Putting Carbon Back Where it Belongs

Once you start dipping into the literature on animals and the carbon cycle, it’s hard to stop. The relatively new field is packed with eye-popping numbers.

A paper published in February notes without drama that “….the total carbon stored in wild mammals and birds is equivalent to roughly eight hours of current anthropogenic fossil fuel emissions” (my emphasis). The statistic anticipates the main point of the paper. The effect of wild mammals and birds on the carbon cycle is less about what they store in their bodies and more about how they influence the ecosystem. The 7 million tons of carbon found in the flesh and sinew of mammals and birds is, in carbon cycling terms, a drop in the bucket. It’s when you consider their munching, defecating, and compacting of the soil and then factor in how this influences fire and soil carbon that the real climate story emerges.

But let’s pause for a minute on the statistic. Eight hours?!

It wasn’t long ago we learned that ninety-six percent of all mammal biomass on earth is found in humans and their domestic animals. This means cows, pigs, chickens, and sheep weigh twenty-four times all the whales, wolves, tapirs, and other wild mammals combined. The harmful effect of domestic animals on the climate is a compelling reason to eat less meat. Another compelling reason is the sheer ratio of domestic animals to wild. It just feels wrong.

I’m not writing this to make the case for vegetarianism or for natural grazing of the Siberian steppe. I’m writing to make you think about how out of whack human influence on the biosphere has become. Every day, humans emit three times the carbon contained in all wild mammals and birds on the planet. Every month, more than ninety. Every year, more than a thousand.

Kim Stanley Robinson’s 2020 book Ministry for the Future tries to envision a world where our species has begun to get a handle on the climate crisis. The feat was not achieved easily and the novel makes it clear lots could still go wrong. But one of the features of Robinson’s world is that wildlife have been given room to roam.  Corridors have been built between previously separated animal populations, habitat has been restored, and people have pulled out of the most biodiverse areas. Wildlife has flooded back, repopulating the available spaces and bringing ecosystems back towards health. That’s something wildlife do. They are tenacious and healing.

They also give us a lift. A Dutch friend of mine once remarked “It gets awfully lonely when all you see are other people.” He was making a plea for more wildlife we can all get behind.  It shouldn’t be too hard.  We know what causes their collapse. 

If we take the steps needed to repair the biosphere, imagine what might happen to that ‘eight-hour’ statistic.  As wildlife starts to rebuild, their carbon mass could climb from eight hours of emissions to twelve, and then to twenty-four. As fossil fuel burning decreases, the number could stretch to a week, a month, and then more. The ratio will start to even out.

There might eventually come a day when fossil carbon is no longer burned and emissions fall close to zero. On that day we might celebrate a new statistic. The mass of carbon in the world’s wild birds and mammals will be appreciably more than the mass of carbon in fossil fuel emissions.

Now that might be a marker of a world back in balance.