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Plastic polluted Arctic islands are dumping ground for Gulf stream
Beaches in the remote Arctic islands were found to be more polluted than European ones due to plastic carried from much further south
Beaches on remote Arctic islands are heavily polluted with plastic, a new expedition has found, demonstrating that the region is the dumping ground for waste carried northwards on the Gulf Stream.
The shorelines of islands in the Svalbard archipelago and of Jan Mayen island were found to be littered with much more plastic waste than on European beaches, despite tiny local populations.
Continue reading...Houston fears climate change will cause catastrophic flooding: 'It's not if, it's when'
Human activity is worsening the problem in an already rainy area, and there could be damage worthy of a disaster movie if a storm hits the industrial section
Sam Brody is not a real estate agent, but when his friends want to move home they get in touch to ask for advice. He is a flood impact expert in Houston – and he has plenty of work to keep him busy.
The Texas metropolis has more casualties and property loss from floods than any other locality in the US, according to data stretching back to 1960 that Brody researched with colleagues. And, he said, “Where the built environment is a main force exacerbating the impacts of urban flooding, Houston is number one and it’s not even close.”
Continue reading...Gas grab and global warming could wipe out Wadden Sea heritage site
The world’s largest unbroken intertidal system and a haven for migratory birds on the Dutch coastline is at risk of sinking out of existence
The world’s largest unbroken intertidal system of sand and mud flats could sink beneath the waves by the end of the century due to sea level rise and subsidence caused by gas drills funded by Barclays and other international banks.
The Unesco world heritage site at the Wadden Sea on the Dutch coast stretches over 10,000 sq km. Its saltmarshes, sandy shoals, dunes and mussel beds host millions of migratory birds every year, as well as thousands of basking seals.
Continue reading...Gods of garbage – in pictures
Fabrice Monteiro travelled to the most polluted places in Africa and created terrifying characters who roamed their midst dressed in eerie debris. They are spirits, he says, on a mission to make humans change their ways
Plovers pose on the dark peat hags
Bleaklow, Derbyshire So sleek, quick and nimble, with butter-gold speckles on its back, this bird is a shy jewel of the moors
The sombre northern flank of Bleaklow has three Black Cloughs, differentiated with admirable directness as Near, Middle and Far. Clough is a northern word, likely Old Norse in origin, for a cleft in a hill.
The overall effect is familiar enough – bleak, desolate, country. But look more closely and the contrasts are spectacular.
Continue reading...Bigger is now better for rooftop solar – even for low energy users
'Little sunfish' robot to swim in to Fukushima reactor
Invitation to comment on listing assessment for Trachystoma petardi (pinkeye mullet)
Invitation to comment on listing assessment for Pseudocheirus occidentalis (western ringtail possum)
Tesla to roll out “multiple” Powerpacks in NSW battery storage win
Clean coal won’t cut it, on costs or emissions, says Climate Council
Boom in rooftop PV shifting peaks, and taking market operator by surprise
Leading regional technical and advisory firm launches new brand, Ekistica
Invitation to comment on listing assessment for Assemblage of species associated with open-coast salt-wedge estuaries of western and central Victoria
Chinese scientists use satellite to smash quantum entanglement record
Carnegie gets nod for 10MW solar farm: “We should have lots of these””
Finkel’s Clean Energy target little more than state’s business-as-usual
Volcanoes under the ice: melting Antarctic ice could fight climate change
Iron is not commonly famous for its role as a micronutrient for tiny organisms dwelling in the cold waters of polar oceans. But iron feeds plankton, which in turn hold carbon dioxide in their bodies. When they die, the creatures sink to the bottom of the sea, safely storing that carbon.
How exactly the iron gets to the Southern Ocean is hotly debated, but we do know that during the last ice age huge amounts of carbon were stored at the bottom of the Southern Ocean. Understanding how carbon comes to be stored in the depth of the oceans could help abate CO2 in the atmosphere, and Antarctica has a powerful role.
Icebergs and atmospheric dust are believed to have been the major sources of this micronutrient in the past. However, in research published in Nature Communications, my colleagues and I examined calcite crusts from Antarctica, and found that volcanoes under its glaciers were vital in delivering iron to the ocean during the last ice age.
Today, glacial meltwaters from Greenland and the Antarctic peninsula supply iron both in solution and as tiny particles (less than 0.0001mm in diameter), which are readily consumed by plankton. Where glaciers meet bedrock, minute organisms can live in pockets of relatively warm water. They are able to extract “food” from the rock, and in doing so release iron, which then can be carried by underwater rivers to the sea.
Volcanic eruptions under the ice can create underwater subglacial lakes, which, at times, discharge downstream large masses of water that travel to the ice margin and beyond, carrying with them iron in particle and in solution.
The role of melting ice in climate change is as yet poorly understood. It’s particularly pertinent as scientists predict the imminent collapse of part of the Larsen C ice shelf.
Researchers are also investigating how to reproduce natural iron fertilisation in the Southern Ocean and induce algal blooms. By interrogating the volcanic archive, we learn more about the effect that iron fertilisation from meltwater has on global temperatures.
A polished wafer of the subglacial calcites. The translucent, crystalline layers formed while in pockets of water, providing nourishment to microbes. The opaque calcite with rock fragments documents a period when waters discharged from a subglacial lake formed by a volcanic eruption, carrying away both iron in solution and particles of iron. Supplied The Last Glacial MaximumDuring the Last Glacial Maximum, a period 27,000 to 17,000 years ago when glaciers were at their greatest extent worldwide, the amount of CO2 in the atmosphere was lowered to 180 parts per million (ppm) relative to pre-industrial levels (280 ppm).
Today we are at 400 ppm and, if current warming trends continue, a point of no return will be reached. The global temperature system will return to the age of the dinosaurs, when there was little difference in temperature from the equator to the tropics.
If we are interested in providing a habitable planet for our descendants, we need to mitigate the quantity of carbon in the atmosphere. Blooms of plankton in the Southern Ocean boosted by iron fertilisation were one important ingredient in lowering CO2 in the Last Glacial Maximum, and they could help us today.
The Last Glacial Maximum had winds that spread dust from deserts and icebergs carrying small particles into the Southern Ocean, providing the necessary iron for algal blooms. These extreme conditions don’t exist today.
Hidden volcanoesNeither dust nor icebergs alone, however, explain bursts of productivity recorded in ocean sediments in the Last Glacial Maximum. There was another ingredient, only discovered in rare archives of subglacial processes that could be precisely dated to the Last Glacial Maximum.
Loss of ice in Antartica’s Dry Valleys uncovered rusty-red crusts of calcite plastered on glacially polished rocks. The calcites have tiny layers that can be precisely dated by radiometric techniques.
A piece of subglacial calcite coating pebbles. This suggests that the current transporting the pebbles was quite fast, like a mountain stream. The pebbles were deposited at the same time as the opaque layer in the calcite formed. SuppliedEach layer preserves in its chemistry and DNA a record of processes that contributed to delivering iron to the Southern Ocean. For example, fluorine-rich spherules indicate that underwater vents created by volcanic activity injected a rich mixture of minerals into the subglacial environment. This was confirmed by DNA data, revealing a thriving community of thermophiles – microorganisms that live in very hot water only.
Then, it became plausible to hypothesise that volcanic eruptions occurred subglacially and formed a subglacial lake, whose waters ran into an interconnected system of channels, ultimately reaching the ice margin. Meltwater drained iron from pockets created where ice met bedrock, which then reached the ocean – thus inducing algal blooms.
We dated this drainage activity to a period when dust flux does not match ocean productivity. Thus, our study indicates that volcanoes in Antarctica had a role in delivering iron to the Southern Ocean, and potentially contributed to lowering CO2 levels in the atmosphere.
Our research helps explain how volcanoes act on climate change. But it also uncovers more about iron fertilisation as a possible way to mitigate global warming.
Silvia Frisia receives funding from ARC.