Extreme Weather Events

Five myths about extreme weather

It feels hot for a reason, and not just in the United States. Last month’s global average land surface temperature was the fourth warmest on record. And July is doing its best to outdo June. According to the National Oceanic and Atmospheric Administration, 49 states — all except Delaware — have had record highs in the past three weeks. In Washington, a heat wave sweeping the East Coast is pushing temperatures into triple digits.

However, while suffering Washingtonians might be forgiven for regarding this summer as an aberration, they would be wrong. Globally, June was the 316th month in a row that had a higher temperature than the 20th century average. So, while it is indeed much hotter than it used to be, we may be witnessing a new normal in heat and other extreme weather. This month’s temperature records may not stand for long.

“Hundred year” weather events happen only once every 100 years.

Hundred-year weather events no longer live up to their name. In 2005, for instance, a devastating “once a century” drought hit the Amazon, only to be followed by another in 2010. Globally, previously rare weather events have been occurring with startling frequency. Consider the massive floods that inundated a fifth of Pakistan last year and submerged eastern Australia and America’s heartland this year. It’s time for meteorologists to come up with a new, more accurate term.

Of course, what scientists actually mean by “one in 100 years” is not that a major flood, drought or hurricane will strike a given place only once a century, but rather that there is a 1 percentchance of such an event in any given year. Either way, the fact that what were once considered hundred-year events seem to be happening more often is consistent with climate models projecting that rising global average temperatures will lead to more frequent and severe extreme weather .

Extreme droughts and extreme floods can’t both be due to climate change.

It seems counterintuitive that climate change could be responsible for both withering droughts and devastating floods. Yet it can. Scientists have found that climate change can trigger periods of intense rainfall followed by long spells of dry weather. This combination of severe rainstorms and droughts, in turn, can lead to more flooding, landslides, soil erosion and other disasters. There are signs in some places that this may already be underway.

Connecting the dots of extreme weather « GCC News Brief

I took a cross-country road trip in late June that became a race to outrun the triple-digit heat waves that have literally buckled highways between the Midwest and the East Coast.

Janet Redman

The record-breaking scorcher was an apt send-off. As I weaved my way across the United States, I found the consequences of extreme weather everywhere I looked.

After the heat, the first sign of something unusual came in Iowa. There, every creek I crossed seemed to overflow its banks. Water pooled in cornfields.

By the time I reached Nebraska, radio advisories warning about bridges closed due to swollen waterways seemed routine.

Late one night, I pulled under an overpass between Sydney and Potter, Nebraska to find refuge from hail big enough that it cracked my windshield. There, I met an off-duty police officer who said he’s spending more and more time cleaning up after an increasing number of tornados and micro-bursts like the one we were trapped in.

Meanwhile, the drought-wracked southwest was blazing. New Mexico was experiencing the largest wildfire in state history, and an all-out battle was being waged by firefighters to steer the flames away from Los Alamos National Laboratory, where radioactive material for making nuclear weapons is housed. Now the concern is contaminated soil being washed into the Rio Grande by flash floods in deforested canyons. Fires in New Mexico, Arizona, Texas, Florida, Georgia, and Colorado are adding up to a record-setting wildfire season.

This year’s waves of floods and fires followed the unprecedented series of tornados that hammered towns in Missouri, Alabama, Kansas, Arkansas, Minnesota and Massachusetts.

Talking about the weather isn’t small talk any more. Something is amiss.

But for some reason we’re loathe to take the next step and connect the dots of extreme floods, heat waves, droughts and storms popping up across the map to reveal the bigger picture: climate change.

For years, scientists have told us that as the planet warms up, we can expect changes in whole patterns of weather and in trends like how much moisture the atmosphere will hold. Some places will get dryer, others wetter and others hotter. In its 2010 State of the Climate report, the National Oceanic and Atmospheric Administration traced some 41 indicators showing that broad shifts and individual extreme events that have occurred over the past year are indeed consistent with scientists’ predictions of a warmer world.

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