Small Volcanic Eruptions Slow Global Warming

[Buster's Uncle]

Small Volcanic Eruptions Slow Global Warming
LiveScience.com
By Becky Oskin  2 hours ago



Sarychev Peak erupts in Russia's Kuril Islands.



Small volcanic eruptions account for part of the global warming slowdown since 2000, a new study suggests.

Until now, the climate impacts of small volcanic blasts were overlooked because their planet-cooling particles cluster below the reach of satellites, scientists reported Oct. 31 in the journal Geophysical Research Letters. It turns out, satellites were missing about 30 percent of these particles, called aerosols, the study found.

Volcanoes blast sulfur dioxide aerosols into the stratosphere, where they cool Earth by blocking some of the sun's solar radiation and reflecting it back into space. The stratosphere is the second layer of Earth's atmosphere, above the one in which humans live (the troposphere). Near the tropical latitudes, these layers meet about 9 miles (15 kilometers) above the Earth's surface. Closer to the polar regions, the boundary drops to about 6 miles (10 km), said lead study author David Ridley, an atmospheric scientist at MIT.

Water clouds befuddle aerosol-monitoring satellites below about 9 miles above Earth's surface, so any aerosols in low, polar stratosphere were potentially missing, Ridley said. In the new study, Ridley and his co-authors checked aerosol concentrations in the high latitudes more directly, with instruments lofted on balloons and lasers that scan particles from the ground. The research reveals that about 30 percent of the planet's stratospheric aerosol particles reside where the stratosphere dips lower, 6 to 9 miles above the surface.

"About one-third of the aerosols have been missed," Ridley told Live Science. The global aerosol total, plugged into a simple climate model, translates into a cooling impact of between 0.09 and 0.22 degrees Fahrenheit (0.05 to 0.12 degrees Celsius) since 2000. That's less than the slowdown in global warming, but researchers think several factors are responsible for the tardy temperature rise. "This is part of the larger puzzle everyone's been working on," Ridley said.

The so-called "global warming pause" is one of many terms for surface temperatures rising more slowly in recent decades than in the past, despite greenhouse gas emissions continuing to grow.

Ridley and his colleagues also tracked the source of aerosols in the lower stratosphere from volcanic eruptions during the 2000s. The eruptions were significantly smaller than 1991's massive Mount Pinatubo outburst in the Philippines, which had a noticeable cooling effect on the global climate.

The results indicate that many small eruptions do pump aerosols into the stratosphere, especially high-latitude volcanoes. For instance, when Sarychev Peak in the Kuril Islands erupted in 2009, almost all of its sulfur dioxide aerosols reached the lower stratosphere, the study reports. (The low altitude of the stratosphere was a factor.)

"This doesn't necessarily mean that every eruption will be able to get sulfur dioxide into the stratosphere and form aerosols, but they are just neglected entirely in the climate models from the [Intergovernmental Panel on Climate Change]," Ridley said. "The fine nuances make quite a big difference in these eruptions."


http://news.yahoo.com/small-volcanic-eruptions-slow-global-warming-132458933.html

[Buster's Uncle]

2014 Will Be Earth's Hottest Year on Record, Despite US Cold
LiveScience.com
By Becky Oskin  2 hours ago



October global temperatures.



Wintry storms could bury Buffalo, New York, under heaps of snow until Christmas, but 2014 will still be the hottest year on Earth since 1880, climate scientists said today (Nov. 20).

"It's becoming pretty clear that 2014 will end up the warmest year on record," said Deke Arndt, chief of the climate monitoring branch at the National Climate Data Center. "The remaining question is, by how much."

The eastern United States was one of Earth's cold zones this year, with temperatures running 2.7 degrees Fahrenheit (1.5 degrees Celsius) below average, scientists from the National Oceanic and Atmospheric Administration (NOAA) said today during the agency's monthly climate briefing. But the bitter cold couldn't offset record-breaking heat waves in California, Europe and Australia this year, nor the incredible warmth in the world's oceans.

"Notably, every major ocean basin and every continent all had some pieces — and some had significant pieces of their area — that were the warmest on record [during 2014]," Arndt said. "It's virtually certain that California will have its warmest year on record, even if California has record cold in December."

October was the sixth straight month of chart-busting heat in the oceans, according to NOAA. Last month was also the hottest October on record for land temperatures.

Combining land and sea temperatures, the average worldwide temperature of 58.43 F (14.74 C) for October 2014 topped the previous high set in October 2003 by 0.02 F (0.01 C). November 2013 through November 2014 is now the warmest 12-month stretch on record for any 12-month period recorded since 1880, NOAA said.

With less than two months left in 2014, the planet is on track to beat the warmest years in the historical record. So far this year, worldwide temperatures are averaging 58.62 F (14.78 C). The entire planet would have to go through a cold snap for 2014 to miss finishing in the top 10. (And it may feel that way for people in eastern North America and eastern Russia, where heavy snows arrived early this year.)

Two giant pools of warmer-than-average water in the Pacific Ocean helped boost global temperatures in 2014, NOAA scientists said. One pool is sloshing around the eastern Pacific along the equator, and is related to the El Niño climate pattern that is struggling to develop. The other pool is a large mass of warm water stretching from Alaska to California. These warm, West Coast waters suggest that a decades-long natural climate pattern called the Pacific Decadal Oscillation (PDC) has flipped into its positive phase, said NOAA forecaster David Unger. The PDO influences weather in North America by shifting the jet stream and changing where rain and snow fall, similar to El Niño's worldwide effects.

Sea surface temperatures in the northern Pacific Ocean haven't been this warm in 10 years, Unger said. "Whether it will stay this way, only time will tell," he said. The PDO has generally been in a negative, or cold phase, since 1998, scientists think.


http://news.yahoo.com/2014-earths-hottest-record-despite-us-cold-132326311.html

[Geo]

It's like they're saying small volcanic eruptions didn't contribute to this slowdown before the year 2000.