About half of the carbon dioxide so far released into the atmosphere has been absorbed by the terrestrial biosphere and oceans. This carbon is then said to be have been stored in ‘sinks’. This work focuses on the scientific review and assessment of the state of knowledge on greenhouse gas emissions and sinks. When forests are cut down, or there are changes in land management, the amount of carbon stored in the terrestrial biosphere changes. Similarly, coastal management may influence the amount of carbon that is taken up and stored by the ocean and by coastal systems. This work focuses on assessing the potential role that management of carbon sinks has in contributing to climate change mitigation and thus avoiding dangerous climate change.
What do we already know?
Emissions of greenhouse gases (GHG) from land use change and forestry are a significant fraction of the total global GHG emissions (33% in 2010). Controlling these emissions, for example through changes in agricultural practises, could make an important contribution to mitigation and is essential to achieve set climate change objectives (2°C or below). However, a changing climate can cause the release of carbon from soils and vegetation where it was previously safely stored on land. This can seriously undermine efforts to mitigate climate change and therefore it is important that this feedback is assessed. Similarly, management practices in some coastal systems could potentially lead to the absorption or storage of more carbon.
What will this research achieve?
The research will examine how much carbon is stored in terrestrial ecosystems and soils, and how vulnerable that carbon is to warming of various levels and management practises, by reviewing the state of knowledge and by analysing existing model results. It will consider how much greenhouse gas mitigation can be achieved from changes in agricultural practises. It will consider the regional consequences of managing carbon sinks on land. Finally, it will consider where there are gaps in knowledge, and what could be done to take forward research beyond the state of the art as summarised in the IPCC Fifth Assessment Report. It will also produce a review and assessment of the current scientific state of knowledge on ‘Blue Carbon’. A widely used definition of Blue Carbon is that carbon which is captured by the world’s oceans and coastal ecosystems. The project will examine the role of blue carbon in the earth’s carbon cycle, considering both stocks and flows; will examine the longevity of the carbon sequestration; the potential for enhancement of this sequestration, and assess potential co benefits (especially to adaptation) of using blue carbon in climate change mitigation.
What is the policy relevance?
A key policy question addressed here is how land use change policies can be used to contribute to climate change mitigation. A second key policy question addressed here is “Is Blue Carbon an important carbon sequestration option in avoiding dangerous levels of climate change’. The project will examine the various definitions of Blue Carbon in use, assess the value of sources of information on Blue Carbon and its support in the scientific literature. In this way the project will assess whether Blue Carbon has a role to play in avoiding dangerous climate change, and will make recommendations for future research on the use of blue carbon in mitigation of climate change.
Research area description and outputs
E1. Review of emissions and sinks associated with land use, land-use change and forestry
Report reviewing and assessing Land-use, land-use change and forestry. View report