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Greenhouse gases caused glacial retreat during last Ice Age

Science Daily - Fri, 08/21/2015 - 07:27
A recalculation of the dates at which boulders were uncovered by melting glaciers at the end of the last Ice Age has conclusively shown that the glacial retreat was due to rising levels of carbon dioxide and other greenhouse gases, as opposed to other types of forces. The data helps to confirm predictions of future glacial retreat, and that most of the world's glaciers may disappear in the next few centuries.

July 2015 was warmest month ever recorded for the globe

Science Daily - Thu, 08/20/2015 - 14:28
The July average temperature across global land and ocean surfaces was 1.46°F (0.81°C) above the 20th century average. As July is climatologically the warmest month for the year, this was also the all-time highest monthly temperature in the 1880-2015 record, at 61.86°F (16.61°C), surpassing the previous record set in 1998 by 0.14°F (0.08°C).

More grasslands in Tibet could bring climate improvements

Science Daily - Thu, 08/20/2015 - 07:23
In the Arctic, enhanced vegetation growth amplifies global warming. On the Tibetan Plateau, however, the situation is the reverse. “The trend in Tibet is the opposite of what we are seeing in the Arctic,” says an expert. “By restoring grasslands there, the climate can be improved – both locally and globally.”

Most comprehensive projections for West Antarctica's future revealed

Science Daily - Tue, 08/18/2015 - 07:57
A new international study is the first to use a high-resolution, large-scale computer model to estimate how much ice the West Antarctic Ice Sheet could lose over the next couple of centuries, and how much that could add to sea-level rise. The results paint a clearer picture of West Antarctica's future than was previously possible.

Substantial glacier ice loss in Central Asia's largest mountain range

Science Daily - Mon, 08/17/2015 - 12:23
Along the Tien Shan, Central Asia's largest mountain range, glaciers have lost 27 percent of their mass and 18 percent of their area during the last 50 years. Glaciers play an important role in the water cycle of Central Asia. Snow and glacier melt from the Tien Shan is essential for the water supply of Kazakhstan, Kyrgyzstan, Uzbekistan, and parts of China.

1,800 years of global ocean cooling halted by global warming

Science Daily - Mon, 08/17/2015 - 12:20
Prior to the advent of human-caused global warming in the 19th century, the surface layer of Earth's oceans had undergone 1,800 years of a steady cooling trend, according to a new study. The results also indicate that the coolest temperatures occurred during the Little Ice Age -- a period that spanned the 16th through 18th centuries and was known for cooler average temperatures over land.

Up to 30 percent less precipitation in the Central Andes in future

Science Daily - Mon, 08/17/2015 - 10:09
Seasonal water shortages already occur in the Central Andes of Peru and Bolivia. By the end of the century, precipitation could fall by up to 30% according to an international team of researchers. In a first for this region, the team compared current climate data with future climate scenarios and data extending back to pre-Inca times.

Heat release from stagnant deep sea helped end last Ice Age

Science Daily - Thu, 08/13/2015 - 13:27
The build-up and subsequent release of warm, stagnant water from the deep Arctic Ocean and Nordic Seas played a role in ending the last Ice Age within the Arctic region, according to new research.

Greenland ice sheet's winds driving tundra soil erosion, study finds

Science Daily - Wed, 08/12/2015 - 12:19
Strong winds blowing off the Greenland Ice Sheet are eroding soil and vegetation in the surrounding tundra, making it less productive for caribou and other grazing animals, carbon storage and nutrient cycling, a study finds.

Melting glaciers feed Antarctic food chain

Science Daily - Tue, 08/11/2015 - 13:03
Nutrient-rich water from melting Antarctic glaciers nourishes the ocean food chain, creating feeding 'hot spots' in large gaps in the sea ice, according to a new study.

Research priorities for Antarctic and Southern Ocean science

Science Daily - Tue, 08/11/2015 - 12:28
An initiative to better understand how melting ice sheets will contribute to sea-level rise, efforts to decode the genomes of organisms to understand evolutionary adaptations, and a next-generation cosmic microwave background experiment to address fundamental questions about the origin of the universe are the top research goals for Antarctic and Southern Ocean science recommended in a new report.

Scientists pioneer method to track water flowing through glaciers

Science Daily - Mon, 08/10/2015 - 12:21
Seismic sensors have, for the first time, been used to track meltwater flowing through glaciers and into the ocean, a critical step to understanding glaciers as climate changes. Meltwater moving through a glacier can increase melting and destabilize the glacier. It can speed the glacier's flow downhill. It can move boulders and other sediments toward the terminus of the glacier. And it can churn warm ocean water and bring it in contact with the glacier, scientists report.

Corrected sunspot history suggests climate change not due to natural solar trends

Science Daily - Fri, 08/07/2015 - 21:07
The Sunspot Number is a crucial tool used to study the solar dynamo, space weather and climate change. It has now been recalibrated and shows a consistent history of solar activity over the past few centuries. The new record has no significant long-term upward trend in solar activity since 1700, as was previously indicated. This suggests that rising global temperatures since the industrial revolution cannot be attributed to increased solar activity.

High-altitude climate change to kill cloud forest plants

Science Daily - Fri, 08/07/2015 - 10:07
Scientists have discovered many tropical, mountaintop plants won't survive global warming, even under the best-case climate scenario. Many of the species they studied will likely not be able to survive in their current locations past 2080 as their high-altitude climate changes, they say.

Glaciers melting faster than ever

Science Daily - Mon, 08/03/2015 - 07:34
The World Glacier Monitoring Service has compiled worldwide data on glacier changes for more than 120 years. Together with its National Correspondents in more than 30 countries, the international service just published a new comprehensive analysis of global glacier changes. In this study, observations of the first decade of the 21st century (2001-2010) were compared to all available earlier data from in-situ, air-borne, and satellite-borne observations as well as to reconstructions from pictorial and written sources.

Earth's magnetic shield is much older than previously thought

Science Daily - Thu, 07/30/2015 - 15:20
Since 2010, the best estimate of the age of Earth's magnetic field has been 3.45 billion years. But now a researcher responsible for that finding has new data showing the magnetic field is far older.

Playing 'tag' with pollution lets scientists see who's 'it'

Science Daily - Wed, 07/29/2015 - 14:52
Using a climate model that can tag sources of soot and track where it lands, researchers have determined which areas around the Tibetan Plateau contribute the most soot -- and where. The model can also suggest the most effective way to reduce soot on the plateau, easing the amount of warming the region undergoes. The study might help policy makers target pollution reduction efforts.

Past and present sea levels in the Chesapeake Bay Region, USA

Science Daily - Tue, 07/28/2015 - 15:24
Scientists write that sea-level rise (3.4 mm/yr) is faster in the Chesapeake Bay region than any other location on the Atlantic coast of North America, and twice the global average (1.7 mm/yr). They have found that dated interglacial deposits suggest that relative sea levels in the Chesapeake Bay region deviate from global trends over a range of timescales.

First measurements taken of South Africa's Iron Age magnetic field history

Science Daily - Tue, 07/28/2015 - 10:59
A team of researchers has for the first time recovered a magnetic field record from ancient minerals for Iron Age southern Africa (between 1000 and 1500 AD). The data, combined with the current weakening of Earth's magnetic field, suggest that the region of Earth's core beneath southern Africa may play a special role in reversals of the planet's magnetic poles.

Washington, DC sinking fast, adding to threat of sea-level rise

Science Daily - Tue, 07/28/2015 - 09:12
New research confirms that the land under the Chesapeake Bay is sinking rapidly and projects that Washington, DC, could drop by six or more inches in the next century -- adding to the problems of sea-level rise.

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