WASHINGTON (Reuters) – carbon dioxide emissions
similar to which today leads to the burning of fossil fuels
and other human activities helped to warm the planet and
end the last ice age about 11,700 years ago,
reported scientists.
In a finding that offers an answer to those who are
skeptical about global warming caused by
males, researchers from Harvard University and the
State University of Oregon and other institutions reported
in the journal Nature that the increase in temperatures is one
as a result of the increase in carbon dioxide.
Climate experts suspected for years that this
it was so, but geological records were confused.
Previous studies noted air bubbles trapped in
ancient ice of Antarctica, which revealed levels of
carbon dioxide in the last stage of the Pleistocene, ago
20,000 to 10,000 years, the period that ended the era of
ice.
In previous investigations, it seemed that you levels of
carbon dioxide had been increasing since it did the
temperature, leading to question climate sceptics
that carbon dioxide was a heat generator
global, both then and now.
This new study was able to observe ice nuclei and
samples of sediments under the sea – the more deep is the
well, oldest sediment, with biochemical information
indicates the temperature through the time – in 80 variation
areas of the planet.
Only in Antarctica the previous studies were
confirmed: the temperatures there rose before
trepara the level of carbon dioxide. But globally, a
increase in the amount of carbon dioxide in the air
preceded the change in temperature, according to this new report.
The increase of CO2 during the end of the Era
ice was important, some 180 to 260 molecules by
million in the atmosphere, a measurement known as parties by
million or ppm, according to the author of the study, Jeremy Shakun.
The great melt
This increase took place some 7,000 years ago, said Shakun
during a conference call. On the other hand, the current level
atmospheric carbon dioxide is 392 ppm, an increase of
around 100 ppm in the last two centuries, added.
“In this century, will probably increase about 100
“”
(ppm) more”, said Shakun, but added that the earth possibly
will not feel the full impact of this increase in dioxide of
carbon for centuries.
“Heat the oceans takes quite some time, and in addition
“
we have ice, extensions and may not melt
“
extensions of ice in 100 years”, said.
But while carbon dioxide pushed temperatures
upward to accelerate the end of the ice age, it was not the
initial cause.
The large initial melting was driven by a tremor
newspaper in the Earth’s crust, scientists said.
In some moments of the tremor, the northern hemisphere was
closer to the Sun and that happened at the beginning of the final stage
from the Pleistocene, when ice extensions covered much
of what is now North America and Europe.
