Wildfires are sweeping B.C. Close to 900 have burned through 600,000 hectares so far this year, blanketing western North America with smoke. Fighting them has cost more than $230 million B次元官网网址� and the season is far from over.
ItB次元官网网址檚 not just B.C. Thousands of people from B.C. to California have fled homes as fires rage. Greenland is experiencing the largest blaze ever recorded, one that Prof. Stef Lhermitte of Delft University in the Netherlands called B次元官网网址渁 rare and unusual event.B次元官网网址� Fires have spread throughout Europe, North America and elsewhere. In June, dozens of people died in whatB次元官网网址檚 being called PortugalB次元官网网址檚 worst fire ever. Meanwhile, from Saskatchewan to Vietnam to New Zealand, floods have brought landslides, death and destruction.
What will it take to wake us up to the need to address climate change? Fires and floods have always been here, and are often natureB次元官网网址檚 way of renewing ecosystems B次元官网网址� but as the world warms, theyB次元官网网址檙e increasing in frequency, size and severity. Experts warn wildfires could double in number in the near future, with the Pacific Northwest seeing five or six times as many. In the western U.S., annual average temperatures have increased by 2 C and the fire season has grown by three months since the 1970s, leading to B次元官网网址渘ew era of western wildfires,B次元官网网址� according to a recent study led by University of Colorado Boulder wildfire experts, published in Proceedings of the National Academy of Sciences.
Climate change doesnB次元官网网址檛 necessarily start the fires B次元官网网址� lightning, unattended campfires, carelessly tossed cigarette butts and sparks from machinery are major causes B次元官网网址� but it creates conditions for more and larger fires. Lightning, which causes up to 35 per cent of CanadaB次元官网网址檚 wildfires and is responsible for 85 per cent of the area burned annually, increases as temperatures rise, with studies showing 12 per cent more lightning strikes for each degree Celsius of warming. Drier, shorter winters and earlier snowmelt extend fire seasons. As the atmosphere warms, it holds more moisture, some of which it draws from forests and wetlands, and increasing precipitation is not enough to offset the drying. This means fuel sources ignite more easily and fires spread faster over greater areas. Outbreaks of pests such as mountain pine beetles B次元官网网址� previously kept in check by longer, colder winters B次元官网网址� have also killed and dried forests, adding fuel to the fires. Because trees and soils hold moisture on slopes, fires can also increase the risk of flash floods when rains finally arrive.
The human and economic impacts are staggering B次元官网网址� from property destruction to firefighting and prevention to loss of valuable resources and ecosystems. As human populations expand further into wild areas, damages and costs are increasing.
Health impacts from smoke put people B次元官网网址� especially children and the elderly B次元官网网址� at risk and drive health care costs up. Wildfires now kill more than 340,000 people a year, mainly from smoke inhalation. Fires also emit CO2, creating feedback loops and exacerbating climate change. Boreal forests in Canada and Russia store large amounts of carbon and help regulate the climate, but theyB次元官网网址檙e especially vulnerable to wildfires.
Suggested solutions are wide-ranging. The authors of the PNAS study recommend letting some wildfires burn in areas uninhabited by people, setting more B次元官网网址渃ontrolledB次元官网网址� fires to reduce undergrowth fuels and create barriers, thinning dense forests, discouraging development in fire-prone areas and strengthening building codes.
These adaptive measures are important, as are methods to prevent people from sparking fires, but our primary focus should be on doing all we can to slow global warming.
According to NASA, EarthB次元官网网址檚 average surface temperature has risen by 1.1 C since the late 19th century, with most warming occurring over the past 35 years, and 16 of the 17 warmest years occurring since 2001. Eight months of 2016 were the warmest on record. Oceans have also been warming and acidifying quickly, Arctic ice has rapidly decreased in extent and thickness, glaciers are retreating worldwide, and sea levels have been rising at an accelerating pace.
Record high temperature events have been increasing while low temperature events have decreased, and extreme weather events are becoming more common in many areas.
TodayB次元官网网址檚 wildfires are a wake-up call. If we are serious about our Paris Agreement commitments, we canB次元官网网址檛 build more pipelines, expand oil sands, continue fracking or exploit extreme Arctic and deep-sea oil.
David Suzuki is a scientist, broadcaster, author and co-founder of the David Suzuki Foundation. Written with contributions from David Suzuki Foundation Senior Editor Ian Hanington.
