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On the other side of the Great Lakes in Ontario, Canada live two species of flying squirrel, the northern flying squirrel (Glaucomys sabrinus) and the southern flying squirrel (Glaucomys volans). These two species inhabit more northerly and southerly ranges, respectively. Climate change means geographic changes in the distribution of temperature and moisture conditions. Because most [...]

The Toba supereruption on the Indonesian island of Sumatra about 74,000 years ago was very likely the biggest volcanic eruption of the past two million years. Ash deposits from the eruption have been found in the Gulf of Arabia, the southern Indian Ocean and South China Sea, indicating the global impacts of this event. Unlike [...]

The official 2012 Atlantic Hurricane Season is now over. Compared to the 30-year average of 12 named storms per year, 2012 was above-normal with 19 named storms, but not an exceptional year. Ten of these storms became hurricanes (annual average is six hurricanes). Only one storm, Michael, became a major hurricane (annual average is three [...]

About 760 petagrams (760 billion tons) of carbon dioxide are held in the atmosphere, which is about the same weight as 140,000 Great Pyramids of Giza. While this may sound like a large number, carbon dioxide takes up only about 0.04 percent of the atmosphere, yet it is a crucial greenhouse gas and without it [...]

Mangrove forests form some of the world’s richest ecosystems. Scientists who study how ecosystems interact with Earth’s climate want to know how much carbon dioxide (CO2) plants take out of the atmosphere and how much CO2 decomposers send back out into the atmosphere. Because mangrove forests feature wet soils that lack oxygen, making it hard [...]

The rapid expansion of drought conditions over the contiguous United States during the past year led to the largest moderate to extreme drought coverage since the 1950s. While the epicenter of the current drought is in the Midwest and central Plains, the drought of the 1950s was centered in the West. The total national extent [...]

America’s costliest natural disasters are often North Atlantic hurricanes striking Florida, the East Coast or the Gulf Coast. While inland flooding, tornadoes, lighting and coastal storm surges account for the majority of monetary damages inflicted by these storms, the hurricane winds themselves also do a good deal of damage. How much structural damage winds inflict [...]

Globally, wildfires affect an average of 1.4 million square miles of land each year. Fire has been an important factor in terrestrial ecosystem development and dynamics for at least 400 million years. Savanna ecosystems, found mostly in Africa between the tropical rainforest and desert ecosystems, burn the most, contributing 47.8 percent of the global dry [...]

Wind speed affects surface evaporation, air quality, soil erosion, wind power generation, etc. Trends in global wind speed due to related large-scale global processes have direct implications for weather and environmental quality as well as indirect implications for the global energy budget via wind speed ‘s influence on aerosol concentrations and the water cycle. Globally, [...]

Collectively forming the largest area of glacial cover outside of Alaska and the Arctic and referred to as Earth’s “third pole,” the Himalayan glaciers are important sources of water for the Indus, Ganges and Bhramaputra river basins, where 800 million people live. Best estimates suggest that the glaciers of the greater Himalaya cover about 15,800 [...]

Albedo describes how much of the Sun’s radiation an object reflects. New snow is very reflective, with an albedo as high as 0.9, meaning that 90 percent of the sunlight that hits it is reflected. Dark asphalt, on the other hand, has an albedo as low as 0.04, meaning it absorbs 96 percent of the [...]

The last two million years of Earth’s history are characterized by swings from cold, glacial periods to warmer, interglacial periods. These swings are part of a cycle lasting about 100,000 years, controlled by gradual changes in Earth’s orbit and the amount of the sun’s energy received by the Earth. As the last warm interglacial ended [...]

Rainfall records from the central United States confirm the old adage that “when it rains, it pours.” While days with at least “moderately heavy” precipitation  ?  precipitation totals exceeding  0.5 inches  ?  account for only 25 percent of all days when it rains, more than 70 percent of the total rain volume falls during moderately [...]

The Yoshino Cherry Trees that surround the Tidal Basin in Washington, DC were a gift from Mayor Yukio Ozaki of Tokyo City to signify friendship between the United States and Japan. 2012 marks the 100th anniversary of their arrival. The cherry blossoms also signify the arrival of spring. Whereas in many other plant species the [...]

The Northeast United States has experienced a particularly mild 2011-2012 winter, with the region’s average January temperature 4.7 degrees Fahrenheit above normal. Vermont was the warm spot, coming in at 6.2 degrees Fahrenheit above normal. This mild winter, however, appears to be part of a longer-term, 50-year trend of warming winter temperatures. The average winter [...]

Ice cover on the Great Lakes peaks in February or early March before beginning its gradual melt, which is generally completed by May or June. Deepwater lakes like Superior take longer to reach peak ice cover than shallow water lakes like Erie, and also take longer to thaw. This means that shallow water lakes are [...]

The extent of the Arctic sea ice, which is usually gauged by its annual minimum extent in September, has been declining by 11.2 percent per decade since 1979. Large-scale effects of this decline impact Earth’s climate, primarily through increased absorption of sunlight by the open oceans. Local effects have also been documented. As ice has [...]

Discussions of climate and climate variability often focus on temperature trends at the Earth’s surface, which is where humans spend most of their time. But the atmosphere holds onto little energy compared to the oceans – the top few feet of the ocean holds as much heat as the entire atmosphere above it! Transfers and [...]

Temperatures have warmed by an average of two degrees Fahrenheit over Earth’s land surface and 0.6 degrees Fahrenheit over the oceans over the past 50 years. These temperature changes have been accompanied by changes in precipitation and seasonal cycles, including lengthening of the growing/frost-free season in temperate and high latitudes. Together, these factors related to [...]

The September/October Arctic sea ice annual minimum this year was the second lowest minimum on record for the 33 year period of satellite observations. The lowest minimum was recorded in 2007. But how do these ice extents relate to what the sea ice has done over the past several hundred or thousand years? Known relationships [...]