Isn’t 417 ppm of Atmospheric Carbon Enough?
By Norris Whiston
Norris Whiston has a BSc in Civil Engineering from University of Rhode Island and Masters in Education from Acadia. Norris is now a retired public school educator and writer of books and materials on nature, environment, history, and genealogy. He also helped develop, build and interpret 35 kilometers of hiking trails in Earltown. His online articles include More Than Just Trees and My Little Bit Won’t Hurt.
In the Pliocene Era, 5.3 – 2.6 million years ago, atmospheric carbon was between 245 – 410 ppm (parts per million), temperatures were 2-3 degrees higher, and much of Earth’s land was savannah, grassland or desert. The warmer oceans caused stronger cyclones and hurricanes, seas were 50-75 ft. higher, and islands and peninsulas (like Nova Scotia and Florida) were under water.
Knowing this history and observing the ecological disasters happening now, we need to fully understand the complexities of carbon sequestration and its first, but not only, nutrient assistant, nitrogen. From that, we need to use the best carbon sequestering means that the Earth can muster, and we need to secure soil carbon stores that have taken thousands of years to accumulate. We certainly shouldn’t pretend, by absurd, self-serving reasoning, that putting more carbon into the atmosphere by (a) harvesting, processing, delivering or (b) burning biomass energy, (c) biofuels, (d) heating pellets, or (e) roasting marshmallows justifies ruining both soil carbon stores and the best ways of sequestering carbon. To avoid the impending calamity, we need to understand:
1. The best forests to sequester carbon contain older trees and broadleaf trees, contain natural nitrogen-fixing capabilities, and are structured in complex layers.
The following are relevant quotes from Time Magazine, BBC News, and Phys.org News, which are based on peer-reviewed articles appearing in the Journals Nature, PLoS Biology, Science, Nature Communications, and Ecology.
1a. A study of 673,046 trees worldwide by the US Department of the Interior found the oldest trees sequester best. Nathan Stephenson, co-author, indicated that it was as if the star player was a 90-year old instead of a 20-year old. 1b. In 2017, researchers, analyzing genomes of hundreds of plants, discovered broadleaf flowering plants could build smaller cells allowing “greater carbon dioxide uptake and carbon gain from photosynthesis.” 1c. “Researchers found that in Europe, trees grown since 1750 have actually increased global warming. The scientists believe that replacing broadleaved species with conifers is a key reason for the negative climate impact.” “Removing trees in an organized fashion tends to release carbon that would otherwise remain stored in forest litter, deadwood and soil.” 1d. “The presence of trees that fix nitrogen could double the amount of carbon a forest stores in its first 30 years of regrowth.” 1e. “Forests that are structurally variable and contain multiple layers of leaves outperform structurally simple forests with a single concentrated band of vegetation.”
2. Soil takes thousands of years to acquire carbon and nutrient stores, has 3 times the carbon of the atmosphere, and is lost to the atmosphere by exposure and warming. Even after 15 years, clearcuts are still losing carbon to the atmosphere, and plantations actually add atmospheric carbon and deplete soil nutrients.
The following are relevant quotes from Soil Science of America, BBC News, Biocap, and Pacific Standard Magazine. These quotes are based on articles in the journal Nature, the work of soil and atmospheric scientists, and reports of The Food and Agriculture Organization of the United Nations.
2a. “It takes 500 to thousands of years to create an inch of topsoil.” 2b. “There's three times more carbon stored in soil than there is in the atmosphere. So imagine if all that carbon was released, we’d get runaway climate change.” 2c. “As soon as we shovel the ground then we are already releasing greenhouse gas emissions.” 2d. Soil is vulnerable to warmth. “Soils from colder regions and those with greater amounts of carbon were seen to emit more as temperatures went up.” 2e. “Even 15 years after harvest, the middle-aged stand was still a net carbon source, releasing up to 5 tonnes of CO2, per year”. 2f. “In reality, biodiversity-challenged plantations are a far less reliable carbon sink than forests. Plantations can sequester only a quarter of the CO2 that functioning woodlands can, and converting forests to plantations actually releases carbon trapped in soil.”
These pictures were taken at the Sheet Harbor terminal. The logs and chips had been old hardwood trees inhabiting structurally complex forests. In their previous condition the trees were useful to Earth at sequestering atmospheric carbon, filtering air, exchanging resources with animals and lower layers of vegetation, throwing shade on their carbon-stored soil, and storing precious water. Now, instead, the trees are a boat ride across the Atlantic to becoming more atmospheric carbon.
In May 2020, NOAA & Mauna Lua Observatory in Hawaii reported AC readings at 417 ppm. Until October, thanks to Earth’s remaining plants, the AC readings will go down. Then, by next May, the readings will rise higher than before. Contributing to the rise will be carbon emissions, agriculture, fires in monoculture forests, overdoing highway shoulders, fragmentation, and deforestation. Isn’t 417ppm of atmospheric carbon enough?