waste products

skade88 writes "This story should remind us all that air pollution controls are not just about addressing global warming. They also help us have cleaner air and fewer health problems resulting from smog and haze. Starting earlier this month, Beijing, China started having worse than normal air pollution issues. On January 14, 2013 the U.S. embassy's air pollution sensors in Beijing found the density of the most dangerous small air particles, PM 2.5, at 291 micrograms per cubic meter of air. The World Health Organization's guidelines for air pollution state that PM 2.5 above 25 micrograms per cubic meter of air is dangerous to a person's health. To put the problem into perspective, NASA has released two orbital photos of Beijing showing before-and-during images of the air pollution. The photo from January 4 shows parts of Beijing still visible from space. The photo from January 14 shows nothing but a huge, thick cloud of haze with no buildings visible."

Read more of this story at Slashdot.

Coal occupies a central position in modern human endeavors. Last year over 7000 megatons were mined worldwide. Powerful, yet dirty and dangerous, use of coal is expanding every year, with 2010 witnessing a production increase of 6.8%. Around 70 countries have recoverable reserves, which some estimates claim will last for over a hundred years at current production levels. Mining for coal is one of the world's most dangerous jobs. While deadliest in China, where thousands of miners die annually, the profession is still hazardous in the West and other regions as well. Our mining and use of coal accounts for a variety of environmental hazards, including the production of more CO2 than any other source. Other concerns include acid rain, groundwater contamination, respiratory issues, and the waste products which contain heavy metals. But our lives as lived today rely heavily on the combustible sedimentary rock. Over 40% of the world's electricity is generated by burning coal, more than from any other source. Chances are that a significant percentage of the electricity you're using to read this blog was generated by burning coal. Gathered here are images of coal extraction, transportation, and the impact on environment and society. The first eight photographs are by Getty photographer Daniel Berehulak, who documented the lives of miners in Jaintia Hills, India. -- Lane Turner (48 photos total)
22-year-old Shyam Rai from Nepal makes his way through tunnels inside of a coal mine 300 ft beneath the surface on April 13, 2011 near the village of Latyrke, in the district of Jaintia Hills, India. In the Jaintia hills, located in India's far northeast state of Meghalaya, miners descend to great depths on slippery, rickety wooden ladders. Children and adults squeeze into rat hole like tunnels in thousands of privately owned and unregulated mines, extracting coal with their hands or primitive tools and no safety equipment. (Daniel Berehulak/Getty Images)

This is a photo of the Atlantis AK1000, a 130 ton, 74-foot-tall tidal turbine that will be installed underwater off the cost of Scotland. It is designed to supply electrical power for 1,000 households.

Sea water, which is 832 times denser than air, gives a 5 knot ocean current more kinetic energy than a 350 km/h wind; therefore ocean currents have a very high energy density. Hence a smaller device is required to harness tidal current energy than to harness wind energy.

Tidal current energy takes the kinetic energy available in currents and converts it into renewable electricity. As oceans cover over 70% of Earth’s surface, ocean energy (including wave power, tidal current power and ocean thermal energy conversion) represents a vast source of energy, estimated at between 2,000 and 4,000 TWh per year, enough energy to continuously light between 2 and 4 billion 11W low-energy light bulbs.

Both the U.S. and the U.K., for example, have enough ocean power potential to meet around 15% of their total power needs.

Good: The World's Largest Tidal Turbine, Unveiled