Volcanic activity may cool global temperatures

Planet Earth has certainly become more active in recent weeks, with an increasing number of earthquakes, including the 7.9-magnitude quake that hit western China Monday, leaving large numbers of casualties in Sichuan province.

Last week, there were major eruptions of the long-dormant Chaiten volcano in southern Chile. For the first time in 9,370 years, Chaiten blasted huge amounts of ash some 20 miles in the upper stratosphere at elevations approaching 110,000 feet.

The last volcanic eruption similar to the one in southern Chile was Mount Pinatubo’s eruption in the Philippines in June 1991. Shortly after that massive explosion, global temperatures quickly cooled about a degree Fahrenheit. However, the Earth’s temperature rebounded later in 1992 and 1993, as the dust and ash dissipated.

With large amounts of dust from Chaiten now in the stratosphere, we should see some additional cooling in the next several months, particularly in the Southern Hemisphere.

If there are other massive volcanic eruptions in the near future, perhaps in the Philippines or Indonesia, the average global temperature may drop by as much as 2 or 3 degrees in a short period of time.

As for local weather, very warm temperatures are finally arriving across the Inland Northwest, bringing the possibility of flooding as the higher-than-average snowpack melts. Up to 12 feet of the snow is still being reported in the higher elevations, especially in North Idaho.

Cool temperatures that have helped snowpacks linger have also put a damper on thunderstorm activity. This has been enhanced by La Nina, the cooler-than-normal sea-surface temperature event that continues to hold on in the waters of the south-central Pacific.

The very warm weather late this week will be caused by a strong ridge of high pressure occurring over our region. The high-pressure system should weaken by early next week, bringing a return of the former stormy weather patterns that have plagued our region, including the possibility of several strong thunderstorms with lightning, heavy downpours, damaging winds and pea-size hail.

The rain, combined with snowpack runoff, would increase the likelihood of more flooding, especially in the lowland areas near the rivers and streams.

I still envision a great weather for the summer ahead. More on that next week.