Monday, May 21, 2007

Starving grey whales linked to global warming?

Grey whales are dying of starvation off the US west coast, and global warming is a possible cause. Too bad, they were just recovering from the end of commercial whaling--out of the frying pan and into the fire.

Climate change is an ocean issue even though you don't know much about it yet. Oceans are already getting more acid as atmospheric CO2 goes up, and that will create harm before warming causes harm. Acidification has already slowed the growth of corals.

Now starving grey whales are the next ocean victim of climate change. What's happening is that warmer water has reduced upwelling of nutrients by increasing ocean stratification (think trying to mix oil and vinegar). Warmer surface water in the ocean makes the top layer refuse to mix with deeper water.

And...deep water is the major source of nutrients that fertilize plankton growth. Once plankton growth is reduced, everything else goes hungry. Now, big grey whales are suffering, after a near-miraculous rebound once whale hunting was stopped.

The alarm on declining plankton isn't coming from only green groups.Crusty oceanographer John McGowan, who taught my first oceanography class at Scripps Institution of Oceanography, is sounding the alarm on declining plankton.

Like I said, climate change is primarily an ocean issue, even though you don't know it yet. It's easy to look at oceans as a threat with sea level rise threatening to flood coastal zones and hurricanes getting worse. But the ocean is more victim than villain and ocean life may well suffer more than life on land. Stay tuned and get active if you want your future to include an ocean that you like.