Could Optimizing The Carbon Sink Be The Answer To Global Warming?

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Source: NOAA Video Carbon in Action

OK. Let’s just all admit it. Al Gore was right – even if the truth was inconvenient at the time. For most of the civilized world, the present day truth is not only inconvenient, but also incontrovertible, inconceivable (in its potential destructive effects), and increasingly (almost) inevitable.

Most of the emphasis has been on the human creation and release of carbon into the atmosphere. Policy makers have focused on rules and incentives to encourage humans to act, well, more human. That hasn’t worked. Nor has public education, threats, or even perceptible changes in the weather related disasters. Some have sought refuge in possible technologic advances – say in new alternative, less polluting,  energy sources. But the economic and political clout of fossil fuel producers, and the real time energy needs of emerging economies around the globe have, for the time being, counter-balanced these progressive efforts.

But wait. Don’t give up on human ingenuity just yet. Maybe we’ve been looking for sanity in all the wrong places. Rather than focus on “carbon in” (which we need to continue to pursue with energy and determination), perhaps we should spend equal time on “carbon out”.

We’ve spent so much energy in associating the word carbon with a mountain of dirty coal that we have almost lost sight of the fact that this atom is the fundamental building block of all life, and of the planet we inhabit. It is anything but solid and static. It’s a highly mobile cycle – moving in and moving out constantly. It anchors the geosphere (soil), the hydrosphere (water), the atmosphere (air), and the biosphere (living organisms).

For the first time, NASA has recently launched a satellite whose purpose is to visualize the carbon cycle in action worldwide. What is already clear is that carbon release is highest, as you would expect in the northern hemisphere. But it moves fast and far with the trade winds. It accumulates in highest concentration during the winter months, when new plants lie dormant, not engaging in photosynthesis, which transmits atmospheric carbon into the soil.

Carbon sinks come in many shapes and sizes – oceans, forests, wetlands, undisturbed soils, grasslands and more. But the most important of these are the oceans. Their capacity to bind carbon is 50 times greater than the atmosphere. They alone absorb 48% of all atmospheric carbon – but that number is rapidly declining.

The movement and absorption of carbon is ocean water is effected by water temperature, the currents and the activity of biologic species through photosynthesis and respiration. In general the lower the ocean temperature, the more carbon it can hold. Northern oceans are colder and possess downward moving currents where the deeper water is colder than surface water. The net effect for carbon then is the “solubility pump” or mixer which delivers carbon to deep storage areas in the ocean where it lies relatively dormant. In contrast, warmer water favors upward currents and the release of stored carbon into the atmosphere.

But there is another piece to the puzzle, and its called the “biological pump”. It seems that when carbon is absorbed into the ocean, very little of it remains in the form of carbon dioxide. Instead it takes on a variety of different dissoved inorganic forms captured in living plankton or calcites, which move slowly but steadily downward. The carbon remains trapped in these living creatures until they decay or die, releasing carbon dioxide in the process.

The average acidity of today’s oceans is a pH of 8.2. That represents a drop of 30% over thew past 100 years. A balanced higher pH is essential for maintaining optimum marine life. But there is more to it than that. Acid pH destroys the shells and outer protective layers of plankton, coral, crabs, clams, and many others. Lose them, and you disable the “biological pump”.

All of the above is why some scientists are advocating incentives that focus on new technologies to enhance carbon capture. Some may focus on improving the viability and functioning of ocean solubility and biologic pumps. Others might reward farming approaches that conserve undisturbed soil and wetlands, or expand forest cover. And others might encourage new technologies that attract and capture carbon, and bury it deep in our earth or oceans, or beyond Earth’s atmospheric borders.

Obviously we need to focus on both over-release of atmospheric carbon and under-removal of the substance. But when it comes to short term and urgently needed actions, we should use our resources wisely, and invest where scientists believe there is the greatest potential for immediate success.