Science and Medicine

Rising Air Pollution Worsens Drought, Flooding, New Study Finds

Our findings have significant policy implications for sustainable development and water resources, especially for those developing regions susceptible to extreme events such as drought and flood.

Increases in air pollution and other particulate matter in the atmosphere can strongly affect cloud development in ways that reduce precipitation in dry regions or seasons, while increasing rain, snowfall and the intensity of severe storms in wet regions or seasons, says a new study by a University of Maryland-led team of researchers.

The research provides the first clear evidence of how aerosols—soot, dust and other small particles in the atmosphere—can affect weather and climate; and the findings have important implications for the availability, management and use of water resources in regions across the United States and around the world, say the researchers and other scientists.

“Using a 10-year dataset of extensive atmosphere measurements from the U.S. Southern Great Plains research facility in Oklahoma [run by the Department of Energy’s Atmospheric Radiation Measurement program]—we have uncovered, for the first time, the long-term, net impact of aerosols on cloud height and thickness, and the resultant changes in precipitation frequency and intensity,” said Zhanqing Li, a professor of atmospheric and oceanic science at Maryland and lead author of the study.

Read more: Rising Air Pollution Worsens Drought, Flooding, New Study Finds

 

Greenhouse Gas Index Continues to Climb

Scientists at NOAA’s Earth System Research Laboratory prepare the AGGI each year from atmospheric data collected through an international cooperative air sampling network of more than 100 sites around the world.

NOAA’s updated Annual Greenhouse Gas Index, which measures the direct climate influence of many greenhouse gases such as carbon dioxide and methane, shows a continued steady upward trend that began with the Industrial Revolution of the 1880s.

Started in 2004, the AGGI reached 1.29 in 2010. That means the combined heating effect of long-lived greenhouse gases added to the atmosphere by human activities has increased by 29 percent since 1990, the “index” year used as a baseline for comparison. This is slightly higher than the 2009 AGGI, which was 1.27, when the combined heating effect of those additional greenhouse gases was 27 percent higher than in 1990.

“The increasing amounts of long-lived greenhouse gases in our atmosphere indicate that climate change is an issue society will be dealing with for a long time,” said Jim Butler, director of the Global Monitoring Division of NOAA’s Earth System Research Laboratory in Boulder, Colo. “Climate warming has the potential to affect most aspects of society, including water supplies, agriculture, ecosystems and economies. NOAA will continue to monitor these gases into the future to further understand the impacts on our planet.”

Read more: Greenhouse Gas Index Continues to Climb

   

Large Asteroid to Pass by Earth, but What If It Didn’t?

According to NASA, the last time an asteroid this size came close to Earth was in 1976, and the next known approach of such a large asteroid will be in 2028.

An asteroid the size of an aircraft carrier will fly near earth Nov. 8. While there is no danger of it hitting the planet, a Purdue asteroid impact expert says a similar-sized object hitting Earth would result in a 4,000-megaton blast, magnitude 7.0 earthquake and, should it strike in the deep ocean, 70-foot-high tsunami waves 60 miles from the splashdown site.

NASA scientists reported that the asteroid 2005 YU55 will pass between earth and the moon and come within 201,000 miles of Earth on its closest approach.

Jay Melosh, an expert in impact cratering and a distinguished professor of earth and atmospheric sciences, physics, and aerospace engineering at Purdue, said the asteroid’s orbit and trajectory mean there is no chance of an impact.

“What is unique about this asteroid flyby is that we were aware of it well in advance,” Melosh said. “Before about 1980 we wouldn’t know about an asteroid of this size until it was already making a close pass, but now it is unlikely that such an asteroid will approach the Earth without our knowledge.”

NASA’s Near Earth Object, or NEO, program (neo.jpl.nasa.gov/) celebrated a milestone earlier this year by announcing that current search programs have discovered more than 90 percent of near-earth objects more than six-tenths of a mile in diameter. A larger number of smaller objects have yet to be found, however.

Read more: Large Asteroid to Pass by Earth, but What If It Didn’t?

   

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