Have we found ANOTHER positive effect of global warming? Melting ice sheets are dumping plankton-boosting iron into earth's oceans
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Huge amounts of dissolved iron currently being released into the oceans from melting ice sheets might cancel out some of the negative effects of global warming, it has been claimed.
A UK team has discovered that summer meltwaters from ice sheets are rich in iron.
This can cause an increase in growth of phytoplankton - which capture carbon, they say.
Figures released earlier this week show the Antarctic Ice Sheet is now losing 159 Gigatonnes of ice each year, enough to raise global sea levels by 0.45 millimetres per year. A UK team has discovered that summer meltwaters from ice sheets are rich in iron, whihch can cause an increase in growth of phytoplankton - which capture carbon, they say.
HOW IT WORKS
It is well known that bioavailable iron boosts phytoplankton growth in many of the Earth's oceans.
In turn phytoplankton capture carbon – thus buffering the effects of global warming.
The plankton also feed into the bottom of the oceanic food chain, thus providing a food source for marine animals.
The researchers say this could effectively 'buffer' the effect of global warming.
The plankton also feed into the bottom of the oceanic food chain, thus providing a food source for marine animals.
The findings, reported in the journal Nature Communications, give new insight into how global warming is affected out planet's ecosystem.
'The Greenland and Antarctic Ice Sheets cover around 10% of global land surface,' said Jon Hawkings of Bristol University, the lead author.
'Iron exported in icebergs from these ice sheets have been recognised as a source of iron to the oceans for some time.
'Our finding that there is also significant iron discharged in runoff from large ice sheet catchments is new.'
The team, comprising researchers from the Universities of Bristol, Leeds, Edinburgh and the National Oceanography Centre, collected meltwater discharged from the 600 km2 Leverett Glacier in Greenland over the summer of 2012, which was subsequently tested for bioavailable iron content.
Meltwater means that the polar oceans receive a seasonal iron boost as the glaciers melt, researchers say
THE POSITIVES OF CLIMATE CHANGE
Despite the catasprophic effects of climate change of some parts of the world, researchers say there are some positive effects. they include
Increased land for agriculture: Presently, vast swaths of the Earth — the northern half of Canada, for instance, and the majority of Russia's land area — aren't suitable for agriculture
Longer growing seasons - and even two harvest
Less energy needed for heating
Arctic resources become available
Boost in alternative energy research
The researchers found that the water exiting from beneath the melting ice sheet contained significant quantities of previously-unconsidered bioavailable iron.
This means that the polar oceans receive a seasonal iron boost as the glaciers melt.
'This means that relatively high iron concentrations are released from the ice sheet all summer, providing a continuous source of iron to the coastal ocean,' said Hawkings.
'This is a substantial release of iron from the ice sheet, similar in size to that supplied to the oceans by atmospheric dust, another major iron source to the world's oceans.
'At the moment it is just too early to estimate how much additional iron will be carried down from ice sheets into the sea.
'Of course, the iron release from ice sheet will be localised to the Polar Regions around the ice sheets, so the importance of glacial iron there will be significantly higher.
'Researchers have already noted that glacial meltwater run-off is associated with large phytoplankton blooms - this may help to explain why'
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