Editor’s Note: The following is an excerpt from the NASA Earth Science in the News column, published in the November/December issue of The Earth Observer newsletter. You can download the current issue here.
America’s Tiny Four Corners Region is an Outsized Methane Hotspot; TIME.com. One small spot in the U.S. Southwest is surprisingly the producer of the largest concentration of methane (CH4) gas seen across the nation. Levels of CH4 over the Four Corners region are more than triple the standard groundbased estimate of the greenhouse gas, as reported in a point study of satellite data by scientists at NASA/Jet Propulsion Laboratory (JPL) and the University of Michigan. CH4 is a heat-trapping gas whose increasing quantities in the atmosphere have fueled concerns about global climate change. The methane “hotspot,” seen on the map as a small splotch—see map above—measures approximately 6475 km2 (2500 mi2) at the junction of Arizona, New Mexico, Colorado, and Utah. For scale, the state of Arizona is about 292,668 km2 (113,000 mi2). But the area generated an annual 0.59 million metric tons of methane between 2003 and 2009—about as much CH4 as the entire coal, oil, and gas industries of the U.K. give off each year.
The Four Corners area (red) is the major U.S. hot spot for methane emissions in this map showing how much emissions varied from average background concentrations from 2003-2009 (dark colors are lower than average; lighter colors are higher). Image Credit: NASA/JPL-Caltech/University of Michigan
Scientists Say Ozone Layer is Recovering; Associated Press. Earth’s protective ozone layer is beginning to recover from its previously reduced levels, largely because of the phase-out since the 1980s of certain chemicals used in refrigerants and aerosol cans, a U.N. scientific panel reported. Scientists said the development demonstrates that when the world’s peoples come together, we can counteract a brewing ecological crisis. For the first time in 35 years, scientists were able to confirm a statistically significant and sustained increase in stratospheric ozone, which shields the planet from solar radiation that causes skin cancer, crop damage, and other problems. From 2000 to 2013, ozone levels climbed 4% in the key mid-northern latitudes at about 48 km (30 mi) above Earth’s surface, said scientist Paul Newman [NASA’s Goddard Space Flight Center (GSFC)].
Deep Ocean Hasn’t Warmed Measurably in a Decade, Says NASA; The Weather Channel. Deep below the ocean surface, there’s a place global warming hasn’t yet reached. According to a study published on October 5, 2014, in Nature Climate Change, scientists at NASA/Jet Propulsion Laboratory (JPL) have found that over the last decade the deepest part of the world’s ocean has not warmed measurably. The scientists analyzed ocean temperatures from between 2005 and 2013 and found that below a depth of approximately 2 km (~1.2 mi)—roughly halfway to the bottom at this location—the global ocean has not warmed nearly as quickly as the top half. The scientists collected the temperature data using both satellite measurements and data from the Argo array, a network of some 3500 floating probes scattered throughout the world that measure ocean temperatures and salinity. “The sea level is still rising,” said study coauthor Josh Willis [JPL] in a news release. “We’re just trying to understand the nitty-gritty details.”
Antarctic Sea Ice Level Breaks Record, NASA Says; CBSNews.com. Sea ice surrounding Antarctica is at an all-time high, even as global temperature averages continue to climb. NASA reports that ice formation in the continent’s southern oceans peaked this year, breaking ice-measuring satellite records dating back to the late 1970s. For the first time since 1979, on September 19, 2014, Antarctic sea ice extent exceeded ~20 million km2 (~7.7 million mi2) whereas the average maximum extent between 1981 and 2010 was ~19 million km2 (~7.3 million mi2). Despite this trend, sea ice as a whole is decreasing on a global scale. Researchers say that, just like global warming, trends have different outcomes in different parts of the world; not every location with sea ice will experience ice loss or gain. “When we think about global warming we would expect intuitively that ice should also be declining in the Antarctic region as in the Arctic,” explained senior research scientist Josefino Comiso [GSFC]. “But station and satellite data currently show that the trends in surface temperatures are most positive in the Arctic, while in the Antarctic region the trends are a mixture of positive and negative trends,” he said, adding that cooling and declining sea surface temperatures could also contribute to a “more rapid advance at the ice edge.”
1934’s Dust Bowl Drought Was the Worst in a Thousand Years for U.S.; NBCNews.com. The drought of 1934 wasn’t just bad, it was the worst. That’s the finding of a reconstruction of North American drought history over the past 1000 years, done by scientists from NASA and Columbia University’s Lamont-Doherty Earth Observatory. Their study, published in the October 17 issue of Geophysical Research Letters, concludes the drought of 1934, during the Dust Bowl years in the North American Plains, was 30% more severe than the next worst, which occurred in 1580, NASA scientists said. The scientists used tree ring records from 1000 to 2005 along with modern observations. They found that the 1934 drought extended across over 71% of western North America, compared with almost 60% during the 2012 drought. “It was the worst by a large margin,” said lead author of the study Ben Cook [NASA’s Goddard Institute for Space Studies—Climate Scientist]. The scientists found two main reasons: a winter high-pressure system over the West Coast that blocked precipitation and spring dust storms that suppressed rainfall.
GRACE Spacecraft Changed the Way Groundwater was Measured; CBS’ 60 Minutes. Leslie Stahl hosted a segment on California’s groundwater issues. The segment described the difficulty in sampling groundwater levels until NASA’s Gravity Recovery and Climate Experiment (GRACE) spacecraft was launched. Mike Watkins [JPL—GRACE Project Scientist] described how GRACE “can tell whether an area has gained water weight or lost it.” Jay Famiglietti [University of California, Irvine] said that he thought the method was “complete nonsense” until he started examining the data, which changed his position. The broadcast noted that Famiglietti was so worried by what he saw in the data that he is working “to alert governments and academics to the problem.”