The island of Greenland experienced more days of melting during 2006 on average than in the last 18 years, according to new NASA-funded research.
The data were gathered by the Special Sensor Microwave Imaging radiometer (SSM/I) flying aboard the Defense Meteorological Satellite Program spacecraft. It can peer through the clouds, and measure the rates of melting every day. During 2006, researchers estimated that portions of Greenland melted for an additional 10 days beyond averages.
Melting water on Greenland will impact global water levels. But the water can also slip down through cracks in glaciers, and lubricate the ice sheet. This can speed up the movement of glaciers, which eject ice into the ocean, and further accelerate sea level rise.
Original Source: NASA News Release
The effects of global warming are already being felt worldwide, but the Earth’s poles are suffering the worst of it. Climate researchers have built a series of models to predict what impact rising temperatures will have on the amount of sea ice in the Arctic Ocean, and it appears they didn’t make these models conservative enough. Sea ice is being depleted at triple the rate that was predicted.
The research was reported in a new study by the National Center for Atmospheric Research (NCAR) and the University of Colorado’s National Snow and Ice Data Center (NSIDC). The authors compared simulations of of past climate to current observations on land and from space. The models estimated that ice would decrease at a rate of 2.5% per decade from 1953 to 2006. But the latest observations show that ice declined at an average rate of 7.8%. In other words, the decline of sea ice is currently about 30 years ahead of schedule from what researchers were originally predicting.
Several factors could have gone into the incorrect models, such as overestimating the thickness of present-day sea ice, or misunderstanding the atmospheric and oceanic circulation that transports heat to the polar regions.
Original Source: UCAR News Release
Planetary geologists propose that our planet once had periods of extreme global freezing nicknamed the “Snowball Earth” eras. During these periods, they supposed, the planet’s temperatures went so low that the oceans froze, and everything was covered in ice. Most sunlight was reflected back into space, perpetuating the icy period.
Continue reading “Snowball Earth Probably Had Warm Spots”
Although it looks ancient and unchanging, the ice sheet in Antarctica is a surprisingly active place. Deep beneath the sheet’s surface, there are waterways, channels and pipes that connect various subglacial “lakes”. These channels can cause these lakes to drain away into the ocean, or transfer water from one to the other.
Continue reading “Satellites Reveal Subglacial Streams in Antarctica”
Oxygen makes up 21% of the Earth’s atmosphere, and we need it to breathe. But early organisms would have found this environment toxic. Ancient bacteria evolved protective enzymes that prevented oxygen from damaging their DNA, but what evolutionary incentive did they have to do this? Researchers have discovered that ultraviolet light hitting the surface of glacial ice can release molecular oxygen. Bacteria colonies living near this ice would have needed to evolve this protective defense. They were then well equipped to handle the growth of atmospheric oxygen produced by other bacteria that would normally be toxic.
Continue reading “How Did Early Bacteria Survive Poisonous Oxygen?”
If you’re going to Antarctica, put on your sunscreen. According to NASA and NOAA scientists, the ozone hole above the Earth’s Southern Hemisphere is the biggest on record. In late September, the new hole reached 27.5 million square km. Even through most countries banned ozone-depleting chemicals many years ago, they’re expected to continue affecting the atmosphere for decades to come.
Continue reading “Biggest Ozone Hole Ever”
Hot enough for you? A new NASA study has found that global temperatures are nearing their hottest level in more than 12,000 years – since the last glaciers covered large portions of the planet. In fact, global temperatures have been going up approximately 0.2° Celsius (.36° Fahrenheit) per decade for the past 30 years. In fact, global temperatures are now within one degree Celsius of the hottest temperatures measured in the last million years.
Continue reading “Warmest World in 12,000 Years”
New data gathered by NASA’s QuikScat satellite has found that ice at the Arctic polar ice cap is disappearing rapidly. Just between 2004 and 2005, the spacecraft measured a loss of 14% of the perennial sea ice; ice that normally lasts all year round. This is an amount of ice measuring 720,000 square kilometers (280,000 square miles), an area the size of Texas. Scientists expect that the coverage of perennial sea ice will continue to decrease this year as well.
Continue reading “Polar Ice is Melting Fast”
Climate scientists have uncovered more evidence that human activities are raising ocean temperatures, spawning more powerful hurricanes. The researchers used 22 different climate models to reproduce ocean temperatures over the last 100 years. They found that human-caused greenhouse gases, ozone and aerosol particles are raising ocean temperatures, which provide energy to the strongest hurricanes.
Continue reading “Human Influences Will Generate More Hurricanes”
New research indicates that periods of global warming in the past triggered the release of vast quantities of methane stored beneath the oceans. These reserves are generated over long periods of time by bacteria and other organisms, but is chemically frozen into the sea floor. Methane is powerful greenhouse gas, and contributes to the general effect of global warming. The emissions peaked 16,000-14,000 years ago, and then again 11,000-10,000 years ago, and could happen again if ocean temperatures rise above some unknown level.
Continue reading “Ancient Ocean Released a Torrent of Methane”