Earth ChangesS


Frog

Mystery of crocs' mass die-off

Gharial
© UnknownSome gharials may be feeding on fish that have large toxic loads
Measuring up to 6m long, with elongated narrow snouts, gharials are one of the world's most distinctive-looking crocodilians.

Just 100 years ago, these fish-eating reptiles were prevalent throughout the Indian subcontinent; but by 2007, there were just 200 breeding adults found in only a handful of rivers in India and Nepal.

Last winter, this already critically endangered species was dealt another cruel blow. Over the space of just five months, more than 100 of the creatures washed up dead on the banks of India's Chambal river - and nobody knew why.

For the past year, herpetologist Rom Whitaker, who runs the Madras Crocodile Bank, has been followed by a BBC Natural World team as he attempted to solve this mystery.

Frog

Did Greenhouse Gases Cause the Earth's Greatest Mass Extinction?

In 1980, scientists Luis Alvarez and his son, Walter, proposed a new explanation for the dinosaurs' disappearance 65 million years ago: a meteor strike. Initially, the idea was met with resistance. But the evidence was convincing: a sediment layer high in iridium, an element common in asteroids, was found the world over, along with a 110-mile-wide impact crater in the Yucatán of the same age. What started as a fringe idea has gone mainstream.

Now scientists are rethinking another of earth's great die-offs. The end-Permian extinction 251 million years ago was the worst of earth's five mass extinctions. Ninety percent of all marine life and 70 percent of terrestrial life disappeared. It took five million years, perhaps more, for the biosphere to recover.

But while the die-off was uniquely devastating, evidence of a single cataclysmic event, like an asteroid strike, hasn't been found in the geological record. Scientists now suspect that "the mother of all mass extinctions" was of Earth's own making. And the more they learn about it, the more parallels they see to today's world: A bout of greenhouse-gas-induced global warming, much like today's, set off a chain of events that culminated in oxygen-depleted oceans exhaling poison gas.

Comment: Notice the tactic of linking some good science with the subtle reassurance that "the asteroids (or comets) are not to blame". Besides "who sez" that the oceans can't become anoxic in conditions of global cooling?


Better Earth

Conservation atlas reveals 'most valuable' forest

A new atlas shows how conservation efforts can most efficiently make use of limited resources by laying out which forests store large amounts of carbon and are also home to a great diversity of animals and plants.

The UN Environment Programme, which released the maps at the ongoing UN climate summit in Poznan, Poland, believes they could guide investments in forest conservation.

"At a time of scarce financial resources and economic concerns, every dollar, euro or rupee needs to deliver double, even triple dividends," says Achim Steiner, executive director of UNEP. "By pinpointing where high densities of carbon overlap with high levels of biodiversity, the atlas spotlights where governments and investors can deal with two crises for the price of one."

Bizarro Earth

Colombia: Deforestation and Deluge, a Recipe for Disaster

The lack of policies against indiscriminate deforestation in river basins, in synergy with the rainy season, which is heavier than usual this year because of the La Niña climate phenomenon, has had devastating effects in Colombia.

This "winter," as the rainy season is called in this country, there have already been 600 local disasters caused by gale-force winds and constant, heavy rainfall. Rivers have burst their banks, and landslides and avalanches of all kinds have occurred, meteorologist Max Henríquez told IPS.

The rains began in September and will probably only let up in mid-December, because of La Niña. "Throughout 2007 and for several months this year we have experienced this climate phenomenon, caused by the cooling of the surface waters in the Pacific ocean, which brings above normal rainfall," the meteorologist said.

Cloud Lightning

US: Rain, Not Dam Malfunction, Caused June Indiana Floods

A report shows that torrential rain, not a dam malfunction, caused the flooding in June that affected one of every seven structures in Columbus, Indiana.

A report from the U.S. Geological Survey summarized reasons for the event, detailed its effects and illustrated its severity with maps, charts and rainfall data. City Engineer Steve Ruble says the study eliminates the possibility of a "smoking gun'' and proves the flooding came from rainfall on June 6 and 7.

Igloo

UK: Thousands Of Homes Lose Power

Snowy road
© UnknownThousands Of Homes Lose Power
The Army was mobilised to help stricken drivers as heavy snow brought traffic chaos and cut power to thousands of homes in northern England.

Hundreds of schools were closed across Northern England and Scotland.

As much as 20cm of snow fell in the Durham Dales, and 17cm was recorded at Redesdale, Northumberland, with driving winds causing drifts on transpennine routes in what was the heaviest snowfall of the winter so fall.

Around 4,450 homes were without power in north-east Yorkshire and north Linclonshire by early evening.

Info

Are climate scientists overselling their models?

At the UN climate negotiations under way in Poland this week, politicians will be poring over forecasts of climate change. It's an opportune moment for physicist Lenny Smith to challenge the climate modellers who he believes are overselling their results. Human activity really is changing the global climate, he tells Fred Pearce, but we must stop pretending that we know the details of how it will all play out
Lenny Smith
© Pal HansenPhysicist Lenny Smith thinks that climate modellers are overselling their results.

You work with climate models, but you have issues with them too. Why?

The temptation to interpret model noise as forecast information invades our living rooms every night. TV weather-forecast maps look so realistic it is hard not to over-interpret tiny details - to imagine that the band of rain passing over Oxfordshire at noon next Saturday requires postponing a barbecue. Rain may indeed be likely somewhere in the area sometime on Saturday, but the details we see on TV forecasts are noise from the models. I think we are having exactly the same problem with climate projections.

Comment: For additional reading on the Climate debate: Climate Change Swindlers and the Political Agenda, Fire and Ice: The Day After Tomorrow and Forget about Global Warming - We're One Step From Extinction!.


Cloud Lightning

Drivers warned as heavy snow hits northern England and Scotland

Forecasters predict hazardous rush-hour driving conditions after 10cm of snow falls in higher areas of country
Guardian Snow
© Scott Heppell/APA Shetland pony stands in a snowy field at Anneld Plain, Co Durham

Evil Rays

Over 200 inches of snow greets Alyeska skiers and riders

Yes you read that right - over 200 inches - 16.7 feet! - of snow. And 117 inches of the total came in the last week at Alyeska Resort, about 40 miles south of Anchorage, Alaska.

Alyeska opened for business on November 26 and according to a press release, with "epic conditions that rival the best opening day on record."

Better Earth

Super-Ant Taking Over Europe

An ant species that originated in the Black Sea region has invaded more than 100 areas across Europe and is moving north. Scientists say if it is not stopped, it will reach northern Germany, Scandinavia and Britain and could invade the whole world.
Live Science Ants
© Credit: Centre for Social Evolution (CSE) at the University of CopenhagenRed dots show where Lasius neglectus has been found.