CARACAS - Global warming resulting from the greenhouse effect will be the top environmental issue at the second-ever Organization of Petroleum Exporting Countries (OPEC) summit of heads of state, slated for September 26 to 28 in Venezuela.

The measures necessary to combat the greenhouse effect ''constitute a real challenge for countries that are highly dependent on revenue from petroleum exports,'' stressed OPEC secretary-general, Rilwanu Lukman, of Nigeria.

Oil exporters would suffer financially if the world complies with the objective to reduce global petroleum consumption by 6.5 million barrels per day by the year 2010.

The emission of gases from combustion is a leading cause of the greenhouse effect, and thus global warming, according to scientists. .

LIMA - Over-fishing, the introduction of foreign species and pollution from urban runoff have all contributed to diminishing the presence of native fish species in Lake Titicaca, located on the Bolivia-Peru border, reducing the population of carachi, ispi, boga and suche fishes.

The biomass (the sum of all living species in a determined location) of the lake dropped nearly 50 percent between 1990 and 1999, according to the latest assessment by the Lake Titicaca Bi-national Special Project, financed by Bolivia, Peru and foreign assistance.

Titicaca, sitting at 3,815 meters above sea level, is the highest large lake in the world and, with its 8,330 square km surface, it is the largest in Latin America. Fish from its waters are a principal source of nutrition for the area's indigenous communities.

RIO DE JANEIRO - The issue of environmental legislation in Brazil, considered to be fairly advanced but rarely applied, will be the center of discussion at a national congress August 28 to 30 in the southern city of Florianópolis.

An effective environmental legal framework, which had its beginnings in the 1970s and 1980s, only began to gather force during the last decade, largely due to social mobilization.

The forestry code, for example, is 35 years old, and the general law on the environment was passed back in 1981, pointed out attorney Raul Telles do Valle, of the non-governmental Social-Environmental Institute, with offices in Brasilia and Sao Paulo.

New laws have set standards for environmental crimes and regulate the use of water, now recognized as an economic resource, but rules on access to biodiversity are still in the provisional stages.

SANTIAGO - A group of students from the University of Chile have united in defense of the environment, launching a campaign to encourage Chileans to get into the recycling habit.

The pro-ecology engineering students hope to raise public awareness through public debates, forums, video presentations and expositions. They are currently working to reactivate programs for separating recyclable waste, which will initially focus on collecting cans. Proceeds will go towards purchasing battery rechargers.

Batteries are one of the worst contaminants of the environment due to the slow degradation and toxicity of their component chemicals. The students' goal is to mitigate this type of pollution by encouraging the use of rechargeable batteries. For more information, write to the university group at gripe@cec.uchile.cl

*Source: Inter Press Service.