Known as the subantarctic mode water, the circulation pattern maintains a nutrient supply for three quarters of ocean life. Sarmiento and colleagues reported the finding earlier this year in the science journal Nature.
If the pattern were to shut down, the effects on marine life would be devastating, Sarmiento said. But whether that will result from global warming is an open question, he noted.
"We really do not know yet. What our study shows is that this is a place where we have to go to understand what is going on, because it is so critically important," Sarmiento said in an interview on the radio program Pulse of the Planet.
The Princeton researcher said another research gap is how to mitigate the effects of climate change, noting that any carbon dioxide added to the atmosphere today will remain a long time before it dissolves in the ocean.
"If carbon dioxide emissions continue to grow at present rates, we will soon reach carbon dioxide levels that are likely to cause quite large climate change," Sarmiento said. "Thus, even though the full impacts of such climate change may not be clearly understood, it behooves us to take any actions we can to bring things under control as soon as we can."
By how much should the global community seek to reduce carbon dixode emissions? The answer, according to Sarmiento, depends largely on two little-understood factors:
how rapidly carbon dioxide is removed from the air by the land and oceans
how the oceans will respond to warming
"What if ocean biology responds to the climate change? How will this affect the rate at which oceans take up anthropogenic carbon? Model analyses suggest that these effects are not large, but the truth is that our confidence in such predictions is limited," he said.
According to Oreskes, the University of California, San Diego, researcher, the affect of aerosols, which are known to cause a cooling effect, is another important area that requires more research. Aerosols are particles of liquid or solid matter suspended in the air. They are emitted from natural and human sources, such as factories.
Research by Steven Maria at Princeton University published in the December 10 issue of Science suggests the cooling effect of aerosols may be significant.
"If this is true, then it means that as we continue to clean up aerosols, which have large, direct effects on human health, we may see a stronger global warming effect," Oreskes said.
Filling such gaps in scientists' understanding of the dynamics of climate change is not enough, Orekes said. She argues that the world also needs to develop new technologies to effectively deal with global climate change.
"We need a serious commitment to the engineering aspects of making renewable energies cost effective," she said. "It's no good asking folks not to do something if you don't give them an alternative."
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