What are the Oceans Telling Us About Climate Change?
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As we celebrate World Oceans Day on Friday, it’s worth pausing to reflect on the current state of our oceans and the biggest challenge they face: climate change. This is no longer a problem for the future; climate change is already underway.
As we celebrate World Oceans Day on Friday, it’s worth pausing to reflect on the current state of our oceans and the biggest challenge they face: climate change. This is no longer a problem for the future; climate change is already underway.
(From The Boston Globe / by Bud Ris) – We now know, for example, that the heat content of the upper layer of the oceans is on the rise. Just a degree or two of change can make a big difference.
As oceans warm, the water actually expands and takes up more space. This is a basic physics phenomenon called thermal expansion. This means that as water temperatures rise, sea level will rise as well, as it has in Boston by about 11 inches over the last 100 years. (Land subsidence is also a factor)
The data now show that the pace of sea level rise is clearly accelerating, meaning that one to two feet of additional sea level rise by the end of the century is now likely. Much more is possible if ice atop the land masses in Greenland and Antarctica also melts. This has major implications for buildings and public infrastructure along Boston’s waterfront and other major cities. The risks of flooding during storm surges will increase.
Ocean warming won’t just affect humans. The geographic distribution, feeding patterns, and reproductive cycles of many marine animals are sensitive to temperature changes of just a few degrees and to changes in salinity and pH, caused by more freshwater runoff and increased carbon absorption. That may explain why most of the North Atlantic right whales that migrate annually up and down the East Coast didn’t show up in the Bay of Fundy in 2010 for the first time in 30 years — and why now — two years later — we are seeing the result in emaciated mothers and calves and a precariously low birth rate. It might also help explain why lobsters are molting weeks earlier in Maine, and why lobster populations south of Cape Cod are in decline.
No region has felt the early impacts of climate change more than the Arctic where sea ice has declined dramatically in recent years — sometimes by as much as 40 percent by the end of the Arctic summer. This again has profound implications. For humans, it means more access to shipping routes, fisheries, and oil resources north of the Bering Strait, for better or worse. For animals like polar bears — the symbol of Arctic life — it means less ice for safe cub rearing and longer distances to swim for food.
Ultimately, we are going to have to change the way we manage and regulate ocean resources. Fisheries managers, for example, can no longer rely on stock assessments alone. They need to look at how the warming of our oceans will affect the distribution and abundance of species like cod and lobster. Or how acidification — a problem related to climate change — will affect the supply of oysters and clams.
Another need — looking at human impacts — is to build more resilience into buildings and public infrastructure along our harbors and shores. Wise urban planners and architects should consider scenarios of 2-5 feet above the current baseline when renovating existing buildings or designing new structures that will last for several decades. We need to adopt best practices and/or permitting standards that ensure sure critical building systems are installed well above sea level, openings where sea water can penetrate during storms are minimized, and sea water can drain safely back into the oceans during storm surges.
At a minimum, we all have a responsibility to get educated. The New England Aquarium is teaming up with other major aquariums across the country to do our part. Together we can reach millions of people. The impacts of climate change on marine life are now a key part of the story told along our exhibit path. It is a story we embrace with increasing urgency.
Bud Ris is president and CEO of the New England Aquarium. He also served on Mayor Thomas Menino’s Climate Action Leadership Advisory Committee.
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<http://www.oceanleadership.org/2012/what-are-the-oceans-telling-us-about-climate-change/?goback=%2Egde_119460_member_122752515>
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