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When put in 2000 US dollars, freezing rain (ice storm) events in America caused an estimated 16.3 billion dollars in total losses between 1949 and 2000 due to downed power lines, downed trees, agricultural losses, transportation accidents and medical costs from injuries due to slippery conditions. Freezing rain events are most frequent in the Northeast, [...]

Ice masses maintain their own local climate through several mechanisms. One mechanism is known as the ice-albedo feedback mechanism: ice is more reflective than surrounding rock or ocean and the more reflective a surface is, the less sunlight it absorbs and the less it warms. Highly reflective ice surfaces promote the cold conditions that allow [...]

Beneath the Antarctic ice sheet lie some of Earth’s final frontiers – networks of subglacial lakes, many of which have been isolated from the atmosphere for as long as 15 million years. Outlet channels allow these lakes to periodically drain into the ocean, refill and drain again. The largest of these lakes, Lake Vostok, lies [...]

Much attention has been given to the decline of sea ice over the North Pole, which fell to a September minimum of 1.6 million square miles in 2007, about 40 percent below normal levels. On the other side of the world, the sea ice that extends from Antarctica’s continental ice sheets out over the ocean [...]

Once water is evaporated from the ocean or a moist land surface, it may spend days traveling through the air. Complicated systems of winds at different levels of the atmosphere can transport moisture (as well as other gases and dust) from the point of origin to remote locations thousands of miles away. While about 30 [...]

For the first half of the Cenozoic (the era spanning 65 million years ago to today), Earth was too warm to support ice sheets and sea levels were much higher than today. Then, about 34 million years ago, the Earth crossed a threshold. Over a period of about 300,000 years, the temperature dropped and ice [...]

Ninety (90) percent of Earth’s ice sits on top of Antarctica, a 5.4 million square mile continent. Virtually all of this area is covered by an ice sheet that can be three miles high with an average thickness of 1.24 miles, giving it an approximate total volume of 7.2 million cubic miles. For Comparison: The [...]

In Brief: Higher temperatures are reducing America’s snowfall, with a few regional exceptions. Snow is not just an inhibitor of holiday travelers, nor is it just a passive product of prevailing weather conditions. Snow is a weather maker in and of itself. Snow-covered ground reflects far more of the sun’s radiation than it otherwise would [...]

In Brief: Less ice cover on the Great Lakes is contributing to more snow regional lake effect snow. Over much of the U.S., the 20th century warming trend means less snow and more rain. In most areas, the lack of cold limits snowfall, but this is not true in the Great Lakes region. Here, temperatures [...]

Since at least 1960, more of Earth’s land glaciers have been shrinking than growing. As these glaciers shrink, they absorb heat from the atmosphere. To release the amount of energy that the glaciers have absorbed over the last 50 years, how many one-megaton hydrogen bombs would you need to detonate? a)    200 b)    1000 c)   [...]

On average, about 20 trillion grams (20 teragrams) of dust are suspended in Earth’s atmosphere, where the dust particles stay for an average of 21 days. Dust is an important part of Earth’s climate – dust affects how clouds develop and how much sunlight reaches the Earth, which affects rainfall. The Dust Bowl of the [...]

Two of the biggest ice masses on Earth are the Greenland and Antarctic ice sheets, which together hold more than 90 percent of Earth’s ice. These ice sheets, particularly the Antarctic ice sheet, help to keep the planet cool by reflecting the sun’s energy. As the Earth begins to warm, the ice melts, which works [...]

In today’s modern Holocene climate, warm surface waters in the tropical oceans gradually transition into the near-freezing surface waters near the poles. During warmer periods of Earth’s distant past, this temperature gradient was far less pronounced. In the early Eocene epoch (56-53 million years ago), average annual temperatures in Siberia and Canada were about 65 [...]

During winter, Lake Superior’s cold water is on the surface and warm water is on the bottom; during summer, the opposite is the case. The “switchover” happens in the late spring or early summer and is an important event, as it “stirs” the water. This stirring brings nutrients (which feed the lake’s wildlife) from the [...]

The rich waters in Alaska’s Arctic and sub-Arctic estuaries provide the Pacific Brant, a small goose that travels in flocks of as many as 500 birds, with a steady supply of eelgrass (its principle food source) during the summer months. Traditionally (before the late 1970′s), almost 90 percent of the population would spend their summers [...]

About 75 percent of the West’s water resources originate in snowpack. Most precipitation in the region occurs during the winter, the period of the year when the reservoirs are replenished after the dry summer and early fall months. The reservoirs are at their high points in the spring. Traditionally, snowpack would last into the late [...]

Most of the West’s water ultimately comes from ice (snowpack/glaciers) and changes in this ice can have stark impacts on streamflow. For example, in North Cascades National Park, where there is now 40 percent less glacial mass than there was in 1850, Lewis Glacier disappeared in 1990. Streamflow in the watershed it fed subsequently declined [...]

While the present interglacial period (Holocene epoch) is defined as the period from approximately 11,700 years ago to present, the Laurentide Ice Sheet, which at glacial maximum extended from the North Pole all the way to the Ohio River, occupied the Hudson Bay until about 8,400 years ago. Before this time, runoff from Canada’s western [...]

Increases in the sensible heat (heat that can be felt and measured with a thermometer) in Earth’s atmosphere translates into sea level rise in two ways: (a) the extra energy in the atmosphere is absorbed by the oceans, causing an expansion of the water and (b) the increase in atmospheric sensible heat is converted into [...]

The Arctic sea ice, a mass of ice that floats on the Arctic Basin, is a key regulatory agent in Earth’s climate system. The ice keeps the planet’s surface temperature from jumping too rapidly by converting sensible heat (heat that we can feel) into latent heat as it melts. It also reflects sunlight much better [...]