Science Daily

On Greenland's ice sheet, a vast icy landscape crisscrossed by turquoise rivers and dotted with meltwater lakes, a small cluster of orange camping tents popped up in late July. The camp, home for a week to a team of researchers, sat by a large, fast-flowing river. Just half a mile (a kilometer) downstream, the river dropped into a seemingly bottomless moulin, or sinkhole in the ice. The low rumble of the waters, the shouted instructions from scientists taking measurements, and the chop of the blades of a helicopter delivering personnel and gear were all that was heard in the frozen landscape.

Earlier this month, a NASA instrument nestled in the belly of a small plane flew over Greenland's ice sheet and the Arctic Ocean's icy waters. Flying above creviced glaciers, chunks of ice floating in melt ponds, and the slushy edges of the ice sheets, the instrument used a rapidly firing laser to measure the elevation of the surface below.

WHRC scientists have counseled the State Department on policies that could control permafrost thaw, including reducing global carbon emissions from fossil fuel use and deforestation, and limiting emissions of 'black carbon,' sooty particles that darken snow and ice and hasten Arctic warming.

The membranes of sediment-entombed archaea are an increasingly popular way to determine ocean surface temperatures back to the age of the dinosaurs. But new results show that changing oxygen can affect the reading by as much as 21 degrees C.

According to the 23-year record of satellite data from NASA and its partners, the sea level is rising a few millimeters a year -- a fraction of an inch. If you live on the U.S. East Coast, though, your sea level is rising two or three times faster than average. If you live in Scandinavia, it's falling. Residents of China's Yellow River delta are swamped by sea level rise of more than nine inches (25 centimeters) a year. These regional differences in sea level change will become even more apparent in the future, as ice sheets melt.

For thousands of years, sea level has remained relatively stable and human communities have settled along the planet's coastlines. But now Earth's seas are rising. Globally, sea level has risen about eight inches (20 centimeters) since the beginning of the 20th century and more than two inches (5 centimeters) in the last 20 years alone. All signs suggest that this rise is accelerating.

Seas around the world have risen an average of nearly 3 inches (8 centimeters) since 1992, with some locations rising more than 9 inches (25 centimeters) due to natural variation, according to the latest satellite measurements from NASA and its partners. An intensive research effort now underway, aided by NASA observations and analysis, points to an unavoidable rise of several feet in the future.

The second ice age during the Cryogenian period was not followed by the sudden and chaotic melting-back of the ice as previously thought, but ended with regular advances and retreats of the ice, according to new research.

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.

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).

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.”

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.

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.

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.

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.

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.

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.

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.

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.

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.