Global warming — Earth’s ‘carb’ overload
Whether the basis for climate change is over-reliance on fossil fuels, loss of jungle canopy, too many chemical fertilizers, a natural phenomenon, all of the above, or none of the above – the fact remains that global temperatures are showing an upward trend.
Some claim the climb is caused by industrialization. Others disagree and point to a Medieval Warm Period and other episodes of global warming through the ages. But the crux of the matter is that, unlike our Middle Ages counterparts, the humans living in this era possess the skills, knowledge, and wherewithal to temper the impacts of rising global temperatures.
We can pull less carbon out of those long-long-long-term storage deposits of coal and oil, plant a few more trees, and let cows eat grass instead of stuffing them with grain. But we can also try to keep temperatures within our own Goldilocks Zone by sequestering more carbon in soils that won’t be disturbed for extended periods of time.
Even if all new sources of carbon were reduced to zero, there’s still too much in the atmosphere now – and it has to go. Scientists are working on numerous projects designed to remove excess carbon from the atmosphere, but soil sequestration remains among the simplest and least expensive solutions.
First, it must be said that the much maligned “greenhouse effect” is actually a good thing. It’s what makes this planet habitable for humans.
In the atmosphere, radiation from the sun generates heat. As it bounces around in the “greenhouse,” some of this heat is absorbed by the earth and some is released back to space. But greenhouse gases like carbon dioxide and methane absorb and trap heat. When there is an excess of this type of gas in the atmosphere, too much heat is trapped and radiated back to the earth, resulting in global warming.
Other greenhouse gases include water vapor and nitrous oxide. Industrial chlorofluorocarbons are highly-regulated, synthetic greenhouse gases.
But carbon dioxide (CO2) has become a primary focus because its increase is associated with human activity. Atmospheric carbon dioxide levels have jumped from 280 parts per million to 400 parts per million since the mid-1800s, which coincide with the early days of the Industrial Revolution.
To reduce carbon compounds in the atmosphere, science looks for ways to naturally or artificially sequester excess carbon for long-term storage.
Putting the atmosphere on a low-carb(on) diet
Limiting and reducing the amount of carbon in the atmosphere is the goal of carbon sequestration.
Vegetation, oceans, and soils are examples of natural sequestration. These carbon sinks naturally absorb atmospheric CO2.
Carbon capture, ocean injection, and geological storage are examples of artificial sequestration. Captured CO2 has a number of industrial uses, including the manufacture of fizzy beverages and plastic bottles. As the costs for these new technologies drop, their uses are expected to rise.
As sinks go, compost use is among the best. Amending soils with raw manures and biochar also sequester carbon, but neither offers such a wide range of other soil-enhancing benefits as does compost use.
Almost everyone can contribute to carbon sequestration
Regenerative agriculture can restore soil health and make a major impact on carbon sequestration. In fact, the Rodale Institute says more than 100 percent of current global CO2 emissions could be sequestered if all pasture and cropland management was based on regenerative agriculture.
But one needn’t be a farmer to create carbon sinks. From backyard to utility easements to parkland, there is opportunity for every community to contribute to the reduction of the planet’s carbon overload.
Know that things like soil type and local climate can influence carbon retention. Tactics must reflect the region, because a good strategy for the arid west may not be the best choice for humid, subtropical Florida.
Yet all sequestration approaches will have one thing in common – decades or centuries-long confinement of that carbon without disturbance:
- Establishing a lawn by incorporating compost? Yes.
- Topdressing a garden plot that is tilled every year? Not so much.
- Using compost to amend a field that is plowed every season? Not that great.
- Planting that same field with perennials or converting it to grassland? Much better.
Any patch of soil that can be amended, planted, and then left undisturbed for many years is a potential carbon sink. This includes every community’s roadsides, athletic fields, and recreation areas.
Bottom line: Earth’s history is peppered with episodes of warming followed by ice ages. Unless humans learn to manage carbon to moderate temperature extremes – no matter the cause — those who survive this era of global warming may learn the hard way that nature always seeks to return to a state of balance.