Carbon Cycles -- Why don't you?

"Welcome to the Pliocene. That was the Earth about three to five million years ago, very different to the Earth we inhabit now. But in at least one respect it was rather similar. This is the last time that carbon dioxide (CO₂) levels were as high as they are today."

This is the text of a blog from the Editor of NASA's Climate Change website, entitled "Entering unknown territory", with this image at the top:

Now that's something to grab your attention!

So the point is that carbon is building up in the atmosphere, in a bigger way than the Earth has seen for a very long, long time. We're in unknown territory as humans. Carbon is cycling all the time around the Earth, but now it seems to be accumulating where we don't want it.

Another place we don't really want it is in our oceans, but it's building up there, too, causing acidification.

We are carbon-based life forms, afterall, so it's good that you're full of carbon -- but do you really want carbon filling up your atmosphere? No....

So let's review the way it's supposed to work (although something's awry at the moment). Here's the picture of the global storehouses of carbon, as well as the cycle generated by human activities, as described by the Intergovernmental Panel on Climate Change (IPCC) in their 2007 report:

So what's going on here? In black in each compartment we see the pre-human levels of carbon; then in red we see the changes that have occurred (as of end 1994) because humans have been diligently moving carbon around, from underground to the atmosphere or the oceans.

The arrows indicate annual "fluxes", or movements, of carbon, and so illustrate the annual human-driven carbon cycle. (source) We should point out some of the major features of this image. The major compartmental changes are that fossil fuels have been depleted -- although there's plenty left! -- whereas the atmosphere and the oceans -- in particular, the deep ocean -- have sucked up a lot of carbon. There are two primary consequences worth mentioning: the atmosphere traps heat, warming the globe, and the ocean becomes more acidic, destroying the base of our food chain. Vegetation, soil and detritus also takes a pretty big hit -- primarily because of deforestation, and other changes in land-use.

So there you have it: we're moving the carbon around, and putting it where it hasn't been, and perhaps shouldn't be. Now the question is this: what will be the consequences? And, as usual, we'll find out! The consequences are opaque -- but, as the National Academies once said (1979), scientists find "...no reason to doubt that climate changes will result and no reason to believe that these changes will be negligible."

The way we prevent adding carbon to the atmosphere is by changing our lifestyles, in both big and small ways. There are things you can do to reduce your personal carbon footprint, as well as the footprints of your community, your government, and ultimately our world. But it's easiest to start with yourself. How can you make changes to reduce the carbon you move around? Try cycling yourself! If you've got an old bike around, take it out, grease that chain, and take a ride to the store or to soccer practice the next time you need to go.

Never doubt that a small group of thoughtful, committed citizens can change the world. Indeed, it is the only thing that ever has.

• A kid-friendly version of the carbon cycle
• The Anthropogenic Carbon Cycle: your questions answered by NOAA.
• "Transition Towns" have been springing up around the world, built on the objective of helping communities prepare for the end of cheap oil and the onset of climate change challenges. There may be a "Transition Town" near you (I'm near Transition Town North Bay, where they say that "[t]he Transition Initiative model is based on four key assumptions:
  • That life with dramatically lower energy consumption is inevitable, and that it's better to plan for it than to be taken by surprise.
  • That our settlements and communities presently lack the resilience to enable them to weather the energy shocks that will accompany peak oil.
  • That we have to act collectively and we have to act now.
  • That by unleashing the collective genius of those around us to creatively and proactively design our energy descent, we can build ways of living that are more connected, more enriching and that recognize the biological limits of our planet.
• The Carbon Dioxide of the Ocean and Its Relations to the Carbon Dioxide of the Atmosphere Cyrus F. Tolman, Jr. (source, 1899). A wonderful historical summary begins this paper (with references which are found in footnotes):

  THIS subject has come to have special importance on account of the investigations of Professor Arrhenius and Dr. Chamberlin on the effects of the atmospheric CO₂. upon the climate of the earth. Some of the earlier important contributions on the subject are as follows:

  1. Tyndall calculated from his experiments that the absorption of radiant heat by atmospheric CO₂ is eighty times that of the oxygen or nitrogen, and that water vapor has an absorbing capacity of ninety-two times that of oxygen or nitrogen.
  2. By repeating and extending Tyndall's experiments, Dr. Lecher and his colleague, Pretner, concluded that carbon dioxide is the only agent in absorbing the sun's heat, and maintaining the earth's temperature above that of space.
  3. Mr. J. S. Keeler criticised the above and stated that the heat is absorbed by carbon dioxide and some other agent; either water vapor or matter in suspension.
  4. Professor Rontgen showed that water vapor has a marked absorption band in the ultra red and, therefore, plays an important part in maintaining the present surface temperature of the earth.
  5. Paschen demonstrated that both these gases play important parts in the atmosphere's heat absorption, and that sometimes one, and sometimes the other is the predominant factor.