There are many turn-offs (beyond Al Gore) from the climate change alarmists, including the hectoring tone, the smug assertions of consensus and the economic know-nothingism.
Clue to Mars' warming is seen
The planet's darkening surface could account for its
temperature rise, scientists report.
Global warming on Mars?
It turns out you don't need belching smokestacks and
city-choking traffic to heat up a planet. Changes in surface reflectivity may
also do the trick, according to research published Thursday in the journal
Nature.
The research team, composed of scientists from NASA's Ames
Research Center in Northern California and the U.S. Geological Survey, compared
images of Mars taken by the Viking missions in the 1970s to pictures taken a
quarter century later by Mars Global Surveyor.
The surface was noticeably darker in the new pictures, said
Lori Fenton, a planetary geologist at the Carl Sagan Center in Mountain View,
Calif., who worked with Ames scientists on the project.
Plugging in a climate model developed at Ames, the research
team said the changes in surface reflectivity could account for a 1 degree
Fahrenheit rise in the surface temperature of the planet."That's a significant
amount," said Rich Zurek, lead Mars scientist at the Jet Propulsion Laboratory
in La Cañada Flintridge, who was not involved in the research.
The scientists believe the changes in surface reflectivity —
known as albedo — are caused by wind-driven dust storms that occasionally sweep
the entire Martian surface. The storms fill the air and cover the surface with
fine grains that are more reflective than the bedrock.Several big storms
preceded the visit of Vikings 1 and 2 in 1975, Fenton said. Comparatively, there
was less heavy wind and, consequently, more light-absorbing bedrock in the
picture taken by Mars Global Surveyor in 2000.
If Mars is getting hotter, that could explain one finding that
has puzzled planetary scientists since it was discovered several years ago: the
loss of carbon dioxide ice at Mars' south pole.The CO2 ice forms a cap on top of
water ice that ranges from several feet to several hundred feet in thickness.
Each of the last few years, scientists have seen holes develop in the CO2 layer
late in the Martian summer.
So does all this mean Mars is undergoing a new round of
climate change like the one that dried up its ancient lakes and drove its water
underground?Fenton is unsure. What's going on at the south pole "is an
indication of at least regional temperature change," she said.
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