Have a glance at Item A1 over on the left sidebar: you will see, if today is August 1 2015, that it shows a figure of 399.54 parts per million. This means that the atmosphere at Mauna Loa Hawaii is, currently, 0.039954 percent carbon dioxide (CO2). That is down 1.2 parts per million from the 400.74 ppm it was yesterday. Should we celebrate this decline, given that climate scientists have been warning us, in ever-urgent tones, against an increase? No.
It is normal for the readings at Mauna Loa to decline slightly during the northern hemisphere summer. Most man-made CO2 is put into the air in the northern hemisphere: that is where most of the world’s cars, power plants, and industrial plants operate. But in the northern hemisphere summer, broad leaf plants and shrubs are in full leaf, catching as many of the solar photons incoming from the sun as possible and using them, via photosynthesis, to turn CO2 into sugar. Needled conifers, like those that make up most of Canada’s Boreal forest, do the same. The sugar manufactured in photosynthesis goes into making the wood in trees, thereby adding that growth ring you see when you look at a sawn tree stump.
But the sugar that trees make via photosynthesis also feeds the fungi that live in a chemical symbiosis with the trees. The fungal symbiont is much like a human: it breathes in oxygen, eats sugar, and breathes out CO2. As an estimated 85 percent of land plants across our planet live in such a symbiosis with fungi, you can imagine that the world “inventory” of such fungi must be enormous. And it is. Mycologist George Barron writes that each tree has associated with its roots literally hundreds of thousands of kilometers of fungal hyphae (threads). He notes that fungi worldwide return around 80 billion tons of carbon to the atmosphere each year. So, as trees breathe in CO2, fungi breathe it out.
Mankind puts around 30 billion tons of CO2 into the atmosphere each year. Though this is much less than fungi’s 80 billion tons, it is nevertheless causing global warming because the plant-fungi system is not absorbing it. Many people believe that planting more trees with help to absorb CO2. That is true, they will, but because trees come in a package with fungi, which breathe out CO2, planting trees will serve only to absorb the CO2 from that symbiosis. Which means that if we humans keep dumping billions of tons of CO2 because of our addiction to fossil fuels, atmospheric CO2 concentration will continue to rise.
But what about the decline in atmospheric CO2 mentioned at the top of this article, you might say. Isn’t that because trees in the northern hemisphere are furiously photosynthesizing with all the extra solar photons? Yes. But that doesn’t mean the fungi with which they live will not themselves see a growth spurt to take advantage of the glut of glucose. More fungi, more CO2 through their respiration.
i.e., fungi will experience such a growth spurt. And the readings from Mauna Loa will soon, within a few months, continue the upward climb they have been on since the Keeling station, which measures the CO2 at Mauna Loa, was established in 1959.
If we want to stop that upward climb in atmospheric carbon, then we have to stop putting carbon into the atmosphere. My home province, Ontario, is on the verge of realizing it can begin leading the world into the zero carbon energy future. That future will be achieved easily, by simply adding a few new Ontario-designed nuclear plants to the provincial electricity grid, then by converting the provincial inventory of heating furnaces that run on carbon emitting fossil fuels to zero-emission, 100-percent-efficient electric heaters.
In one easy fell swoop, which wouldn’t take much more than a single decade, that will wipe out an entire 30 million ton category from Ontario’s CO2 inventory.