Japan has backed down from a highly controversial plan to hunt endangered humpback whales off Antarctica, after fierce criticism by Australia. The Japanese whaling fleet, however, still plans to hunt almost 1,000 whales this season. Today's decision will save 50 humpback whales that Japanese whalers had planned to catch and kill in Antarctic waters.

Global water consumption increased sixfold in the last century--more than twice the rate of population growth--and will continue growing rapidly in coming decades. Yet readily available freshwater is a finite resource, equivalent to less than one percent of the water on Earth. What's more, water and populations are unevenly distributed across the globe; arid and semi-arid regions receive only two percent of all surface runoff yet account for 40 percent of the global land area and house half of the world's poor. Finally, our existing freshwater resources are under heavy threat from overexploitation, pollution, and climate change. Given these trends, equitably providing adequate water resources for agriculture, industry and human consumption poses one of the greatest challenges of the 21st century.

A fierce storm on Sunday resulted in massive 18-foot waves, which split a Russian oil tanker in two and sank two Russian freighters nearby. The tanker spilled at least 560,000 gallons of fuel into a strait which leads to the Black Sea, and officials say it may take years to clean up. The tankers sank in the Strait of Kerch, which links the Black Sea and the Sea of Azov in the northeast. The two ships were carrying a total of around 7,150 tons of sulfur, according to Sergei Petrov, Russia's Ministry of Emergency Situations regional spokesperson.

Indoor air pollution causes 1.6 million premature deaths every year and afflicts nearly half of the world's population, predominantly the rural poor. This makes it the second leading environmental health threat in the world and a critical barrier to poverty alleviation in low-income countries. Yet this issue is rarely discussed outside of public health circles, probably because the health consequences of indoor air pollution are not immediate and can be difficult to trace. Thus, indoor air pollution remains a quiet and neglected killer, with lack of global awareness being one of the primary obstacles to the widespread implementation of existing, proven interventions.

The United Nations Environment Programme (UNEP) has released a comprehensive report on the current state of the global environment. Climate change, food and water shortage and a decline in biodiversity threaten humanity's survival, so urgent action is necessary, the report warns.  UNEP's Global Environment Outlook: environment for development (GEO-4) report involved the work of about 390 experts in various fields from around the world.

While the GEO-4 report salutes some improvements, for example the increased public awareness of environmental issues and political interest, it also warns that "There are no major issues ... for which the foreseeable trends are favourable." Although the report sets out a gloomy scenario, its main aim is to call for action.

In a "fireside chat" at Yale University on Wednesday, prominent naturalists Edward O. Wilson and Peter H. Raven predicted dire consequences for the planet's biodiversity and habitability unless current trends in consumption and environmental degradation are reversed. The two scientists were awarded the Addison Emery Verrill Medal by the Peabody Museum of Natural History for their contributions to natural science before a capacity crowd at Yale's Sprague Hall. Both are known for their environmental activism as well as extensive research and popular writing.

If greenhouse gas emissions continue in the "business as usual" trend, two-thirds of the world's polar bears may become extinct by 2050, according to a study released last month by the U.S. Geological Survey. The series of nine reports prepared by the USGS are intended to aid the U.S. Fish and Wildlife Service's upcoming decision on whether to designate the polar bear threatened under the Endangered Species Act. The period of public comments on these reports, which ended today, was the final period of public input before the January 9, 2008 final listing determination.

The listing process has been closely watched by many environmental groups since its beginning in February 2005 for its importance not only in determining the fate of the polar bear species, but also its far-reaching potential to force U.S. action to curb greenhouse gas emissions. If the polar bear is listed, all federal agencies will be prohibited from taking any action that will be likely to jeopardize the bear's continued existence or adversely modify its critical habitat. This could potentially include permits for resource extraction, power-plant operation, and shipping routes through the Arctic.

Without action soon to reduce greenhouse gases, especially ones that disproportionately warm polar regions, polar bears could very possibly become the first mammals to lose 100 percent of their habitat by global warming.