Study of 11,300 years of weather suggests record warming ahead...Global Warming blamed.

[Leroy N. Soetoro]

http://www.latimes.com/news/science/la-sci-climate-warming-
20130308,0,1220004.story

By observing several indirect indicators, researchers looking at weather
patterns since the end of the last Ice Age predict that average surface
temperatures will be at their highest point in human experience by the end
of this century.

First the good news: In the last 11,300 years, humans have endured a
planet warmer than today's, even as they set about building their earliest
civilizations.

Now the bad news: That will no longer be true 87 years from now, according
to scientists who have conducted a comprehensive analysis of the planet's
climate history since the world's ice sheets began their most recent
retreat from North America and Europe.

New research into Earth's ancient climate is providing a clearer, more
detailed view of how the planet's average surface temperature fluctuated
over the period known as the Holocene epoch, which continues today. It's
the time in which humans truly began making their mark on the planet,
abandoning their hunting and gathering traditions and adopting a settled,
agricultural lifestyle.

In a study published in Friday's edition of the journal Science,
researchers used eight indirect temperature indicators � such as pollen
and shells from marine organisms � to chart long-term global warming and
cooling trends. The research team concluded that temperatures in the last
decade had not exceeded the Holocene's steamiest periods from thousands of
years ago. However, if current warming trends hold, those records will be
broken by the end of the century.

�By the year 2100, we will be beyond anything human society has ever
experienced,� said study leader Shaun Marcott, a postdoctoral researcher
at Oregon State University's College of Earth, Ocean and Atmospheric
Sciences.

According to NASA, the average global temperature for 2012 was 58.3
degrees Fahrenheit, making it the ninth-hottest year in recorded history.
However, there is no single, agreed-upon method of calculating these
temperatures, so scientists tend to discuss climate change by highlighting
deviations from a specific reference point.

While a 1-degree Fahrenheit increase sounds small, it represents an
enormous amount of heat energy. For instance, a 10-degree drop would
plunge the world into another period of major glaciation, while every 1.8-
degree increase would gradually amount to a roughly 65-foot rise in sea
level due to melting polar ice, according to NASA climatologist James
Hansen.

Previous efforts to measure past climate conditions have relied heavily on
measurements of tree ring thickness. At high latitudes, tree growth is
controlled mostly by temperature, so thick rings suggest warm years. But
trees don't live longer than several thousand years, so those efforts have
focused on shorter periods of time � just 1,500 to 2,000 years.

These earlier studies have also featured �hockey stick� graphs, in which
average temperatures fluctuate in a long band that vaguely resembles the
shaft of a hockey stick before rising sharply in the last 100 years, like
the hockey stick's blade. Such diagrams have generated virulent criticism
from those who rebut the idea that man-made greenhouse gases are heating
the climate.

Marcott and colleagues from Harvard University said that by estimating
temperature fluctuations for the entire Holocene, they hoped to provide a
new perspective on the debate.

The researchers collected data from 73 sites across the globe, on land and
beneath the sea. They included ice cores from Greenland, stalagmites in
Borneo, and fossilized pollen in Scandinavia.

Some of the data came from the shells of long-dead aquatic microbes that
were buried as many as 50 feet or more below the ocean floor. The shells'
chemical makeup gives scientists clues about the water temperature at the
time the creatures existed � shells formed in warm water will have a
greater percentage of stable oxygen isotopes, while shells formed in cold
water will have a lower ratio.

Similarly, sediment core samples taken from the bottom of a pond, lake or
ocean will contain fossilized pollen grains, which have very distinctive
shapes when viewed under a microscope. By examining the variety of species
and their abundance, scientists can gauge the area's past climate.

Trans fats produced by a type of algae were also used in the study as
temperature indicators. The chemical bonds of these fat molecules, called
alkenones, change according to water temperature. When the algae die, the
alkenones sink to the bottom of the sea or lake bed, where they are mostly
preserved.

What the researchers found was a climate that warmed and cooled gradually
over a period of milleniums, then experienced a sudden, unprecedented rise
in temperatures � similar to earlier hockey stick graphs.

After the retreat of vast ice sheets in the Northern Hemisphere, global
average temperature rose roughly 1 degree from the start of the Holocene
to about 9,500 years ago, authors found. Average temperatures then
plateaued for roughly 4,000 years, with the exception of two relatively
short-lived spikes.

After that, things began to cool again. From about 5,500 years ago to
roughly a century ago, average global surface temperature dropped 1.3
degrees.

But what concerns many scientists is what occurred next: In just the last
100 years, the average temperature has increased by 1.3 degrees. Although
global temperatures of the last decade have not exceeded peak Holocene
highs, they are warmer than 75% of the epoch.

�Global temperature, therefore, has risen from near the coldest to the
warmest levels of the Holocene within the past century,� the researchers
wrote.

By the end of the century, climate warming models predict an additional
increase of 2 to 11.5 degrees, due largely to carbon emissions, the study
noted.

The Science study was not the first to use such proxies to assess the
ancient climate, but it was the first to pull together so many of them
from all over the world, the researchers said. Previous studies used only
regional data, which may be influenced by localized events like monsoons
and the cyclical ocean-warming phenomenon known as El Ni�o.

Michael Mann, a physicist and climatologist at Pennsylvania State
University who was not involved in the study, said the paper was important
because it illustrated clearly that the rate and magnitude of recent
warming was unprecedented in at least the last 11,000 years.

�We know that there were periods in the past that were warmer than today �
for example, the Cretaceous period 100 million years ago,� he said. �The
real issue is the rate of change, because that's what challenges our
adaptive capacity.�

Mann, who was among the first climate scientists to introduce the hockey
stick graph a decade ago � and has been strongly criticized by climate
warming skeptics ever since � said the authors should prepare themselves
for similar judgment.

�I am certain that professional climate-change deniers will attack the
study and the authors, in an effort to discredit this important work,�
Mann said.

monte...@latimes.com

--

Barack Obama, reelected by the dumbest and most fearful people in the
history of the United States of America.

Eric Holder, racist black murdering United States Attorney General, still
has his job.

Nancy Pelosi, Democrat criminal, accessory before and after the fact to
improper vetting of Barry Soetoro aka Barack Hussein Obama, a confirmed
felon using SSAN 042-68-4425, belonging to a dead man.

Obama ignored the brutal killing of an American diplomat in Benghazi, then
relieved American military officers who attempted to prevent said murder
in order to cover up his own ineptness.

Obama continues his goal of disarming America after known mentally
disturbed liberal Adam Peter Lanza killed 20 school children and 6 adults
in Sandy Hook Connecticut on December 14, 2012. Every single liberal
inspired and authored gun control law in existence failed to prevent this
tragedy.

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[1treePetrifiedForestLane]

the Holocene; you is when ... or, was,
til teh IPCC basically ignored urban heat-islanding,
viz the (old) US Climate Reference Network,
a database of 28 weatherstations that were still rural,
at the time of inception.