A wildfire or wildland
fire is a fire in an area of combustible vegetation that occurs in the countryside or rural area.
Depending on the type of vegetation where it occurs, a wildfire can also be
classified more specifically as a brush fire, bush fire, desert
fire, forest fire, grass fire, hill fire, peat fire, vegetation
fire, or veld fire. Fossil charcoal indicates that wildfires began soon
after the appearance of terrestrial plants 420 million years ago.
With the recent increase in temperature, there might be an increase in raging fires says Experts.
Paris (AFP) - Out-of-control wildfires like the ones that
brought destruction to southern Europe, North America and parts of South Africa
in recent weeks will likely become more frequent as global temperatures soar
under climate change, experts say.
More than 10,000 people had to flee raging fires in southern
France this week, and several villages were evacuated in Portugal just weeks
after another blaze killed more than 60 people there.
In South Africa in June, nine people died and some 10,000
people were evacuated from their homes as fires raged through the
drought-stricken Western Cape region, while this month some 40,000 people have
had to flee wildfires in western Canada, where officials declared a state of
emergency.
In California, some 8,000 people were evacuated last week
ahead of fires that razed vast swathes of forest.
-
What causes wildfires? -
Long
periods of heat cause vegetation to become dry and inflammable, easily set
alight by lightning, spontaneous combustion, or fires lit by humans.
The more the mercury climbs, the higher the risk for more,
and more intense, wildfires.
Scientists say the average global temperature has risen by
one degree Celsius (1.8 degrees Fahrenheit) since the Industrial Revolution,
when mankind started emitting heat-trapping greenhouse gases from burning
fossil fuels into the atmosphere.
Most of the world's nations agreed in Paris in 2015 to limit
overall warming to 2 C.
But experts say this will not be enough, and severe
heatwaves and drought will grow worse regardless.
And it is not just heat to blame for fires.
A recent study showed that extreme thunderstorms formed due
to higher temperatures, and were the main driver for massive fires in Alaska
and Canada in recent years. More storms mean more lighting to ignite fires.
-
Are there more fires today? -
According
to Thomas Curt, a researcher at France's Irstea climate and agriculture
research institute, big fires of over 100 hectares, and "megafires"
over 1,000 hectares, have been "a growing problem worldwide and notably in
Mediterranean Europe".
And NASA research shows that fires have increased in Canada
and the American west, as well as in regions of China, India, Brazil and
southern Africa.
-
Why? -
According
to NASA, "a warming and drying climate," was to blame.
"Climate change has increased fire risk in many
regions," according to the space agency.
The UN's World Meteorological Organization (WMO) said last
month that parts of Europe, the Middle East, North Africa and the southwestern
United States experienced extremely high May and June temperatures.
Globally, surface temperatures over land and sea were the
second highest on record for January to May.
Italy, Portugal and most of France had winter rainfall 20-30
percent under the seasonal norm, according to French climatologist Michele
Blanchard.
Almost three-quarters of Portugal, where 75,000 hectares of
forest have burnt since January, has been battling a severe drought since June.
According to the WMO, more than a third of Portuguese
weather stations measured temperatures over 40 degrees Celsius over a weekend
in June when the fires began.
In France, several towns in the south broke June temperature
records.
Large parts of South Africa, meanwhile, experienced an
historic drought and crippling water shortages.
Scientists are loath to ascribe any particular drought,
heatwave, or other weather event to climate change -- a phenomenon that can
only be measured over decades, but note that these events took place within an
overall warming trend.
-
What about the future? -
Climate
change will unlock "more heatwaves... with more evaporation and more
intense drought," said Blanchard.
A 2016 study of the European Commission showed that the
fire-prone surface area of southern Europe could double in the 21st century.
A study published in Nature Climate Change in June said
three-quarters of the global population will be exposed to potentially deadly
heatwaves by 2100 unless greenhouse gas emissions are curbed.
Even with aggressive cuts, it said, nearly half of the
population will be exposed.
According to the authors of another study published by the
same journal in May, fire is the most significant risk to forests, which cover
about a third of global land surface.
And it was clear that "risks caused by fires... will
increase in the context of climate change," they said -- citing
devastating forest blazes in Canada and Russia in recent years.
-
What to do? -
Apart
from long-term efforts to rein in global warming, some forest will have to be
cut back, undergrowth cleared, and residential areas moved further from
scrubland and forest borders, to reduce the risk to life and property.
"The focus... should shift from combating forest fires
as they arise to preventing them from existing, through responsible long-term
forest management," says green group WWF.
(source: yahoo)
No comments:
Post a Comment