Offsetting carbon or removing carbon from the atmosphere has become one of the many solutions in dealing with increasing carbon emissions. The US and UK have been doing carbon trading for some time to neutralise their carbon emissions from its industries and individual emissions.
How carbon offsetting works
Carbon offsetting scheme works when individuals or companies invest or pay environmental projects around the world to balance out their own carbon footprint. The projects are usually based in developing countries and most commonly designed to reduce future emissions (Clark, 2011).
This can involve introducing clean energy technologies or soaking up CO2 directly from the air through the planting of trees, Clark (2011) says.
He mentions as an example a typical British family would pay around 45pounds to neutralise a year’s worth of gas and electricity use, and a return flight from London to San Francisco would be around 20 pounds per ticket.
In the Western hills of Montana, ranchers are paid to let their grasses grow to offset carbon in the atmosphere; one ranch owner received a $30 thousand check for the carbon absorption its grasses do (Ahearn, 2008).
While purchasing carbon credits from ‘polluters’ is voluntary how it works is through their “cap and trade” system.
Ahearn (2008) explains further:
- Ten north-eastern states have agreed to implement an upper limit to the amount of greenhouse gas emissions the industries can release in the atmosphere, and if they exceed the limits, companies would purchase carbon credits to neutralise their emissions like the stock exchange market.
- This type of scheme has been successful in reducing sulphur dioxide emissions, responsible for acid rain.
- Not all ranches are equal when it comes to the amount of carbon it absorbs and it must pass a method of soil tastings and the amount of rain it received each year.
Fertile grasslands can absorb 20 percent more carbon than arid soils, says Joel Brown, a rangeland management specialist at the US Department of Agriculture’s Natural Resources Conservation Services. He helps determine how much to pay ranchers for sequestering carbon (Ahearn, 2008).
How carbon is absorbed in the soil.
In Ahearn’s Scientific American article “Carbon-Offset Cowboys Let Their Grass Grow,” here is how it works:
- Grass absorbs carbon dioxide the same way trees do, but on a smaller scale through photosynthesis when a plant takes carbon from the atmosphere and uses it to build more plant matter. When grasses die or trees are cut down it releases carbon dioxide in the atmosphere, but their roots also release carbon into the soils’ fungi.
- Stephen Porder, a biogeochemist at Brown University says that when roots or fungi die, it is eaten by some microbe or worm and a portion of that carbon gets stabilized. It gets stuck into a clay mineral or a particle and stays in the soil.
- The best way to maximize the amount of carbon absorption in the soil is to maximise grass growth.
- Overgrazing and drought are the biggest challenges to carbon sequestration because they prevent plants from putting down healthy roots.
Best management practices in ranch farming are crucial
For ranchers to continue trading carbon offsets, Ahearn (2008) pointed out:
- One of the vital things they did was to cut the number of its cattle.
- They also need to show even rotations of grazing around the ranch and, a plan to prevent overgrazing in the event of drought.
- Ranchers will also have to agree to be audited every year to ensure that they are following the requirements to continue with carbon trading.
The Chicago Climate Exchange, a body that oversees carbon trading, says that it is ‘wary’ in relying too much on rangelands for carbon sequestrations because they do not absorb as much carbon as rain forest do, plus that the science on how grazing and droughts affect soil sequestration is fairly new.
For ranch owners, their contribution to carbon absorption may not be very significant, but this is an opportunity for them apply ‘best management practices’ says Michael Walsh, executive vice president of the exchange (Ahearn, 2008).
Imagine if all countries will be adopting and practising diligently their carbon offsetting and sequestration programs, then climate adaptation and mitigation will be taken to a whole new level.