All is not well at the ends of the world. A warming Arctic may release enough methane currently trapped in submarine permafrost to trigger an economic meltdown. A warming Antarctica will impact krill habitats, affecting the marine food chain and lives of countless marine animals. The situation is not any better in the belly of the world either, as the practice of hydraulic fracturing used in gas mining has been proved to trigger earthquakes. Read more

Arctic warming poses potential economic meltdown

If the Arctic Ocean warms enough to release much of the methane stored beneath the seabed, the cost could almost equal the value of the global economy, scientists say

By Tim Radford in Climate News Network (4 August 2013):

The true cost of an ice-free Arctic summer could be counted in lives lost, communities flooded and economies ruined, three scientists warn.

Methane in the submarine permafrost could be released on such a scale that the cost to the world’s economy could reach $60 trillion.

The value of the entire world economy in 2012 was $70 trillion.

Gail Whiteman is at the school of management at Erasmus University in Rotterdam, Peter Wadhams is a professor of ocean physics at the University of Cambridge and Peter Hope is at the Judge Business School in Cambridge.

All three argue, in the journal Nature, that while businesses consider the benefits of Arctic warming in terms of shorter sea routes and easier access to fossil fuel reserves, the potentially catastrophic consequences are being ignored.

The problem they foresee is relatively straightforward and has been of concern to climate scientists for years. For all human history, the Arctic Ocean has been capped by ice.

Beneath the ice is sunless ocean, and beneath the ocean is permanently frozen seabed, and within the seabed are billions of tonnes of marsh gas or natural gas stored as frozen methane hydrate.

For the past 30 years, the ice has been reducing both in volume and in area, and in September 2012 reached an all-time low.

Some researchers calculate that by the 2050s, the Arctic Ocean will be ice-free in September.

But, says Wadhams, beneath the ice cap the ocean was effectively maintained at freezing point, which meant that the ocean floor below remained permanently at freezing point, which meant that methane hydrate, held under pressure for millions of years below the ocean floor, stayed safely locked away.

Once the ice is gone, the sea starts to absorb solar radiation, and last year reached almost 7°C.

The East Siberian Sea covers a shallow shelf, 50 to 100 metres deep, and in recent summers a joint Russian-US research team has been measuring releases of methane from the warming sea bed.

Methane is a powerful greenhouse gas: it is relatively short-lived in the atmosphere, but it is also 23 times more potent than carbon dioxide as an agent of global warming.

So a massive and sustained release of 50 billion tonnes of methane from the East Siberian shelf alone, they calculated, would speed up global warming, bring forward the date at which the world would warm by 2°C by between 15 and 25 years, change weather patterns, precipitate extremes of flooding, drought and storms, bring health risks, mostly for those in the developing world – and have major implications for national economies.

To find out just how much of a disaster could occur, they took an economic model used for the British Government’s 2006 Stern Review of the Economics of Climate Change, and ran it 10,000 times to find a mean economic cost, which is how they arrived at the $60 trillion figure.

But, of course, had they factored in other consequences of global warming – ocean acidification is one of them – the figure could have been still higher. Gail Whiteman described the data they had arrived at as “incredibly compelling” and warned that it presented an economic timebomb.

“All nations will be affected, not just those in the far north, and all should be concerned about changes occurring in the region”, the authors warn. “More modelling is needed to understand which regions and parts of the world economy will be most vulnerable.”

They also warn that it may be impossible to avoid large releases of methane without major reductions in global emissions of carbon dioxide, and they urge the World Economic Forum to ask world leaders to consider what might lie beyond short-term gains from a more open Arctic.

“Arctic science is a strategic asset for human economies because the region drives critical effects in our biophysical, political and economic systems”, they write. “Without this recognition, world leaders and economists will miss the big picture.”

Source: www.climatetimes.com/

Warming Antarctic seas likely to impact on krill habitats

21 August 2013:

Antarctic krill are usually less than 6 cm in length but their size belies the major role they play in sustaining much of the life in the Southern Ocean. They are the primary food source for many species of whales, seals, penguins and fish.

Krill are known to be sensitive to sea temperature, especially in the areas where they grow as adults. This has prompted scientists to try to understand how they might respond to the effects of further climate change.

Using statistical models, a team of researchers from the British Antarctic Survey and Plymouth Marine Laboratory assessed the likely impact of projected temperature increases on the Weddell Sea, Scotia Sea and Southern Drake Passage, which is known for its abundance of krill. This region has experienced sea surface warming of as much as 1°C over fifty years. Projections suggest this could rise by another 1°C by the end of the 21st century.

The models are based on equations which link krill growth, sea surface temperature, and food availability. An analysis of the results, published this week in the online journal PLOS ONE, suggests warming, if continued, could reduce the area of growth habitat by up to 20%.

In the early life stages krill require deep water with low acidity and a narrow range of temperatures for their eggs to successfully hatch and develop. The larvae then feed on algae on the underside of sea ice.

The adults require suitable temperatures and enough of the right type of food (larger phytoplankton) to successfully grow and reproduce. Many of these critical environmental features (temperature, acidity, sea ice and food availability) could be affected by climate change.

The projected effects of warming are not evenly spread. The island of South Georgia is located within the area likely to be worst affected. Here the reduction in krill habitat could be as much as 55%. The island is home to a range of animals such as fur seals and macaroni penguins that depend upon krill, and others, such as black-browed albatrosses, which eat substantial amounts of krill as well as fish and squid. The researchers say animals which don’t travel far to forage, such as fur seals, would be most affected by the projected changes.

Krill is also being commercially fished, although there is nothing to suggest current levels are unsustainable. In fact, at less than 1% of estimated biomass, catches are much lower than most other commercial fisheries.

But the Antarctic krill fishery took 68% of its total catch between 1980 and 2011 from the area of projected habitat degradation. The scientists suggest improved management systems to ensure the fisheries take into account both growing demand for catches and climate change.

Lead author, Dr. Simeon Hill, a marine biologist at BAS, said:

“Each year, growth of Antarctic krill in the Southern Ocean produces new material that weighs twice as much as all the sugar produced in the world. Krill grow fastest in cold water and any warming can slow down or stop growth, reducing the food available for wildlife. Our research suggests that expected warming this century could severely reduce the area in which krill can successfully grow.”

Although there is evidence that warming seas pose a threat to Antarctic krill habitats the team of researchers believe this can be significantly reduced by putting effective management systems in place.

Source: www.antarctica.ac.uk

Does fracking cause earthquakes or not?

By Andreas Späth for News 24 (23 July 2013):

Last week I asked (and tried to answer) the question whether or not fracking causes groundwater pollution. Another issue that’s been in the news lately and one that causes a fair amount of confusion concerns the connection between the controversial oil and gas extraction method and earthquakes.

On one level, the answer to this one is straight forward enough: yes, fracking does cause earthquakes. In simplistic terms, the pressurised fluids injected into fracking wells lubricate pre-existing but dormant fault planes and thus increase the likelihood that they rupture, causing two adjoining bodies of rock to slide and grind past each other and the ground above to shake.

But that only addresses part of the matter. The more pertinent concern is how severe these fracking-related seismic events are.

In 2011, the British Geological Survey confirmed that two earth tremors near Blackpool in North-West England were most likely to have been the result of exploratory shale gas drilling operations employing fracking in the area and the company doing the drilling, Cuadrilla Resources, accepted responsibility for the events.

Causing earthquakes

The quakes in question were very weak, however, with magnitudes of 2.3 and 1.5 on the Richter scale respectively, and they caused neither damage nor injuries.

A recent study by a group of British scientists identified merely three earthquakes caused by human activity that could be attributed to fracking since 1929 – one each in the USA, Canada and the UK. The largest of these occurred in the Horn River Basin in Canada and had a magnitude of 3.8.

While the study “established beyond doubt” that fracking can indeed cause earthquakes, the lead author, Professor Richard Davies of Durham University concluded that it’s not a significant mechanism for inducing tremors that can actually be felt by anyone other than a seismologist using fairly sensitive measuring equipment.

So if fracking is ever going to happen in South Africa, a direct increase in earthquakes powerful enough to cause damage or injury is not something we should worry about a whole lot. Which is, of course, not the same as saying that fracking won’t cause damage and injury in a number of other ways – it will!

But this is not quite the end of the story. While fracking itself is not a major inducer of dangerous earthquakes, a closely associated activity may well be.

Fracking produces millions of litres of wastewater in the USA every year and a lot of that waste is disposed of by pumping it into deep underground wells. Over 150 000 of these injection wells are now in operation in the country to get rid of wastewater from the oil and gas fracking operations.

This practice (which is illegal in the EU) has been directly linked to significantly more severe earthquakes than those caused by fracking itself. In 2011, for example, a 5.7 magnitude tremor in Oklahoma believed to be caused by injection wells for fracking wastewater was felt in 17 states, destroyed 14 homes and injured two people.

In Arkansas, earthquakes of magnitude 2.5 and larger have increased drastically since similar injection wells became operational in 2009 (up from just one in 2007 to 157 in 2011) and 98% of them occurred within 6 kilometres of three wells after wastewater injection started.

The verdict

In the whole of the American Midwest, in what should naturally be a tectonically stable region, “a remarkable increase” in the rate of earthquakes of magnitude 3 and higher has been documented since the fracking boom took off there.

This month, researchers showed that in areas that have undergone extensive underground injection of fluids, significantly tremors can be triggered by much larger earthquakes thousands of kilometres away. The event in Oklahoma I mentioned above, for instance, is likely to have been set off by a magnitude 8.8 quake in Chile.

So what’s the verdict in a nutshell?

Current scientific opinion suggests that fracking in and of itself is unlikely to cause dangerous earthquakes. If, however, large quantities of wastewater from fracking operations are injected into disposal wells, the area in question is likely to become susceptible to more powerful and potentially damaging earthquakes.

• Andreas is a freelance writer with a PhD in geochemistry

Source: www.news24.com/