50 for the Future – Blue Carbon

Our recent publication, 50 for the Future, lists 50 things that we believe should happen in Scotland over the next 50 years to benefit both people and wildlife. In this week's 50 for the Future article, Dr Sam Collin, the Trust's Marine Planning Officer, discusses the important role that our seas play in reducing the effects of climate change.

 

Number 35: Protect and enhance natural 'blue carbon' stores in our seas to reduce the effects of climate change.

 

Since the industrial revolution in the 1800's, the level of carbon dioxide (CO2) in the Earth's atmosphere has increased at an exponential rate – increasing from 278 parts per million (ppm) in pre-industrial times to approximately 400 ppm today – with no sign of stopping. The impact of elevated CO2 levels can already be seen in rising global temperatures, increases in ocean acidity and changes in animal and plant behaviour.

It is now broadly accepted that ignoring the impact of climate change could have devastating consequences for wildlife and human well-being, and that earnest efforts are needed to reduce CO2 emissions. In 2009, the Climate Change (Scotland) Act was passed, which signified the Scottish Governments commitment to reducing greenhouse gas emissions (including CO2) and transitioning to a low-carbon economy. The Act set ambitious targets of reducing greenhouse gas emissions by 42% by 2020 and 80% by 2050.

A reduction in CO2 emissions will be fundamental to reducing Scotland's carbon footprint, but it is not the only element to consider. Nature is very efficient at drawing CO2 from the atmosphere and storing it as carbon in living and non-living material – think of trees photosynthesising CO2 into oxygen and organic carbon. This process of converting CO2 into organic material is called carbon sequestration .

A painted goby surrounded by coral-like maerl. © Paul Naylor

Habitats on land, such as rainforests and peatlands, are well known for their ability to sequester carbon, but despite having a higher storage capacity, the 'blue' carbon habitats of the marine environment have been largely overlooked. The oceans absorb carbon from the atmosphere, which then becomes available for marine wildlife to use. All sorts of organisms, from microscopic coccolithophores – species of phytoplankton that forms a calcite shell – to coral reefs and kelp forests draw carbon from the water and can store it for months (e.g. kelp) or even thousands of years (e.g. maerl beds).

Scotland's seas contain a wealth of blue carbon habitats – the standing stock of kelp alone has been estimated to hold over a million tonnes of carbon. However, pressures from human activities such as bottom-trawl fishing practices, coastal development and pollution, have heavily degraded these habitats and subsequently reduced their potential to store carbon. To reverse this trend, we must work towards enhancing the health of Scotland's marine environment and protecting important blue carbon habitats.

To fully realise the potential of blue carbon in Scotland, the following must happen:

  • Our knowledge of the distribution, stock health and enhancement opportunities for blue carbon habitats needs to improve to allow for accurate measurements of its contribution to Scotland's climate change targets;
  • The value of marine habitats as carbon stores needs to be acknowledged within the designation and management process of Scotland's network of Marine Protected Areas;
  • Important blue carbon habitats and carbon sinks need to be recognised and integrated into Scotland's regional marine planning system; and
  • Artificial barriers along Scotland's coastline need to be removed to allow natural realignment and restoration of lost or damaged blue carbon habitats, in particular the recovery of saltmarshes.
Thongweed in the background and kelp in the foreground – both fast-growing species that sequester carbon. © Paul Naylor

Protecting marine habitats will play an essential role in enhancing the blue carbon contribution to reducing Scotland's carbon footprint, but there are some human activities that can also contribute to carbon sequestration. For example, the cultivation of seaweed and mussels can assist with capturing and storing carbon, while simultaneously improving water quality, providing habitats for fish and other species, and producing carbon-neutral products.

Scotland's drive to reduce its carbon footprint is opening doors for novel management approaches and innovative developments that should be embraced and supported where possible. Scotland's ambitious climate targets are achievable and the role of blue carbon will be vital in meeting them.

For more information on Scotland's blue carbon potential, please read the Trust's briefing on blue carbon.

Let us know your thoughts by emailing thefuture@scottishwildlifetrust.org.uk or Tweet @ScotWildlife using #50fortheFuture.

 Dr Sam Collin is the Scottish Wildlife Trust's Marine Planning Officer.

Preface

In this week's 50 for the Future article, Dr Sam Collin discusses the important role that our seas play in reducing the effects of climate change.

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