by Daniel Brouse and Sidd Mukherjee
Q: Is hemp a good solution for carbon sequestration (carbon sinks) and/or beneficial to the environment?
A: No, not really. In general, hemp only acts as a carbon sink while it is growing and left unharvested. The harvesting usually negates any net-negative carbon sink. (ie more CO2 is released in the harvesting than is being sequestered.) In addition, production of oil, pulp, fibers, or other products usually results in a large carbon footprint. Hemp is not known to be more efficient in the production of anything. It’s also important to note, plant based oils and alcohols result in more low level ozone than petroleum, not to mention, any carbon that is combusted is converted to CO2. Ozone is killing many trees and humans (Death By Ozone, 2016).
Q: Remember the awful hole in the ozone layer in the 80-90’s? Don’t we want more ozone?
A: No. Ozone is a volatile gas and changes form rapidly. In general, there are 2 types of ozone — Tropospheric and Stratospheric. Tropospheric is low level ozone and deadly to life on earth. Stratospheric is in the upper level atmosphere (stratosphere) that protects life on earth (The Ozone Know Zone, 2005).
Q: Won’t the carbon be sequestered in the fiber and stay there until it rots (and hemp is resistant to rotting)?
A: Saying the carbon will stay in the fiber is partially correct… it will also stay in the leaves and the roots. The leaves and roots will decay faster. But, as for the fibers, to harvest them takes more carbon than the carbon that is sequestered. In all cases of plants as carbon sinks, it does nothing to solve the problem of the CO2 in the atmosphere that was released by fossil fuels. Plants are just a temporary store for their own carbon. Trees absorb and release about the same amount of carbon over a 100-year cycle (with many shorter time cycles for the leaves — about 1-2 years.) Comparatively, hemp’s cycle is only a few years. Another important factor in calculating the length of time of a carbon sink with plants is that plants also breath: “Plants release up to 30 per cent more CO2 than previously thought.” During daylight and night there is the process of plant respiration in which plants breath in O2 and breath out CO2. This is different than during daylight hours when a separate process called photosynthesis takes in carbon dioxide and releases oxygen. Plants release up to 30 per cent more CO2 than previously thought, 2017)
Q: Would it is better to have tarmac than grow hemp? Even though hemp can replace petroleum-based plastic with biodegradable products?
A: No, not at all. We should plant as many plants with the longest sink-cycle (trees). Most importantly we should stop releasing CO2 that has been sequestered for millions of years. Then, we should figure how to re-sequester CO2 for millions of years.
Hemp has far more benefits and significantly less costs than petroleum products; however, agriculture in general has many costs (in fact, the invention of flooded rice paddy agriculture thousands of years ago in China was one of the first major human causes of climate change.” The origins of human-influenced climate change may be traced back 5,000 years“, 2004) Monoculture of hemp, corn, and other bio-fuels release all the CO2, create more ozone and require vast areas of land. Having a single crop produced in large scale has a devastating effect on biodiversity. Bio-plastics and other petroleum substitutes create the same sort of environmental problems. They don’t instantly bio-degrade. They initially breakdown into micro-bio-plastics.
The little live creatures on this planet have evolved for a couple billion years to eat what plants make — like carbohydrates. So, they eat carbohydrates much faster than they can eat hydrocarbons from fossil fuels. (But they are working on it, we already see evolution in that direction.)
Unfortunately, there are no good carbon sinks known to Man (other than petroleum / hydrocarbons.) The best solution is to stop human Green House Gas emissions. A study published in the Journal Nature, The contribution of insects to global forest deadwood decomposition found, “Worldwide, dead and decaying wood releases roughly 10.9 gigatons of carbon every year. This is roughly 115% of annual fossil fuel emissions.”
“We found both the rate of decomposition and the contribution of insects are highly dependent on the climate, and will increase as temperatures rise,” study co-author David Lindenmayer said.
At present, bio derived packaging is to be preferred to fossil derived packaging since the former made out of carbohydrate will break down faster than fossil derived hydrocarbon. More important, the bio derived packaging is only returning to the atmosphere recently obtained CO2, since the plants from where the packaging came would decay anyway. But, if fossil plastic decays, that’s dumping into the atmosphere fossil C which was buried hundreds of millions of years ago. Maybe it’s a good thing the little bugs haven’t yet found a widespread, efficient way to eat fossil plastic.
Relative to petroleum, plants are much more beneficial. Hydrocarbons have a much greater cost to the environment. Relative to trees, hemp is far more costly; however, the real solution is to cut down on packaging and consumption.