Menu
Science blog
Map of the universe years in the making
Rogue bug may cause IVF failure
Technology decodes Alhambra inscriptions
Sonar causes deafness in dolphins
GM stem cells treat autoimmune disease
Nickel crash kick-started evolution
GPS inhalers track asthma triggers
Urban design turning kids off being active
Cleaning up oil spills can be bad for fish
Fluoro sensors to monitor recycled water
First cloned camel born in Dubai
Cephalopods share common toxic armoury
New evidence of aspirin risk for elderly
Salmonella vaccine could come from space
Porpoise-like sub swims with the current
Microbes thrive on iron under the ice
Blinking tower lights could save birds
Tradition can curb climate change: meeting
Coolest brown dwarf in universe found
'Silent' heart attacks quite common: study
World's land slipping in quality
Warning over 'natural' menopause therapies
Complex life pushed back in time
Lice may suppress asthma, allergies
  Coal supply may be vastly overestimated
The world's coal supply suggests reserves may be vastly overestimated and we could be facing an unprecedented global energy crisis, according to a US expert.

On the flip side, a dwindling supply of coal could also throw the brakes on global warming, some argue.

Common knowledge about coal is that major producing nations like China, the United States and Australia, have enough to last hundreds of years, far beyond the reach of oil, which may already be in its twilight years.

But worldwide coal production could plateau as early as 2025, according to one new estimate, and a growing group of scientists are concerned that fossil fuel supplies may begin dwindling by mid-century.

Last year, David Rutledge of the California Institute of Technology analysed the coal production patterns of five regions around the world - eastern Pennsylvania, France, Germany's Ruhr Valley, the United Kingdom and Japan - each of which was producing at less than a tenth of its peak levels.

He found that each of the depleted regions followed a rough bell curve of production; initial production was followed by a steep ramp-up, a plateau near peak levels, and then a consistent decline.

When he applied the same formula to coal data from around the world, the results were startling.

The United Nations Intergovernmental Panel on Climate Change's maximum estimate for extractable coal is about 3000 billion tonnes. Rutledge's calculations suggest just 600 billion tonnes.

The problem with the IPCC estimate is that it lumps coal reserves, which are easy to mine, with coal resources, which may be impossible to mine.
Time for rethink

Rutledge's study also shows that, historically, national governments in the five regions have overestimated their reserves by a factor of four on average.

"These appraisals are large-scale issues," he says. "But they're done by governments. What's the incentive for governments not to give a number that is too high?"

James Murray of the University of Washington agrees.

In a talk being presented later this month at the American Geophysical Union Joint Assembly, he plans to call for a re-evaluation of IPCC emissions scenarios, all 40 of which overstate humanity's ability to emit the greenhouse gas carbon dioxide, according to Rutledge's numbers.

The committee's projections predict CO2 levels in the atmosphere to approach 500 parts per million by 2050, if emissions continue on their current trend.

But Rutledge's work suggest that even if humans burn all the coal and oil we can get our hands on, we won't be able to push CO2 past 450 ppm. Oil sands and other unconventional fossil fuels probably won't add much to that total.

Murray and Rutledge diverge on the question of climate effects, though.

Using IPCC models, Rutlgedge argues that global temperatures won't get higher than 2°C above pre-industrial levels, at the lower end of what scientists think might spark 'dangerous' climate change.

"We're still going to have global warming, and it's a serious threat," says Murray. "I have no doubt the IPCC dramatically underestimates climate sensitivity."

Regardless of climate impacts, the concern over looming energy scarcity may be more acute than ever.

"I think we'll see peak coal somewhere between 2025 and 2035," says Richard Heinberg of the Post Carbon Institute in California. "This has huge economic implications. Without growth in our energy supplies, it's very difficult to see how we're going to grow the economy."
Roads kill more than malaria: study
Seagrass link to seahorse upright posture
Black band disease hits Great Barrier Reef
Hobbit feet reignite debate
Lizards soak up sunshine vitamin
Canada sequences swine flu virus
Termites are a miner's best friend
'Hide and seek' costly to HIV
Giant trilobites had complex social lives
Midnight sun too much for some
More toxics added to 'dirty dozen' list
Rogue galaxies prompt rethink on Newton
Acupuncture relieves back pain: study
Blazars shed light on black hole physics
Unfaithful offspring get head start
Daydreamers might solve problems faster
Coal supply may be vastly overestimated
Science and unis are winners in the budget
Heartbeat key for blood growth in embryos
Neck pain worse for women in the office
Busty figurine a 'Paleolithic Playboy'
Plant cells help bees get a grip
Space trio to give sharper view of cosmos
Sea creatures inspire CO2 sponge
Genetic link between period onset and BMI
Researchers find bacteria in clouds
Sustainable farm research 'under threat'
Tree leaves monitor pollution levels
Menu
Stay upright during labour, say experts
Antarctic ice growth linked to ozone hole
Fires fuelling global warming: study
Methane climate shock 'less likely'
Genome map reveals cow's genetic makeup
Microbe bubble machine stores energy
Stress gives reef fish wonky ears
Swine flu remains a mystery
Perception is in the ear of the beholder
Solar wind gives asteroids a tanning
Researchers find grain's memory gene
PET bottles potential health hazard
Researchers find first common autism gene
Fossil fuel use must fall to 25%: study
'WaveRider' poised for hypersonic flight
Big cuttlefish 'at risk' from desalination
Glaciers show north-south climate divide
Mobile phones help cardiac rehab
Dancing birds feel the beat
Mushrooms may yield vitamin D bonanza
Dingoes may be a native's best friend
Dud treatments more easily spread
U2 comet dust predates solar system
Australian CO2 delay sends 'mixed message'