The Oceans and Global Warming

An Example: Starving Sea Birds

Some signs already show that the marine food web is fraying. In 2005 on the U.S. West Coast and 2004 in Britain, hundreds of thousands of seabirds failed to breed. Dead seabirds like cormorants and Cassin's auklets have washed up on West Coast beaches.

Juvenile rockfish counts were the lowest they had been off California in more than 20 years. Most alarming, small crustaceans like krill -- a critical link in the ocean's food web -- suffered steep declines.

The culprit for the collapse appears to be slackening upwellings, which decreased phytoplankton blooms in these coastal areas. Fewer phytoplankton mean fewer fish, leaving the birds to face mass starvation.

Monitoring of the oceans off Hawaii over the last 20 years shows that upwellings are decreasing. Scientists suspect that this is an effect of global warming.

The debate over global warming has shifted from whether it is happening to how to avoid catastrophic damage. Significant changes loom for seabird and fish communities, ocean circulation patterns and basic processes of ocean chemistry.

"We're facing warming waters and major alterations in many oceanic processes and ocean chemistry, damage to coral reefs, and effects from sea level rise on marine ecosystems," says Environmental Defense scientist Doug Rader.

Without emissions cuts, the effects will be even worse.

"The ship is already in motion, and it will take immediate action to turn it away from the danger ahead," sums up Environmental Defense climate scientist Dr. James Wang.