At a Washington, D.C., press conference on Thursday, September 19, 2019, Amazon announced a plan to be carbon neutral by 2040. CEO Jeff Bezos also pledged to talk with other executives of major companies about their moving in the same direction.
Gregg Marland, professor at the Research Institute for Environment, Energy, and Economics at Appalachian State University explained the significance of the move in that the 44.4 million tons of carbon dioxide emitted by Amazon last year amounted to “greenhouse gas emissions [of] about 85% of the emissions of Switzerland or Denmark.”
The Amazon plan includes the purchase of 100,000 electric vans from Rivian Automotive for deliveries, along with installation of solar panels and other renewable energy to get the company to 100% renewables by 2030, a 40% increase over what’s already in place.
Also on Thursday, Google announced its own increased investment in renewable energy.
REDUCTION AND REMOVAL
Amazon’s carbon footprint seems huge, but when compared alongside the accumulated totals over decades and centuries it isn’t. According to the Washington, D.C.-based World Resources Institute (WRI), “Since the Industrial Revolution, humans have emitted more than 2,000 gigatons of carbon dioxide into the atmosphere. (A gigaton is a billion metric tons.) The thickening blanket of heat-trapping greenhouse gases is the cause of the global warming we are experiencing today.”
Amazon’s carbon-neutral overhaul is very important, especially given the company’s size and ability to influence other corporations, but we have reached the point, according to climate scientists, where the effort now must be joined by active carbon removal. Writing for WRI, James Mulligan explains, “In fact, most climate scenarios show we’ll need to remove billions of metric tons of carbon dioxide annually by midcentury, while also ramping up emissions reductions.”
It almost sounds like science fiction to think about removing specific gases from the air, but it’s one of the most widespread, natural processes going on around us, albeit invisibly.
A new initiative at WRI called CarbonShot is researching options for carbon removal at scale in the United States. The project has identified six key areas.
1. Forests: The planet breathes through the silent process of photosynthesis. Trees especially are very efficient at pulling CO2 from the atmosphere, mixing it with water, activating the removal of electrons with the energy of sunlight, and ultimately releasing oxygen into the air. Expanding and restoring existing forests can, according to WRI, capture about 3 metric tons of CO2 for every acre of temperate forest. The cost is less than $50 per metric ton, and side benefits include cleaner water and air.
2. Farms: Soils store carbon, so efforts could increase soil carbon per acre in the more than 900 million acres of agricultural land. You can do this by planting cover crops to increase photosynthesis, and using compost on the fields to store the compost’s carbon in the soil. Improved science will be required to determine balances and the long-term effects and possible deficits of this type of carbon storing.
3. BECCS: The bio-energy with carbon capture and storage is still an art in development. The process was first described in 1998 in Dr. Robert H. Williams book Ecorestructuring in a chapter titled “Fuel decarbonization for fuel cell applications and sequestration of the separated CO2.” In the 20 years since, there has been progress, but problems remain such as bioenergy crops might replace food production or natural ecosystems. Using agricultural residues and garbage instead of crops grown for energy conversion might be an alternative.
4. Direct Air Capture: Chemically scrubbing carbon dioxide directly from the air and then storing it in the ground or in other stable materials is practical and efficient, but it remains costly. The process is energy-intensive, and one study cited by WRI estimates it would cost about $94-$232 per metric ton removed.
5. Seawater Capture: The underwater equivalent of direct air capture, the process removes existing carbon from seawater which forces the water to remove more carbon from the air to reestablish its own natural balances. The U.S. Navy has developed a prototype seawater capture device, but this technology is only at a beginning stage.
6. Enhanced Weathering: The process called “weathering” happens when certain minerals turn carbon into a solid. This process takes a very long time when it occurs naturally, but work is underway to discover how to speed the process up. This could involve improving the way certain minerals are exposed to CO2 in the air or oceans. Experiments are being conducted forcing air through mine tailings of the right minerals, pumping alkaline spring water from underground to the surface to be exposed to air, and even developing enzymes that disintegrate mineral deposits to increase their surface area.
Which of these technologies, if any, will prove the most efficient is an open question, but there’s no doubt that the sequester and storage of CO2 has become a major effort in climate control research.
AN EOS BIOREACTOR
The recently announced Eos Bioreactor from Hypergiant Industries is a 3′ by 3′, 7′ tall bioreactor that captures and stores carbon from the atmosphere while producing clean bio-fuels that can be used to provide energy to urban buildings. Key to its operation is the impressive ability of algae to produce up to 5 times the biomass per unit area as terrestrial plants. The process involves photosynthesis, and the manufacturer’s claim is that it can capture as much carbon from the air as an acre of trees, making it 400 times more efficient than trees.
The reactor uses a specific type of algae called chlorella vulgaris, a green microalgae that also serves as a protein-rich food additive in Japan. The algae is suspended in tubes and a water-filled tank, and air is pumped through the suspensions which are exposed to artificial light. The CO2/water/air/light engine is managed by AI software that learns to maintain the balances for the most efficient capture and energy production.
Hypergiant describes the Eos parts and process this way: “Algae is the central ingredient in our bioreactor. Without it, the Eos is just a bunch of tubes. The algae in the bioreactor consumes carbon dioxide. As algae consumes CO2, it produces biomass. This biomass can be harvested and processed to create fuels, oils, nutrient-rich high-protein food sources, fertilizers, plastics, cosmetics, and more.”
Hypergiant has promised to release, to the public, the design of the bioreactor later this year in order to interest others in this type of environmental solution. In 2020, the company will have details about when the machines will be commercially available.