Greenpeace warns of the danger faced by two ecosystems:
The Amazon
The "Zero Forest" bill (PL 6424/2005) currently before the Brazilian Congress would substantially weaken Brazil's Forest Code. Currently, privately owned land must maintain at least 80% of the original vegetation. Zero Forest would reduce that to 50%. (You can sign the petition against Zero Forest here.) Business interests are also attempting to remove protections for areas that have more stringent protections, areas like mountaintops and the rivers themselves. And business interests are trying to have the states instead of the federal government regulate deforestation. As the states make their income from taxing these businesses, the states have more of an incentive to be lax with deforestation regulations.
Deforestation would be emphysema to the "World's Lungs," destroying the most biodiverse region on the planet and releasing stored greenhouse gases. Important species, possibly including medicinal plants, have yet to be discovered. And the problem is more than a simple environmental one. Tribes native to the region depend on the forest, and 85% of slaves in Brazil are found in deforested regions of the Amazon.
The Bering Sea
The Bering's pollock fishery is in danger of collapse, losing 50% of its population in just one year. The population drop is so significant that seals and sea lions are washing up on Alaskan shores, dead from starvation. And again, the problems are more than environmental. Destroying the pollock fishery is obviously not in the long-term interest of the fishing industry or the Alaskan coastal towns that depend on it.
But there is no need for a tragedy of the commons scenario. The North Pacific Fisheries Management Council can set fishing limits. (You can write to the Council here.) However, the Council met last week and reduced the 2009 pollock catch limit by only 18.5%; Greenpeace denounced the reduction as a "half-measure," having urged a 55% reduction.
What You Can Do
Besides writing and petitioning through the links provided above, you can donate to Greenpeace here.