Posts Tagged ‘climate change’

Physicist Steven Desch has come up with a novel solution to the problems that now beset the Arctic. He and a team of colleagues from Arizona State University want to replenish the region’s shrinking sea ice – by building 10 million wind-powered pumps over the Arctic ice cap. In winter, these would be used to pump water to the surface of the ice where it would freeze, thickening the cap.

The pumps could add an extra metre of sea ice to the Arctic’s current layer, Desch argues. The current cap rarely exceeds 2-3 metres in thickness and is being eroded constantly as the planet succumbs to climate change.

“Thicker ice would mean longer-lasting ice. In turn, that would mean the danger of all sea ice disappearing from the Arctic in summer would be reduced significantly,” Desch told the Observer.

Desch and his team have put forward the scheme in a paper that has just been published in Earth’s Future, the journal of the American Geophysical Union, and have worked out a price tag for the project: $500bn (£400bn).

It is an astonishing sum. However, it is the kind of outlay that may become necessary if we want to halt the calamity that faces the Arctic, says Desch, who, like many other scientists, has become alarmed at temperature change in the region. They say that it is now warming twice as fast as their climate models predicted only a few years ago and argue that the 2015 Paris agreement to limit global warming will be insufficient to prevent the region’s sea ice disappearing completely in summer, possibly by 2030.

“Our only strategy at present seems to be to tell people to stop burning fossil fuels,” says Desch. “It’s a good idea but it is going to need a lot more than that to stop the Arctic’s sea ice from disappearing.”

The loss of the Arctic’s summer sea ice cover would disrupt life in the region, endanger many of its species, from Arctic cod to polar bears, and destroy a pristine habitat. It would also trigger further warming of the planet by removing ice that reflects solar radiation back into space, disrupt weather patterns across the northern hemisphere and melt permafrost, releasing more carbon gases into the atmosphere.

Hence Desch’s scheme to use wind pumps to bring water that is insulated from the bitter Arctic cold to its icy surface, where it will freeze and thicken the ice cap. Nor is the physicist alone in his Arctic scheming: other projects to halt sea-ice loss include one to artificially whiten the Arctic by scattering light-coloured aerosol particles over it to reflect solar radiation back into space, and another to spray sea water into the atmosphere above the region to create clouds that would also reflect sunlight away from the surface.

All the projects are highly imaginative – and extremely costly. The fact that they are even being considered reveals just how desperately worried researchers have become about the Arctic. “The situation is causing grave concern,” says Professor Julienne Stroeve, of University College London. “It is now much more dire than even our worst case scenarios originally suggested.’

Last November, when sea ice should have begun thickening and spreading over the Arctic as winter set in, the region warmed up. Temperatures should have plummeted to -25C but reached several degrees above freezing instead. “It’s been about 20C warmer than normal over most of the Arctic Ocean. This is unprecedented,” research professor Jennifer Francis of Rutgers University told the Guardian in November. “These temperatures are literally off the charts for where they should be at this time of year. It is pretty shocking. The Arctic has been breaking records all year. It is exciting but also scary.”

Nor have things got better in the intervening months. Figures issued by the US National Snow and Ice Data Center (NSIDC), in Boulder, Colorado, last week revealed that in January the Arctic’s sea ice covered 13.38 million sq km, the lowest January extent in the 38 years since satellites began surveying the region. That figure is 260,000 sq km below the level for January last year, which was the previous lowest extent for that month, and a worrying 1.26 million sq km below the long-term average for January.

In fact, sea ice growth stalled during the second week of January – in the heart of the Arctic winter – while the ice cap actually retreated within the Kara and Barents seas, and within the Sea of Okhotsk. Similarly, the Svalbard archipelago, normally shrouded in ice, has remained relatively free because of the inflow of warm Atlantic water along the western part of the island chain. Although there has been some recovery, sea ice remains well below all previous record lows.

This paucity of sea ice bodes ill for the Arctic’s summer months when cover traditionally drops to its lower annual level, and could plunge to a record minimum this year. Most scientists expect that, at current emission rates, the Arctic will be reliably free of sea ice in summer by 2030.

By “free” they mean there will be less than 1m sq km of sea ice left in the Arctic, most of it packed into remote bays and channels, while the central Arctic Ocean over the north pole will be completely open. And by “reliably”, scientists mean there will have been five consecutive years with less than 1m sq km of ice by the year 2050. The first single ice-free year will come much earlier than this, however.

And when that happens, the consequences are likely to be severe for the human and animal inhabitants of the region. An ice-free Arctic will be wide open to commercial exploitation, for example. Already, mining, oil and tourism companies have revealed plans to begin operations – schemes that could put severe strain on indigenous communities’ way of life in the region.

Equally worrying is the likely impact on wildlife, says Stroeve. “Juvenile Arctic cod like to hang out under the sea ice. Polar bears hunt on sea ice, and seals give birth on it. We have no idea what will happen when that lot disappears. In addition, there is the problem of increasing numbers of warm spells during which rain falls instead of snow. That rain then freezes on the ground and forms a hard coating that prevents reindeer and caribou from finding food under the snow.”

Nor would the rest of the world be isolated. With less ice to reflect solar radiation back into space, the dark ocean waters of the high latitudes will warm and the Arctic will heat up even further.

“If you warm the Arctic you decrease the temperature difference between the poles and the mid-latitudes, and that affects the polar vortex, the winds that blow between the mid latitudes and the high latitudes,” says Henry Burgess, head of the Arctic office of the UK Natural Environment Research Council.

“Normally this process tends to keep the cold in the high north and milder air in mid-latitudes but there is an increasing risk this will be disrupted as the temperature differential gets weaker. We may get more and more long, cold spells spilling down from the Arctic, longer and slower periods of Atlantic storms and equally warmer periods in the Arctic. What happens up there touches us all. It is hard to believe you can take away several million sq km of ice a few thousand kilometres to the north and not expect there will be an impact on weather patterns here in the UK.”

For her part, Stroeve puts it more bleakly: “We are carrying out a blind experiment on our planet whose outcome is almost impossible to guess.”

This point is backed by Desch. “Sea ice is disappearing from the Arctic – rapidly. The sorts of options we are proposing need to be researched and discussed now. If we are provocative and get people to think about this, that is good.

“The question is: do I think our project would work? Yes. I am confident it would. But we do need to put a realistic cost on these things. We cannot keep on just telling people, ‘Stop driving your car or it’s the end of the world’. We have to give them alternative options, though equally we need to price them.”

THE BIG SHRINK
The Arctic ice cap reaches its maximum extent every March and then, over the next six months, dwindles. The trough is reached around mid-September at the end of the melting season. The ice growth cycle then restarts. However, the extent of regrowth began slackening towards the end of the last century. According to meteorologists, the Arctic’s ice cover at its minimum is now decreasing by 13% every decade – a direct consequence of heating triggered by increased levels of carbon dioxide in the atmosphere.

Climate change deniers claim this loss is matched by gains in sea ice around the Antarctic. It is not. Antarctic ice fluctuations are slight compared with the Arctic’s plummeting coverage and if you combine the changes at both poles, you find more than a million sq km of ice has been lost globally in 30 years.

https://www.theguardian.com/world/2017/feb/12/plan-to-refreeze-arctic-before-ice-goes-for-good-climate-change

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The army base at Camp Century in Greenland was abandoned in the ’60s, leaving behind buried toxic waste that may become exposed by the end of the century. (Photo: U.S. Army/Wikimedia Commons)

by Sami Grover

When the Cold War ended, much of the world breathed a huge sigh of relief. And while the immediate threat of nuclear armageddon may have faded, there are countless sites around the world that are still burdened with the toxic legacy of military superpowers.

As global climate change reshapes our world, at least one such site is in danger of becoming a more immediate problem.

As reported over at Scientific American, Camp Century in northwest Greenland was a U.S. military base abandoned in the mid-1960s. When American forces shipped out, they left behind literally thousands of tons of waste buried deep inside tunnels that were dug out of the thick, year-round ice. Not unreasonably — given that the tunnels were 120 feet below the surface, and that fresh snow fell every year to bury the tunnels ever deeper — an assumption was made that the waste would remain buried for tens of thousands of years. But we all know what they say about assumptions…

With the rapid rate of Greenland’s ice melt (which CNN reports is off to a record start this year), concerns are surfacing that the buried waste — which includes everything from radioactive coolant to toxic PCBs — will be exposed much sooner than previously thought. A new study led by glaciologist William Colgan of York University in Toronto suggests that while cleaning up the site will have to wait until melting brings it closer to the surface, now would be a good time for world powers to start thrashing out who is responsible for such long abandoned waste materials.

http://www.mnn.com/earth-matters/climate-weather/stories/melting-ice-could-expose-cold-war-toxic-waste


The Temple of Quechula was built in 1564 but later abandoned and ultimately submerged by a dam. Now drought conditions in Chiapas have seen it rise again.

The ruins of a 16th century church have emerged from the waters of a reservoir in Mexico.

The water level in the Nezahualcóyotl reservoir in Chiapas state has dropped by 25m (82ft) because of a drought in the area. The church, known as the Temple of Santiago or the Temple of Quechula, has been under nearly 100ft of water since 1966.

The church, which is believed to have been built by Spanish colonists, is 183ft long and 42ft wide, with a bell tower that rises 48ft above the ground.

It was built in 1564, the Associated Press reported, because of an expected surge in population, but abandoned after plague hit the area between 1773 and 1776.

“It was a church built thinking that this could be a great population center, but it never achieved that,” architect Carlos Navarretes said. “It probably never even had a dedicated priest, only receiving visits from those from Tecpatán.”

http://www.theguardian.com/world/2015/oct/19/drought-mexican-church-reservoir

There is no precedent in contemporary weather records for the kinds of droughts the country’s West will face, if greenhouse gas emissions stay on course, a NASA study said.

No precedent even in the past 1,000 years.

The feared droughts would cover most of the western half of the United States — the Central Plains and the Southwest.

Those regions have suffered severe drought in recent years. But it doesn’t compare in the slightest to the ‘megadroughts’ likely to hit them before the century is over due to global warming.
These will be epochal, worthy of a chapter in Earth’s natural history.

Even if emissions drop moderately, droughts in those regions will get much worse than they are now, NASA said.

The space agency’s study conjures visions of the sun scorching cracked earth that is baked dry of moisture for feet below the surface, across vast landscapes, for decades. Great lake reservoirs could dwindle to ponds, leaving cities to ration water to residents who haven’t fled east.

“Our projections for what we are seeing is that, with climate change, many of these types of droughts will likely last for 20, 30, even 40 years,” said NASA climate scientist Ben Cook.

That’s worse and longer than the historic Dust Bowl of the 1930s, when “black blizzards” — towering, blustery dust walls — buried Southern Plains homes, buggies and barns in dirt dunes.

It lasted about 10 years. Though long, it was within the framework of a contemporary natural drought.

To find something almost as extreme as what looms, one must go back to Medieval times.

Nestled in the shade of Southwestern mountain rock, earthen Ancestral Pueblo housing offers a foreshadowing. The tight, lively villages emptied out in the 13th century’s Great Drought that lasted more than 30 years.

No water. No crops. Starvation drove populations out to the east and south.

If NASA’s worst case scenario plays out, what’s to come could be worse.

Its computations are based on greenhouse gas emissions continuing on their current course. And they produce an 80% chance of at least one drought that could last for decades.

One “even exceeding the duration of the long term intense ‘megadroughts’ that characterized the really arid time period known as the Medieval Climate Anomaly,” Cook said.

That was a period of heightened global temperatures that lasted from about 1100 to 1300 — when those Ancestral Pueblos dispersed. Global average temperatures are already higher now than they were then, the study said.

The NASA team’s study was very data heavy.

It examined past wet and dry periods using tree rings going back 1,000 years and compared them with soil moisture from 17 climate models, NASA said in the study published in Science Advances.

Scientists used super computers to calculate the models forward along the lines of human induced global warming scenarios. The models all showed a much drier planet.

Some Southwestern areas that are currently drought-stricken are filling up with more people, creating more demand for water while reservoirs are already strained.

The predicted megadroughts will wrack water supplies much harder, NASA Goddard Space Flight Center said.

“These droughts really represent events that nobody in the history of the United States has ever had to deal with,” Cook said.

Compared with the last millennium, the dryness will be unprecedented. Adapting to it will be tough.

http://www.cnn.com/2015/02/14/us/nasa-study-western-megadrought/index.html

Climate change could affect the ratio of human males to human females that are born in some countries, a new study from Japan suggests. The researchers found that male fetuses may be particularly vulnerable to the effects of climate change.

Since the 1970s, temperature fluctuations from the norm have become more common in Japan, and at the same time there has been an increase in the deaths of male fetuses, relative to the number of deaths of female fetuses in that country, according to the study.

Over this period, the ratio of male to female babies born in the country has been decreasing, meaning there have been fewer and fewer male babies born relative to the number of female babies born.

http://www.livescience.com/48070-male-fetus-climate-change.html