Pollution

Pollution

Methane levels hold steady

Levels of the greenhouse gas methane have plateaued for the first time in about 200 years, shows a report in Geophysical Research Letters. Methane is second only to carbon dioxide in contributing to our planet's warming. The gas - belched out by fossil-fuel burning, rice paddies, festering farm manure and landfill sites - has been accumulating since the industrial revolution. Now the tide may be turning, say Ed Dlugokencky of the National Oceanic and Atmospheric Administration (NOAA) in Boulder, Colorado, and his team. They found that levels steadied between 1999 and 2002, according to measurements from 43 ground-based stations around the world.

The reason for the change is unclear. Dlugokencky believes that a big contributing factor was the break-up of the Soviet Union in 1991. Oil and gas production fell, and the industry became more efficient at plugging gas leaks from pipes and wells.

Experts say the plateau is no cause for complacency. Increasing fossil-fuel consumption in developing nations, or renewed drilling for natural gas, might boost methane again. "The trajectory is still moving up," says David Blake, an atmospheric chemist at the University of California, Irvine.

The finding highlights how small steps to cut methane emissions could slow global warming, he says. Leaking gas pipelines could be capped and incentives introduced to encourage landfill owners and farmers to use methane to run power generators.

Earlier studies hinted at a slowing in the long-term rise in methane - but Dlugokencky's conclusion is based on particularly frequent and accurate measurements..

Taiwan, the largest manufacturer of compact discs in the world, will begin to recycle this product as early as next July, when required regulations have been established, Environmental Protection Administrator Chang Juu-en said yesterday.

Officials from the Environmental Protection Administration (EPA) yesterday were criticized by legislators for their lax efforts to recycle compact discs, which are composed of plastic materials and diverse metals, including aluminum, gold, silver and titanium.

According to legislators, Taiwan produces 5.5 billion compact discs annually, including 4.7 billion discs for overseas markets. Common compact discs are classified into read-only memory (CD-ROM), recordable disc (CD-R) and rewritable disc (CD-RW).

Democratic Progressive Party (DPP) Legislator Cheng Kuei-lien yesterday urged the administration to establish regulations encouraging the public to recycle discs.

"More than 800 million compact discs are sold annually on the domestic market. It's inappropriate to dispose of the discs only in landfills or incinerators," Cheng said.

If compact discs are dumped at landfills, he said, soil and groundwater would be polluted by heavy metals. In addition, burning compact discs containing plastic materials in incinerators might produce the dangerous chemical dioxin.

Chang said that the EPA had entrusted the Industrial Technology Research Institute with conducting a feasibility study on recycling compact discs. The final report will be completed by the end of this year.

"We estimate that the product will be efficiently recycled as early as July next year, if related regulations are established," Chang said.

Cheng's colleagues, including Kuo Jung-tsung of the DPP, and Chen Li-hui and Chang Tsai-mei of the Chinese Nationalist Party (KMT), also expressed their concerns over pollution resulting from untreated compact discs.

According to Chen Hsiung-wen , director-general of the EPA's Bureau of Solid Waste Management, the administration so far had no clear picture of the amount of unwanted compact discs that had to be recycled annually.

But according to a preliminary study by the institute, which estimates that discs have a 4-year lifespan and a 2 percent damage rate during the recording process, about 60 million compact discs weighing 990 tonnes are discarded annually in Taiwan. This conservative estimation excludes discs with defects discarded by the manufacturing sector.

According to a Ministry of Economic Affairs publication in December last year, discs damaged during the manufacturing process accounts for about 10 percent of total production.

According to the EPA, there has been only one environmental service company so far that systematically recycles compact discs. The Kaohsiung-based company, which received its license in August, is expected to recycle as many as 300 million compact discs annually. The company now produces 400 tonnes of plastic materials a month from discarded and recycled compact discs. Meanwhile, two other companies are applying for similar licenses.

Administration officials said that it's worthwhile to recycle unwanted compact discs because the production volume is still increasing significantly.

In addition to production, officials said, other factors affecting the recycling of compact discs would be considered, including potential environmental pollution, consumer behavior, the market economy and executive strategies. Australia life-line for Barrier Reef

The Reef is one of Australia's greatest icons

The Australian Government has submitted a plan to parliament to make the Great Barrier Reef the most protected coral reef system in the world. It wants to increase so-called green zones, where commercial and recreational fishing