Lost golden toad heralds climate’s massive extinction threat

Hexbyte Glen Cove

The golden toad was the first species where climate change has been identified as a key driver of extinction.

Those lucky enough to have seen them will never forget.

For just a few days every year, the elfin cloud forest of Costa Rica came alive with crowds of golden toads the length of a child’s thumb, emerging from the undergrowth to mate at rain-swelled pools.

In this mysterious woodland the cloud drapes over mountain ridges and “the trees are dwarfed and wind-sculpted, gnarled and heavily laden with mosses,” said J Alan Pounds, an ecologist at the Monteverde Cloud Forest Preserve in Costa Rica.

“The soils are very dark and so golden toads would stand out like animal figurines. It was quite a spectacle.”

Then in 1990, they were gone.

The golden toad was the first species where climate change has been identified as a key driver of extinction.

Its fate could be just the beginning.

For years, researchers have warned that the world is facing both a climate and a biodiversity crisis. Increasingly they say they are connected.

One in 10 face extinction

Even if warming is capped at the ambitious target of 1.5 degrees Celsius above pre-industrial levels, the UN’s Intergovernmental Panel on Climate Change says nearly one in 10 of all species face an extinction threat.

The golden toad was only found in Monteverde’s highland forest. So when trouble hit, the species was completely wiped out.

“It was pretty clear about 99 percent of the population declined within a single year,” said Pounds, whose research into the disappearance of the golden toad was cited in the IPCC’s February report on climate impacts.

Climate change was barely on the research radar when Pounds first arrived in Costa Rica in the early 1980s to study amphibians.

But global warming was already beginning to take its toll.

In the cloud forests of Costa Rica clouds drapes over mountain ridges.

After the disappearance of the golden toad, the Monteverde harlequin frog and others, researchers compared datasets on temperature and weather patterns with those on local species.

They found not only the signature of the periodic El Nino weather phenomenon, but also trends linked to changes in climate.

Climate ‘trigger’

The die-offs occurred after unusually warm and dry periods.

Pounds and his colleagues linked the declines to chytridiomycosis infection, but concluded that disease was only the “bullet—climate change was pulling the trigger.

“We hypothesised that climate change and resultant extreme events were somehow loading the dice for these kinds of outbreaks,” Pounds told AFP.

It was not an isolated incident.

The expansion of the chytrid fungus globally, along with local climate change “is implicated in the extinction of a wide range of tropical amphibians,” according to the IPCC.

The fingerprints of global warming have since been seen in other disappearances.

The Bramble Cay melomys, a small rodent living on a low-lying island in the Torres Strait, was last seen in 2009.

The only mammal endemic to the Great Barrier Reef, its populations were battered by sea-level rise, increased storm surges and tropical cyclones—all made worse by climate change.

Vegetation that provided its food plummeted from 11 plant species in 1998 to just two in 2014. It was recently declared extinct.

Today, climate change is listed as a direct threat to 11,475 species assessed by the International Union for Conservation of Nature. Around 5,775 are at risk of extinction.

Graphic on the golden toad species whose extinction has been blamed on global warming.

#MeToo for species

The main reason why climate change is increasingly cited as a threat to so many species is that its impacts are becoming more obvious, said Wendy Foden, the head of the IUCN’s climate change specialist group.

But there is also a growing understanding of the enormous variety of effects.

Beyond extreme weather, warming can also cause species to move, change behaviour or even skew to having more male or female offspring.

And that’s on top of other human threats like poaching, deforestation, overfishing and pollution.

In 2019, a report by UN biodiversity report experts said one million species could disappear in the coming decades, raising fears that the world is entering a sixth era of mass extinction.

“It’s absolutely terrifying,” said Foden, adding that warnings of catastrophic biodiversity loss have often been overlooked.

“We need a #MeToo movement for species, a whole wake up on what we are doing.”

Almost 200 countries are currently locked in global biodiversity talks to try to safeguard nature, including a key milestone of 30 percent of Earth’s surface protected by 2030.

But Foden said the threat of climate change means that the response will have to go beyond traditional conservation.

“That can’t happen anymore, even in the most remote wilderness, climate change will affect it,” Foden said.

In some cases, people will need to choose which species to save.

Take the endangered African penguin in South Africa, which Foden wrote about for the IPCC report on climate impacts.

Forced to nest in the open after humans mined their guano nesting sites, the adults now have to swim ever further to find fish, likely because of a combination of overfishing and climate change. Meanwhile, the chicks in exposed nests can die from heat stress.

“We are down to the last 7,000 breeding pairs. At this point, every penguin counts,” Foden said.

Africa’s only nesting penguin was reclassified as endangered last year after being nearly wiped out.

Cloudless forest

In Monteverde, even the clouds have changed.

While rainfall has increased somewhat over the past 50 years, Pounds said it has become much more variable.

In the 1970,s the forest saw around 25 dry days a year on average—in the last decade it has been more like 115.

The mist that used to keep the forest wet during the dry season has reduced by around 70 percent.

Pounds said sometimes tourists in the area stop him and ask directions to the Cloud Forest.

“And I say: ‘You’re in it,'” he said.

“It often feels more like a dust forest than a cloud forest.”

Researchers have also seen steep declines in frogs, snakes and lizards and changes in the bird populations. Some have moved uphill to cooler areas, others have vanished from the area completely.

As for the golden toad, last year a team from the Monteverde Conservation League, supported by the conservation group Re:wild, launched an expedition to look for the golden toad in its historic habitat in the Children’s Eternal Rainforest, after tantalising rumours of sightings.

But in vain.

Meanwhile, Pounds and his colleagues continue to keep an eye out for the golden toad during the rainy season.

“We haven’t completely given up,” he said.

“But with each passing year, it looks less likely that they’re going to reappear.”



© 2022 AFP

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Hexbyte Glen Cove Last seven years on track to be hottest on record: UN

Hexbyte Glen Cove

Recent years have seen an onslaught of extreme weather, including wildfires made more intense by climate change.

The years from 2015 to 2021 are on track to be the seven hottest on record, the World Meteorological Organization said on Sunday, warning that the planet was heading into “uncharted territory”.

The preliminary WMO state of the report, launched as the UN COP26 climate conference opens, said that from greenhouse gas emissions threatens “far-reaching repercussions for current and future generations”.

Based on data for the first nine months of the year, the WMO said 2021 was likely to be between the fifth and seventh on record—despite the cooling effect of the La Nina phenomenon that lowered temperatures at the beginning of the year.

“From the ocean depths to mountain tops, from melting glaciers to relentless extreme weather events, ecosystems and communities around the globe are being devastated,” said United Nations Secretary-General Antonio Guterres in a statement on the report.

He added that the two-week COP26 climate conference “must be a turning point for people and planet”.

The WMO found that the average temperature for 2021 was around 1.09 degrees Celsius higher than pre-industrial levels.

And the average temperature over the last 20 years (2002-2021) for the first time exceeded the symbolic threshold of 1C above the mid-19th century, when humans began burning on an industrial scale.

This will “focus the minds of delegates at COP26 aspiring to keep global temperature rise to within the limits agreed in Paris six years ago”, said Stephen Belcher, chief scientist at Britain’s Met Office.

The 2015 Paris Agreement saw countries agree to cap global warming at “well below” 2C above pre-industrial levels, and 1.5C if possible.

Since then the world has seen a litany of weather disasters including record-shattering wildfires across Australia and Siberia, a once-in-a-thousand-years heatwave in North America and extreme rainfall that caused massive flooding in Asia, Africa, the US and Europe.

“Extreme events are the new norm,” said WMO Secretary-General Petteri Taalas.

“There is mounting that some of these bear the footprint of human-induced .”

‘Unimaginable’ consequences

The state of the climate report is a snapshot of planetary health, including temperatures, extreme weather, glacier retreat and ice melt.

Ocean acidification due to the absorption of carbon dioxide by the seas was “unprecedented” in at least 26,000 years, the WMO said, adding that this will lessen the ability of the oceans to take in more C02.

Meanwhile, sea level rise—mainly caused by the expansion of warming sea water and the melting of ice on land—was at a new high.

The report is “shocking and deeply disturbing and yet another wake-up call to world leaders that time has run out for talk”, said Jonathan Bamber, Director of the Bristol Glaciology Centre, in comments to the Science Media Centre.

He said on the current trajectory, sea level rise could exceed two metres (more than six feet) by 2100, which could displace some 630 million people worldwide.

“The consequences of that are unimaginable,” said Bamber.

“What is required now is profound and comprehensive action by every nation and state actor to limit further and deeper climate breakdown.”



© 2021 AFP

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Last seven years on track to be hottest on record: UN (2021, October 31)
retrieved 31 October 2021
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