Global perils of dirt, glaciers and lizardocalypse overblown, say boffins
Another three ways the world isn't ending right now
Posted in Science, 21st May 2013 04:59 GMT
A trio of new studies out this week have undermined three of the basic ideas underpinning the belief that the world is facing imminent doom as a result of human carbon emissions and perhaps-associated global warming in past decades. It would seem that the menaces of a runaway feedback loop driven by carbon belching from overheated Arctic dirt, surging sea levels powered by melting mountain glaciers, and imminent extinction for cuddly tropical lizards are all a lot less likely than scientists had previously thought.
Arctic dirt belch peril
First up: It's long been suggested that rising global temperatures like those seen in the 1980s and 1990s might cause chilly soils in Arctic regions to vent off much of the carbon locked within them, so further warming the world and releasing even more carbon in a terrifying runaway feedback loop until all the Earth became a baking lifeless hell.
Indeed this idea has been so common that when a couple of California-based boffins, Seeta Sistla and Josh Schimel, headed up to a long-running experimental site in northern Alaska to look into the matter lately, they "had made certain assumptions", according to a university statement highlighting their research.
"We expected that because of the long-term warming, we would have lost carbon stored in the soil to the atmosphere," admits professor Schimel.
"Net soil carbon hasn't changed after 20 years," confirms the initially puzzled Sistla.
The two boffins believe this is because as the local plants warmed up, they grew more and so pulled more carbon from the atmosphere - so putting it back into the soil again.
"It's a surprising counterbalance," says prof Schimel.
Read all about it courtesy of blockbusting boffinry mag Nature, here .
Glacier melt sea-biggening waterworld flood inundation MENACE
Everyone remembers the knockabout IPCC prediction that mountain glaciers around the world would all melt by the year 2035, not only starving the hungry millions of India as their rivers dried up but also causing the world's seas to rise by serious amounts with resultant floods, tsunamis, devastation etc.
The 2035 timeline was subsequently admitted to be bunk, but many scientists remained worried about glacier melt. The major Antarctic and Greenland ice sheets are so huge that it's generally admitted they would take a very long time indeed to melt - thousands of years, probably - even if so inclined, but glaciers are much smaller and might turn to water in much less time.
In particular, estimates put together by scientists observing glaciers on the ground seemed to suggest some cause for alarm. But then results from the new GRACE ice-scanner satellites last year  showed that in fact the glaciers of the world are simply not much affected.
This has now been further confirmed by a new NASA study of satellite data. We learn  courtesy of the US space agency:
The study builds on a 2012 study using only GRACE data that also found glacier ice loss was less than estimates derived from ground-based measurements.
"Ground observations often can only be collected for the more accessible glaciers, where it turns out thinning is occurring more rapidly than the regional averages," says Alex Gardner, Earth scientist at Clark University in Massachusetts.
"That means when those measurements are used to estimate the mass change of the entire region, you end up with regional losses that are too great ... Without having these independent observations, there was no way to tell that the ground observations were biased."
So, even if global warming carries on - it's been on hold for over a decade at the moment, but many scientists think that could be just a blip - it would seem that the seas aren't going to rise at any rate which would be a problem.
Lizards - the pandas of the tropics, maybe - not doomed after all
And finally today, it seems that tropical forest lizards, generally thought by all experts to be facing a scaly armageddon at the hands of human carbon emissions, are actually, not.
According to a press release issued by ivy-league academic hothouse Dartmouth College:
Human-caused climate change may have little impact on many species of tropical lizards, contradicting a host of recent studies that predict their widespread extinction in a rapidly warming planet.
"Studies conducted to date have made uniformly bleak predictions for the survival of tropical forest lizards around the globe [but] our data show that four similar species, occurring in the same geographic region, differ markedly in their vulnerabilities to climate warming," the authors of the study write in the learned journal  Global Change Biology. "Moreover, none appear to be on the brink of extinction. Considering that these populations occur over extremely small geographic ranges, it is possible that many tropical forest lizards, which range over much wider areas, may have even greater opportunity to escape warming."
So that's all right then.