Cement, Energy and Environment

Ocean acidification is the result of C0 2 dissolving in seawater and lowering its pH. Scientists know that a drop in ocean pH affects carbon cycle, reducing carbonate ions that corals use to build shells. Now a study has shown that C0 2 - induced increase in acidity disrupts aquatic nitrification rate. The nitrification process is central to nitrogen cycle in which marine microorganisms convert one form of nitrogen ammonium - into nitrate, a form other aquatic organisms require. Marine biologist Michael Beman, from University of California and his team collected five seawater samples from Atlantic and Pacific oceans from depths ranging from 45 m to 240 m. They modified the pH from 8.09-7.99 to 7.99-7.85 - either by mixing C0 2 through the bottles or adding dilute acid. Nitrification rate was measured and watched over 11 to 120 hours. They contended that acidification could reduce nitrification rate by 3- 44 per cent within next few decades. They noted that if at pH8 oceanic ammonia constitutes five per cent of total ammonia and ammonium, by 2100, acidification cou ld reduce available ammonia by 50 per cent. "The decreased pH levels can impact marine nitrogen cycle by reducing nitrification rate that directly affects microbial productivity and marine food web," said Richard Feely, chemical oceanographer at Pacific Marine Laboratory, Seattle, But there could be a silver lining - reduction of nitrous oxide, a greenhouse gas. The nitrification process produces nitrous oxide through oxidation of ammonium by aquatic nitrifier bacteria. "It is possible that decrease in nitrification will reduce nitrous oxide," Beman said. Courtesy: Down to Earth, January 16 - 31, 2011, P 47. CHINA, INDIA, BRAZIL PUSH US FOR DEEPER GHG CUTS China, India, Brazil, and South Africa have said that the US must pledge deeper cuts in GHG emissions to help make progress in the UN climate talks, sharpening divisions between rich and poor countries on how to combat global warming. The four developing nations at the talks in Cancun, Mexico, also called on industrialized economies to provide more aid for countries seeking to clean up their energy industries. Courtesy: TERI (The Energy and Resources Institute) Newswire, 1-15 December 2010, P16. 2010 TO BE AMONG THREE WARMEST YEARS, UN SAYS This year is set to be among the three warmest since records began in 1850, and caps a record warm decade that is a new indication of man-made climate change, the UN said. "The trend is of very significant warming," Dr. Michel Jarraud, head of the WMO, told a news conference on the sidelines of a meeting of almost 200 nations in the Mexican resort of Cancun trying to curb global warming. He said 2010, so far, was slightly warmer than both 1998 and 2005, the previous top two, but could slip if December is cool month. The WMO said that land and sea surface temperatures, so far, in 201 0 were 0.55 °C {1 °F) above a 1961 -1990 average of 14°C (57.2 °F). The years 2001-2010 were the warmest 10-year period, it said. Courtesy: TERI (The Energy and Resources Institute) Newswire, 1-15 December 2010, P17. WORLD'S GLACIERS MELTING AMID WARMER TEMPERATURES: UN STUDY Glaciers around the world are melting amid warmer global temperatures, especially near the North and South Poles, and particularly Alaska, Argentina, and Chile, according to a study by the UNEP. The report, compiled from an array of scientific studies, found that glaciers in northwest US and southwest Canada and in the high mountains of Asia, including the Hindu Kush of the Himalayas, also have been melting. The report was released as 194 nations meet for a second week of climate negotiations in Cancun. While expectations have been muted, some government envoys have said they're hopeful that some smaller agreements can be reached on issues such as financing for developing countries to mitigate the impacts of climate change, such as flooding and coastal erosion, and transparency for emission– reduction actions, that many nations have pledged or are pursuing. While it could take centuries for many glaciers to completely disappear, smaller glaciers at lower elevations are melting faster, including glaciers that provide water for nearby communities, the UNEP study found. Courtesy: TERI (The Energy Resources Institute) Newswire, 1-15 December 2010, Pp 17-18. 36