Global warming and climate change may be the most challenging threat the human species has ever faced. It demands a unified, focused, and organized effort from all of us around the world to transition to a net-zero carbon economy, and reducing the amount of carbon dioxide in the atmosphere.
Hemp and Other Carbon Dioxide Removal Strategies
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Table of Contents
Anthropogenic Climate Change
Since the late 1800s, scientists have suspected human-produced (anthropogenic) changes in atmospheric greenhouse gases would likely cause climate change. In 1856, Eunice Foote discovered the heat-trapping properties of water vapour, carbon dioxide, and air when heated in the sun. These properties were further identified by Irish physicist, John Tyndall, in 1859.
The current observed trend in global temperatures cannot be attributed to natural climate change. In fact, scientists can only account for recent global warming by including the effects of human-caused greenhouse gas emissions, which have increased since pre-industrial times due to the burning of fossil fuels compounded by population growth.
Focused On Carbon Dioxide
How each greenhouse gas contributes to the greenhouse effect depends on three main factors: how much is in the atmosphere, how long they remain in the atmosphere, and how strongly they impact the atmosphere – measured in global warming potential (GWP). For example, methane’s 20-year GWP is 56 times that of CO2, and its 100-year GWP is 21 times that of CO2. However, CO2 has an atmospheric lifetime of 300-1,000 years compared to 9-15 years for methane, and there is about 200 times more CO2 in the atmosphere than methane.
Pre-industrial levels of atmospheric CO2 were approximately 278 parts per million (ppm), compared to the daily average of 415 ppm as of December 31, 2020. To put this into context, based on ice core records of the past 800,000 years, CO2 concentration in the atmosphere ranged from about 185 ppm during ice ages to 300 ppm during warm periods. The concentration of atmospheric carbon is at an unprecedented level that hasn’t been observed in at least the last 800,000 years. We are in a climate crisis.
Reducing Atmospheric Carbon
In its special report Global Warming of 1.5˚C, the Intergovernmental Panel on Climate Change (IPCC) asserts the most catastrophic effects of climate change could be averted by limiting global warming to 1.5˚C. The report describes ways of achieving this – all of which depend on removing carbon dioxide from the atmosphere.
To achieve this goal, organizations around the world need to become either “net-zero” or “carbon negative.” Net-zero, also called “zero-carbon” or “carbon neutrality,” means carbon emissions emitted by day-to-day operations are either zero or offset by investing in initiatives certified to remove carbon dioxide from the atmosphere. Carbon negative, also called “climate positive,” means company day-to-day operations go beyond achieving net-zero carbon emissions and actually remove carbon dioxide from the atmosphere.
Carbon emissions can also be eliminated from the source by means of government initiatives such as carbon taxes, carbon markets, electrifying transportation, decentralized micro-grid power generation, and more. However, since the CO2 already in the atmosphere can affect climate for hundreds to thousands of years, we must not only transition to a zero-carbon economy, we must also implement carbon dioxide removal (CDR) strategies on a massive scale.
Carbon Dioxide Removal Strategies
A variety of carbon dioxide removal (CDR) strategies have been used at large scale for decades and more are on the horizon in different stages of development. Each strategy has pros and cons, varying in cost, benefits, and risks.
Afforestation and Reforestation
Forests around the world store almost a third of the world’s emissions. Reforestation is the restoration of forests where they have been damaged or depleted, while afforestation is the establishment of new forests where none were previously. In comparison to reforestation, afforestation could compete for land used for agriculture and affect local and regional biodiversity and ecosystems.
Soil Carbon Sequestration
Soil carbon sequestration, also called “carbon farming,” leverages and amplifies the natural process where plants absorb carbon from the atmosphere during photosynthesis and transfer it into the pedosphere (soil) when they die and decompose.
While soil can store large amounts of carbon in the beginning, its ability to absorb carbon decreases as it becomes saturated after 10 to 100 years depending on climate, soil type, and how it is managed. Minimal tillage, cover crops, crop rotation, and crop residue decomposition all help store more carbon in the soil.
Biochar is charcoal produced by pyrolysis – high-temperature decomposition of plant material, or biomass, in the absence of oxygen so as to avoid combustion. It is one of the most affordable CDR strategies and is used to improve soil quality and crop yield.
Biochar has been found to pose relatively low risks in terms of negative environmental impacts which may include particulate matter, acidification, and eutrophication as potential trade-offs – though more research is required.
Bioenergy with Carbon Capture and Storage (BECCS)
BECCS involves burning biomass to generate electricity at a power plant while capturing and injecting the resulting emissions into the geosphere (Earth) where they are sequestered in geologic formations.
At this point, BECCS is under development and is expensive, however is considered potentially one of the most effective carbon dioxide removal strategies for providing long-term carbon storage. It would require enormous changes in agriculture, forest, and biomass waste management, for, if managed improperly, it could negatively impact biodiversity, ecosystems, and food production as well as generating GHGs through unsustainable agriculture practices and fertilizer use.
Direct Air Carbon Capture and Storage (DACCS)
DACCS filters carbon dioxide directly out of the atmosphere by using fans to move air over liquid or solid compounds that bind to CO2 as it comes into contact with them. These compounds release the captured CO2 when later exposed to heat and chemical reactions, which is then compressed and sequestered underground.
While DACCS offers great potential as a CDR strategy, it is still in the early stages of development. It is also worthwhile to consider the implications large-scale DACCS could have on the environment stemming from extracting, refining, transporting, and disposing of the materials required to capture the carbon emissions.
This CDR strategy leverages a natural process in which CO2 chemically bonds with reactive substances like peridotite or basaltic lava. This chemical process forms solid carbonate minerals, such as limestone, potentially storing CO2 for millions of years. Fluids containing CO2 produced at carbon capture stations may be combined with these reactive substances, or pumped into naturally occurring reactive rock formations.
Carbon mineralization has the potential to provide a non-toxic, economical, and permanent way of storing large amounts of carbon. However, because this strategy is in the early stages of development, more research into the possibility of contaminating water and triggering earthquakes is required.
Rocks and soil react with the CO2 in the air or acid rain (atmospheric CO2 dissolved in rainwater) to create bicarbonate, which is eventually carried by the process of erosion into the ocean where it is stored. Enhanced weathering leverages and amplifies this natural process by spreading pulverized rock, such as basalt or olivine, on the land or in the ocean.
While enhanced weathering could improve soil quality and help neutralize ocean acidification in addition to sequestering carbon, more research into the effects it may have on soil pH and chemical properties, ecosystems, and groundwater is required.
The Blue Carbon Initiative
Blue carbon refers to carbon dioxide removed from the atmosphere by oceanic plant growth, and its subsequent burial of decaying organic matter in the soil. Mangroves, salt marshes, seagrasses, macroalgae (saltwater plants), and other plants in tidal wetlands sequester over half of the carbon in coastal ecosystems. However, they are being destroyed by runoff, pollution, drought, and coastal development.
The Blue Carbon Initiative is an international, worldwide effort to mitigate climate change through the management of coastal ecosystems. By restoring, creating, and managing coastal ecosystems, their carbon storage could potentially double while also improving water quality, supporting marine life, and providing storm protection.
The Prodigious Potential of Hemp
Prodigious is defined as “remarkably or impressively great in extent, size, or degree,” and is the perfect word, in my opinion, to describe the unfathomable and unbelievable potential industrial hemp has to combat the climate crisis. Illegal to cultivate for the last 60-80 years, one can’t help but to wonder if we would be in a climate crisis today if it wasn’t.
Hemp has been cultivated for thousands of years due to its incredible versatility; used to produce various products ranging from food, clothing, textiles, rope, medicine, paper, construction materials, and now biodegradable plastics, biofuels, and more. Aside from providing a potential systemic revolution of the consumer, commercial, and industrial goods industries, it also offers great potential for combating the climate crisis and other environmental, social, and economic problems around the world.
The United Nations’ 17 Sustainable Development Goals (SDGs) recognize environmental, social, and economic strategies must go hand-in-hand to achieve holistic sustainability on Earth. The versatility of hemp provides opportunity in helping to achieve 8 of the 17 goals: #2 (Zero Hunger), #3 (Good Health and Well-being), #7 (Affordable and Clean Energy), #9 (Industry, Innovation and Infrastructure), #11 (Sustainable Cities and Communities), #12 (Responsible Consumption and Production), #13 (Climate Action), and #15 (Life on Land).
A Profitable Cover Crop For Farmers
Cover crops are plants used in the crop rotation process to regenerate the soil for the following growing season. Planting cover crops offers many benefits: weed suppression, erosion protection, soil aggregate stability, reducing surface crusting, adding active organic matter, breaking hardpan, nitrogen fixation, nitrogen scavenging, and suppression of soil-borne diseases and pests.
Hemp’s rapid growth cycle makes it very competitive with weeds, resulting in little to no harsh herbicide requirements, and translates to more CO2 sequestration into the soil, not to mention the many products that can be made from hemp. One ton of hemp can absorb approximately 1.62 tons of CO2 making it one of the best crops in the fight against global warming.
Carbon markets allow for the trading of carbon credits. Selling carbon credits produced through growing hemp could offer a much welcome revenue stream for farmers, and buying them could help large corporations follow through on pledges to reduce carbon emissions – a win-win-win situation.
In addition to revenue streams provided by selling the raw material from growing hemp and the resulting carbon credits, unused biomass could be sold to be used in BECCS or to make biochar, in my opinion, making hemp a very, if not the most, profitable cover crop.
Decreasing pressure on forests and their ecosystems allows them to regenerate and improve their ability to absorb carbon. Hemp can help alleviate demand for wood products, and reduce our impact on forests. Its fibre has very similar properties to that of wood and can be used to make hemp-based alternatives for many wood products – paper products, fuel pellets, etc. The difference, however, is hemp matures for harvest in four months compared to 20-80 years for trees, and yields nearly four times more fibre per acre.
While all hemp-based products sequester carbon, building materials derived from hemp such as hempcrete, hemp insulation, and even hemp “wood” products are gaining popularity as awareness of their embodied carbon and their use in sustainable construction continues to grow.
Hempcrete is a biocomposite, a thermal construction material used in walls, floors, and ceilings. It is composed of hemp hurd or shiv mixed with a lime-based binder and water. The combination of the carbon absorbed through hemp when grown and the carbonization of the lime binder during the curing process is greater than the carbon emitted during the production of hempcrete – making it one of the only carbon-negative building materials.
Considering the carbon negativity of hemp building materials and how hemp has been illegal to cultivate for the past 60-80 years, I encourage you to imagine what the world would look like today if most if not all homes were built with sustainable hemp building materials – a world where climate-change-producing carbon had been stored in our homes, the various products we use in our everyday lives, and the soil in which the hemp was grown.
Complex ecosystems, biodiversity, and symbiotic relationships maintain the delicate balance of life on Earth as we know it. These ecosystems have adapted and evolved to well-established climates over long periods of time. However, the rapid acceleration of climate change due to human activity threatens to disrupt ecosystems around the world. Species will be forced to adapt to rapid changes in regional climates around the world to survive, which is most concerning as the loss of one species has a cascading ripple effect and losing key species will lead to catastrophic, irreversible consequences to the environment, our societies, and our economies – we must take action.
How can you leverage your skills to help combat the climate crisis? Learn about and get involved in local and worldwide initiatives like the Sustainable Development Goals (SDGs), Race to Zero, Project Drawdown, Climate Reality Project, Exponential Roadmap Initiative, TED Countdown, We Don’t Have Time, 350, and many more.
With a unified, focused, and organized effort, we will overcome this challenge. We’re all in this together. Humanity depends on it.
More To Explore
We can all help combat the climate crisis by decreasing the impact we have on forests and the biodiversity they provide, and by preserving forests’ ability to absorb carbon dioxide. An opportunity presents itself to alleviate demand for wood products by transitioning to hemp-based alternatives.