Ocean Currents May Offset Global Warming Over Coming Decade
16 May 2008 Author: Bilig In: Nature & Environment
Global warming is set to stall over the next 10 years as natural variations in ocean currents counteract manmade climate change.
Researchers modelling the climate of Europe and North America found that a major ocean current that brings warm water northwards is set to weaken, potentially offsetting temperature rises caused by human activity.
A team led by Noel Keenlyside at the Leibniz Institute for Marine Science in Germany focused on an ocean current known as the meridional overturning current or MOC. The current acts as a huge conveyor belt, bringing warm water into the North Atlantic and returning cold water to the south.
Scientists believe the ocean current strengthens and weakens on a natural cycle with a 70 to 80-year period. When the current is strong, it brings warmer water and a milder climate to northern regions.
The team’s models, which were checked against historical temperature changes, suggest the current will weaken enough to cool the North Atlantic, while temperatures in the tropical Pacific are unlikely to change.
The study appears in the journal Nature today.
“Our results show that global mean temperatures may plateau or cool weakly over the next 10 years because of natural fluctuations, but in the long term temperatures will continue to rise,” said Dr Keenlyside. “This doesn’t change the bottom line on global warming.”
Reports from the UN Intergovernmental Panel on Climate Change suggest carbon emissions could drive global temperatures up by as much as 0.2C each decade.
An ancient global warming episode drastically changed the planet. Life on Earth needed 200,000 years to recover. What we’re headed for in the next century could be even bigger.
Whales vs. warriors. That’s how one judge views the current debate over the Navy’s testing of high-powered sonar, which some scientists say has caused massive whale strandings and panicked behavior. The Navy argues that the tests are critical, and that high-frequency sonar is the best way to detect quiet enemy submarines.
The National Resources Defense Council sued the Navy to stop its latest round of testing, set to take place off the Southern California coast, and a federal appeals court sided with the Navy, granting a temporary go-ahead. One judge wrote that it’s a question of the safety of our whales vs. that of our warriors, but another noted that there’s no reason the Navy couldn’t take certain precautions during its testing to avoid hurting marine life. The fight isn’t over—another hearing is scheduled for November 5.
Via: LATimes
