12th October 2016
Climate change has doubled western US forest fires
A study by the Earth Institute at Columbia University finds that wildfires in the western US have doubled in area over the last 30 years due to climate change.
In July and August, the Roaring Lion wildfire devoured more than 8,000 acres of forest, along with over 60 homes and outbuildings in eastern Montana's Bitterroot Range. Here, the fire burns through dense conifers, 31st July 2016. Credit: Mike Daniels.
A new study concludes that human-induced climate change has doubled the area affected by forest fires in the western U.S. over the last 30 years. According to the study, since 1984 heightened temperatures and resulting aridity have caused fires to spread across an additional 16,000 square miles than they otherwise would have – an area larger than the states of Massachusetts and Connecticut combined. The authors warn that further warming will increase fire exponentially in coming decades. The study appears today in the peer-reviewed journal Proceedings of the National Academy of Sciences.
"No matter how hard we try, the fires are going to keep getting bigger, and the reason is really clear," said Park Williams, co-author and bioclimatologist at Columbia University's Lamont-Doherty Earth Observatory. "Climate is really running the show in terms of what burns. We should be getting ready for bigger fire years than those familiar to previous generations."
Fires in western forests began increasing abruptly in the 1980s, as measured by area burned, the number of large fires, and length of the fire season. Those increases have since continued, and recently scientists and public officials have in part blamed human-influenced climate change. The new study is perhaps the first to quantify that assertion.
"A lot of people are throwing around the words climate change and fire – specifically, last year fire chiefs and the governor of California started calling this the 'new normal,' " said lead author John Abatzoglou, a professor of geography at the University of Idaho. "We wanted to put some numbers on it."
Warmth drives fire by drying out the land. Warmer air holds more moisture, and the air sucks it out of plants, trees, and dead vegetation on the ground, as well as soil. Average temperatures in forested parts of the U.S. West have increased by 1.4°C (2.5°F) since 1970, and are expected to continue rising in the future. The resultant drying effect is evident in the expansion of fires. Williams published a study last year showing how climate-driven removal of moisture from land worsened the recent California drought, which was accompanied by widespread fires.
Satellite image of wildfires in California, August 2015. Credit: NASA/Goddard/Jeff Schmaltz/MODIS Rapid Response Team/Lynn Jenner
The overall increase in fire since the 1980s is about twice what the researchers attribute to climate change; the rest is due to other factors, they say. One has been a long-term natural climate oscillation over the Pacific Ocean, which has steered storms away from the western United States. Another is firefighting itself. By constantly putting out fires, authorities have allowed areas they "saved" to build up more dry fuel, which later ignites, causing ever more catastrophic blazes. The costs of firefighting have risen sharply in step – last year, the federal government alone spent more than $2.1 billion. "We're seeing the consequence of very successful fire suppression, except now it's not that successful anymore," said Abatzoglou.
The authors teased out the effects of climate warming from other factors by looking at eight different systems for rating forest aridity; these included the Palmer Drought Severity Index, the MacArthur Forest Fire Danger Index and the Canadian Forest Fire Danger Rating System. They then compared such measurements with observations of actual fires and large-scale climate models that estimate man-made warming. The crunched data showed that 55% of the increase in fuel aridity expected to lead to fires could be attributed to human-influenced climate change. Climate's role in increasing such aridity has grown since 2000 and will continue to do so, the researchers say. Previous studies have tried to understand the effects of climate on wildfires in parts of Canada, but nothing has been done for the United States on this scale, until now.
Globally, wildfires of all kinds have been increasing, often with a suspected climate connection. A huge fire that levelled part of Fort McMurray, Alberta, this May (see video below) is thought to have been the result of a warming trend that is drying out the northern forests. Fires are even spreading beyond, into the tundra, in places where blazes have not been seen for thousands of years.
The effects go beyond loss of trees and other vegetation. A 2012 study estimates that smoke from fires worldwide causes long-term health effects that kill some 340,000 people each year. Carbon released to the air adds to the burden of greenhouse gases already there, producing even more warming. Soot settling on snow and ice causes them to absorb more heat and melt faster.
Williams believes that ultimately, so many western forests will have burned, they will become too fragmented for fires to spread easily, and the growth in wildfires will cease. But, he explains, "There's no hint we're even getting close to that yet. I'd expect increases to proceed exponentially for at least the next few decades." In the meantime, he says, "It means getting out of fire's way. I'd definitely be worried about living in a forested area with only one road in and one road out."
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14th September 2016
A tenth of the world's wilderness lost since the 1990s
A tenth of the world's wilderness is reported to have disappeared in the last 20 years – an area twice the size of Alaska – with the Amazon and Central Africa being the hardest hit regions. If trends continue, there will be few areas of wilderness left untouched by human activity by 2050.
Scientists in the latest issue of Current Biology have reported catastrophic declines in wilderness areas around the planet over the last two decades. Their study describes alarming losses comprising one-tenth of global wilderness since the 1990s – an area twice the size of Alaska and half the size of the Amazon. Their findings underscore an immediate need for international policies to recognise the value of wilderness areas and to address the unprecedented threats they will face in the future, the researchers say.
"Globally important wilderness areas – despite being strongholds for endangered biodiversity, for buffering and regulating local climates, and for supporting many of the world's most politically and economically marginalised communities – are completely ignored in environmental policy," says Dr James Watson of the University of Queensland in Australia, and Wildlife Conservation Society in New York. "Without any policies to protect these areas, they are falling victim to widespread development. We probably have one to two decades to turn this around. International policy mechanisms must recognise the actions needed to maintain wilderness areas before it is too late."
Watson says much policy attention has been paid to loss of species, but comparatively little is known about larger-scale losses of entire ecosystems, especially wilderness areas which tend to be relatively understudied. To fill that gap, he and his colleagues mapped wilderness areas around the globe, with "wilderness" being defined as biologically and ecologically intact landscapes free of any significant human disturbance. The researchers then compared their current map of wilderness to one produced by the same methods in the early 1990s.
Credit: Watson et al.
This comparison showed that a total of 30.1 million km² (around 23% of the world's total land area) now remains as wilderness, with the majority being located in North America, North Asia, North Africa, and the Australian continent. However, comparisons between the two maps show that an estimated 3.3 million km² (almost 10%) of wilderness area has been lost in the intervening years. Those losses have occurred mostly in South America, which has experienced a 30% decline in wilderness, and Africa, which has experienced a 14% loss.
"The amount of wilderness loss in just two decades is staggering" says Dr Oscar Venter of the University of Northern British Colombia. "We need to recognise that wilderness areas, which we've foolishly considered to be de facto protected due to their remoteness, are actually being dramatically lost around the world. Without proactive global interventions, we could lose the last jewels in nature's crown. You cannot restore wilderness once it is gone, and the ecological processes that underpin these ecosystems are gone, and it never comes back to the state it was. The only option is to proactively protect what is left."
The UN and others have ignored globally significant wilderness areas in key multilateral environmental agreements, says Watson, and this must change: "If we don't act soon, there will only be tiny remnants of wilderness around the planet, and this is a disaster for conservation, for climate change, and for some of the most vulnerable human communities on the planet. We have a duty to act for our children and their children."
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6th September 2016
Latest update of threatened species list brings good and bad news
The IUCN has removed the giant panda from its endangered species list, but added the eastern gorilla to its critically endangered list.
Left: Giant Panda (by leungchopan). Right: Eastern Gorilla (by Fiver Löcker, CC BY-SA 2.0)
The World Conservation Congress, which convenes every four years, is currently being held in Hawaii, USA. The International Union for Conservation of Nature and Natural Resources (IUCN), which organises the meetings, has just released an update to its "Red List" of species threatened with extinction. This brings some good news, but also a number of worrying developments.
On the plus side, the Giant Panda (Ailuropoda melanoleuca) has now been moved from "Endangered" to "Vulnerable", following decades of efforts to protect and restore the forests on which the animals depend. Their increased population and improved status confirms that the Chinese government's policies are effective. However, climate change is predicted to eliminate more than 35% of the Panda's bamboo habitat later this century and could therefore reverse the gains made since the 1990s.
To protect this iconic species, the IUCN emphasises it is critical that the effective forest protection measures are continued and that newly emerging threats are fully addressed. The Chinese government is planning to expand its existing conservation policy for the species, which the IUCN says must be strongly supported to ensure its effective implementation.
From left to right: Extinct (EX), Extinct in the wild (EW), Critically endangered (CR), Endangered (EN), Vulnerable (VU), Near threatened (NT), Least concern (LC).
Graphic credit: Peter Halasz
Although the news is encouraging for giant pandas, other species are facing much greater challenges. The Eastern Gorilla – the largest living primate – has been moved from "Endangered" to "Critically Endangered" due to a devastating population decline of more than 70% in 20 years. Its population is now thought to be fewer than 5,000.
Grauer's Gorilla (G. b. graueri), one of the two subspecies, has lost 77% of its population since 1994, declining from 16,900 individuals to only 3,800. Killing or capture of great apes is illegal; yet hunting represents the greatest threat to Grauer's Gorillas. The second of the species, the Mountain Gorilla (G. b. beringei), has been faring better, increasing in number to around 880 individuals.
Four of the six great apes – the Eastern Gorilla, Western Gorilla, Bornean Orangutan and Sumatran Orangutan – are now listed as Critically Endangered, whilst the Chimpanzee and Bonobo are listed as Endangered.
"To see the Eastern Gorilla – one of our closest cousins – slide towards extinction is truly distressing," said Inger Andersen, the IUCN Director General. "We live in a time of tremendous change and each IUCN Red List update makes us realise just how quickly the global extinction crisis is escalating. Conservation action does work and we have increasing evidence of it. It is our responsibility to enhance our efforts to turn the tide and protect the future of our planet."
Habitat ranges of the eastern gorilla (left) and the giant panda (right). Credit: IUCN, species assessors and the authors of the spatial data. [CC BY-SA 3.0]
The latest Red List includes almost 83,000 species of animals and plants, of which nearly 24,000 are threatened with extinction. The IUCN, its Species Survival Commission and nine partner institutions will jointly commit more than US$10 million, as part of an ambitious strategic plan that aims to double the number of species assessed on the Red List by the year 2020.
"The world is changing fast and dramatically," said Dr M Sanjayan, senior scientist from Conservation International. "Now more than ever, amid the updates to the Red List, it's crucial to identify and track the elements of nature that need protection the most. Monitoring the diversity of life is a fundamental part of all our efforts to understand the changes happening on our planet and focusing our conservation efforts so that people and nature can thrive."
"Illegal hunting and habitat loss are still major threats driving many mammal species towards extinction," said Carlo Rondinini, Coordinator of the mammal assessment at Sapienza University of Rome. "We have now reassessed nearly half of all mammals. While there are some successes to celebrate, this new data must act as a beacon to guide the conservation of those species which continue to be under threat."
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