Since this report seems to have sparked a wider debate in the media about the relative carbon benefits of biomass fuels, I thought that it might be helpful if I pointed out some of the ways that this is argued, to shed a bit of light on the subject.
First things first: trees absorb carbon as they grow, and typically release it when they die (through decomposition or combustion) though this is not automatically the case, and trees which are harvested for long lived timber products or which are left in low oxygen conditions (such as bogs) may retain carbon for many years. Taken in isolation, burning wood may look like a bad thing as it immediately releases carbon dioxide but this is certainly not the whole story. Continue reading Biomass and carbon: a climate disaster?→
Deforestation rates across the Amazon remain high, despite large reductions since the start of the 21st century. Assessing the climate impact of this is difficult, due to the complex interactions between the atmosphere and the biosphere.
Some of these interactions are clear and well understood, such as deforestation releasing stored carbon and removing a carbon sink. However, others are much more complex; trees emit various atmospheric trace gases and aerosols which react in the atmosphere in a number of ways, forming climate-warming gases, such as O3, and aerosols, which have a cooling effect through interactions with incoming radiation and cloud formation.
Currently, the project is assessing one of the physical impacts of deforestation, namely the change in brightness of the surface. Forests tend to have a darker colour when compared to open land and thus reflect a lower percentage of incoming radiation; we can describe this as a low surface albedo. Therefore, the removal of trees produces a slight cooling effect when examining surface albedo in isolation. Continue reading Albedo changes in the Amazon due to deforestation→
In past centuries, home heating and cooking in the British Isles involved the burning of wood, mainly in open hearths. The Romans developed underfloor heating using hot air (the ‘hypocaust’) but this still relied on wood combustion. The first wood-burning stove was patented in Strasbourg in 1557, but by the industrial revolution urban houses were typically heated with coal. By the mid Twentieth century oil, gas and electricity had become the fuel of choice largely due to the introduction of the Clean Air act, which curtailed the use of household ‘dirty’ coal, but open fires and stoves remained popular where they could be accommodated, especially in rural areas.
In recent years, ‘aspirational lifestyle’ marketing by stove manufacturers (and TV shows like Grand Designs), along with the availability of new biomass-based fuels (pellets and briquettes), have been driving a resurgence – with some even suggesting that because wood is technically a renewable energy source, woodfuel is a clean and green way to heat your home. But is it? And what are the other implications?
After the heavy rains and flood damage of last winter, the need to protect communities from flooding has never been more important. Natural Flood Management – using the natural capacity of rivers, wetlands and woodlands to reduce downstream flood risk – has become a buzzword. But there are still major gaps in our understanding of how the natural world can be harnessed to help reduce flooding.
The University of Leeds, with support from UBoC, is taking a leading role in the effort to better understand the potential of Natural Flood Management. The University hosts water@leeds – one of the largest interdisciplinary centres for water research in any university in the world – making it the ideal location to lead research efforts.
UBoC’s Ed Butt and Dom Spracklen have published a paper in Nature.com’s Scientific Reports: “Population exposure to hazardous air quality due to the 2015 fires in Equatorial Asia” – with researchers from Newcastle UK, Boulder Colorado USA, Singapore, Bloomington USA and Riau Province Indonesia.
The full authorship is P. Crippa, S. Castruccio, S. Archer-Nicholls, G. B. Lebron, M. Kuwata, A. Thota, S. Sumin, E. Butt, C. Wiedinmyer & D. V. Spracklen. (See here for individual links) http://www.nature.com/articles/srep37074
(Co-Authors: Catherine Scott, University of Leeds; Stephen Arnold, University of Leeds; Sarah Monks, University of Colorado and NOAA; Pauli Paasonen, University of Helsinki; Ari Asmi, University of Helsinki)
Last week was a big week for climate policy. Last Tuesday the countries of the EU ratified the Paris agreement, taking it past the threshold required to make it legally binding – which will happen as soon as the 4th of November.
United Bank of Carbon is a not-for-profit collaboration between businesses and environmental scientists, which protects and restores forests and other greenery, through environmentally and socially-responsible partnerships with local communities. We undertake research, support forest and woodland projects in the UK and the tropics that deliver CSR/PR benefits, provide carbon reduction consultancy, and arrange offsetting for unavoidable carbon emissions