From a plant in Peru that was flash frozen 5,000 years ago,
we have evidence that past climate change happened in
hours. Another reason we know there was sudden climate
change 5,200 years ago is from the prehistoric man called
Otzi, who was frozen in the Alps around that time and only
discovered a few years ago, since the Alps are melting. "We
know that the Ice Man, a preserved Neolithic hunter exposed
by a retreating glacier in the European Alps, was trapped by
the ice around 5,200 years ago," says geologist Lonnie
Thompson. "If it happened in the past, it might
happen again, and that
type of abrupt event in today's world would mean worldwide
chaos, both economically and socially."
Thompson and his team are looking for more frozen plants
that may be have been exposed by the retreating glacier in
the Peruvian Andes Mountains. So far, they've found the
body of a small insect, perfectly preserved and frozen 210
feet below the surface and three individual pieces of plants
that were frozen at a depth of 384 feet. The flash frozen
plant from 5,000 years ago is their most amazing find. "This is
a soft-bodied plant," he says. "It had to be captured by a
very large snowfall at the time, a snowfall and climate change
that began very abruptly, fast enough to capture a plant but
not kill it. That is astounding.
"We know the first plant could not have been exposed at any
time during in that 5,200-year history or it would have
decayed," he says, meaning that the glacier has remained
frozen for over 5,000 years?until now. They found a second
plant about 4 miles away, which DNA testing shows has been
buried for 2,200 years, which is a time when other records
show there was abrupt climate change.
Thompson's team is working quickly so they can retrieve any
frozen plants and insects that are there before the glacier
melts completely. When they started surveying the area in
1963, it was retreating at a rate of 15.4 feet a year, but the
melt has accelerated to the rate of 672 feet per year, which
is 40 times as fast.
Thompson says, "Something happened 5,200 years ago that
was abrupt and very large-scale." But what caused it?and
will it happen again?
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