EXTINCTION 100 TIMES MORE LIKELY NOW

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Extinction risks vastly underestimated: study

Wed Jul 2, 1:41 PM ET

Some endangered species may face an extinction risk that is up to a hundred times greater than previously thought, according to a study released Wednesday.

By overlooking random differences between individuals in a given population, researchers may have badly underestimated the perils confronting threatened wildlife, it said.

"Many larger populations previously considered relatively safe would actually be at risk," Brett Melbourne, a professor at the University of Colorado and the study's lead author, told AFP.

There are more than 16,000 species worldwide threatened with extinction, according to the International Union for Conservation of Nature (IUCN).

One in four mammals, one in eight birds and one in three amphibians are on the IUCN's endangered species "Red List".

In a study released on Wednesday by the journal Nature, Melbourne said the current models used draw up such lists typically look only at two risk factors.

One is the individual deaths within a small population, such as Indian tigers or rare whales.

When a species dwindles beyond a certain point, even the loss of a handful of individuals can have devastating long-term consequences, Melbourne explained.

There are less than 400 specimens of several species of whale, for example, and probably no more than 4,000 tigers roaming in the wild.

The second commonly-used factor is environmental conditions that can influence birth and death rates, such as habitat destruction, or fluctuations in temperature or rainfall, both of which can be linked to climate change.

Melbourne and co-author Alan Hastings from the University of California at Davis argue that these factors must be widened in order to give a fuller picture of extinction risk.

They say that two other determinants must be taken into account: male-to-female ratios in a species, and a wider definition of randomness in individual births and deaths.

These complex variables can determine whether a fragile population can overcome a sudden decline in numbers, such as through habitat loss, or whether it will be wiped out.

"This seems subtle and technical, but it turns out to be important," Melbourne said in an email. "Population sizes might need to be much larger for species to be relatively safe from extinction."

The new mathematical tool will be most useful for biologists who want to assess the survival prospects of species such as marine fish whose numbers can suddenly fluctuate and for which data is limited, the authors say.

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JUST ANOTHER NAIL-BITER

Runaway Global Warming 635 Million Years Ago

LiveScience Staff

LiveScience.comWed May 28, 4:16 PM ET

A sudden and extreme case of runaway global warming 635 million years ago was caused by an abrupt release of methane, a powerful greenhouse gas, scientists said today.

The methane seeped from ice sheets that covered much of the planet toward the end of a frigid era called Snowball Earth. The gas escaped gradually at first and then very quickly from clathrates, or methane ice that forms and stabilizes beneath water ice sheets. As the water ice melted, pressure was relieved on the clathrates and they began to de-gas.

The transition represents one of the earliest known cases of what scientists now call a climatic tipping-point.

The big question scientists are now pondering: Could it happen again?

"Our findings document an abrupt and catastrophic global warming that led from a very cold, seemingly stable climate state to a very warm, also stable, climate state - with no pause in between," said geologist Martin Kennedy of the University of California at Riverside, who led the research team.

"What we now need to know is the sensitivity of the trigger," Kennedy said. "How much forcing does it take to move from one stable state to the other - and are we approaching something like that today with current carbon dioxide warming?"

Also called marsh gas, methane is a colorless, odorless gas. As a greenhouse gas, it is about 30 times more potent than carbon dioxide.

Methane clathrates still exist in Arctic permafrost and beneath the oceans at continental margins. Kennedy said it's possible that very little warming could unleash this trapped methane, potentially warming the planet by tens of degrees.

Kennedy and colleagues collected hundreds of marine sediment samples in South Australia for stable isotope analysis, an important tool used in climate reconstruction. They found the broadest range of oxygen isotopic variation ever reported from marine sediments, which they attribute to melting waters in ice sheets as well as destabilization of clathrates by glacial meltwater.

"Today we're conducting a global-scale experiment with Earth's climate system," Kennedy said, "and witnessing an unprecedented rate of warming, all with little or no knowledge of what instabilities lurk in the climate system and how they can influence life on Earth."

He said Nature did a similar experiment 635 million years ago, "and the outcome is preserved in the geologic record. We see that strong forcing on the climate, not unlike the current carbon dioxide forcing, results in the activation of latent controls in the climate system that, once initiated, change climate to a completely different state."

The research, detailed in the May 29 issue of the journal Nature, was supported by the National Science Foundation and NASA's Exobiology Program.

Top 10 Ways to Destroy Earth Global Melt: Sea Ice Seen From Orbit How Lowly Bacteria Froze Earth Solid Original Story: Runaway Global Warming 635 Million Years Ago

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RAIN, RAIN: GO AWAY!

It has been raining here for three days and nights. Not just rain, but downpours with high winds! Every tiny defect in the galvanized iron roofs of the people in Costa Rica has been exaggerated many fold. We've got big pots scattered all over the house and/or attic to collect the water from the leaks. It is impossible now to do any repairs because we haven't had even ten minutes of sunshine in which to work. This is a Central American country not far from the equator. And it has been COLD!

My wood-burning stove's chimney pipe burnt through a month ago, and I've been waiting for my neighbor and builder, Carlos, to finish another project so that he can come over here and make a new chimney. Now, with a big hole in the chimney pipe, I cannot use the stove to heat the house and dry out some of the air. And my solar hot water heater is no longer producing hot water. So no hot showers. I do have LP gas for my kitchen stove and we are only losing electricity sporatically (as usual) so no big problems with cooking or lights, etc. I have a huge back-up water tank holding potable water in case of national potable water service failures, but that doesn't look as though it will be a problem.

I have chronic sinus problems and now I've been having sinus bleeds and much pain for two days. A result of very low pressure systems over the country. Ouch!

But it could be much, much worse. We did have three little earthquakes a couple of days ago, but they caused no damage, thank goodness! Guanacaste Province in the north had been in the depths of a very serious drought! Cattle died and crops withered. Now they are suddenly dealing with major flooding.

I have just learned that this nasty weather system has been declared a tropical storm and is moving toward Nicaragua where it is expected to make landfall. Poor Nicas! The economy of Nicaragua is in shambles and Costa Rica is flooded with illegal immigrants fleeing starvation and seeking some kind of income to send to families in Nicaragua. So that poor nation certainly doesn't need more troubles! The tiny isthmus called Central America doesn't need more trouble. It has been plagued by war, disease, hunger, floods, earthquakes, and dictatorships! Costa Rica and Panama are making some progress toward a better life for its citizens, but the rest of Central America still has a long, long way to go.

Does it seem that this year has already been one of the most devastating in memory for natural disasters worldwide? Or am I seeing things with a jaundiced eye?

It is hard for people who have enough and more than enough security to carry them through any rough times to realize what the reality is for the people caught in the aftermath of a natural disaster. It is worse than a return to the stone age in terms of living day to day. It is surviving a minute at a time in constant fear and post-traumatic stress without enough food, water, or shelter and with the menacing possibilities that even worse tragedies lie ahead for survivors. We lucky few in this world who never have to live for months without bathing, with only enough water to sip a bit at a time, with scavenging for food, with cold, wet, and hunger gnawing at their bodies while grief and fear and anger battle in their souls - we lucky few cannot begin to imagine the true horror of these disasters.

And I wonder if this is not just a fluke of nature, but the beginning of the end. Is it too late to save life on this planet? Are we now facing another great extinction such as the one that wiped out the dinosaurs?

Don't just sit there shrugging! Do something useful! It's now or never, Folks!