How Does Your Garden Grow?

"It's the whole Earth -- it's every plant."
"I've been referring to this as a carbon bubble."
"You see ecosystems storing more carbon for the next fifty years, but at some point, you hit a breaking point."
J. Elliott Campbell, University of California, Merced

A new study has concluded that in the last century plants on this planet have been thriving, growing at a vastly accelerated rate; far more so than at any comparable time in the last -- wait for it -- 54,000 years. How would botanical, environmental and other scientists, looking to the past know this? Elementary, my dear Watson, and the result of this study has been published in the journal Nature; that plants have been and are, converting 31 percent more carbon dioxide into organic matter than was the case before, say, the Industrial Revolution.

Now that should strike a chord. After all, it has been since the Industrial Revolution that the release of man-made carbon dioxide from all the energy being consumed to operate mechanical devices that form the framework output of the modern world, has emanated. The burning of fossil fuels; coal, oil, gas, to create energy to operate all the machines, commercial, domestic, that reflect the world of today and its busy management of all of our resources.

Dr. Campbell and colleagues understand full well that the increase in the presence of carbon dioxide in the atmosphere has resulted from what our use of resources is pumping into the atmosphere. But he also realizes that the increased levels of carbon dioxide in the atmosphere have benefited the flora of the Globe we call home. It is fertilizing plants with the circulatingcarbon in the super growth amounting to over 23 metric tons annually; three times the amount of carbon in all crops every year harvested on Earth.

There has been a 40 percent increase of concentrated carbon dioxide in the atmosphere since 1850. A fact that scientists theorized must be benefiting plants that depend on carbon dioxide to enable them to flourish and grow. Experimental measurements of carbon dioxide and its impact on plant growth instructed scientists that greater amounts of carbon dioxide indeed have been responsible for runaway plant growth. Another discovery was that plants in different parts of the world respond differently.

Scientists discovered a promising way to measure plant growth in the mid-2000s, by studying a molecule named carbonyl sulfide present in a few hundred parts per trillion in the atmosphere; roughly a million times lower than the concentration in the atmosphere of carbon dioxide, but which plants draw in along with carbon dioxide. Once carbonyl sulfide enters plant tissue, it is destroyed, and concomitantly the level of carbonyl sulfide in the atmosphere drops, while plants thrive.

It was in Antarctica that scientists next went to test their theory where the air at the South Pole is well placed to tell the story of carbonyl sulfide levels reflecting worldwide plant growth, for as ice forms in Antarctica, it captures bubbles of air, creating a historical record of the atmosphere. So Dr. Campbell and his group of researchers analyzed carbonyl sulfide records dating from the last 54,000 years to discover that over the course of several thousand years following the ice age, the gas decreased notably.

The decline reflecting the glaciers' retreat, and as land was uncovered, plants emerged and began the process of intake and destruction of carbonyl sulfide. Human activity since the Industrial Revolution has added additional carbonyl sulfide, but that was not found to be reflected other than marginally in the ice because plants have been busy withdrawing the gas from the atmosphere. Because the additional carbon dioxide has been used by plants, less has been retained in the air o contribute to global warming.

While the planet has been seen to have warmed 0.8 degrees Celsius since 1880, but for the greening of the Earth, it would be warmer still. The unknown in all of this is what occurs should carbon dioxide emissions continue their rise. More plant growth could be the result. On the other hand climate models warn that plants are set to suffer as temperatures rise, even as there is an anticipated shift in rainfall.