Preposterous Guru

In research described as "terrifying" by an independent expert, scientists predict the future for frogs, toads, newts and salamanders is even more bleak than conservationists had realised.

Around half of amphibian species are in decline, while a third are already threatened with extinction. But scientists now predict that areas with the highest diversity of amphibian species will be under the most intense threat in the future.

And they warn that a three-pronged threat could also cause populations to decline faster than previously thought.

Like many creatures, amphibians have been hit hard by climate change and habitat loss. But they have also been decimated by the spread of the deadly fungal disease chytridiomycosis.

One in three of the world's amphibians are on the International Union for Conservation of Nature's red list of endangered species. These include the Malagasy rainbow frog that lives in the rocky forests of Madagascar. It has the ability to inflate itself when under attack and can climb vertical rock faces. Found in an area smaller than 100 square kilometres, it is a prime target for the pet trade.

The Chinese giant salamander is also critically endangered. The largest of all amphibian species, it can grow to more than a metre long. Overexploitation for food has led to a catastrophic decline in the last 30 years.

European species are also threatened. Scientists predict climate change, habitat destruction and disease could drive more than half of all Europe's frogs, toads and newts to extinction within 40 years.

Now the largest study of its kind has found that it is in areas where amphibian diversity is at its highest that the greatest threat lies.

Researchers led by Dr Christian Hof, from the University of Copenhagen, used computer modelling to predict the impact of climate change, the effect of habitat loss from urbanisation and farming and, finally, the fungal disease on amphibian populations.

"What we found looking at climate change, for example, is that many tropical regions, such as northern South America, the Andes and parts of Africa, will be highly impacted," said Hof. The team then compared this map of impact with the global distribution of more than 5,500 species of amphibians.

The results, published in the Journal Nature, show that two-thirds of the areas with the richest diversity of frog and salamander species will be affected by one or more of these threats by 2080.

Scientists also found that some of the threats overlapped.

The regions where amphibian populations are expected to suffer most from climate change tended to overlap with the areas that could suffer most from habitat destruction. The fungal disease, on the other hand, was more isolated.

"What we still have not really understood is the mechanistic interaction between them, like how does land use change or the fragmentation of habitats influence the potential responses of a species to climate change," said Hof.

Overlapping threats could mean that estimates of the rate of amphibian decline are too optimistic and that populations could decline even faster than previously thought.

Helen Meredith, amphibian conservationist at the Zoological Society of London, said: "Looking into 2080, it seems there will be more extinctions of species of amphibians, which is terrifying as a third of all amphibian species are threatened with extinction now.

"Data is deficient for a quarter of them, which means we don't know whether they are threatened with extinction or not and about half of all amphibian populations are in decline. And that is just what is happening at the moment."

Less than 2cm long, this toad is adapted to living in the spray of the Kihansi and Mhalala waterfalls in the Udzungwa mountains of Tanzania.

Found in one lake in Mexico, it is critically endangered. The species is unusual because it is neotenous: it never develops into an adult.

Four-fifths of the species has been wiped out by the Chytrid fungus. Extinct in the wild.

This toxic species lives in the Colombian rainforest. Habitat destruction for logging and agriculture has left it critically endangered.

The change could have a major impact on the expanding human population, with major food sources like fish likely to reduce in size and crops expected to grow smaller and less reliably than today.

Species which are unable to adapt quickly enough are at risk of extinction as ecosystems shift dramatically, altering the balance of food and other resources needed for survival.

Researchers argue that warmer and drier weather causes plants and animals to reach smaller sizes, while more variable rainfall levels raise the risk of failed crop years.

Over the past century animals including toads, tortoises, blue tits, Soay sheep and red deer have all started to reduce in size, they said.

Lower levels of sea ice have even resulted in polar bears getting smaller, according to a report in the Nature Climate Change journal.

Dr David Bickford and Jennifer Sheridan of the National University of Singapore wrote: "The consequences of shrinkage are not yet fully understood, but could be far-reaching for biodiversity and humans alike.

"Because recent climate change may be faster than past historical changes in climate, many organisms may not respond or adapt quickly enough. This implies that species may go extinct because of climate change."

One major issue is that not all plants and animals will shrink at the same rate, throwing finely balanced ecosystems out of kilter, the researchers said.

Reduced food supplies are likely to mean that animals at the top of their food chains - including humans - will grow to smaller sizes, have fewer offspring, and be more vulnerable to disease, they added.

Cold blooded animals, particularly amphibians, are at the highest risk because having a smaller size will put them at greater risk of drying up in warmer temperatures.

During the past century global average temperatures have risen by almost 1C, and climate experts predict 7C of warming by 2100.

A separate study of 1,700 plant, insect, bird and amphibian species has shown that 80 per cent are already moving 6.1km closer to the poles every ten years, and 87 per cent are breeding or flowering more than two days earlier each decade.

Fossil evidence dating from the Palaeocene-Eocene Thermal Maximum 55 million years ago, when temperatures rose by three to seven per cent and precipitation levels dropped 40 per cent - shows that invertebrates like beetles, bees and ants became 50 to 75 per cent smaller.

Other species ranging from single-celled diatoms to squirrels and woodrats have also been shown to decrease in size during previous periods of global warming.

Experimental research suggests that for every additional degree Celsius, a variety of plants lose between three and 17 per cent in size and fish shrink by six to 22 per cent.

Mass extinction of species will be "inevitable" if current trends continue, researchers said.

Overfishing, pollution, run-off of fertilisers from farming and the acidification of the seas caused by increasing carbon dioxide emissions are combining to put marine creatures in extreme danger, according to the report from the International Programme on the State of the Ocean (Ipso), prepared at the first international workshop to consider all of the cumulative stresses affecting the oceans at Oxford University.

The international panel of marine experts said there was a "high risk of entering a phase of extinction of marine species unprecedented in human history". They said the challenges facing the oceans created "the conditions associated with every previous major extinction of species in Earth's history".

"The findings are shocking," said Alex Rogers, scientific director of Ipso. "As we considered the cumulative effect of what humankind does to the ocean, the implications became far worse than we had individually realised. This is a very serious situation demanding unequivocal action at every level. We are looking at consequences for humankind that will impact in our lifetime, and worse, our children's and generations beyond that."

The flow of soil nutrients into the oceans is creating huge "dead zones", where anoxia - the absence of oxygen - and hypoxia - low oxygen levels - mean fish and other marine life are unable to survive there.

Hypoxia and anoxia, warming and acidification are factors present in every mass extinction event in the oceans over the Earth's history, according to scientific research. About 55m years ago, as much as half of some species of deep-sea creatures were wiped out when atmospheric changes created similar conditions.

In recent years, human effects on the oceans have increased significantly. Overfishing has cut some fish populations by more than 90%. Pollutants, including flame-retardant chemicals and detergents are absorbed into particles of plastic waste in the sea, which are then ingested by marine creatures. Millions of fish, birds and other forms of life are choked or suffer internal ruptures from ingesting plastic waste.

During 1998, record high temperatures wiped out about 16% of the world's tropical coral reefs.

The scientists called on the United Nations and governments to bring in measures to conserve marine ecosystems. Dan Laffoley, of the International Union for the Conservation of Nature, said: "The world's leading experts on oceans are surprised by the rate and magnitude of changes we are seeing. The challenges for the future of the oceans are vast, but unlike previous generations we know what now needs to happen. The time to protect the blue heart of our planet is now, today and urgent".

Most of the remaining wild oysters in the world, or about 75 percent, can be found in five locations in North America, said the study published in BioScience, the journal of the American Institute of Biological Sciences.

An international team of researchers led by Michael Beck of the Nature Conservancy and the University of California, Santa Cruz, examined the condition of native oyster reefs in 40 ecoregions, including 144 bays.

"Oyster reefs are at less than 10 percent of their prior abundance in most bays (70 percent) and ecoregions (63 percent)," said the study.

The study also did not include oyster reefs in parts of South Africa, China, Japan, and North and South Korea.

Other studies and observations in those areas "suggest that wild oyster abundance was much higher in the past and that reefs have declined greatly in abundance or have disappeared altogether," the authors said.

The one bright spot in the oyster world was in the Gulf of Mexico, where native oyster catches are "the highest in the world despite significant declines in abundance and reefs," according to the study.

Five regions where oyster catches were globally the highest were located in eastern North America, from the Virginia coast southward and also in the Gulf of Mexico.

Oysters are important to ecosystems because they filter impurities from water and provide food and employment for people living in coastal communities.

The decline in oyster population often begins when trawling or dredging destroys the structure of parts of the reef, leaving surviving oysters vulnerable to stresses in the environment.

In some cases, non-native species of oysters are introduced after a population decline, and they bring with them diseases that further kill off the native oysters.

The dense forests of the Amazon soak up more than one-quarter of the world's atmospheric carbon, making it a critically important buffer against global warming. But if the Amazon switches from a carbon sink to a carbon source that prompts further droughts and mass tree deaths, such a feedback loop could cause runaway climate change, with disastrous consequences.

"Put starkly, current emissions pathways risk playing Russian roulette with the world's largest forest," said tropical forest expert Simon Lewis, at the University of Leeds, and who led the research published today in the journal Science. Lewis was careful to note that significant scientific uncertainties remain and that the 2010 and 2005 drought - thought then to be of once-a-century severity - might yet be explained by natural climate variation.

"We can't just wait and see because there is no going back," he said. "We won't know we have passed the point where the Amazon turns from a sink to a source until afterwards, when it will be too late."

Alex Bowen, from the London School of Economics and Political Science's Grantham research institute on climate change, said huge emissions of carbon from the Amazon would make it even harder to keep global greenhouse gases at a low enough level to avoid dangerous climate change. "It therefore makes it even more important for there to be strong and urgent reductions in man-made emissions."

The revelation of mass tree deaths in the Amazon is a major blow to efforts to reduce the destruction of the world's forests by loggers, one of the biggest sources of global carbon emissions. The use of satellite imagery by Brazilian law enforcement teams has drastically cut deforestation rates and replanting in Asia had slowed the net loss. Financial deals to protect forests were one of the few areas on which some progress was made at the 2010 UN climate talks in Cancún.

The 2010 Amazonian drought led to the declaration of states-of-emergencies and the lowest ever level of the major tributary, the Rio Negro. Lewis, with colleagues in Brazil, examined satellite-derived rainfall measurements and found that the 2010 drought was even worse than the very severe 2005 drought, affecting a 60% wider area and with an even harsher dry season.

On the ground, the researchers have 126 one-hectare plots spread across the Amazon, in which every single tree is tagged and monitored. After 2005, they counted how many trees had died and worked out how much carbon would be pumped into the atmosphere as the wood rotted. In addition, the reduced growth of the water-stressed trees means the forest failed to absorb the 1.5bn tonnes of carbon that it would in a normal year.

Applying the same principles to the 2010 drought, they estimated that 8.5 billion tonnes of CO2 will be released - more than the entire 7.7bn tonnes emitted in 2009 by China, the biggest polluting nation in the world. This estimate does not include forest fires, which release carbon and increase in dry years.

"The Amazon is such a big area that even a small shift [in conditions] there can have a global impact," said Lewis.

Lewis said that two such severe droughts in the Amazon within five years was highly unusual, but that a natural variation in climate over decade-long periods cannot yet be ruled out. The driving factor of the annual weather patterns is the warmth of the sea in the Atlantic. He said increasing droughts in the Amazon are found in some climate models, including the sophisticated model used by the Hadley centre. This means the 2005 and 2010 droughts are consistent with the idea that global warming will cause more droughts in future, emit more carbon, and potentially lead to runaway climate change. "The greenhouse gases we have already emitted may mean there are several more droughts in the pipeline," he said.

Brazilian scientist Paulo Brando, from the Instituto de Pesquisa Ambiental da Amazônia (Amazon Environmental Research Institute), and co-leader of the research said: "We will not know exactly how many trees were killed until we can complete forest measurements on the ground. It could be that many of the drought-susceptible trees were killed off in 2005. Or the first drought may have weakened a large number of trees so increasing the number dying in 2010."

Brando added: "Our results should be seen as an initial estimate. The emissions estimates do not include those from forest fires, which spread over extensive areas of the Amazon during hot and dry years and release large amounts of carbon."
Climate tipping points

Scientists know from the geological record that the Earth's climate can change rapidly. They have identified a number of potential tipping points where relatively small amounts of global warming caused by human activities could cause large changes in climate. Some tipping points, like the losses to the Amazon forests, involve positive feedback loops and could lead to runaway climate change.

Arctic ice cap: The white ice cap is good at reflecting the Sun's warming light back into space. But when it melts, the dark ocean uncovered absorbs this heat. This leads to more melting, and so on.

Tundra: The high north is warming particularly fast, melting the permafrost that has locked up vast amounts of carbon in soils for thousands of years. Bacteria digesting the unfrozen soils generate methane, a potent greenhouse gas, leading to more warming.

Gas hydrates: Also involving methane, this tipping point involves huge reservoirs of methane frozen on or just below the ocean floor. The methane-water crystals are close to their melting point and highly unstable. A huge release could be triggered by a little warming.

The study of the collapse of Earth's marine life 378 to 375 million years ago suggests that the planet's current ecosystems, which are struggling with biodiversity loss, could meet a similar fate.

Although Earth has experienced five major mass extinction events, the environmental crash during the Late Devonian was unlike any other in the planet's history.

The actual number of extinctions wasn't higher than the natural rate of species loss, but very few new species arose.

"We refer to the Late Devonian as a mass extinction, but it was actually a biodiversity crisis," said Alycia Stigall, a scientist at Ohio University and author of the PLoS ONE paper.

"This research significantly contributes to our understanding of species invasions from a deep-time perspective," said Lisa Boush, program director in the National Science Foundation (NSF)'s Division of Earth Sciences, which funded the research.&

"The knowledge is critical to determining the cause and extent of mass extinctions through time, especially the five biggest biodiversity crises in the history of life on Earth. It provides an important perspective on our current biodiversity crises."

The research suggests that the typical method by which new species originate--vicariance--was absent during this ancient phase of Earth's history, and could be to blame for the mass extinction.

Vicariance occurs when a population becomes geographically divided by a natural, long-term event, such as the formation of a mountain range or a new river channel, and evolves into different species.

New species also can originate through dispersal, which occurs when a subset of a population moves to a new location.

In a departure from previous studies, Stigall used phylogenetic analysis, which draws on an understanding of the tree of evolutionary relationships to examine how individual speciation events occurred.

She focused on one bivalve, Leptodesma (Leiopteria), and two brachiopods, Floweria and Schizophoria (Schizophoria), as well as a predatory crustacean, Archaeostraca.

These small, shelled marine animals were some of the most common inhabitants of the Late Devonian oceans, which had the most extensive reef system in Earth's history.

The seas teemed with huge predatory fish such as Dunkleosteus, and smaller life forms such as trilobites and crinoids (sea lilies).

The first forests and terrestrial ecosystems appeared during this time; amphibians began to walk on land.

As sea levels rose and the continents closed in to form connected land masses, however, some species gained access to environments they hadn't inhabited before.

The hardiest of these invasive species that could thrive on a variety of food sources and in new climates became dominant, wiping out more locally adapted species.

The invasive species were so prolific at this time that it became difficult for many new species to arise.

"The main mode of speciation that occurs in the geological record is shut down during the Devonian," said Stigall. "It just stops in its tracks."

Of the species Stigall studied, most lost substantial diversity during the Late Devonian, and one, Floweria, became extinct.

The entire marine ecosystem suffered a major collapse. Reef-forming corals were decimated and reefs did not appear on Earth again for 100 million years.

The giant fishes, trilobites, sponges and brachiopods also declined dramatically, while organisms on land had much higher survival rates.

The study is relevant for the current biodiversity crisis, Stigall said, as human activity has introduced a high number of invasive species into new ecosystems.

"Even if you can stop habitat loss, the fact that we've moved all these invasive species around the planet will take a long time to recover from because the high level of invasions has suppressed the speciation rate substantially," Stigall said.

Maintaining Earth's ecosystems, she suggests, would be helped by focusing efforts and resources on protection of new species generation.

"The more we know about this process," Stigall said, "the more we will understand how to best preserve biodiversity."

The better known issues of climate change and loss of biodiversity are both rooted in the global loss of fertile soil, said Gnacadja, as the soil harbours a huge stock of carbon and the health of creatures living in the soil underpins global food production and forest growth. The reason desertification has not been a priority is because 90% of the 2.1 billion people who live in drylands live in developing countries, he said.

"Even in their own countries, they are the poorest among the poor and live in remote areas," said Gnacadja. "The world is driven by city dwellers: political leaders are setting agendas to satisfy people who live in the cities, we therefore tend to perceive soil as just dust, or mud, or a dumping place. But if we don't preserve that first 20cm of soil, where will we get our food and water from?" Half the world's livestock are raised on drylands and a third of crops, especially wheat.

The impacts of climate change - rising temperatures and more erratic rainfall - are here already from Latin America to the Sahel, said Gnacadja. Adding to the pressure on land is rising global population, which is expected to pass the 7 billion mark next year and reach 9 billion by 2050. As well as the consequences for food and water, violent conflicts and migration will also increase, he said, affecting those living outside drylands.

"Increased aridity is making the drylands the most conflict prone region of the world," he said. "If you really want to look at the root causes of the conflicts in Somalia and Darfur, and drylands of Asia, you will understand that people in their quest to have access to productive land and water for life, they end up in conflict." He also cited nothern Nigeria, where increased aridity means lack of fodder is driving herders south into the areas farmed for corn. "Conflict is almost inevitable."

Desertification and rising aridity were the ultimate cause of the food price crisis of 2007-8, Gnacadja said, as it began with a drought in Australia. This year's price spike started with a drought in Russia. Another example of desertification's impact was the loss of land bordering the Gobi desert leading to record dust storms that damage the health of people in Seoul in South Korea, thousands of kilometres away.

Gnacadja, a former environment minister in Benin, said combating desertification and soil degradation requires better land management, better equipment and new technology to manage water, drought resistant seeds and payment to communities for preserving the soil. He said he welcomed the new Green Climate Fund and the Redd deal to tackle deforestation agreed at the UN's climate change talks in Cancún last week.

It could also help unravel one of the great unsolved mysteries of the universe.

''This is a major discovery," said Prof Rob Thompson, the head of physics and astronomy at the University of Calgary, who was one of the lead scientists behind the project.

"It could enable experiments that result in dramatic changes to the current view of fundamental physics or in confirmation of what we already know now."

Under a theory expounded in 1931 by the eccentric British physicist Paul Dirac, antimatter is ordinary matter in reverse.

Delegates from more than 190 countries meeting in Nagoya, Japan, agreed at the 11th hour on an ambitious conservation programme to protect global biodiversity and the natural habitats that support the most threatened animals and plants.

"This agreement reaffirms the fundamental need to conserve nature as the very foundation of our economy and our society," said Jim Leape, director general of the conservation group WWF International.

"Governments have sent a strong message that protecting the health of the planet has a place in international politics, and countries are ready to join forces to save life on Earth," Mr Leape said.

One of the 20 targets agreed by the delegates was to extend national parks to increase the area of protected land in the world from 12.5 per cent to 17 per cent, and the area of protected oceans from 1 per cent to 10 per cent by 2020. Another target is to lift threatened species from the risk of extinction.

Environment ministers from around the globe also agreed on rules for sharing the commercial benefits of nature's genetic resources between governments and companies, a key trade and intellectual property issue that could be worth billions of dollars in new funds for developing nations.

One idea enshrined in the new protocol is to set up a special fund from a proportion of the profits made from commercial products derived from biological material collected decades or even centuries ago from natural habitats in the developing world.

Caroline Spelman, Britain's Environment Secretary, said last night from Nagoya: "We have also agreed an historic protocol which has been 18 years in the making, establishing a regime where developing countries will allow access to their genetic and natural resources in return for a share of the benefits for their use."

This feature of the agreement was the biggest stumbling block to a deal because of concerns by developing nations that they would miss out on the revenues generated by Western companies that discover new drugs and medicines derived from studying the chemistry and genetics of species living in regions rich in biodiversity.

Developing nations, particular in Africa, had argued they had not benefited in the past from their natural resources which had been developed into lucrative products by wealthy Western countries.

Poorer countries had insisted that the cost of increasing their spending on the conservation of natural habitats had to be offset by some financial mechanism that paid them for the benefit of the genetic resources they were protecting.

Johansen Voker of Liberia's Environmental Protection Agency had said: "The forest and the other biological resources we have serve the general interests of the global environment. So we expect assistance to be able to effectively conserve our environment for the common good of the world community."

The Nagoya meeting agreed to establish an International Regime on Access and Benefit Sharing of Genetic Resources to lay down the basic ground rules on how nations co-operate in obtaining genetic resources from animals, plants and fungi.

Achim Steiner, head of the UN Environment Programme, which administers the Convention on Biological Diversity, said: "This is a day to celebrate in terms of a new and innovative response to the alarming loss of biodiversity and ecosystems. And a day to celebrate in terms of opportunities for lives and livelihoods in terms of overcoming poverty and delivering sustainable development."

Last week, a report by the Zoological Society of London warned the populations of mammals, birds, reptiles, amphibians and fish have declined by 30 per cent over 40 years and that one-fifth of all vertebrate species are threatened with extinction.

Home to one of the richest cactus communities in the world, the desert also harbours a rare example of an inland-desert wetlands - Cuatro Cienegas. Snails and fish there have radiated into many species, some restricted to a single pool.

Reefs in the tropical western Pacific are the world's most diverse. Some off western New Guinea are home to 525 species of reef fish and 450 species of coral. The world trade in aquarium fish and large food fish is having a devastating impact, as is sedimentation and pollution.

Large populations of marine mammals, birds and fish depend, directly or indirectly, on shrimp-like krill in surrounding waters. One of the last relatively intact marine ecosystems, the peninsula is a breeding ground for many species. Increased ultraviolet radiation due to ozone depletion threatens the area.

The rugged terrain of the northern Andes hosts an enormous diversity of habitats. Single peaks or valleys are home to several species of birds, orchids, and other organisms found nowhere else. One of the world's highest concentrations of endemic birds inhabits peaks on the Ecuador-Colombia border.

The Atlantic forest region, most of it in Brazil, is a criticially endangered ecosystem. Less than 7 per cent of the original vegetation remains. Early naturalists found forests draped with orchids and bromeliads and ringing with the sounds of animals. Today, the four endemic species of tamarins are all endangered, including the black-faced tamarin, which was discovered by scientists only in 1990.

This area in South Africa holds a unique collection of hard-leaved and evergreen shrubs called 'fynbos' and is home to more than 8,000 plant species, around 70 per cent of which are endemic. The greatest threats to this diverse plant life are invasive alien species and habitat loss.

From Portugal to Jordan, from Morocco to southern France, this eco-region is fragmented and threatened by burning, grazing, human settlement and tourism. The region is one of five sites of Mediterranean shrub land in the world, which collectively contain 20 per cent of all terrestrial plant species.

A large number of endemic species, some traced back to forebears on the ancient supercontinent of Gondwana, have evolved on India's long-isolated western mountain ranges. Sixteen bird species and at least 1,500 plant species live only in this region. Pressure from expanding human population, logging and farming is intense.

Earth's largest unbroken forest, this is among the last regions vast enough to allow populations of large predators to interact naturally with prey. A network of wetlands is a critical breeding habitat for many species of waterfowl, shorebirds and the endangered Siberian crane.

One of the last great forest wildernesses, long-isolated New Guinea has never been colonised by monkeys or most other large mammals. Their niches are filled instead by reptiles, marsupials and birds.

The flora and fauna of New Zealand, once part of Gondwana, evolved in isolation for around 80 million years. New Zealand has one of the world's increasingly threatened rain forests, where flightless parrots nest. More than 80 per cent of New Zealand's plant species are endemic.