Pages: 1 ... 121 122 [123]   Go Down
Print
Author Topic: Pluto in Cap, the climate, ecology and environment topic  (Read 134010 times)
Rad
Moderator
Most Active Member
*****
Posts: 28032


« Reply #1830 on: Aug 31, 2015, 08:54 AM »

How the diets of early humans explain our eating habits

The Conversation
31 Aug 2015 at 10:16 ET                   

Much attention is being given to what people ate in the distant past as a guide to what we should eat today. Advocates of the claimed palaeodiet recommend that we should avoid carbohydrates and load our plates with red meat and fat. Its critics, on the other hand, argue that these are the same ingredients that would set us up for heart attacks. Moreover, these animal-derived foods require more space to produce on our crowded planet filled with starving humans.

A factual foundation for the debate is provided by a review of the eating patterns of early humans and how we adapted to digest starches softened by cooking. The researchers contend that it was digestible starches that provided extra energy needed to fuel the energy needs of bigger brains, rather than extra protein from meat to grow these brains.

But the most striking thing about human diets is just how variable they have been and the adaptations that have taken place. Furthermore, the American evolutionary biologist Marlene Zuk in her book Paleofantasy contends that these dietary adaptations are not fixed on what our ancestors ate in caves at some time in the past.

So are our energy, or protein, needs much different from other mammals of similar size? Brains demand a lot of energy but so does the liver and the digestive tract. The extra nutrition that we need for brain work may be counterbalanced, at least partially, by a lesser need for:

    a long gut to process poor quality foods, or
    a large liver to handle nasty chemicals in these plant parts.

Once built, a large brain does not require extra sources of protein to maintain its activities.

My studies on the dietary requirements of savanna-inhabiting herbivores highlight how these animals must cope with the dry season when most herbage is brown and indigestible even with the aid of microbial symbionts in the gut.

But carnivores do not have this problem because the dry season is when weakened herbivores are most readily killed, especially when they concentrate around scarce waterholes.

The role of carbs among early humans

Meat has long been part of human diets, along with carbohydrates provided by fruits, tubers and grains. We can get by without it, obtaining protein from milk or, with some planning, from legumes.

The early humans that consumed most meat were the Neanderthals, who lived in Europe many thousand years ago, but were not our ancestors. Meat formed the crucial lean-season food for the Neanderthal people during successive winters when plants were seasonally buried under deep snow, but later also for the modern humans who spread through Eurasia and displaced them around 40 000 years ago.

Unlike tropical Africa, meat could be stored during the freezing winters of the far north to provide a reliable food source, especially in the form of large carcasses of elephant-like proboscideans.

This led to a wave of large mammal extinctions as humans spread rapidly into Australia and entered the Americas towards the end of the last Ice Age. By that time hunting technology had been honed and meat routinely supplemented plant food, but the latter remained the dietary staple for African hunter-gatherers like the Bushmen or San people into modern times.

The food journey within evolution

Coping with the intensifying dry season in the expanding African savanna was a critical issue for human ancestors during the evolutionary transition from ape-men to the first humans between three and two million years ago. How did our ape-men ancestors gather sufficient to eat during this time of the year when nutritious fruits and leaves were scarce?

This was when meat, or at least the marrow left within bones, could have become a nutritional fallback, probably acquired by scavenging from animal carcasses not completely consumed by big fierce carnivores, along with underground storage organs of plants.

Obtaining this meat required more walking and hence longer limbs, hands freed to carry, security in numbers and stone weapons to throw at threatening carnivore fangs, but not much expansion in cranial capacity. These were features of the early Australopithicines.

At this early time, another branch of ape-men, placed in the genus Paranthropus, took a different adaptive route. They developed huge jaws to chew on tough plant foods extracted from underground storage organs to get them through the dry season.

The last representative of this genus faded out nearly a million years ago when this strategy eventually became unviable. About that time the lineage leading to early humans discovered cooking, or at least how to use it effectively to make starches stored by plants more readily digestible, according to the article in The Quarterly Review of Biology.

Adding this reliably found source of energy to the proteins acquired more opportunistically by hunting animals or gathering shellfish provided the means to survive through seasonal bottlenecks in food availability and build even bigger brains and the adaptations that followed.

A supporting adaptation was to store more body fat to get through the lean periods, especially among women supporting dependent offspring. This works against us now that foods supplying carbohydrates are plentiful.

The modern day dilemma

The problems we currently face are that we retain a craving for sugar, which was scarce the past, while most of the starchy carbohydrates we eat are highly refined. This means losing out on the other nutrients in plant parts like minerals and vitamins, and most basically fibre.

A meat-based diet could have a role to play for people who have a propensity to store fat by filling the gut for longer and alleviating desires to snack on sweets between meals. More important generally is the need to exercise so that we are hungry enough to consume sufficient food to provide the scarce micronutrients that we also require for healthy bodies.

The best advice is to eat lots of things: meat if you can afford it and justify its planetary costs to produce, but also all kinds of good food, as least refined and processed as you can obtain (apart from wines).

By Norman Owen-Smith, University of the Witwatersrand

Norman Owen-Smith is Emeritus Research Professor of African Ecology at University of the Witwatersrand

Logged
Rad
Moderator
Most Active Member
*****
Posts: 28032


« Reply #1831 on: Today at 05:21 AM »

August 31, 2015

Pacific Ocean trenches may be younger than previously thought

by Brett Smith
Red Orbit

A newly published report in the journal Nature Geoscience has found some deep trenches at the bottom of the Pacific Ocean to be much younger than previously thought and gives tantalizing new clues to how the Earth’s crust cracks open along the ocean floor.

The new report focuses on the development of subduction zones, or the boundaries where the Earth’s tectonic plates collide.

A subduction zone marks the collision between Earth’s tectonic plates, which are massive slabs of crust gradually moving over the planet’s surface over the course of millions of years. When two tectonic plates encounter each other at a subduction zone, one flexes and slides under the other.

Studying the "ring of fire"

Subduction zones were not discovered until the 1960s, but they happen all around the Pacific Ocean. Their frequency around the edges of the Pacific has led to the nickname, “ring of fire,” for the circular pattern. Subduction zones are the cause of many of the world’s largest earthquakes, volcanic eruptions, tsunamis, and other geological events.

In the study, the team analyzed core samples obtained from a subduction zone in the ocean south of Japan. The samples were extracted from water around 4,800 feet deep in the Pacific floor.

“From the core samples, we were able to date the sediments both with fossils and records of Earth’s past magnetic field reversals,” study author Kara Bogus, of Texas A&M’s International Ocean Discovery Program (IODP), said in a press release. “We found that this igneous crust is much younger – about 50 million years – than we originally thought. The fact that it is younger, coupled with its chemical composition, tells us how the subduction zone began.”

Bogus noted the study addresses one of the main unanswered questions in plate tectonics: how subduction zones start, or “initiate”.

“When these plates push under each other into the Earth, hot magma is created that erupts from volcanoes on the surface plate, such as has occurred in the Northern Mariana Islands,” Bogus said. “It’s half the story in plate tectonics. We understand well the other half (how the plates move apart from each other and create new crust), but we are just beginning to understand this half.”

“Overall, our results mean that we need to modify our subduction inception models,” she added.


* JOIDES-1a.jpg (158.58 KB, 1000x784 - viewed 0 times.)
Logged
Rad
Moderator
Most Active Member
*****
Posts: 28032


« Reply #1832 on: Today at 05:37 AM »

Full scale of plastic in the world's oceans revealed for first time

Over five trillion pieces of plastic are floating in our oceans says most comprehensive study to date on plastic pollution around the world

Oliver Milman
9/1/2015
Guardian

More than five trillion pieces of plastic, collectively weighing nearly 269,000 tonnes, are floating in the world’s oceans, causing damage throughout the food chain, new research has found.

Data collected by scientists from the US, France, Chile, Australia and New Zealand suggests a minimum of 5.25tn plastic particles in the oceans, most of them “micro plastics” measuring less than 5mm.

The volume of plastic pieces, largely deriving from products such as food and drink packaging and clothing, was calculated from data taken from 24 expeditions over a six-year period to 2013. The research, published in the journal PLOS One, is the first study to look at plastics of all sizes in the world’s oceans.

Large pieces of plastic can strangle animals such as seals, while smaller pieces are ingested by fish and then fed up the food chain, all the way to humans.

This is problematic due to the chemicals contained within plastics, as well as the pollutants that plastic attract once they are in the marine environment.

“We saw turtles that ate plastic bags and fish that ingested fishing lines,” said Julia Reisser, a researcher based at the University of Western Australia. “But there are also chemical impacts. When plastic gets into the water it acts like a magnet for oily pollutants.

“Bigger fish eat the little fish and then they end up on our plates. It’s hard to tell how much pollution is being ingested but certainly plastics are providing some of it.”

The researchers collected small plastic fragments in nets, while larger pieces were observed from boats. The northern and southern sections of the Pacific and Atlantic oceans were surveyed, as well as the Indian ocean, the coast of Australia and the Bay of Bengal.

The vast amount of plastic, weighing 268,940 tonnes, includes everything from plastic bags to fishing gear debris.

While spread out around the globe, much of this rubbish accumulates in five large ocean gyres, which are circular currents that churn up plastics in a set area. Each of the major oceans have plastic-filled gyres, including the well-known ‘great Pacific garbage patch’ that covers an area roughly equivalent to Texas.

Reisser said traversing the large rubbish-strewn gyres in a boat was like sailing through “plastic soup.”

“You put a net through it for half an hour and there’s more plastic than marine life there,” she said. “It’s hard to visualise the sheer amount, but the weight of it is more than the entire biomass of humans. It’s quite an alarming problem that’s likely to get worse.”

The research found that the gyres themselves are likely to contribute to the problem, acting as “shredders” to the plastic before dispersing it.

“Our findings show that the garbage patches in the middle of the five subtropical gyres are not the final resting places for the world’s floating plastic trash,” said Marcus Eriksen, another of the report’s co-authors. “The endgame for micro-plastic is interactions with entire ocean ecosystems.”

The research, the first of its kind to pull together data on floating plastic from around the world, will be used to chart future trends in the amount of debris in the oceans.

But researchers predict the volume will increase due to rising production of throwaway plastic, with only 5% of the world’s plastic currently recycled.

“Lots of things are used once and then not recycled,” Reisser said. “We need to improve our use of plastic and also monitor plastics in the oceans so we get a better understanding of the issue.

“I’m optimistic but we need to get policy makers to understand the problem. Some are doing that – Germany has changed the policy so that manufacturers are responsible for the waste they produce. If we put more responsibility on to the producer then that would be part of the solution.”

****************

Microplastic deposits found deep in world's oceans and seas

Study of 12 sites concludes that deep sea sediments are acting as a sink for substantial quantities tiny pieces of plastic

Adam Vaughan
9/1/2015 09.57 GMT
Guardian

Scientists believe they have solved the mystery of where tens of thousands of tonnes of missing tiny pieces of plastic are ending up – and the answer lies in the mud and sand on the ocean floor.

Researchers have previously been puzzled by why they found much less plastic on the ocean surface than they expected, but a study by a British and Spanish team concludes that deep sea sediments are acting as a sink for such “microplastics”.

Analysing samples from 12 sites in the Atlantic Ocean, Mediterranean Sea and Indian Ocean taken between 2001 and 2012, they found for the first time that substantial quantities of microplastics – which measure less than 1mm in length – had accumulated in deep sea sediment.

The tiny fibres were found at depths from 300m down at the shallowest in the Mediterranean to over 3,000m deep, at volumes 1,000 times higher than those at the surface of the sea.

Prof Lucy Woodall, of the Natural History Museum in London and the paper’s lead author, said: “This is the tip of the iceberg. Fibres are ubiquitous in our oceans and they do appear to be quite abundant in comparison with similar studies that have looked at similar things. The fundamental message of the paper is really quite simple: they’re there. Now we need to find out what the impacts are on our environment.”

A study earlier this month, the most comprehensive of its kind so far, estimated there are more than 5tn pieces of plastic in the world’s oceans, weighing nearly 269,000 tonnes. But the authors, who collected tens of thousands of pieces of plastic and then extrapolated that to model how many would be found worldwide, cautioned that the amount was just 0.1% of annual global plastic production.

The new work sampling deep sea sediments, published in the Royal Society Open Science journal on Wednesday, found pieces of plastic that were commonly 2–3 mm in length and less than 0.1 mm in diameter.

“The prevalence of plastic microfibres in all sediment cores and on all coral colonies examined suggests this contaminant is ubiquitous in the deep sea. Furthermore, the wide variety of polymer types detected reveals that the accumulation and deposition of microfibres in the deep sea is complex and that they arise from a variety of domestic and industrial sources,” the study said.

Woodall added: “Pretty much everything [is a potential source for what we found]. Just look around in our environment, our computers have plastic, our bags have, our cups have. All those things can potentially end up in the ocean, so to pinpoint any particular source is just not possible.”

The abundance of plastic at such depths has potentially negative ramifications for marine life, though the study says more research is needed. “A range of organisms are known to ingest microplastics, and there is concern this could result in physical and/or toxicological harm,” the authors warn.

****************

Drowning in plastic

We’ve all heard stories of islands of floating rubbish in the middle of the oceans, but it’s the trillions of barely visible microscopic fragments that are set to be the world’s next ecological emergency. Lucy Siegle reports

Lucy Siegle
9/1 2015 08.00 GMT
Guardian

I just sat next to a coral reef and watched the sharks go by,” says Céline Cousteau. The filmmaker is talking about a recent dive in Australia, when for once she left her camera behind. “There’s a certain grace when a massive tiger shark acknowledges your presence but just swings by. It doesn’t have time for you.” But then Cousteau is more comfortable in the ocean than most of us, as you might expect from the daughter of environmentalist Jean-Michel and granddaughter of Jacques, whose films first brought the deep to the surface.

Increasingly Cousteau finds herself battling to preserve not just the family legacy but the ocean itself. A member of the World Economic Forum Council on Oceans, she has spent the past few days at Davos pushing to move ocean issues up the global agenda. “My grandfather said: ‘People protect what they love.’ And my father followed with: ‘How can you protect what you don’t understand?’ I see my role as explaining to people why the health of oceans matters.”

In particular, it will be difficult to explain to future generations how and why humanity decided to use the planet’s oceans as a dustbin for plastic, a material known for its durability. Perhaps we thought it magically evaporated. Trillions of pieces are now swirling around the planet’s great oceanic gyres. Gyres occur when airflows moving from the tropics to the polar regions create a clockwise rotating air mass, which then drives oceanic surface currents in the same direction. It is here, where winds are light, that the plastic debris of our throwaway lives is dramatically visible.

Scientists and explorers are also drawn to the gyres, especially the so-called Eastern Garbage Patch in the north Pacific, the largest of the five major examples. Indeed, the trend threatens to displace the destruction of the Amazon rainforest as the ecological cause célèbre. Global adventurers (including David de Rothschild on a boat, Plastiki, made of plastic bottles) have headed to the Eastern Garbage Patch to raise public awareness, monitor the flux of plastic and to vlog for National Geographic.

While these swashbucklers have made an important contribution, however, they do not tell the full story. Richard Thompson, professor of marine biology at Plymouth University, wants to solve a huge mystery: rather than being stunned by the amount of plastic swirling around in the ocean, he has always wondered why there isn’t more.

It first occurred to him that something was missing when, as a PhD student, he co-ordinated beach clean-ups for the Marine Conservation Society. “Everyone collected the more exciting pieces, running to get a tyre or fishing net but trampling over thousands of bits of fragmented plastic,” he says. Once he started teaching his own students, he challenged them to find the smallest bits of plastic possible. They came back with sand samples and “from the start we saw pieces that didn’t look natural”. Rather than fancy field trips, he spent (and still spends) a good bit of time out in all weathers in the English Channel, just up from Plymouth’s Tamar estuary, with a trawl net.

Sieving the ocean is a thankless task. There are hundreds of variations of plastic polymers, and the natural world also throws up decoys: two tiny fragments in a test tube look to my eyes like so-called “mermaid’s tears”, small pellets which are a raw material in the manufacture of plastic that have spilled into the environment. More than 250bn are produced each year. “Actually,” says Thompson, “those are squid eyes.” In the ocean they’d naturally biodegrade.

In Lost at Sea: Where is All the Plastic?, a landmark study published in Science in 2004, Thompson and his team were able to demonstrate to the world that plastic litter seen in the gyres was only the start of the problem. The study coined the term microplastics (now commonly used) to describe tiny pieces of plastic under 5mm in diameter. Using the samples he had collected around Plymouth he showed microscopic plastic fragments to be abundant in the water column. He also used a cache of plankton samples dating back to the 1960s, collected on stretches of sea between Aberdeen and the Shetlands and between Sule Skerry and Iceland, very far from the subtropical gyres. Again these revealed microplastics but also proved that they had increased substantially since the 1960s, alongside our production and consumption of plastic. Thompson had his proof that microscopic pieces of plastic are potentially presenting a huge threat to the oceans.

After the 2004 study, he continued his plastic detection, doggedly crunching the numbers. Even taking into account microplastics on the ocean’s surface as well as all the more obvious junk monitored in the gyres, it didn’t add up. Each year globally we manufacture, at the very least, 300m tonnes of plastic, and the “flux” of plastic to the world’s oceans is suggested to be at least 0.1% of all plastic. Thompson added in “legacy plastic”, the results of six decades of producing plastic waste. But still there was a deficit. Where on earth was it?

Every detective needs a breakthrough moment. Thompson and his team had two. The first was in 2014, when they came across samples of sea ice from remote Arctic locations and tested it for microplastics. The results were extraordinary. Thompson found in some cases that the Arctic ice contained concentrations of microplastics greater even than in the Pacific gyre. What became apparent was that as it formed, sea ice concentrated natural particulates from the water column, drawing in a high level of microplastics.

I always imagined that this would be the point when scientists high-five each other and whoop for joy. But the discovery of a proportion of the missing plastics was cold comfort to a conservationist like Thompson. Not only did it illustrate the extensive reach of manmade plastics, but it also raised a second issue: if Arctic ice continues to melt at its current rate, then more than one trillion pieces of microplastic could be released. The toxicological and long-term environmental effects of this are unknown. Besides, Thompson’s figure still came up short even if he factored in the plastic residing in the bellies of seabirds.

The next breakthrough came from 3,000 metres below the ocean surface. Thompson received a call from Dr Lucy Woodall of the Natural History Museum, who had been surveying the deep seabed and found mystery particles. Far from bobbing around on the surface of the five gyres, an abundance of microplastics were likely to have accumulated at the bottom of the sea. Seemingly buoyant particles sank as they weathered, were colonised by organisms or caught up in storms. Another huge sink had been uncovered.

And there we might end, if this was just an eco whodunit. The bad news is that plastic contamination stretches from the seabed to Arctic ice and shorelines as far south as Punta Arenas, Chile. As Thompson puts it: “Everywhere we’ve looked so far for plastic contamination, we’ve found it.” But what is the impact of all this plastic, which can be ingested by almost every species and stored in their tissue? Now that Thompson has begun to work out where the plastic goes, he needs to quantify its impact.

“Plastic itself isn’t the problem,” he says. “It’s the way we use it that turns this wondrous material into a major waste problem.” The question remains: can we change our habits in time? It will take more than the efforts of the Plymouth University marine science department and a few dedicated environmentalists to make a difference.

Céline Cousteau, meanwhile, remains contemplative about the aquatic universe of which her family has done so much to raise awareness. If he were alive today, it’s hard not to think that her grandfather Jacques would be devoting his energies to raising awareness of the plastic pandemic. “It’s a privilege to have access to an underwater world,” Céline says. “Down there it’s sort of quiet, but loud at the same time.”

*************

‘Fifty miles out we could smell the pollution’: sailing amid the ocean litter

Justin Chisholm asks the sailors racing around the world about the state of the seas

Drowning in plastic: the world’s next ecological emergency

Justin Chisholm
Sept 1 2015 08.00 GMT
Guardian

For the majority of landlubbers, the fact that the world’s oceans are clogging up with the detritus of a rampant consumer society can easily be ignored. For most, the watery expanses beyond our coastlines might just as well be another planet.

Not so for the crews of the fleet of high-speed ocean racing yachts currently competing in the Volvo Ocean Race around the world, which spend up to three weeks at a time at sea racing day and night. For them the effects of ocean littering are all too obvious.

British double Olympic silver medallist Ian Walker skippers the Abu Dhabi Ocean Racing team and is competing in his third race around the world. In more than 100,000 miles of ocean racing, Walker says he hasn’t hit anything major – yet. It may be just a matter of time – on a high-speed training run across the Atlantic this summer Walker and his crew narrowly missed hitting a household fridge-freezer bobbing in the middle of the ocean.

“We passed within a boatlength of it,” Walker remembers. “Fortunately we saw it. It could easily have put a hole in our boat.”

As incongruous as having to dodge a fridge-freezer mid-ocean might seem, Walker says that encounters with manmade waste afloat on the ocean happen all too often.

“The most common things we see are plastic bottles and fishing debris like buoys and rope, but I remember sailing near the Philippines in the South China Sea and we had to weave our way through a whole lot of cut logs – just like someone had emptied a trailer-load in the sea.”

Like all good mariners, the sailors keep a watch for objects floating in their path during the day. “Wherever we are, we see plenty of plastic bottles bobbing by – with and without tops,” says New Zealander Daryl Wislang. “Generally they are completely encrusted with barnacles, which gives you some idea of how long they have already been around.”

Once darkness falls, all the sailors can do is hope they don’t run into anything as they charge along at more than 30 knots (35mph). At those speeds a collision with a log or a fridge-freezer would almost certainly cause catastrophic damage to the hull, keel and rudders – at best putting the crew out of the race and at worst endangering their lives.

“It’s my biggest fear,” Walker confesses. “There’s nothing you can do except keep your eyes open during the day and keep the watertight doors closed in the bow at night in case the worst happens.”

The two most debris-ridden sea areas Walker has raced through are the coastline of Vietnam and the Malacca Straits between Indonesia and Malaysia. “In addition to fishing nets and domestic waste, you have to deal with plenty of natural debris, too – floating islands of trees and reeds are a common sight.”

Despite stories of seafarers encountering remote mid-ocean “islands of trash”, Walker says he has never seen anything like that and describes the open oceans he has sailed as “very, very clean. But things deteriorate dramatically as you approach land,” he adds. “It is only by sailing in the clean ocean that you realise how dirty the water is near land.”

Walker says the most dramatic example of coastal pollution he has witnessed was during the 2008-09 Volvo Ocean Race on the leg from Qingdao, China, to Rio de Janeiro in Brazil (the controversial choice as the venue for the Rio 2016 Olympic sailing regatta). “We were about 50 miles out when the water suddenly changed colour from blue to brown. Straightaway you could smell the pollution. I would never swim in the sea there.”

Although some ocean debris falls or gets thrown from cargo ships or is left behind by fishing vessels, by far the greatest proportion originates on land and finds its way out to sea by a deliberate act. “It is never good to see the negative effect that we humans have on our planet. I am always shocked when I walk on the beach at home in the UK at how much rubbish there is, particularly after a big storm,” he says. “In all cases I think the polluter must be forced to pay, whether it is sewage, shipping containers or other rubbish. Authorities need to stop treating the oceans as a rubbish dump and start treasuring them for what they are – one of mankind’s finest natural assets.”


* 6a03adfa-6ebd-4684-9c8a-0bc4806f191a-2060x1236.jpeg (129.76 KB, 620x372 - viewed 0 times.)

* 179571de-e7d8-4a39-82bf-ad6bef672f58-2060x1236.jpeg (85.72 KB, 620x372 - viewed 0 times.)

* 3000.jpg (133.65 KB, 620x372 - viewed 0 times.)

* 5734b88c-4d2b-49cf-a14d-0faaf4cdaeb5-2060x1236.jpeg (94.61 KB, 620x372 - viewed 0 times.)
Logged
Rad
Moderator
Most Active Member
*****
Posts: 28032


« Reply #1833 on: Today at 05:56 AM »

Barack Obama in Alaska: global fight against climate change starts here

President says massive areas of ice disappearing every year are not some far-off problem but ‘a leading indicator of what the entire planet faces’

Dan Roberts in Washington
Tuesday 1 September 2015 05.27 BST
Guardian

Shrinking Alaskan glaciers served as a vivid backdrop for Barack Obama’s latest push for action on climate change in Anchorage on Monday night as he warned that the equivalent of 75 blocks of ice the size of the national mall in Washington were melting from the state every year.

The president, who will visit the nearby Seward glacier on Tuesday to see its shrinkage for himself, urged international participants at the Glacier conference to act fast before it was too late to limit the impact not just on the region but the whole world.

“The Arctic is at the leading edge of climate change, a leading indicator of what the entire planet faces,” warned Obama, who said new research showed 75 gigatons of ice were disappearing from Alaskan glaciers annually – each gigaton the equivalent of a block stretching from the Capitol to the Lincoln memorial and four times as high as the Washington Monument.

“Climate change is no longer some far-off problem,” he added. “Climate change is already disrupting our agriculture and ecosystems, our water and food supplies, our energy and infrastructure.”

Obama struck an optimistic tone about the growing global consensus around the need to limit carbon dioxide emissions. “This year in Paris has to be the year that the world finally reaches an agreement to protect the one planet that we’ve got while we still can,” he said.

“This is within our power. This is a solvable problem – if we start now.

“We are starting to see that enough consensus is being built internationally and within each of our own body politics that we may have the political will to get moving.”

In particular the president hinted at further announcements during the remainder of his three-day trip to Alaska, which is designed to highlight the threat from carbon emissions and strengthen the domestic political case for new power station regulations.

“Over the course of the coming days I intend to speak more about the particular challenges facing Alaska and the United States as an Arctic power and intend to announce new measures to address them,” he said.

Nonetheless the president was greeted with environmental protests before his speech, with campaigners criticising his support for offshore oil drilling in the state.

Click to watch: <iframe src="https://embed.theguardian.com/embed/video/environment/video/2015/sep/01/this-has-to-be-the-year-the-world-agrees-on-climate-change-says-obama-in-alaska-video" width="560" height="315" frameborder="0" allowfullscreen></iframe>


* Capture.JPG (29.65 KB, 699x347 - viewed 0 times.)
Logged
Rad
Moderator
Most Active Member
*****
Posts: 28032


« Reply #1834 on: Today at 05:57 AM »

Climate change brings cyclone risk to Persian Gulf, study warns

Shallow and warm waters of the Persian Gulf, where cyclones have never been recorded, might generate future storms that threaten cities such as Dubai

Reuters
Tuesday 1 September 2015 09.57 BST

Climate change is bringing small risks that tropical cyclones will form in the Persian Gulf for the first time, in a threat to cities such as Dubai or Doha which are unprepared for big storm surges, a US study said on Monday.

Tampa in Florida and Cairns in Australia, two places where cyclones already happen, would be increasingly vulnerable to extreme storms this century, according to the report, based on thousands of computer models.

The shallow and warm waters of the Persian Gulf, where cyclones have never been recorded, might generate the storms in future as a side-effect of global warming, according to the study in the journal Nature Climate Change.

“You can’t always rely on history” to predict the future, lead author Ning Lin of Princeton University told Reuters of the findings she reached with Kerry Emanuel of the Massachusetts Institute of Technology.

For the Persian Gulf the probability of cyclones “is very low but ... if you build a nuclear power plant you have to consider these things,” she said.

For Dubai, for instance, a storm surge of 1.9 metres (6 feet and 3 inches) in height could be expected once every 1,000 years based on recent climate warming, and one of 4 metres (13 feet and one inch) once every 10,000 years, the scientists estimated.

They dubbed such extreme tropical cyclones “grey swans”, saying they could not be predicted from history alone. The metaphor is inspired by “black swans”, judged impossible by Europeans until they were found in Australia.

Some past studies have also pointed to risks of abrupt changes in the climate system linked to global warming, including that the Arctic Ocean could be ice-free in summer or that monsoon rains could veer off track.

Jean-Pascal van Ypersele, a vice chair of the UN’s Intergovernmental Panel on Climate Change, said the build-up of greenhouse gases from human activities means more energy accumulates in the climate system.

“Bad climate surprises may happen,” he told Reuters at UN talks in Bonn on a deal to slow climate change.

Monday’s study said the closest cyclone to the Persian Gulf was in 2007, when Cyclone Gonu in the Arabian Sea struck Oman and Iran, killing 78 people and causing $4.4bn (£2.Cool in damage.

The study said that extreme hurricanes now likely to hit Tampa only once every 1,000 years, causing a storm surge of 4.6 metres, would occur every 60 to 450 years by the late 21st century. Cairns would also be vulnerable to worsening storms.


* ce8b4f4a-3d82-4c91-b1e9-ae5d748aa758-2060x1236.jpeg (63.49 KB, 620x372 - viewed 0 times.)
Logged
Rad
Moderator
Most Active Member
*****
Posts: 28032


« Reply #1835 on: Today at 05:59 AM »

Dutch government to appeal against carbon emissions ruling

Environment minister says Netherlands will contest court ruling ordering it to cut emissions steeper, but government will begin complying in the meantime

Reuters
Tuesday 1 September 2015 10.54 BST

The Dutch government will appeal against a district court ruling ordering it to cut emissions of greenhouse gases faster than currently planned, in a politically sensitive case that is being closely watched by policy-makers abroad.

Deputy Minister for the Environment Wilma Mansveld wrote in a letter to parliament on Tuesday that the government would contest the 24 June ruling which ordered it to slash emissions by 25% from 1990 levels by 2020.

But the government said it will also begin implementing the lower court’s ruling because the filing of an appeal does not undo its obligation to comply.

Urgenda, an environmental group that filed the lawsuit on behalf of 900 Dutch co-plaintiffs, said it looked forward to the appeal process and urged the government to do more to slow climate change.

The ruling, a rare intervention by the judiciary in the global warming debate, is being closely watched by policy makers and environmentalists as a legal precedent.

Mansveld’s letter said it was the first time that a judge found that the government should achieve a minimum emissions reduction.

The government of conservative prime minister Mark Rutte “questions the application of international law,” and agreements such as the Kyoto Protocol on climate change, it said.

“Due to the consequences for climate policy...it is desirable for the ruling to be considered by a higher court,” it said.

The Netherlands, a laggard among developed countries in cutting emissions after reducing spending on alternative energy during the financial crisis, used record amounts of coal in the first five months of this year.

Dutch greenhouse gas emissions fell 5% in 2014 from a year earlier, Statistics Netherlands (CBS) said on Tuesday, citing the mild winter and lower fossil fuel use.

“These lower emissions were dampened by higher use of coal and less gas by electricity producers,” it said. “Emissions were 15% than 1990 levels.“

Based on current government policy, the Netherlands will achieve a reduction of 17% at most in 2020, which is below a norm of 25-40% for developed countries, a summary of the ruling said.

Not many developed countries are on track in making deep cuts such as those as demanded by the court, which were based on scenarios by the UN panel of climate scientists in 2007 for limiting rising temperatures.

The European Union is targeting reductions of at least 20% by 2020 from 1990 levels, while the United States is aiming for about a 4% cut.


* fe8f442f-1f2c-47ee-9385-a19c20eaaa76-2060x1236.jpeg (71.61 KB, 620x372 - viewed 0 times.)
Logged
Rad
Moderator
Most Active Member
*****
Posts: 28032


« Reply #1836 on: Today at 06:06 AM »

How Christchurch used the earthquake to return the city to its cycling roots

After the 2011 disaster, residents were asked what they wanted from the city once known as ‘Cyclopolis’. They demanded a greener, more people-focused Christchurch – and investment in new cycleways means it is starting to happen

Charles Anderson in Christchurch
Tuesday 1 September 2015 00.01 BST
Guardian

There has been a slight change in Glen Koorey’s daily 20-minute bicycle ride to work over the last four years. In the weeks following Christchurch’s devastating earthquake in 2011, in which 185 people were killed and large portions of the CBD were levelled, there was no way to drive through the city. Buildings lay crumbled. Roads were cracked and split. Basic infrastructure was torn apart.

For months stretching into years, it remained nearly impossible to navigate the city without having to divert into myriad detours before eventually arriving at your destination. Cycling, says Koorey, became a simpler means of transport.

“At work if there was an aftershock and you were told to go home, it was a lot easier to go on a bike than drive.”

Slowly, Koorey has watched Christchurch recover – the roads repaired, the buildings rebuilt and the infrastructure reengineered. But he has also seen a change in attitude for a city that had long neglected its two-wheeled commuters.

Koorey is a transport engineer by trade and teaches at the local University of Canterbury. But before all that he was, and always has been, a cyclist. In the aftermath of the earthquake, he became a voice for cycling advocates. He presented to the local council on how the city could build back better – this time with cycling in mind.

    In 1924, the council estimated there were 40,000 cyclists in the city – half the population at the time

The city had an opportunity for change and asked its citizens what it wanted of the new Christchurch. One of the resounding calls from the public was that it wanted a greener and more people-focused city – and one of the more obvious ways to achieve this was to invest in cycling infrastructure.

“The key thing is that council asked the question and that often doesn’t happen,” Koorey says. “You shouldn’t have to have an earthquake for this to happen.”

The model to transform was based on those northern European countries that are famed for their cycling infrastructure – particularly the Netherlands and Denmark. Koorey was interested in how they did what they did. After all, 40 years ago Amsterdam, the bastion of cycle-friendly cities, was heading down the same path as Christchurch. It had not invested in infrastructure, and the proliferation of low-cost cars and cheap petrol saw its streets bulging with vehicles. But then Amsterdam had its own earthquake of sorts, says Koorey: a terrible record of children being killed by motorists. It took that self-reflection to turn the city around. Now, 32% of Amsterdam traffic is made up of bicycles.

New Zealand has a way to go. Cycling here accounts for 1.4% of trips, and 3% of all all commutes. In Christchurch this rises to 7% – making it the country’s unofficial cycling capital. But that number used to be much higher. In fact, Christchurch was once known as “Cyclopolis” and as the “Copenhagen of the south”.

You can still find old black-and-white films of commuters clogging the city’s streets. But in these films there are not traffic lights, roundabouts and intersections; instead, there are hundreds of cyclists all merging, all organically going about their day. In 1924, the council estimated there were 40,000 cyclists in the city – half the population at the time.

Koorey believes that, one day, Christchurch can become more than “just” the Copenhagen of the south. He thinks it can become one of the best cycling cities in the world.

“I’ve had the chance to see a lot of good places for cycling,” he says, “but really they are not too far ahead of what Christchurch is now doing” (that is, investment and thinking smarter about how to promote cycling). Almost NZ$160m (£67m) has been promised from government to build 13 new cycleways planned for the city.

    The key thing is that council asked the question … You shouldn’t have to have an earthquake for this to happen
    Glen Koorey

Creating good cycling infrastructure starts with doing the basics right, such as having well-designed intersections and creating “quiet streets”, where few cars are allowed and only at 30kmh. Along with installing separated cycle lanes, there are means by which to change perceptions of how city transport should function.

According to Koorey, when you include the associated health benefits, there is an eight-to-one benefit-to-cost ratio that comes with cycling investment. “What’s good for cycling is good for people generally,” he says.

This philosophy has shone through in other projects throughout Christchurch. Groups such as Frocks on Bikes encourage women to take up cycling. Bike events have seen the city closed to cars to show residents what Christchurch could look like in the future. Pop-up central city bike workshops such as RAD have been built by young community-minded citizens wanting to get involved in the rebuild – a hallmark of the Christchurch recovery. A cycle share project, Spark Bikes, also started in August on a two-year pilot programme that saw 40 bikes installed in five different locations around the central city.

“There is a renaissance of cycling all around the place,” Koorey says. “We need all that in addition to the infrastructure to make it fun.”

One of the biggest barriers to cycling being fully embraced here is the perception of safety. Koorey says the local media has made much of cycling deaths over the past several years – 12 since 2009. He says by virtue of having more cyclists that any other city in the country they have more accidents, but per capita the numbers are actually quite good. Even in the Netherlands, because of the sheer volume of cyclists, they still have 180 deaths a year.

Then there are the oft-cited road rage incidents between cyclists and motorists. One 51-year-old cyclist was even fined by the police for impeding traffic on a narrow and winding hill road on the outskirts of the central city. Koorey says out of that confusion good discussions can be had, and will need to be had if the city is to fully embrace a cycling future.

It will take about five years before the city’s major cycleways are off the ground. By then, Koorey anticipates that Christchurch’s cycling commuters will have doubled. Then give it a few more years, he says, and his vision of a world-class cycling city that rivals the Northern Europeans may actually take shape: “I don’t see why not.”


* 4dd5412b-ff18-4546-9458-a1a36dfaa8de-620x372.jpeg (180.48 KB, 860x516 - viewed 0 times.)

* Christchurch back when it was known as ‘cyclopolis’.jpeg (131.45 KB, 620x468 - viewed 0 times.)

* A map of Christchurch’s proposed new cycleways.jpeg (114.41 KB, 619x402 - viewed 0 times.)

* 3784ec6f-faa1-490d-8f79-f15f8ee408cc-620x372.jpeg (178.02 KB, 860x516 - viewed 0 times.)
Logged
Rad
Moderator
Most Active Member
*****
Posts: 28032


« Reply #1837 on: Today at 06:09 AM »

CS Monitor

Why researchers are concerned about 'grey swan' hurricanes

Scientists are working to quantify the risk of exceptionally devastating hurricanes. While such events are extremely rare, researchers encourage city planners and officials to prepare for storm surges far beyond what they have previously seen.

By Michael Holtz, Staff writer August 31, 2015   

Tampa hasn’t experienced a major tropical storm since 1921, but a new study has put city planners there on notice.

Researchers at Princeton and the Massachusetts Institute of Technology named the city in a new paper that warns of potentially devastating storms they’ve dubbed "grey swans." Unlike Black Swans, which are truly unpredictable events, grey swans are highly unlikely but can be predicted with a degree of confidence.

"We are considering extreme cases," Ning Lin, an assistant professor of civil and environmental engineering at Princeton, said in a statement. "These are relevant for policy making and planning, especially for critical infrastructure and nuclear power plants."

Professor Lin teamed up with Kerry Emanuel, a professor of atmospheric science at MIT, to create computer models to examine potential storm hazards for three cities: Tampa; Cairns, Australia; and Dubai, United Arab Emirates.

Their findings, published Monday in the journal Nature Climate Change, show that powerful storms could generate devastating storm surges in all three cities.

Tampa is at particular risk in the United States because it sits on low-lying land surrounded by a bay of shallow water, reports Smithsonian Magazine. After plugging in Tampa Bay’s historical climate data from 1980 to 2005, the researchers ran 7,000 simulated hurricanes in the area. Their model showed that a grey swan storm could create surges of up to 18 feet tall, well higher than the 11-foot surges generated in the 1921 storm.

Professor Emanuel told The Washington Post that the purpose of the study was “to raise awareness of what a very low probability, very high impact hurricane event might look like.” But he and Lin both concede that such super storms are highly unlikely. Under current climate conditions, they have about a 1 in 10,000 chance of occurring in an average year.

“With climate change, these probabilities can increase significantly,” they write in the paper. For Tampa, those odds increase to between 1 in 3,000 and 1 in 1,100 by 2050 and between 1 in 2,500 and 1 in 700 by the end of the century.

Lin told Smithsonian that it’s important to predict the extremes and then “prepare for them as much as we can rather than wait for the consequences.”


* 931896_1_0831-WGREYSWAN_standard.jpg (177.49 KB, 600x400 - viewed 0 times.)
Logged
Pages: 1 ... 121 122 [123]   Go Up
Print
Jump to: