Tweet “This study reverses previous findings."
8/4/14, "Climate change not so global," University of Queensland, Australia
"Scientists are calling for a better understanding of regional
climates, after research into New Zealand's glaciers has revealed
climate change in the Northern Hemisphere does not directly affect the
climate in the Southern Hemisphere.
The University of Queensland study showed that future climate changes
may impact differently in the two hemispheres, meaning a generalised
global approach isn’t the solution to climate issues.
UQ School of Geography, Planning and Environmental Management Head Professor Jamie Shulmeister
said the study provided evidence for the late survival of significant
glaciers in the mountains of New Zealand at the end of the last ice age –
a time when other ice areas were retreating.
“This study reverses previous findings which suggested that New
Zealand's glaciers disappeared at the same time as ice in the Northern
Hemisphere,” he said.
“We showed that when the Northern Hemisphere started to warm at the
end of the last ice age, New Zealand glaciers were unaffected.
“These glaciers began to retreat several thousand years later, when
changes in the Southern Ocean led to increased carbon dioxide emissions
”This indicates that future climate change may impact differently in
the two hemispheres and that changes in the Southern Ocean are likely to
be critical for Australia and New Zealand.”
The study used exposure dating of moraines - mounds of rocks formed
by glaciers - to reconstruct the rate of ice retreat in New Zealand’s
Ashburton Valley after the last glacial maximum – the time when the ice
sheets were at their largest.
The researchers found that the period from the last glacial maximum
to the end of the ice age was longer in New Zealand than in the Northern
They also found that the maximum glacier extent in New Zealand
occurred several thousand years before the maximum in the Northern
Hemisphere, demonstrating that growth of the northern ice sheets did not
cause expansion of New Zealand glaciers.
“New Zealand glaciers responded largely to local changes in the
Southern Ocean, rather than changes in the Northern Hemisphere as was
previously believed,” Professor Shulmeister said.
“This study highlights the need to understand regional climate rather than a global one-size-fits-all.”
The research was conducted in collaboration with the University of Griefswald, Germany, the Australian Nuclear Science and Technology Organisation, and the University of Canterbury, New Zealand, and published in the Proceedings of the National Academy of Science in July."
Peer reviewed study cited above:
7/28/2014, "The early rise and late demise of New Zealand’s last glacial maximum," PNAS.org, Henrik Rothera,1 David Finkb, James Shulmeisterc, Charles Mifsudb, Michael Evansd, and Jeremy Pughe,2
"This record from a key site in the midlatitude
Southern Hemisphere shows that the largest
glacial advance did not coincide with the coldest temperatures during
We also show that the regional post-LGM
ice retreat was very gradual, contrary to the rapid ice collapse widely
This demonstrates that glacial records
from New Zealand are neither synchronous with nor simply lag or lead
ice sheet records, which has important
implications for the reconstruction of past interhemispheric climate
linkages and mechanisms.".
"Recent debate on records of southern midlatitude glaciation has focused
on reconstructing glacier dynamics during the last
glacial termination, with different
results supporting both in-phase and out-of-phase correlations with
glacial signals. A continuing major
weakness in this debate is the lack of robust data, particularly from
the early and maximum
phase of southern midlatitude glaciation
(∼30–20 ka), to verify the competing models....These
findings preclude the previously inferred
rapid climate-driven ice retreat in the Southern Alps after the onset of
1. Our record documents an early last
glacial maximum, an overall trend of diminishing ice volume in New
Zealand between 28–20
ka, and gradual deglaciation until at
least 15 ka."
"This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1401547111/-/DCSupplemental."
NASA confirms above conclusions: Unlike the Arctic, the Antarctic is isolated from major population centers and emissions they produce, in particular it's not exposed to wind driven black carbon from Asia:
4/8/2009, "Aerosols May Drive a Significant Portion of Arctic Warming," nasa.gov/topics
"The Arctic region has seen
its surface air temperatures increase by 1.5 C (2.7 F) since the
mid-1970s. In the Antarctic, where aerosols play less of a role, the
surface air temperature has increased about 0.35 C (0.6 F)....
Since decreasing amounts of sulfates and increasing amounts of black
carbon both encourage warming, temperature increases can be especially
rapid. The build-up of aerosols also triggers positive feedback cycles
that further accelerate warming as snow and ice cover retreat.
In the Antarctic, in contrast, the impact of sulfates and black carbon
is minimized because of the continent’s isolation from major population
centers and the emissions they produce....
A new study, led by climate scientist Drew Shindell of the NASA Goddard
Institute for Space Studies, New York, used a coupled ocean-atmosphere
model to investigate how sensitive different regional climates are to
changes in levels of carbon dioxide, ozone, and aerosols.
The researchers found that the mid and high latitudes are especially
responsive to changes in the level of aerosols. Indeed, the model
suggests aerosols likely account for 45 percent or more of the warming
that has occurred in the Arctic during the last three decades. The
results were published in the April issue of Nature Geoscience....
Sulfates, which come primarily from the burning of coal and oil, scatter
incoming solar radiation and have a net cooling effect on climate. Over
the past three decades, the United States and European countries have
passed a series of laws that have reduced sulfate emissions by 50
percent. While improving air quality and aiding public health, the
result has been less atmospheric cooling from sulfates.
At the same time, black carbon emissions have steadily risen, largely
because of increasing emissions from Asia. Black carbon -- small,
soot-like particles produced by industrial processes and the combustion
of diesel and biofuels -- absorb incoming solar radiation and have a
strong warming influence on the atmosphere."...
Peer reviewed study cited in above NASA article:
3/22/2009, "Climate response to regional radiative forcing during the twentieth century," Nature Geoscience, Drew Shindell1 and
Added: The entire Southern Hemisphere is lucky to have avoided being geoengineered by George Bush #1:
George Bush #1 signs Clean Air Act amendments in 1990, making rules stricter than 1970 and 1977 versions. Top left, clapping, Bush EPA chief William Reilly, plucked from his WWF president job by Bush. In particular the 1990 law reduced sulfur dioxide emissions which Bush said caused acid rain.
Unfortunately this exacerbated global warming in Northern latitudes:
Post 1970 global warming "is driven by efforts to reduce
in general and acid deposition in
particular."...2011 PNAS study
2009 NASA graph shows warming of Arctic latitudes after US Clean Air Acts of 1970, 1977 and 1990:
Image from Nasa.gov.
4/8/2009, "Half of recent arctic warming may not be due to greenhouse gases," Houston Chronicle, Eric Berger
July 19, 2011 PNAS study finds post 1970 warming "is driven by efforts to reduce
in general and acid deposition in
particular, which cause sulfur emissions to decline."
7/19/2011, "Reconciling anthropogenic climate change with observed temperature 1998–2008," PNAS.org
Robert K. Kaufmanna,1 Heikki Kauppib, Michael L. Mann, and James H. Stock
"The post 1970 period of warming, which constitutes a
portion of the increase in global surface
temperature since the mid 20th century, is driven by efforts to reduce
in general and acid deposition in
particular, which cause sulfur emissions to decline while the
concentration of greenhouse
gases continues to rise (7)."...
In a section titled "Results" the PNAS study says cooling sulfur emissions rose somewhat after 2002 due to extreme acceleration of China's coal use, which "partly reverses a period of declining sulfur emissions that had a warming effect of 0.19 W/m2 between 1990 and 2002." (Subhead "Results")
For reference, the purpose of this 2011 PNAS study was to address "the lack of a clear increase in global surface temperature between 1998 and 2008:"
"Data for global surface temperature indicate little warming between 1998 and 2008."... (1)