Warming
of oceans due to climate change is unstoppable, say US scientists
Seas
will continue to warm for centuries even if manmade greenhouse gas
emissions were frozen at today’s levels, say US government
scientists
Suzanne
Goldenberg / Thursday 16 July 2015 18.23 BST /
http://www.theguardian.com/environment/2015/jul/16/warming-of-oceans-due-to-climate-change-is-unstoppable-say-us-scientists
The warming of the
oceans due to climate change is now unstoppable after record
temperatures last year, bringing additional sea-level rise, and
raising the risks of severe storms, US government climate scientists
said on Thursday.
The annual State of
the Climate in 2014 report, based on research from 413 scientists
from 58 countries, found record warming on the surface and upper
levels of the oceans, especially in the North Pacific, in line with
earlier findings of 2014 as the hottest year on record.
Global sea-level
also reached a record high, with the expansion of those warming
waters, keeping pace with the 3.2 ± 0.4 mm per year trend in sea
level growth over the past two decades, the report said.
Scientists said the
consequences of those warmer ocean temperatures would be felt for
centuries to come – even if there were immediate efforts to cut the
carbon emissions fuelling changes in the oceans.
“I think of it
more like a fly wheel or a freight train. It takes a big push to get
it going but it is moving now and will contiue to move long after we
continue to pushing it,” Greg Johnson, an oceanographer at Noaa’s
Pacific Marine Environmental Laboratory, told a conference call with
reporters.
“Even if we were
to freeze greenhouse gases at current levels, the sea would actually
continue to warm for centuries and millennia, and as they continue to
warm and expand the sea levels will continue to rise,” Johnson
said.
On the west coast of
the US, freakishly warm temperatures in the Pacific – 4 or 5F above
normal – were already producing warmer winters, as well as
worsening drought conditions by melting the snowpack, he said.
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The extra heat in
the oceans was also contributing to more intense storms, Tom Karl,
director of Noaa’s National Centers for Environmental Information,
said.
The report
underlined 2014 as a banner year for the climate, setting record or
near record levels for temperature extremes, and loss of glaciers and
sea ice, and reinforcing decades-old pattern to changes to the
climate system.
Four independent
data sets confirmed 2014 as the hottest year on record, with much of
that heat driven by the warming of the oceans.
Globally 90% of the
excess heat caused by the rise in greenhouse gas emissions is
absorbed by the oceans.
More than 20
countries in Europe set new heat records, with Africa, Asia and
Australia also experiencing near-record heat. The east coast of North
America was the only region to experience cooler than average
conditions.
Alaska experienced
temperatures 18F warmer than average. Spring break-up came to the
Arctic 20-30 days earlier than the 20th century average.
“The prognosis is
to expect a continuation of what we have seen,” Karl said.
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