We've all seen the headlines about melting sea ice in the Arctic. It is tangible harbinger EVIDENCE of the enormous quantities of carbon dioxide, or CO2, our industrial world has pumped into the atmosphere.
But there is another equally insidious peril below sea level. Alaskans are at the forefront of "the other carbon dioxide problem" -- ocean acidification. Some of the CO2 pollution dissolves into the ocean, creating carbonic acid and making the ocean more acidic.
No one fully knows what this change will do to the oceans. But we do know that if we don't reverse this soon, we'll end up with a drastically different ocean, to the detriment of nearly everyone who depends on it. Think jellyfish instead of salmon.
Acidification makes it harder for organisms to make shells or other protective structures -- they essentially dissolve in the more acidic water. This change poses new risks for a vast range of ocean life, from clams and coral reefs, to crabs, shrimp, lobsters, krill, sea urchins, sea snails, and some kinds of plankton, to name a few.
Acidification can affect the growth of marine plants and the potency of many marine toxins. It makes it harder for animals in general to breathe. It makes fish grow oversized ear bones, called otoliths, potentially affecting their ability to orient themselves in the water.
It even makes the ocean noisier, by increasing the efficiency of sound transmission. It very likely does a lot of other things that haven't been discovered yet.
Natural volcanic vents that produce CO2 provide a glimpse of how marine ecosystems respond to acidification. The view is bleak. Calcifying organisms like clams, corals and crabs disappear. The marine food web is drastically simplified, and the ocean loses its ability to support fish and other species that humans like to harvest, including the salmon, halibut, crabs and other bounty we enjoy here in Alaska.
A more acidic ocean will be fundamentally alien to human experience.
Because carbon dioxide dissolves better in colder water, ocean acidification is happening fastest near the poles, including here in Alaska. Essentially irreversible ocean changes are expected along Alaska's Arctic continental shelf within a decade. If acidity is allowed to triple by the end of this century, it could transform the ocean into something fundamentally alien to human experience.
There is only one practical way to avoid ocean acidification, and that is by reducing our emissions of carbon dioxide. The United States is responsible for 20 percent of global emissions, and because we are so wasteful in our energy use, we have the best opportunity to reduce emissions.
As individuals, we can all take simple actions: turn off lights, inflate car tires to proper pressure, put high energy-using items like water heaters on timers.
As a nation, we could cut our emissions in half relatively painlessly by doing three simple things:
• Encourage personal energy conservation through a carbon tax with a full, equal rebate to each American, perhaps through their income tax returns.
• Support investment in alternative energy sources such as wind power, along with a high-efficiency power transmission network.
• Convert our coal-fired power plants to natural gas, which releases half the carbon dioxide per kilowatt generated.
Taking these steps would set a powerful example for other high-emitting countries such as China and India, and would put our economy on a far more sustainable footing.
The solution will require all of us to make changes. We still have the opportunity to bequeath to our descendants an ocean that would be familiar to prior generations of humanity -- but not for much longer. The economic cost to our descendents of our failure to act is incalculable.
Dr. Jeffrey Short, a marine chemist, is Pacific Science Director for the marine conservation organization Oceana in Juneau. Jim Ayers has more than 30 years experience with policy issues in Alaska. He lives in Juneau and is currently Vice President of Oceana.
By DR. JEFFREY SHORT and JIM AYERS