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SCIENCE NEWS OF THE YEAR | Earth
230 million years | Age of “dawn runner” fossil
Record high tie Analyses
from NASA and the National
Oceanic and Atmospheric
Administration rate 2010 as
tied with 2005 for the hottest year on record, followed
closely by 1998. Others rank
2010 as the second hottest
(SN: 2/12/11, p. 17).
argues that Christopher
Columbus and other New
World explorers may have
set off a series of events contributing to Europe’s Little
Ice Age (SN: 11/5/11, p. 12).
o
Riches from on high Many
of the precious metals
mined today were delivered via a bombardment of
stony meteorites (illustrated
above) that pummeled the
Earth and left craters on the
moon billions of years ago
(SN: 10/8/11, p. 11).
Waistline growth Ice melting
off Greenland and Antarctica
has changed the shape of the
Earth, making it more bulgy
at the equator, scientists find
(SN: 7/16/11, p. 13).
Polar flip The occasional
swapping of the north and
south magnetic poles may be
tied to plate tectonics; when
landmasses have bunched
together, Earth’s magnetic
field has begun flipping soon
after (SN: 11/19/11, p. 9).
Early meat-eater
Researchers uncover a
fossil of a pint-sized meat-eater named Eodromaeus, or
“dawn runner” (above), that
dates to 230 million years
ago, the dinosaurs’ earliest
days (SN: 2/12/11, p. 10).
Tipping point An analysis
reveals that a small change in
rainfall or other factors can
cause an ecosystem to switch
abruptly between forest and
savanna (SN: 11/5/11, p. 5).
Chiseled from below
Molten material rising from
beneath is chiseling chunks
of rock off the bottom of the
Colorado Plateau, possibly
explaining why this area has
lifted upward over millions
of years (SN: 5/21/11, p. 12).
Quick colonizers Fossils
dating to 530 million years
ago suggest that Earth’s first
animals colonized freshwater earlier than thought,
soon after diverse forms
appeared in marine habitats
(SN: 6/4/11, p. 9).
Extinction causes New
studies suggest that gassy
volcanic eruptions (SN:
1/15/11, p. 12) and acidifying
oceans (SN: 10/8/11, p. 10)
could have contributed to the
mass extinction at the end
of the Permian period, some
250 million years ago.
Climate meddlers Humans
removing trees to work the
land put nearly 350 billion
metric tons of carbon into
the atmosphere by 1850,
researchers suggest (SN:
4/23/11, p. 17). Another team
Big blowup Geologists find
evidence for one of the biggest volcanic eruptions ever,
in southern Java 21 million
years ago (SN Online: 8/6/11).
Warming slowdown
The planet’s overall temperature has been climbing upward,
but that trend stalled during the early 2000s —and now
scientists think they can explain why. Several studies suggest that tiny sulfur-rich particles called aerosols, which
shield the Earth from the sun’s incoming rays, are to blame.
Some of those particles come from volcanic eruptions,
such as the Soufrière Hills volcano in Montserrat that has
been puttering along since 1995. Although such eruptions
aren’t as dramatic as the 1991 eruption of Mount Pinatubo
in the Philippines, which cooled the whole planet for several years, the aerosols from several small volcanoes are
enough to add up to a cooling in;uence (SN: 8/13/11, p. 5).
Also playing a role are coal-burning power plants, particularly in Asia. Sulfur particles coming from the plants mostly
counterbalanced the warming produced by their carbon
dioxide emissions (SN: 7/30/11, p. 17).
Soufrière Hills volcano in Montserrat has spit cooling sulfur
particles into the atmosphere over the last decade.
Overall, the buildup of carbon dioxide is expected to keep
sending temperatures upward —a trend observed by three
independent research teams and con;rmed this year by yet
another analysis performed by the Berkeley Earth Surface
Temperature group. —Alexandra Witze
