I
remember, just a a couple of years ago articles like this one were
uncommon. Now we see such general information every few days.
Earth
'Locked Into' Temperatures Not Seen in 2 Million Years
2015 was the warmest year since modern record-keeping began in 1880, according to a new analysis by NASA's Goddard Institute for Space Studies. The record-breaking year continues a long-term warming trend — 15 of the 16 warmest years on record have now occurred since 2001.Scientific Visualization Studio/Goddard Space Flight Center
By
Nika Knight
28
September, 2016
Earth
is the warmest it's been in 100,000 years, a new reconstruction of
historical temperature data finds, and with today's level of fossil
fuel emissions
the planet is "locked into" eventually hitting its highest
temperature mark in 2 million years.
The new
research published
Monday in Nature was
done by Carolyn Snyder, now a climate policy official at the U.S.
Environmental Protection Agency, as a part of her doctoral
dissertation at Stanford University, according
to the
Associated Press (AP).
Snyder
"created a continuous 2 million year temperature record, much
longer than a previous 22,000 year record. [Snyder's reconstruction]
doesn't estimate temperature for a single year, but averages
5,000-year time periods going back a couple million years," AP
reported.
"We
do find this close relationship between temperature and greenhouse
gases that
is remarkably stable, and what the study is developing is the
coupling factor between the two," Snyder toldNational
Geographic.
EcoWatch
It's Official: August Was the 16th Consecutive Record-Breaking Hottest Month http://ow.ly/knoX304qZL8
AP
further reports:
Temperatures
averaged out over the most recent 5,000 years—which includes the
last 125 years or so of industrial emissions of heat-trapping
gases—are generally warmer than they have been since about 120,000
years ago or so, Snyder found. And two interglacial time periods, the
one 120,000 years ago and another just about 2 million years ago,
were the warmest Snyder tracked. They were about 3.6 degrees (2
degrees Celsius) warmer than the current 5,000-year average.
With
the link to carbon dioxide levels and taking into account other
factors and past trends, Snyder calculated how much warming can be
expected in the future.
"Snyder said if climate factors are the same as in the past—and that's a big if," AP noted, "Earth is already committed to another 7 degrees or so (about 4 degrees Celsius) of warming over the next few thousand years."
Nature described
Snyder's findings in greater detail in an article accompanying
her published study:
"Even
if the amount of atmospheric CO2 were to stabilize at current levels,
the study suggests that average temperatures may increase by roughly
5 degrees C over the next few millennia as a result of the effects of
the greenhouse gas on glaciers, ecosystems and other factors. A
doubling of the pre-industrial levels of atmospheric CO2 of roughly
280 parts per million, which could occur within decades unless people
curb greenhouse-gas emissions, could eventually boost global average
temperatures by around 9 degrees C."
"This
is not an exact prediction or a forecast," Snyder told Nature,
advising caution regarding her study's temperature predictions. "The
experiment we as humans are doing is very different than what we saw
in the past."
There
has been some controversy in the scientific community following
publication of Snyder's research: several climate
scientists told National
Geographic that they felt Snyder's estimate of future temperature
rise, far higher than many previous estimates, was an outlier,
signaling that her methods were faulty.
NRDC
A new report warns that ocean warming is the "greatest hidden challenge of our generation”: http://on.nrdc.org/2cxFlPs
via @EcoWatch
Michael
Mann,
an influential climate researcher at Penn State University who was
not involved in Snyder's research, told Mashable
that "I regard the study as provocative and interesting, but the
quantitative findings must be viewed rather skeptically until the
analysis has been thoroughly vetted by the scientific community."
Other
scientists said they were intrigued by Snyder's findings and hope her
study leads to additional research. Jeremy Shakun, a climate
researcher at Boston College, told AP that "Snyder's work is a
great contribution and future work should build on it."
"It's
a useful starting place," Snyder said to Nature about
her research. "People can take this and improve upon it as more
records become available in the future."
Climate Nexus
The latest from Jason Box (26 September, 2016)
Abrupt Climate Change & Greenland: Prof Jason Box (September 2016)
Speed of Arctic changes defies scientists
Alex Kirby
29
September, 2016
The
Arctic climate is changing so quickly that science can barely keep
track of what is happening and predict the global consequences, the
UN says.
LONDON,
29 September, 2016 – In
an unusually stark warning a leading international scientific body
says the Arctic climate is changing so fast that researchers are
struggling to keep up. The changes happening there, it says, are
affecting the weather worldwide.
The World
Meteorological Organisation (WMO)
says: “Dramatic and unprecedented warming in the Arctic is
driving sea level rise, affecting weather patterns around the world
and may trigger even more changes in the climate system.
“The
rate of change is challenging the current scientific capacity to
monitor and predict what is becoming a journey into uncharted
territory.”
The
WMO is the United Nations’ main agency responsible for weather,
climate and water.
Its
president, David
Grimes,
said: “The Arctic is a principal, global driver of the climate
system and is undergoing an unprecedented rate of change with
consequences far beyond its boundaries.
Arctic collaboration
“The
changes in the Arctic are serving as a global indicator – like ‘a
canary in the coal mine’ – and are happening at a much
faster rate than we would have expected.”
He
was speaking before addressing the first White
House Science Ministerialmeeting
in Washington DC, held to develop international collaboration on
Arctic science.
Climate
change is causing global average temperatures to rise: 2014, 2015 and
the first eight months of 2016 have all been record-breakers. The
Arctic is warming at least twice as fast as the global average, in
places even faster: the Canadian town of Inuvik has warmed by almost
4°C since 1948, about four times more than the global figure.
The
increasing loss of Arctic sea ice is threatening
polar bears across
their range; melting sea ice is affecting
the Arctic climate in a feedback loop;
and scientists expect melting permafrost will release
more carbon dioxide and methane.
The
WMO secretary-general, Petteri
Taalas,
said the Arctic changes had also been a factor in unusual winter
weather patterns in North America and Europe. He said the thawing of
the permafrost could release vast quantities of greenhouse gases into
the atmosphere.
“These
are part of the vicious circles of climate change which are the
subject of intense scientific research”, he said.
“The Arctic is a principal, global driver of the climate system and is undergoing an unprecedented rate of change with consequences far beyond its boundaries”
Despite
its certainty that the Arctic is in trouble, the WMO says it is hard
to establish the implications of what is happening there. The Arctic
makes up about 4% of the Earth’s surface, but the WMO says it
is “one of the most data-sparse regions in the world because
of its remoteness and previous inaccessibility.
“Lack
of data and forecasts in the Arctic does impact on the quality of
weather forecasts in other parts of the world.”
That’s
a worry which is echoed at the other end of the planet. A
study led
by Dr Julie Jones,
from the department of geography at the University of Sheffield, UK,
says limited data on Antarctica’s climate is making it difficult
for researchers to disentangle changes caused by human activity from
natural climate fluctuations.
It
was only when regular satellite observations began in 1979 that
measurement of surface climate over the Antarctic and the Southern
Ocean became possible, says the study, published in the
journal Nature
Climate Change.
To
gain a longer view, Dr Jones and her colleagues used a compilation of
records from natural archives such as ice cores from the Antarctic
ice sheet, which show how the region’s climate has changed over the
last 200 years.
Separating signals
They
confirmed that human-induced changes have caused the belt of
prevailing westerly winds over the Southern Ocean to shift towards
Antarctica.
But
they conclude that for other changes, including regional warming and
sea ice changes, the observations since 1979 are not yet long enough
for the signal of human activity to be clearly separated from the
strong natural variability.
The
shift in the westerly winds has moved rainfall away from southern
Australia. This year is set to be the country’s hottest on record.
Dr
Jones said: “The Antarctic climate is like a giant jigsaw puzzle
with most of the pieces still missing.
“There
are some parts of the picture which are clear, particularly the way
that climate change is causing westerly winds to shift southwards,
but there are still huge gaps that we need to fill in order to fully
understand how much human activity is changing weather in the
region.” – Climate
News Network
No comments:
Post a Comment
Note: only a member of this blog may post a comment.