Antarctic ice loss creates new carbon sink
Over the past 50 years, the Antarctic Peninsula has warmed by about 3°C,
and the melting ice has created huge areas of open water that have been
colonised by phytoplankton – tiny plants that form the basis
of the ocean food chain. These organisms absorb dissolved CO2 for use in photosynthesis, and are so abundant that they account for half of all the oxygen produced by plants on Earth. When they die, they drop to the seabed and form ‘mats’ that are buried under sediment, potentially locking up carbon for millions of years.
The BAS scientists compared records of glacial retreat around the coast of the peninsula with the amount of chlorophyll – the green pigment that is essential for photosynthesis – in the ocean. Their findings, published in Global Change Biology, suggest that the ice loss has created at least 24,000 square kilometres of new open water in which phytoplankton have bloomed. It’s estimated that this carbon sink absorbs 3.5 million tonnes of carbon a year – equivalent to 12.8 million tonnes of CO2, but only a fraction of that produced by human activity.
Professor Lloyd Peck of the BAS, the lead author of the report, said: ‘Although this is a small amount of carbon compared to global emissions of greenhouse gases in the atmosphere, it is nevertheless an important discovery. It shows nature’s ability to thrive in the face of adversity.
‘If more Antarctic ice is lost as a result of climate change, then these new blooms have the potential to be a significant biological sink for carbon.’
January 2010
of the ocean food chain. These organisms absorb dissolved CO2 for use in photosynthesis, and are so abundant that they account for half of all the oxygen produced by plants on Earth. When they die, they drop to the seabed and form ‘mats’ that are buried under sediment, potentially locking up carbon for millions of years.
The BAS scientists compared records of glacial retreat around the coast of the peninsula with the amount of chlorophyll – the green pigment that is essential for photosynthesis – in the ocean. Their findings, published in Global Change Biology, suggest that the ice loss has created at least 24,000 square kilometres of new open water in which phytoplankton have bloomed. It’s estimated that this carbon sink absorbs 3.5 million tonnes of carbon a year – equivalent to 12.8 million tonnes of CO2, but only a fraction of that produced by human activity.
Professor Lloyd Peck of the BAS, the lead author of the report, said: ‘Although this is a small amount of carbon compared to global emissions of greenhouse gases in the atmosphere, it is nevertheless an important discovery. It shows nature’s ability to thrive in the face of adversity.
‘If more Antarctic ice is lost as a result of climate change, then these new blooms have the potential to be a significant biological sink for carbon.’
January 2010
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