Are Our Oceans Dying?
Phytoplankton has declined 40% in 60 years as
figures reveal Earth has been getting hotter since the Eighties
Marine diatom cells (Rhizosolenia setigera), which are an
important group of phytoplankton in the oceans. Much of life on
Earth depends on these tiny creatures which are now in massive
decline
Microscopic marine algae which form the basis of the ocean food
chain are dying at a terrifying rate, scientists said today.
Phytoplankton, described as the 'fuel' on which marine
ecosystems run, are experiencing declines of about 1 per cent of
the average total a year.
According to the researchers from Dalhousie University in Canada
the annual falls translate to a 40 per cent drop in
phytoplankton since 1950.
The research into phytoplankton comes as a separate report today
offered evidence that the world has been warming for the past 30
years.
The reduction in the amount of algae in the seas could have an
impact on a wide range of species, from tiny zooplankton to
marine mammals, seabirds, fish and humans.
If confirmed, the decline of the phytoplankton would be a more
dramatic change change to nature's delicate balance than the
loss of the tropical rainforests, scientist said.
The research, published in the journal Nature, said the declines
were linked to rising sea-surface temperatures and changes in
the conditions of the ocean, particularly close to the equator.
Most of the declines were seen in polar and tropical regions and
in the open ocean, where most phytoplankton are produced.
The scientists suggested that in warmer oceans there was less
movement between the layers of the sea, reducing the amount of
nutrients delivered from deep water to the surface ocean.
As phytoplankton need both sunlight and nutrients to grow, the
limits on the amount of nutrients in the upper layer of the sea
affects production of the algae.
A new study today published a series of data
that showed that many indicators of climate change, such as
sea-surface temperature (above) are rising
In addition, large-scale fluctuations in the climate, such as El Nino
in the Pacific, affect phytoplankton on a year-to-year basis, the
scientists said.
The research adds to the evidence that global warming was altering
the oceans, with the changes in phytoplankton potentially having an
impact on the health of the seas and on fisheries which people rely on
for food.
Lead author Daniel Boyce said: 'Phytoplankton is the fuel on which
marine ecosystems run. A decline in phytoplankton affects everything up
the food chain, including humans.
Co-author Boris Worm, said: 'Phytoplankton are a critical part of our
planetary life support system.
'They produce half of the oxygen we breathe, draw down surface carbon
dioxide and ultimately support all our fisheries.
'An ocean with less phytoplankton will function differently and this
has to be accounted for in our management efforts.'
Fellow author Marlon Lewis added: 'Climate-driven phytoplankton
declines are another important dimension of global change in the oceans,
which are already stressed by the effects of fishing and pollution.'
The figures showed that land-surface
temperature had also risen dramatically in the past 30 years
It comes as scientists today announced that the world is
'unequivocally' warming and has been for the past 30 years.
Researchers at the Met Office compiled data from a series of several
independent studies including sea levels, air temperature, humidity and
glacier loss.
The review also said the past decade had been the warmest on record,
while Met Office scientists said this year was on track to be the
warmest ever.
The report comes in the wake of the 'climategate' furore around
climate science, which stemmed from emails stolen from the University of
East Anglia's Climatic Research Unit (CRU).
The scandal prompted prompted claims from sceptics that scientists
were manipulating data to back up a theory of global warming.
They were since been cleared of any wrongdoing but were accused by an
inquiry set up in the wake of the scandal of being secretive and
unhelpful.
But today's report published as part of the annual State of the
Climate review led by the National Oceanographic and Atmospheric
Administration, shows that global warming is 'undeniable', scientists
said.
Sea levels have also risen steadily since
the turn of the century
The Met Office looked at surface temperature records and other
aspects of climate that scientists predict will change as a result of
increased levels of greenhouse gases, such as warming of the ocean,
increased humidity and reductions in Arctic sea ice.
For each of the 10 indicators they compiled several studies done
independently of each other, revealing broad agreement between different
analyses on what was happening to the climate.
Seven of the areas, including air and sea surface temperatures, the
amount of heat in the ocean and humidity, were on the rise, while three
areas - the extent of Arctic sea ice, glaciers and winter snow cover in
the northern hemisphere - were in decline.
Dr Stott said: 'Despite the variability caused by short-term changes,
the analysis conducted for this report illustrates why we are so
confident the world is warming.
'When we look at air temperature and other indicators of climate, we
see highs and lows in the data from year to year because of natural
variability.
'Understanding climate change requires looking at the longer-term
record. When we follow decade-to-decade trends using different data sets
and independent analyses from around the world, we see clear and
unmistakable signs of a warming world.'
A new image shows September Arctic sea ice
in 1979, the first year these data were available, and 2009.
September Arctic sea ice is one of the 10 key indicators of a
warming planet, the report said today
Many believe that the rise in temperatures around the world is a
natural, cyclical process of the world warming and cooling over time.
An Ipsos Mori survey of 1,822 people for Cardiff University in June
found 40 per cent believed the seriousness of global warming was
exaggerated.
But Dr Stott said studies showed the changes were consistent with an
increase in greenhouse gases, which provided the 'glaringly obvious
explanation' for why the climate was changing.
But he said it was possible the reason for the warming could be due
to something scientists had not thought of - an 'unknown unknown' - but
the patterns of change were not consistent with other suggested causes,
such as solar activity or volcanoes.
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