Underground Coal Fires -- a Looming Catastrophe
Coal burning deep underground in China, India and Indonesia is threatening
the environment and human life, scientists have warned. These large-scale
underground blazes cause the ground temperature to heat up and kill surrounding
vegetation, produce greenhouse gases and can even ignite forest fires, a panel
of scientists told the annual meeting of the American Association for the
Advancement of Science in Denver. The resulting release of poisonous elements
like arsenic and mercury can also pollute local water sources and soils, they
warned.
"Coal fires are a global catastrophe," said Associate
Professor Glenn Stracher of East Georgia College in Swainsboro, USA. But
surprisingly few people know about them.
Coal can heat up on its
own, and eventually catch fire and burn, if there is a continuous oxygen supply.
The heat produced is not caused to disappear and under the right combinations of
sunlight and oxygen, can trigger spontaneous catching fire and burning. This can
occur underground, in coal stockpiles, abandoned mines or even as coal is
transported. Such fires in China consume up to 200 million tones of coal per
year, delegates were told. In comparison, the U.S. economy consumes about one
billion tones of coal annually, said Stracher, whose analysis of the likely
impact of coal fires has been accepted for publication in the International
Journal of Coal Ecology. Once underway, coal fires can bum for decades, even
centuries. In the process, they release large volumes of greenhouse gases,
poisonous fumes and black particles into the atmosphere.
The
members of the panel discussed the impact these fires may be having on global
and regional climate change, and agreed that the underground nature of the fires
makes them difficult to detect. One of the members of the panel, Assistant
Professor Paul Van Dijk of the International Institute for Geo-Information
Science and Earth Observation in the Netherlands, has been working with the
Chinese government to detect and monitor fires in the northern regions of the
country.
Ultimately, the remote sensing and other techniques
should allow scientists to estimate how much carbon dioxide these fires are
emitting. One suggested method of containing the fires was presented by Gary
Colaizzi, of the engineering firm Goodson, which has developed a heat-resistant
grout (a thin mortar used to fill cracks and crevices), which is designed to be
pumped into the coal fire to cut off the oxygen
supply. |
