Ever since it was first recognized as a real phenomenon, the
“pause” in global temperature increases (and increasing divergence from climate
model projections), has been wished-away by the die-hard faithful, or
explained-away by speculative grant-mongers, despite a complete lack of
evidence, as migrating to the deep ocean
waters.
Now, a new “study” not only accepts and reinforces the
reality of the model-defying hiatus, but attempts to explain it away, at least
in part, as the result of volcanism.
Someone needs to call John Kerry and his boss, and let them
in on the secret: natural processes are driving temperature movement on Earth!
The article reported in Nature Geoscience also goes further,
acknowledging decreased solar radiance and insolation as part of the
explanation:
“Small volcanic eruptions help explain a hiatus in
global warming this century by dimming sunlight and offsetting a rise in
emissions of heat-trapping gases to record highs, a study showed on Sunday.
Eruptions of at least 17 volcanoes since 2000 … ejected
sulfur whose sun-blocking effect had been largely ignored until now by climate
scientists, it said.The pace of rising world surface temperatures has slowed since an exceptionally warm 1998, heartening those who doubt that an urgent, trillion-dollar shift to renewable energies from fossil fuels is needed to counter global warming.”
But wait, there’s more!
The paper’s authors not only acknowledge the lack of significant temperature
rise despite explosive growth in CO2 emissions, they look to other factors,
including solar irradiance as possible explanations for the models’ miserable
failures to anticipate the lack of warming to match the CO2 rise.
"This is a complex detective story," said Benjamin Santer of the Lawrence Livermore National Laboratory in California, lead author of the study in the journal Nature Geoscience that gives the most detailed account yet of the cooling impact of volcanoes.
"Volcanoes are part of the answer but there's no factor that is solely responsible for the hiatus," he told Reuters of the study by a team of U.S. and Canadian experts.”
A “complex detective story?"
Didn’t those eminent “climate scientists,” Gore, Kerry and
Obama just tell the U.S. and the world that we all must be punished with 40%
higher energy costs because “the science is settled?”
Apparently, Dr. Santer and his colleagues from across the
globe didn’t hear or weren’t listening.
“Santer said other factors such as a decline in the
sun's output, linked to a natural cycle of sunspots, or rising Chinese
emissions of sun-blocking pollution could also help explain the recent slowdown
in warming.
The study suggested that volcanoes accounted for up to 15
percent of the difference between predicted and observed warming this century.
All things being equal, temperatures should rise because greenhouse gas
emissions have hit repeated highs.”
“Despite continued growth in atmospheric levels of
greenhouse gases, global mean surface and tropospheric temperatures have shown
slower warming since 1998 than previously. Possible explanations for the
slow-down include internal climate variability, external cooling influences and
observational errors. Several recent modelling studies have examined the
contribution of early twenty-first-century volcanic eruptions to the muted
surface warming.”
jw
(Reuters) - Small volcanic eruptions help explain a hiatus
in global warming this century by dimming sunlight and offsetting a rise in
emissions of heat-trapping gases to record highs, a study showed on Sunday.
Eruptions of at least 17 volcanoes since 2000, including
Nabro in Eritrea, Kasatochi in Alaska and Merapi in Indonesia,
ejected sulfur whose sun-blocking effect had been largely ignored until now by
climate scientists, it said.
The pace of rising world surface temperatures has slowed
since an exceptionally warm 1998, heartening those who doubt that an urgent,
trillion-dollar shift to renewable energies from fossil fuels is needed to
counter global warming.
Explaining the hiatus could bolster support for a U.N.
climate deal, due to be agreed by almost 200 governments at a summit in Paris
in late 2015 to avert ever more floods, droughts, heatwaves and rising sea
levels.
"This is a complex detective story," said Benjamin
Santer of the Lawrence Livermore National Laboratory in California, lead author
of the study in the journal Nature Geoscience that gives the most detailed
account yet of the cooling impact of volcanoes.
"Volcanoes are part of the answer but there's no factor
that is solely responsible for the hiatus," he told Reuters of the study
by a team of U.S. and Canadian experts.
Volcanoes are a wild card for climate change - they cannot
be predicted and big eruptions, most recently of Mount Pinatubo in the
Philippines in 1991, can dim global sunshine for years.
Santer said other factors such as a decline in the sun's
output, linked to a natural cycle of sunspots, or rising Chinese emissions of
sun-blocking pollution could also help explain the recent slowdown in warming.
The study suggested that volcanoes accounted for up to 15
percent of the difference between predicted and observed warming this century.
All things being equal, temperatures should rise because greenhouse gas
emissions have hit repeated highs.
TEMPORARY RESPITE
"Volcanoes give us only a temporary respite from the
relentless warming pressure of continued increases in carbon dioxide,"
said Piers Forster, Professor of Climate Change at the University of Leeds.
A study by the U.N. Intergovernmental Panel on Climate
Change last year suggested that natural variations in the climate, such as an
extra uptake of heat by the oceans, could help explain the warming slowdown at
the planet's surface.
The IPCC projected a resumption of warming in coming years
and said that "substantial and sustained" cuts in greenhouse gas
emissions were needed to counter climate change.
It also raised the probability that human activities were
the main cause of warming since 1950 to at least 95 percent from 90 in 2007.
Despite the hiatus, temperatures have continued to rise - 13 of the 14 warmest
years on record have been this century, according to the World Meteorological
Organisation.
"Volcanic
contribution to decadal changes in tropospheric temperature"
Benjamin D. Santer, Nature Geoscience (2014) doi:10.1038/ngeo2098
Despite continued growth in atmospheric levels of greenhouse gases, global mean surface and tropospheric temperatures have shown slower warming since 1998 than previously. Possible explanations for the slow-down include internal climate variability, external cooling influences and observational errors. Several recent modeling studies have examined the contribution of early twenty-first-century volcanic eruptions to the muted surface warming. Here we present a detailed analysis of the impact of recent volcanic forcing on tropospheric temperature, based on observations as well as climate model simulations. We identify statistically significant correlations between observations of stratospheric aerosol optical depth and satellite-based estimates of both tropospheric temperature and short-wave fluxes at the top of the atmosphere. We show that climate model simulations without the effects of early twenty-first-century volcanic eruptions overestimate the tropospheric warming observed since 1998. In two simulations with more realistic volcanic influences following the 1991 Pinatubo eruption, differences between simulated and observed tropospheric temperature trends over the period 1998 to 2012 are up to 15% smaller, with large uncertainties in the magnitude of the effect. To reduce these uncertainties, better observations of eruption-specific properties of volcanic aerosols are needed, as well as improved representation of these eruption-specific properties in climate model simulations.
No comments:
Post a Comment