e360 digest
27 Sep 2012:
High-Arctic Summers
Are Warmer than Any Time in 1,800 years
Summer temperatures on the Norwegian archipelago of Svalbard in the High Arctic
are now higher than during any time over the last 1,800 years, including a period of higher temperatures in the northern hemisphere known as the
Medieval Warm Period, according to a new study. In an analysis of algae
Arctic Tipping Point:
A North Pole Without Ice
Scientists say this year’s record declines in Arctic sea ice extent and volume are powerful evidence that the giant cap of ice at the top of the planet is on a trajectory to largely disappear in summer within a decade or two, with profound global consequences.
READ MORE buried in deep lake sediments, a team of scientists calculated that summer temperatures in Svalbard since 1987 have been 2 to 2.5 degrees Celsius (3.6 to 4.5 degrees F) warmer than during the Medieval Warm Period, which lasted from roughly 950 to 1250 AD. The Medieval Warm Period is often cited by climate change skeptics as proof that the planet has experienced periods of high temperatures in recent centuries unrelated to the burning of fossil fuels. “Our record indicates that recent summer temperatures on Svalbard are greater than even the warmest periods at that time,” said William D’Andrea, a climate scientist at Columbia University. The algae, which make more unsaturated fats in colder periods and more saturated fats in warmer periods, reveal critical clues about past climates. Scientists were able to date the lake specimens by analyzing grains of glass emitted by a series of well-known Icelandic volcanoes that left unique chemical time markers. The study is published in the journal
Geology.

Yale Environment 360 is
a publication of the
Yale School of Forestry
& Environmental Studies.
Twitter: YaleE360
e360 on Facebook
Donate to e360
View mobile site
Bookmark
Share e360
Email newsletter
Subscribe to our feed:
About e360
Contact
Submission Guidelines
Reprints

South African photojournalist Adam Welz documents the harrowing relocation of six white rhinos to a region that has lost all its rhinos to poaching.
View the gallery.
Opinion
Reports
Analysis
Interviews
e360 Digest
Podcasts
Video Reports
Biodiversity
Business & Innovation
Climate
Energy
Forests
Oceans
Policy & Politics
Pollution & Health
Science & Technology
Sustainability
Urbanization
Water
Antarctica and the Arctic
Africa
Asia
Australia
Central & South America
Europe
Middle East
North America

A
Yale Environment 360 video explores Ecuador’s threatened Yasuni Biosphere Reserve with scientists inventorying its stunning forests and wildlife.
Watch the video.
The latest
from
Yale
Environment 360 is now available for mobile devices at
e360.yale.edu/mobile.
In a
Yale Environment 360 video, photographer Pete McBride documents how increasing water demands have transformed the Colorado River, the lifeblood of the arid Southwest.
Watch the video.

Top Image: aerial view of
Iceland. © Google & TerraMetrics.
The Warriors of Qiugang, a
Yale Environment 360 video that chronicles the story of a Chinese village’s fight against a polluting chemical plant, was nominated for a 2011 Academy Award for Best Documentary (Short Subject).
Watch the video.