Friday, March 14, 2008

Save Peat to Curb CO2 Emissions.

The overall level of CO2 in the atmosphere depends both on its sources and its sinks, and of the latter category, peat is a major player. When peat is in a healthy condition it acts as a sink (store) for carbon, but when it begins to be degraded the carbon is released in the form of CO2 and methane and overall it ends up as a burden on the level of CO2 in the atmosphere (methane is oxidised in the troposphere to CO2). The UK contains around 15% of the world's peat, a material which holds twice the amount of carbon that forests do. However, particularly in the English part of the UK, the quality of peat has been detrimentally affected by drainage, and as a consequence has begun to dry-out in the peat-bogs that contain it.

A combination of overgrazing, burning and pollution from industry has been accused for this phenomenon, and the higher temperatures that have prevailed during the past decade are thought to have compounded the situation. It is estimated that the amount of carbon stored in peat-bogs in the UK is equivalent to 20 years of emissions from industry here, and that the impact of industrialisation over two centuries or so has damaged their natural state.

The National Trust has urged that landowners be rewarded for maintaining the health of their peatlands, since its experts believe that degradation of peat bogs is acting as an additional source of atmospheric carbon, although exactly how much is not clear. The situation is reminiscent of the impact of rainforest destruction, in that not only is a carbon sink being attenuated, but previously stored carbon is being released, both exacerbating the effects of fossil-fuel derived emissions of CO2: a real double-whammy.

There is evidence that the bogs in Scotland are still acting as net sinks for atmospheric CO2 while in England they are net sources of CO2 as a result of "poisoning" by centuries of sulphur and heavy-metal pollution. In the Peak District, specifically the High Peak estate (owned by the National Trust) , 1,350 hectares (3,500 acres) of bog were measured to release 37,000 tonnes of CO2 per year, which is equivalent to the output from 18,000 cars.

The National Trust advises landowners to raise water-levels in the bogs by blocking gullies and improving their general health by reducing grazing on them, preventing fires and controlling local tourism. It proposes that landowners should be entitled to earn carbon-credits for protecting the bogs such that emissions from them are reduced. There are many arguments that can be voiced both for and against carbon-credits, but if other "manufacturers" are due them, then why not producers of the bounty from the land? Such "credits" could then be marketed e.g. via the EU "European Emissions Trading Scheme".

Apparently, Defra (Department for Environment, Food and Rural Affairs) is well aware of the problem, and large areas of peat-bogs are now being managed so as to maintain their "sink" role and capacity through agri-environment schemes, along with a reconsideration of other kinds of environmental stewardship to "combat the negative effects of climate change", i.e. to cut atmospheric CO2 levels. It is believed that it is not too late to preserve peatlands if "good practice" is carried out, otherwise there is a real danger of losing the greatest carbon-sink for the UK.

Whatever happens regarding emissions of CO2 from fossil fuels, which will be curbed inevitably as the latter begin to dwindle in supply irrespective of government efforts to cut these emissions through policy, it is of course important to retain the intrinsic carbon capture capacity of the planet otherwise the net benefit is doubtful. I suspect that the health of the world's "wildernesses" will return in the absence of human interference through pollution, emissions and other territorial impacts, but by then I wonder how many of us there will be left?

Related Reading.
"Preserve peat bogs for climate", By Richard Black.


Anonymous said...

Chris Turner of

and author of "The Geography Of Hope: A Tour Of The World We Need" provides examples of communities recently made sustainable by revamping and restructuring their respective energy requirements. Here's an excellent interview, according to Chris Turner:


Professor Chris Rhodes said...

Thanks George,

I've just ordered a copy of the book. It seems to be approximately how I am beginning to feel about the survival of humankind. i.e. that we need to gear-down in our use of energy, there is no other choice.

The consequences however are profound...