Whilst peatlands cover just 3% of the world’s surface, they contain nearly a third of all organic carbon on earth . In fact, they’re second only to ocean deposits as the world’s most important stores of carbon. It might also surprise you to know that they contain twice as much carbon as all the world’s forests put together! It is remarkable then, that peatlands have until fairly recently received relatively little attention in the discussion of how best to tackle the issue of future climate change.
Peatlands are very efficient at absorbing carbon from the carbon cycle and locking it away – a process called sequestration. In fact, in their natural state, most peat bogs function as carbon ‘sinks’ meaning that they absorb and store more carbon than they release. This is important as it prevents this carbon from entering the atmosphere as carbon dioxide and methane, two of the major greenhouse gasses (GHGs) and contributors to climate change.
The problem is that peatlands are under threat and, as a result, many are at serious risk of becoming carbon ‘sources’ – meaning they release more carbon than they sequester. We have already discussed the role of carbon dioxide, methane and other GHGs play in climate change, so when we remember quite how much carbon is locked up in the worlds peatlands, the idea that this is escaping makes for an alarming reality.
The first and most immediate threat is peatland degradation at the hands of humans. Over many years, bogs all over the world have suffered and been damaged by human activities including afforestation, drainage, burning, cutting for fuel and fertilizer and grazing. Peatlands are very delicate systems. So much so that they are often referred to as ‘unbalanced ecosystems’, meaning that organic matter is produced faster than it decays, which is why they act as carbon sinks. When bogs are damaged by humans, this delicate balance can be upset and the rate of decay can increase dramatically, releasing GHGs into the atmosphere. It is estimated that 3,000 million tonnes of carbon dioxide is being released into the atmosphere by bogs that have been damaged by human activity. This is equivalent to approximately 10% of all the world’s fossil fuel emissions.
If that wasn’t bad news enough, then consider this: things are only going to get worse. Climate change itself will reinforce the pressure on peatlands and is likely to cause them to increase their GHG emissions further still. Firstly, the majority of climate scientists agree that many areas of the world are likely to experience warmer, drier conditions as a result of climatic changes in years to come. Now, peat bogs love water. If they become drier, they decompose more quickly – that’s the whole basis of some of our analyses, after all! As we’ve just discussed, decomposing peat releases more GHGs into the atmosphere – put simply, the lower the water tables, the higher the emissions become.
There is another threat facing peatlands and their precious carbon stores too. As temperatures increase towards the poles, peat that is currently frozen all year round will start to melt. The thawing of this ‘permafrost’ will allow the bogs distributed across the northern tundra to degrade, potentially releasing the carbon locked up inside.
Doesn’t all this makes for fairly miserable reading? The peatlands that we Bogologists find so fascinating could end up contributing significantly to future climate change.
But it’s not all doom and gloom – there are things that we can do to help stop this happening.
Luckily, the people who write climate policies are starting to realise that peat bogs are not a ‘footnote’ in the climate change discussion, but a huge and important chapter! Initially, the benefits of restoring and conserving peatlands was not really recognised by policy makers. Fortunately, this is changing.
In May 2013, a carbon dioxide concentration of 400 parts per million was measured at Mauna Loa Observatory in Hawaii. This might not sound like a lot but, in fact, it is the highest level recorded in human history. The diagram below demonstrates just how fast carbon dioxide levels have accelerated in the last hundred years or so.
The Kyoto Protocol – an international treaty adopted in 1997, which sets targets for developed countries to reduce their GHG emissions – has been modified recently to acknowledge the role peatlands can play in mitigating against climate change. It has now been agreed that reductions in emissions resulting from programmes which restore and conserve peatlands can count towards these targets. If countries come in under target, they can sell the remainder of their emission ‘allowance’ to other countries. This system has become known as ‘carbon-trading’. The ‘currency’ in this new system is often referred to as carbon-credits. It is hoped that assigning a real economic value to the restoration and conservation of peatlands will provide a further incentive for people to preserve bogs.
The International Union for Conservation of Nature (IUCN) Peatland Programme suggest that peatland conservation projects represent a very cost-effective method of addressing climate change – a natural form of carbon capture and storage! They also reveal that peatlands in the UK alone have the potential to sequester 3 million tons of carbon dioxide every year!
So now that we’re talking economics, is it feasible to put a monetary value on the world’s peatlands? Obviously many believe that these precious ecosystems should be saved, regardless of any financial gain which may accrue as a result, but we have to admit we live in a world where money talks. Value estimates of anything between US$1000 and US$45,000 have been placed on a single hectare of peatland. So when we scale this up to encompass the world’s 400 million hectares of peatland, the numbers get rather large. Our bogs could be worth anywhere between US$400,000 million and US$18 billion. Now for the really astonishing bit. That figure is per year! Some argue that if the market for peat-based carbon-credits takes off, this price could soar even higher.
There are complications, of course – it wouldn’t be science if there weren’t! Some Bogologists have found that ‘re-wetting’ drained peat bogs, a technique often used in restoration programmes, can actually result in increases in methane production. This increase is likely to be small in relation to the overall GHG emissions of a degrading peat bog but still, we need to know more. Although most of our work focuses on past climate changes, this is just one example of how our research can aid our understanding of future changes too.
The second thing that we can do to prevent further damage to our peatlands, as well as the environment more generally, is simple. Change our lifestyles. Make no mistake, human-induced climate change is happening. It is not a distant worry. It is happening right now and it will continue to happen. We’re past the point of no return unfortunately, but there are still ways that we can make its effects less damaging. The first is to reduce the concentration GHGs in the atmosphere to a level at which Earth’s climate system can carry on functioning at a level that we are used to, which some suggest is around 350 ppm.
So, by reducing our own personal carbon footprints, we can be part of a global movement to live more sustainably and not at the cost of our earth and our children and grandchildren who will have to live on it. This also has a direct knock-on for protecting peat bogs. If we can help reduce the chances that some peatlands will dry out, or that more permafrost will melt in the northern regions of North America, Russia and northern Europe, we may be able to stop more carbon being released into the atmosphere. There’s also a more immediate way in which every one of us can reduce the damage we are doing to peatlands – stop buying peat-based compost!!
We still have a long way to go. A Natural England report has found that in England alone less than 1% of peatlands are now ‘undisturbed’. Thankfully, more and more schemes are being started around the world to restore and preserve our peatlands. One such example, based in the UK, is aiming to restore nearly 1 million hectares of bog and the UK Biodiversity Action Plan estimate that 1.5 million tonnes of carbon dioxide emissions will be saved by 2015 as a result.
So, peatlands will play one of two roles in the future of human-induced climate change. We can make them part of the problem, by damaging them so much that they release many millions of tonnes of GHGs into the atmosphere; or, we can make them part of the solution, by protecting, restoring and valuing them – allowing them to continue the steady and reliable sucking up of carbon, locking it away safely, just like they have done for thousands of years.
Relevant literature and links:
Natural England (2010) England’s peatlands – carbon storage and greenhouse gases. Natural England. NE 257.
Dunn, C. and Freeman, C. (2011) Peatlands: our greatest source of carbon credits? Carbon Management, 2(3), 289-301.
International Union for Conservation of Nature (IUCN), UK Committee (2009) Peatland Programme. Briefing – Peatlands and Climate Change http://www.iucn-uk-peatlandprogramme.org/resources/46
United Nations Framework Convention on Climate Change (UNFCCC) (2008) Kyoto Protocol Reference Manual. On Accounting for Emissions and Assigned Amount.