Biodiversity

New study shows that window of opportunity is fast closing for humanity to save planet’s ability to support life on Earth as we’ve known it

The study is the most comprehensive look yet at the impact of climate change on biodiversity loss, analysing 131 existing studies on the subject. The stresses on wildlife and their habitats from global warming is in addition to pressures such as deforestation, pollution and overfishing that have already seen the world lose half its animals in the past 40 years. (Photo: Pinterest)

by Jon Queally, Common Dreams

One in six of all animal and plant species on Earth could become extinct from impacts related to climate change if human society does not dramatically reduce its emission of greenhouse gases, according to new research published in the journal Science on Thursday.

Conducted as a meta-analysis of existing research done on the possible impact of climate change on species loss, the new study—titled Accelerating Extinction Risk From Climate Change—found that the range of predicted loss went from no species loss at all (0%) to as much as 54% in extreme scenarios, but that a synthesis of the existing data and new modeling offered a clearer view of what the future may hold.

Mark Urban, professor of ecology at the University of Connecticut and lead author of the new study, says its most worrying findings are not set in stone but should come as a warning to humanity and world leaders that action on climate must come soon if the planet is to maintain its existing biodiversity and ability to support life. Though its conclusions are considered “predictive” and based on various models of what the future may look like, the study warns that as warming continues to increase in the coming decades the rate of extinctions could accelrate rapidly.

“We have the choice,” Urban told the New York Times in an interview. “The world can decide where on that curve they want the future Earth to be.”

And as Urban writes in the study:

In 1981, [NASA’s Dr. James] Hansen and colleagues predicted that the signal of global climate change would soon emerge from the stochastic noise of weather (26). Thirty years later, we are reaching a similar threshold for the effects of climate change on biodiversity. Extinction risks from climate change are expected not only to increase but to accelerate for every degree rise in global temperatures. The signal of climate change–induced extinctions will become increasingly apparent if we do not act now to limit future climate change.

As the Guardian reports:

The study is the most comprehensive look yet at the impact of climate change on biodiversity loss, analysing 131 existing studies on the subject. The stresses on wildlife and their habitats from global warming is in addition to pressures such as deforestation, pollution and overfishing that have already seen the world lose half its animals in the past 40 years. […]

The study also emphasises that even for the animals and plants that avoid extinction, climate change could bring about substantial changes in their numbers and distribution.

Jamie Carr at the climate unit of the International Union for Conservation of Nature, which compiles the most authoritative list of endangered species worldwide, said: “The loss of one in six species, would be an absolute tragedy, not only because it is sad to lose any part of our rich natural world, but also because biodiversity is fundamental in providing important functions and services, including to humans.

“Such significant changes to biological systems would undoubtedly have knock-on effects, and could potentially result in the collapse of entire systems.”

Even as the study arrived at its “dire” 16 percent extinction rate by assessing available research, Professor John J. Wiens, an evolutionary biologist at the University of Arizona, was among experts who told the Times the reality could end up much worse. According to Wiens, the number of extinctions “may well be two to three times higher.”

As the Times notes:

Dr. Urban found that the rate of extinctions would not increase steadily, but would accelerate if temperatures rose.

Richard Pearson, a biogeographer at University College London, called the new meta-analysis “an important line in the sand that tells us we know enough to see climate change as a major threat to biodiversity and ecosystems.”

But he said that Dr. Urban was likely underestimating the scale of extinctions. The latest generation of climate extinction models are more accurate, Dr. Pearson said: sadly, they also produce more dire estimates.

For his part, Urban seemed most interesting in making sure his research added to that of the broader scientific community which has called on government leaders to do act on climate. As he told the Guardian, “This isn’t just doom and gloom. We still have time. Extinctions can take a long time. There are processes that could be important in mediating these effects, for example evolution, but we really need to very quickly start to understand these risks in a much more sophisticated way.”

But ‘proactive intervention’ could still avert marine disaster, researchers find

“Although defaunation has been less severe in the oceans than on land, our effects on marine animals are increasing in pace and impact,” the researchers write. (Photo: Phil’s 1stPix/flickr/cc)

by Deirdre Fulton, Common Dreams

Marine wildlife at all levels of the food chain has been badly damaged by human activity, says a new report that urges immediate and “meaningful rehabilitation” if we are to avert mass extinction in the world’s oceans.

“We may be sitting on a precipice of a major extinction event,” Douglas J. McCauley, an ecologist at the University of California, Santa Barbara and an author of the study, told the New York Times.

The report, published Thursday in the journal Science, finds that habitat loss, mismanagement of oceanic resources, climate change, and the overall “footprint of human ocean use” have resulted in a phenomenon known as “defaunation”—a decline in animal species diversity and abundance.

“Although defaunation has been less severe in the oceans than on land, our effects on marine animals are increasing in pace and impact,” reads the study abstract. “Humans have caused few complete extinctions in the sea, but we are responsible for many ecological, commercial, and local extinctions. Despite our late start, humans have already powerfully changed virtually all major marine ecosystems.”

“Humans have profoundly decreased the abundance of both large (e.g., whales) and small (e.g., anchovies) marine fauna,” it continues. “Such declines can generate waves of ecological change that travel both up and down marine food webs and can alter ocean ecosystem functioning.”

Just as the Industrial Revolution during the 1800s decimated the huge tracts of forests, driving many terrestrial species to extinction, industrial use of the oceans threatens to destroy marine habitats and in turn damage the health of marine wildlife populations.

Report co-author Steve Palumbi of Stanford University listed several emerging threats to the oceans: “There are factory farms in the sea and cattle-ranch-style feed lots for tuna. Shrimp farms are eating up mangroves with an appetite akin to that of terrestrial farming, which consumed native prairies and forest. Stakes for seafloor mining claims are being pursued with gold-rush-like fervor, and 300-ton ocean mining machines and 750-foot fishing boats are now rolling off the assembly line to do this work.”

Timeline (log scale) of marine and terrestrial defaunation. If left unmanaged, the authors predict that marine habitat alteration, along with climate change (colored bar: IPCC warming), will exacerbate marine defaunation. (Credit: Science)

“Human activities are negatively impacting the ocean at an ever increasing and unsustainable rate, and we must freeze the footprints of industrial activities and commercial fishing,” Oceana marine scientist Amanda Keledjian told Common Dreams. “Oceana applauds these researchers for their work, because assessing the oceans from a holistic perspective is the only way to understand the scope at which we must act to reverse collapsing fisheries and continued habitat degradation.”

According to the Times:

Scientific assessments of the oceans’ health are dogged by uncertainty: It’s much harder for researchers to judge the well-being of a species living underwater, over thousands of miles, than to track the health of a species on land. And changes that scientists observe in particular ocean ecosystems may not reflect trends across the planet.

Dr. [Malin L.] Pinsky, Dr. McCauley and their colleagues sought a clearer picture of the oceans’ health by pulling together data from an enormous range of sources, from discoveries in the fossil record to statistics on modern container shipping, fish catches and seabed mining. While many of the findings already existed, they had never been juxtaposed in such a way.

A number of experts said the result was a remarkable synthesis, along with a nuanced and encouraging prognosis.

“I see this as a call for action to close the gap between conservation on land and in the sea,” said Loren McClenachan of Colby College, who was not involved in the study.

The report authors say the effects of human activity in the ocean are still reversible: “Proactive intervention can avert a marine defaunation disaster of the magnitude observed on land.”

Oceana’s Keledjian echoed that appeal. “This study reminds us that it is critical to do everything we can to protect vulnerable species and the ocean ecosystems on which they depend,” she said. “While much remains unknown about the state of the oceans, we cannot wait to act until we know with 100 percent certainty that extinctions and devastation are upon us, because that will already be far too late.”

As planet warms, one in six species face total extinction: Study

Humans have brought world's oceans to brink of 'major extinction event'

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