Tuesday, 13 September 2011

Accidental Burning of Fossil Fuels

(aka, Accidental Emissions from Fossil Fuels)
Next week, I will present at the Royal Academy of Engineering a brief poster summarizing the work that I have developed with the generous funding of the RAEng/Leverhulme Fellowship. The poster is here (pdf). A related seminar I gave at UC Berkeley in July can be watched in youtube here (and see at the end of this post). The following reproduces the content of the poster:

World energy use and climate change science have led to concerns on sustainability, man-made burning of fossil fuels, and carbon emissions. Most attention is paid to energy efficiency, clean technologies and new resources. But unintentional and non-anthropogenic sources contributing to the problem have been ignored. Smouldering megafires, the largest and the longest-burning fires on Earth (>6,000 years), take place in all continents except Antarctica, and burn fossil fuels accidentally.

Smouldering of carbonaceous media (flameless combustion) is the most persistent fire phenomenon on Earth. Photo by Jens Buurgaard Nielsen (wikipedia).
Very large smouldering fires of carbonaceous natural media (coal seams and peatlands) have burnt since past millennia for long periods of time (months, years, decades). Peat fires burn during the warm/dry season in Indonesia, Canada, Russia, and USA. Hundreds of coal fires continuously burn in USA, China and India. Globally, the problem has grown to a current carbon release equivalent to 10-30% of man-made emissions, and a coal consumption rate five times faster than that of Germany.

Oct 1997: aerosol imaging by NASA TOMS shows the vast smoke haze released by smouldering peat fires in Indonesia. Photo by NASA.
Smouldering phenomena involve the burning of fossil fuels and are carbon-positive. This creates a positive feedback mechanism in the climate system: Moisture deficit and self-heating of carbonaceous media are enhanced under warmer climates and lead to more frequent smouldering fires. Warmer temperatures at high latitudes are already resulting in large smouldering fires in the Arctic (e.g., Alaska 2010).

Positive feedback by smouldering fires in the climate system (topics I study are represented by red arrows)

Stopping these fires is an engineering task at the Earth-scale. RAEng states that “geoengineering provides options in which the Earth’s climate is deliberately manipulated to offset the effects of global warming due to increasing levels of greenhouse gases”. I am contributing to this through the study of the ignition, spread, emissions, and suppression of smouldering phenomena. I aim to develop both fundamental understanding and technological solutions to this problem.

Accidental Burning of Fossil Fuels (RAEng 2011)