Wildfire season spreading

July 14, 2015
Smoke billows from burnt trees in the Valle de las Cinco Villas, in Asin near Zaragoza on July 5, 2015
Smoke billows from burnt trees in the Valle de las Cinco Villas, in Asin near Zaragoza on July 5, 2015

The wildfire season globally has lengthened by almost 20 percent in 35 years as the average temperature has risen, a climate change study said Tuesday.

"Fire weather seasons have lengthened across 29.6 million square kilometres (11.4 million square miles) of the Earth's vegetated surface," said a paper in the journal Nature Communications.

This resulted in a 18.7-percent increase in season length overall.

"We have shown that combined surface weather changes over the last three-and-a-half decades have promoted global wildfire weather season lengthening," said a team of scientists in the United States and Australia—two countries particularly affected by wildfires.

The researchers used climate data and three indices of fire danger, to produce an overview of fire season length from 1979 to 2013.

Weather is the largest driver of fire risk—temperature, humidity, rainfall and wind speed all influence the frequency and intensity of wildfires. These factors, in turn, are all affected by a changing climate.

Wildfires play a crucial role in clearing forests, improving grazing and boosting new plant growth, but also pose a threat to human life and property, and nature.

About 350 million hectares are burnt every year, said the report. Fighting wildfires cost the United States about $1.7 billion (1.5 billion euros) per year over the past decade, and Canada about $1 billion.

Total wildfire costs in Australia in 2005 were estimated at nearly $9.4 billion, or 1.3 percent of , said the report.

Over the study period, the global land area with "unusually" hot years increased by 6.3 percent per decade, said the team.

"Fire weather season length and long weather season affected area significantly increased across all vegetated continents except Australia," they reported.

And they warned: "If these trends continue, increased wildfire potential may have pronounced global socio-economic, ecological and climate system impacts."

In a separate study in the same journal, scientists said nearly two-thirds of the ocean has experienced an increasing impact from human activities in the five years from 2008 to 2013.

The change, they said, was driven mainly by pressures like anomalies in , ocean acidification and ultraviolet radiation—more even than fishing or pollution.

Explore further: Image: Canadian wildfires continue and increase

More information: Nature Communications, DOI: 10.1038/ncomms8537

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5 comments

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Earthman
2.3 / 5 (3) Jul 15, 2015
Nothing to do with AGW/CC. Nothing to see here. Move along.
gkam
2.3 / 5 (3) Jul 15, 2015
How can we have more fires? The goobers tell me it is getting cooler, not warmer.
Abel Adamski
3.7 / 5 (3) Jul 15, 2015
Earthman, dream on
When you guys are telling us the earth hasn't warmed and we are cooling, please explain the heat in the Arctic circle and the Pacific and Indian oceans, the droughts in South America, the caribbean, the US, in Asia etc.
Permanent land ice loss, melting permafrost and all happening up to 25 times faster than any period in the geological record going back millions of years.

Please explain I would really love to know the reasons and the Natural mechanisms
Must be the faries
Abel Adamski
3.7 / 5 (3) Jul 15, 2015
gkam,
Wait just a while, a year or so. So far record hot year globally.

Global Cooling, a reprise of the first time around in the 70's, media hype and distortion.
Maybe read what the rest of the science community has to say.
Full Solar minimum delivering cooling effect of approx 0.5C, compared with by then a warming CO2e of approx 4C, no contest
gkam
2.3 / 5 (3) Jul 15, 2015
Abel, Earthman was being sarcastic.

Me, too.

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