The Carbon Sink Theory

PMU199,                                                                                                                                         Bon soir!

Feeling grey?

Winter in Toronto is a pastel panorama.  As the days run short and ‘seasonal mood’ kicks in, carbon dioxide levels in the atmosphere are high due to a decrease in photosynthesis activity.  Ever present is the seasonal carbon cycle.  However what is it about CO2 that speaks climatic calamities?

Tim Appenzeller’s, The Case of the Missing Carbon (National Geographic) investigates the mystery of change in natures delicate ecosystems.  This is a razor fine balance between environmental carbon sinks (the missing carbon) to carbon sources.  Appenzeller’s preamble summates –  ‘natures role can be unpredictable’, so where in nature can we look for salvation?  He dedicates his article to a few scientific theories that suggest perhaps it is time for us to think about creating our own carbon sinks.  Geologic and carbon sequestrations? Reforestation and biochar? Iron fertilization?  I wish this article dove into cost, conscience, and a broader geography (results) to spark additional reciprocity!

How are carbon sinks identified?  By observation and experiment.  The basic premise is the scientific analysis of natural carbon sinks in the environment i.e. forests, grasslands, soil, waters of the ocean, etc.  A carbon sink is anything that absorbs more carbon than it releases. Comparing the impact of carbon input into the atmosphere by humans and nature, to my surprise Appenzeller’s statistics revealed that the natural biological process steals back roughly half of the carbon dioxide we emit in a continuous cycle, absorbing some of our excess emissions.  This has been argued to slow carbon dioxide’s build up in the atmosphere, delaying the effects on climate.  If this is true, for how long?  Scientists don’t know.  The counterclaim though, is one to fear.

An exponential growth would change beneficial ecosystems from carbon sinks to sources, releasing more carbon dioxide into the atmosphere than they absorb.  These doubts have led to more research into the environment to understand the case of the missing carbon. Harnessing these natural elements, some scientists and engineers argue, could be enhanced so that carbon sinks could ‘hold out’ or even grow, slowing the effect of global warming.  Sounds like ‘science fiction’?

Welcome to the world of modern science! Arizona’s Biosphere 2

Few…doubt that this greenhouse warming of the atmosphere is already taking hold. Melting glaciers, earlier springs, and a steady rise in global average temperature are just some of its harbingers. By rights it should be worse. Each year humanity dumps roughly 8.8 billion tons (8 metric tons) of carbon into the atmosphere, 6.5 billion tons (5.9 metric tons) from fossil fuels and 1.5 billion (1.4 metric) from deforestation. But less than half that total, 3.2 billion tons (2.9 metric tons), remains in the atmosphere to warm the planet. Where is the missing carbon? “It’s a really major mystery, if you think about it,” says Wofsy, an atmospheric scientist at Harvard University.

The backdrop for these hopes and fears is a natural cycle as real as your own breathing and as abstract as the numbers on Wofsy’s instruments. In 1771, about the time of the first stirrings of the industrial revolution and its appetite for fossil fuel, an English minister grasped key processes of the natural carbon cycle. In a series of ingenious experiments, Joseph Priestley found that flames and animals’ breath “injure” the air in a sealed jar, making it unwholesome to breathe. But a green sprig of mint, he found, could restore its goodness. Priestley could not name the gases responsible, but we know now that the fire and respiration used up oxygen and gave off carbon dioxide. The mint reversed both processes. Photosynthesis took up the carbon dioxide, converted it into plant tissue, and gave off oxygen as a by-product.  The world is just a bigger jar.

I provided more direct sources from the article for some context.  Ultimately since then lots has changed in terms of research and experimentation.  The article rests on a conclusion of uncertainty of what could happen to the Earths carbon sinks, thus alternatives are discussed.  Geologic and carbon sequestrations are the most advanced projects by far.  The twofold success: keeping carbon out of the atmosphere, while high-pressure injection could also be used to collect the last drops of oil (gas) out of a depleted field.  Encouraging news for researchers who are working on schemes that would allow humanity to keep burning fossil fuels without ‘dire’ consequences for climate.  The ocean floor, coal, old oil, and gas fields, or deep, porous rock formations I believe, provide much needed opportunism that is already backed by years of investment and research.  The sounds of tapping old deposits, wastelands and deep reserves secures in my mind, a reduced conscience of repercussion based on the premise that these efforts may alleviate the carbon dioxide impact in the Earths atmosphere than previously before.  Thoughts?