to start reversing global carbon emissions. According to Lackner, "this technology can reduce carbon emissions — a leading cause of climate change.”
Photograph: Mekht / Unsplash
Mechanical Trees VS Real Trees
Lackner’s Mechanical Trees and real trees both have the ability to absorb CO₂. Planting trees is an effective way to remove and store excess CO₂ from the atmosphere. There’s just one problem — we don't have enough space on Earth to plant all the trees that would be required to ‘offset’ our current global emissions. In fact, we’d need to plant half a trillion trees to capture approximately 205 gigatons of carbon. “If you add up how much carbon we need to get back from the atmosphere we simply don’t have enough land to grow the trees,” said Lackner.
Plus, those trees would have to be protected from being cut down, which releases the stored carbon back into the atmosphere. But, he said, “two hundred and fifty large scale Mechanical Tree™ farms have the capacity to capture one gigaton of CO2”. Pretty amazing, right?
These Mechanical Trees certainly aren't as beautiful as real trees, but in the future, they may become a useful tool to remove excess CO₂ from the atmosphere!
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