weather events

The Pacific Northwest Heatwave | Earth Wise

August 18, 2021 By EarthWise Leave a Comment

The late-June heatwave in the Pacific Northwest shattered temperature records in dozens of locations. Cities like Portland and Seattle saw historic high temperatures and one town in British Columbia saw temperatures hotter than ever recorded in Las Vegas.

An international team of weather and climate experts analyzed this extreme weather event and came to a preliminary conclusion that it was a 1-in-1000-year event in today’s climate. “Today’s climate” means the already warmer conditions that the world is experiencing as a result of the changing climate.

If that analysis is accurate, then such an extreme temperature event would have been at least 150 times rarer in the era before global warming. In other words, they concluded that it would have been a 1-in-150,000-year event, which means that it would have been virtually impossible in pre-industrial times.

Given that they estimated that the extreme temperatures were a 1-in-1000-year event at this point, it would follow that such events are not about to become commonplace any time soon. On the face of it, that is somewhat comforting to hear.

However, all of this assumes that global warming will not radically change the statistical distribution of global temperatures. If that assumption fails to hold, then all bets are off. Perhaps temperatures like those experienced in the Pacific Northwest might be a 1-in-50-year event, for example, but we just don’t realize it yet. Follow-up studies will be looking for evidence of significant changes in the distribution of weather events. For now, a 1-in-1000-year event means there is only a 0.1% chance of occurring in a given year. That’s good news for the residents of that region.

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Preliminary analysis concludes Pacific Northwest heat wave was a 1,000-year event…hopefully

Photo, posted June 4, 2016, courtesy of Jody Claborn via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Expensive And Dangerous Storms | Earth Wise

August 7, 2020 By EarthWise Leave a Comment

Severe storms are getting more and more common. Early in July, the United States experienced its 10th billion-dollar weather disaster of the year – the earliest this has happened. It also marks 2020 as the sixth consecutive year with at least 10 such extreme weather events, which is also a record. With the country struggling with the effects of a global pandemic, extreme weather is pretty much the last thing we need.

This year’s 10 storms have primarily consisted of tornadoes, damaging winds, and hail. Seven out of the 10 storms were in the South or Southeast. An Easter Sunday outbreak in that region saw 190 tornadoes and 36 people were killed that day.

Since 1980, the US has averaged nearly 7 billion-dollar weather disasters per year. But the last five years have seen nearly 14 severe storms on average. The way things are going this year, there will probably be more than that number.

This year’s growing total does not include the looming hurricane season, which is widely predicted to be more active than usual. Because so many places in the South are still recovering from earlier disasters, they are particularly vulnerable to the effects of an active hurricane season.

Meanwhile, much of the country is suffering from drought conditions, making wildfires a major concern. Recent years have seen deadly and destructive wildfires in many places, notably in California two years ago. Between hurricanes and wildfires, the prospects are alarming for what could turn out to be a disastrous year for expensive and dangerous severe weather.

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US hits 10th billion-dollar weather disaster of the year — at a record pace

Photo, posted March 3, 2020, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Rising Threat Of Rising Seas | Earth Wise

February 3, 2020 By EarthWise Leave a Comment

Global sea level rose by about 6 inches during the 20th century. It is currently rising more than twice as fast and accelerating. The rate of rise was 2.5 times faster from 2006 to 2016 than it was for nearly all of the 20th century.

Sea level rise occurs when glaciers and ice sheets lose mass. Much of that meltwater comes from Greenland and Antarctica. But levels also rise because, as water warms, it expands. Added to that are the effects of human activities such as groundwater depletion and a geological phenomenon called isostatic adjustment that is going on in parts of the East Coast where the land is actually sinking.

In Atlantic Canada, sea level rise is outpacing the global average and has already led to boardwalks swamped by swelling tides, drowned forests, submerged wharfs, and threatened historic shoreline buildings.

Recent research suggests that globally, land now occupied by 300 million people could be affected by floods at least once a year by 2050 unless carbon emissions are significantly reduced, and coastal defenses strengthened. (This new figure is more than three times higher than earlier estimates).

Researchers at Dalhousie University in Nova Scotia are studying nature-based strategies for mitigating the effects of the rising seas. These include conserving or restoring coastal ecosystems like dunes, wetlands, and reefs which could provide protection at a lower cost than building seawalls and other man-made obstacles. Wetlands, for example, can reduce the force of waves and act as obstacles to storm surges, while also trapping sediment and stemming erosion. Wetlands also serve as important carbon stores, but it is estimated that roughly half of the world’s coastal wetlands have been lost over the past 100 years to human activity and extreme weather events.

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The Looming Threat of Rising Sea Levels – And What We Can Do About it

Photo, posted February 14, 2015, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.