Wyrd - OE: that which has become; fate-shaping; destiny-unfolding

Monday, 12 November 2012

Ten tall-tales from the skeptics – the come-backs to topple them

Photo Credit: WireWizard
First published on EarthTimes as "Ten tall-tales from the climate change skeptics

The devil has all of the best songs, so they say. And the climate-change denial camp have certainly banged out their tunes to good effect, over the last few years. It's not hard to see why the clamor of the climate skeptics has won more and more of those thronging in the stalls. But if you're caught out by one of those seductive refrains from the naysayers, what you need is counter-melody to cut them short. So what are the top-ten comebacks to the tall-tales often peddled by the denialist community?

1 Warming isn't really happening, it's all down to the 'urban heat-island effect'
The consensus that the planet is warming didn't just drop off of a graph of dodgily-placed thermometers. Yes, cities and towns are warmer than the countryside, and yes, urban areas have swallowed rural ones over the last century. But climate scientists try to correct for these when working out the globe's average temperature.

And the indicators that temperatures are rising come from a myriad of sources, not just land-based temperature records. Satellites, tree-rings, snow and ice-cores, stalactites and corals – all of these are used to piece together the global temperature record. And they confirm that the recent warming is unprecedented.

Monday, 5 November 2012

Black stain or clean climate?

First published on Earth Times as "Clean stoves could save lives and maybe the climate too"

Flecks of soot from a smoky open fire in India blacken more than just the roofs of the hut it is smoldering in. Fine particles of such smoke lodge deep in the lungs of women preparing meals, gifting them a dark scourge of ill-health and premature death. That same black soot floats higher into the air, where it helps to change the way clouds form - and so to warm the climate. Some specks may even end up coating ice in the frozen extremes of the planet, dulling their pristine surfaces, and hastening the melt of glaciers and ice-caps.

And recent reports suggest that the weakening monsoon in India, and unprecedented storms in the Arabian Sea, may owe their genesis to the smoggy brown clouds gathered over the Indian sub-continent. For such tiny little particles, soot appears to be having mammoth impacts, and in a host of different ways. But the problem of soot is not one of those tangled and knotted issues that needs an impossibly herculean effort to sort out. It may be that its dark legacy can be addressed by something as simple as a clean-burning stove.

From cooking to climate change

The problem of the gathering smoggy clouds over many parts of the developing world has been visible for decades. But only recently have all of the implications become apparent. Some of the particles making up the haze come from wildfires; some from coal-burning power stations; some from diesel-fumes, as urban traffic swells. But in many places, and especially in the Indian sub-continent, a large share comes from cooking stoves. It is thought that up to 3 billion people worldwide still cook over open fires or stoves, filling their homes, and the local atmosphere, with smoke. Maybe 800 million of these people are in India, in both cities and villages. And the sheer number of their cooking fires is helping to build up a 2 mile-thick hazy cloud over much of South Asia.

Thursday, 6 September 2012

Drying wetlands threaten a climate unraveling

Credit : Natural Resources Canada, Canadian Forest Service
Everyone knows about 'our' carbon – the thin thread of black that we spin out into the atmosphere as man-made carbon-dioxide emissions. It's the direct byproduct of all our frantic making and heating, flying and driving; the restless energy that defines our modern age. And equally well-known is its consequence -- 'our' carbon is providing much of the impetus behind the globe's rising thermometer.

But that spooling out of long-buried fossil carbon isn't the only way in which we're pulling at the threads of the planet's complex tapestry. Another thread, that scientists are just starting to understand, is that of the carbon sunk into the wetland wildernesses of peats and bogs. And a study, released last year in Nature Communications, confirms the less-than-firm grip that researchers have on the flow of carbon, for these murkier parts of the planet.

It seems that what was thought to be a carbon sink is able to transform itself into a massive carbon pump - literally in just a flash of smoke.

Carbon is pooled in many places in the complex flow of the carbon cycle. Such 'sinks' are places where carbon is not easily released from, and so is kept from boosting the atmospheric CO2 count. In that sense carbon stores are important buffers against runaway global warming. The biggest such stores are to be found in the oceans, and deeply-buried rocks. But wetlands also play a part in storing carbon, on a smaller scale.

Wednesday, 29 February 2012

When Arctic ice goes, the North wind blows..

"Global warming is now making our winters colder!"

Only the craziest of eco-doom mongerers would be foolish enough to spout such nonsense, surely? The threat from a warming planet may take many guises, but making us colder – that's plainly on the 'wing-nut' side of things, isn't it. But in fact just such a claim is now being made, not by the deep-green fringe of the environmental movement – but by respected climate scientists from Columbia University, Georgia Tech and China's Institute of Atmospheric Physics. And the tale that their research lays out, in the most recent edition of the PNAS, is anything but a madman's babblings.

Patterns all-a-flux on the climate's patchwork quilt 

Instead, their paper coolly describes how the patchwork-quilt climate of the northern hemisphere is quickly unravelling, as the world warms. And for some – including parts of North America, Europe and Asia – the new pattern has plenty of colder winters woven into the fabric. That's something that no-one living there can fail to have noticed, in recent years. Deep snows and freezing temperatures have made themselves unwelcome guests, repeatedly, over the last four winters. But the culprit for all that cold may turn out to be the very thermostat dials being turned up, to keep us snug – all thanks to the global warming being bought on by higher greenhouse gas emissions.

The story begins 30,000 feet up, with the wandering band of winds – the polar jet stream – whistling around the Arctic regions, at up to 250 mph. This high, narrow wind-belt in fact marks the boundary between the cold airs at the North pole, and the warmer moist airs of the temperate zones. The jet stream keeps all that cold where it should be, up north – and the stronger the jet stream is, the more tightly those frigid airs are locked in at the pole. It's when the jet stream weakens and slows, that the cold air has a chance to spill down below the Arctic Circle, bringing harsher winters in its wake.

The sea-ice, the cliff and the snow

The driver for the jet stream, and the wall of winds separating the cold north from the warmer south, arises precisely from that stark contrast in temperatures. The cold dense air at the pole sinks to form high pressure; while the warmer air surrounding it rises, making a ring of low pressure systems. And the frozen sea-ice over the Arctic ocean acts as an anchor,  providing a deep pool of cold that is one of the drivers for a strong jet stream. 

But something has changed of late, and changed dramatically. The Arctic's cap of sea-ice, which was slowly receding thanks to global warming, fell off a cliff in 2007. Sea-ice volumes for the last 5 years have been half, or less, what they were before 2007 – as can be seen in the plummeting graph above. With less sea-ice after each summer's melt, those waters up north are taking longer to freeze over in the autumn.

That's where the team of researchers looking for reasons for the last few winters of record snowfalls – have turned, in the search for an explanation. ′For the past four winters, for much of the northern US, east Asia and Europe, we had this persistent above-normal snow cover,'  paper co-author Dr Jiping Liu, of Georgia Tech, explained. In order see if there was a connection between less sea-ice for the Arctic, and more snow for us, the team looked afresh at the mounds of sea-ice and snow data from 1979 to 2010. They also ran computer simulations that modeled the climate, with simulated sea-ice being reduced, as has unfolded in the real-world.

Spinning top ready to topple

The conclusions drawn from these two different approaches were the same, according to Dr Liu. More open water at the start of winter means more heat is passed back into the air, when the sea freezes. That heat makes the winter Arctic air mass warmer, and so softens the contrast in air temperatures. That in turn makes the jet stream more weak and wobbly – a bit like a spinning top losing speed, and on the verge of toppling over.

′We think the recent snowy winters could be caused by the retreating Arctic ice altering atmospheric circulation patterns by weakening westerly winds, increasing the amplitude of the jet stream and increasing the amount of moisture in the atmosphere,' he said. ′These pattern changes enhance blocking patterns that favor more frequent movement of cold air masses to middle and lower latitudes, leading to increased heavy snowfall in Europe and the Northeast and Midwest regions of the United States.′

So while the world gets relentlessly warmer – on average, and over a number of years – some of us are getting slaps of rude winter cold, much more often we used to. It's almost as if the planet is pressing out its own desperate S.O.S to the world's big polluters. And the madness, maybe, is not in the planet's contradictory message, but in the perpetrators – addicted to fossil-fueled growth – who continue to ignore it, at their own peril.