China’s dreadful air pollution seems to have got a bit better

Air pollution strikes Beijing on 6 November 2017

Air pollution strikes Beijing on 6 November 2017

Wu Hong/EPA-EFE/REX/Shutterstock

China has taken some baby steps towards cleaning up its horrendous air pollution – but there is a long way still to go.

Eastern China, especially Beijing, is notorious for its smogs, driven by the country’s rapid industrialisation. On Friday Beijing issued an orange smog alert, the second highest danger level. By Monday, levels of PM2.5 – pollution consisting of tiny particles 2.5 micrometres across or less – were up to 158 micrograms per cubic metre. Similarly high levels triggered orange alerts in Tianjin and some cities in Henan, Hebei, Shandong and Shanxi provinces, according to the Xinhua news agency.

In 2013, horrendous Beijing smogs prompted a national outcry and the launch of a comprehensive air pollution control plan. According to a new study, this plan has had some success – despite the ongoing smogs.

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The study used satellite measurements to estimate pollution concentrations. It claims that PM2.5 levels fell nationally by 21 per cent between 2013 and 2015, going from 60.5 to 47.5 micrograms of PM2.5 per cubic metre of air. That is still way higher than the World Health Organization’s recommended limit of 10 micrograms per cubic metre. Average levels in Europe mostly remain below 25 micrograms.

Nevertheless, the reduction should have cut the number of associated deaths from heart attacks and strokes by nine per cent, from 1.22 to 1.10 million.

Cleaner skies

“Our study marks the first estimate of the impact of this stringent action plan on pollution levels and mortality rates from 2013 to 2015,” says lead author Yixuan Zheng of Tsinghua University in Beijing.

“Given pollution concentrations are very weather-dependent, the jury is still out on whether this is a real step forward to China achieving clean air, but it’s certainly an encouraging move in the right direction if correct,” says Frank Kelly of Kings College London, UK.

According to official figures, Beijing cut its PM2.5 levels to 60 micrograms per cubic metre for the first nine months of this year. That is 3.2 per cent down on last year and 34.8 per cent down from 2013. This week, Beijing’s authorities began testing the last of four gas-burning power stations, which collectively will cut the city’s coal consumption by 9.2 million tonnes a year, according to Xinhua.

Still, senior members of China’s central government admit that it could take until 2035 to meet their air-quality targets. “People should be patient about improvements in air quality, as it will take time to solve such a big problem,” said minister of environmental protection Li Ganjie at the Party Congress of the Communist Party in October. “We understand that current air quality fails to meet people’s expectations.”

Journal reference: Environmental Research Letters, DOI: 10.1088/1748-9326/aa8a32

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Study shows need for adaptive powered knee prosthesis to assist amputees

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Research into wearable robotics shows how amputees wearing such devices adapted when presented with a real-world challenge: carrying a weighted backpack. “The device we tested was a powered knee prosthesis — it has a motor to actuate the knee and a fixed ankle joint,” said researcher Andrea Brandt. Five people of varied ages and physical attributes were recruited to take part in the study. After walking on a lab treadmill both with and without a backpack adding 20 percent of their body weight, and with and without the load-bearing power settings, the study subjects reported having more difficulties when carrying the load with the prosthetic device set at the normal setting. The results could help device manufacturers and clinicians expand the utility of these important devices, and could help researchers develop smarter controllers that adapt to real-world demands.

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Old Scientist: Why aren’t there more British Nobels?

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“DOES epidemic disease come from space?” In the relatively sober 1970s, this headline must have been even more alarming than it would be in our present era of fake news. Especially atop an article by famous astronomer Fred Hoyle and astrobiologist Chandra Wickramasinghe, arguing that infamous epidemics like the deadly Spanish flu of 1918-19 had been brought to Earth on interplanetary debris. Both authors were proponents of panspermia, the theory that life began elsewhere in the universe and came here aboard comets and meteorites. This belief arguably cost Hoyle a Nobel prize, although perhaps his notorious bluntness, verging on rudeness, may have been a factor too. The article, published in our 17 November 1977 edition, ended with a plea to keep a “continual microbiological vigil of the stratosphere… to eliminate the havoc which will ensue from extraterrestrial invasions in the future”.

By 1992, the declining frequency of Nobel prizes awarded to UK scientists was beginning to trouble us. In our 7 November edition, Ben Martin said this showed the nation’s shrinking status in world science, but conceded that one explanation for the worrying trend might be that “gifted scientists are being encouraged to apply their skills in industry”.

So is research worthwhile only if it turns a profit? Fourteen years later, at least one sector of British science was doing just that. In our 4 November 2006 edition, we sang the praises of biotechnology: the jobs market was booming and half the country’s biotech companies had recently taken on extra staff. A map identified areas of the UK where research and development companies and institutions were gathered, with clusters not surprisingly found around Cambridge and Oxford.

The chair of biotechnology’s UK industry body almost certainly wasn’t being rude when he told us “the UK is bloody good at it”. But that’s not what they hand out Nobel prizes for.

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A third of animals are vanishing as roads spread through forests

Aerial view of a road cutting through a forest

Making more edge cases

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Imagine you could teleport to any forest on Earth. When you land, you have a 50 per cent chance of being within half a kilometre of the forest’s edge. That is how badly our planet’s forests have been sliced and diced.

A new study shows that 85 per cent of animals are being affected by living in these dismembered forests. The findings will help conservationists figure out how best to protect these species.

While the fragmentation of forests is known to affect biodiversity and ecosystems, the effects studied so far are local and specific to particular species, making for a chaotic picture. Marion Pfeifer of Newcastle University in the UK and her colleagues came up with a new method to make sense of the data.

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Instead of simply separating regions into forest and non-forest, they also took into account changes to the land that surrounds the forests. Using existing population data, they mapped the abundances of 1673 vertebrate species – including amphibians, reptiles, birds and mammals – in 22 tropical regions in the Americas, Asia and Africa. These included many threatened species such as the Sunda pangolin and Baird’s tapir.

Of the species whose abundance changed near forest edges, 46 per cent have become more abundant over the last few decades, compared with 39 per cent that became less abundant. This may be good news for some species, although life on the forest edge may well change their behaviours.

However, others that prefer to live deep in the forest only reached their peak abundances more than 200 to 400 metres from the forest edges. These species seem to be dependent on large, continuous forests. If forests continue to be fragmented, these species may be driven out.

Roads everywhere

“It’s a tremendously important study, because it integrates such a large amount of data for nearly 2000 vertebrate species,” says William Laurance of James Cook University in Queensland, Australia. “In some ways, it confirms our worst fears.”

Laurance emphasises that forests in tropical developing nations will be particularly affected by the fast pace of road-building there. In a paper published last week, he and his colleagues estimated that, of the projected 25 million kilometres of paved roads that will be built by 2050, about 90 per cent will be in these regions (Current Biology, doi.org/cfpw).

“Roads typically open up a Pandora’s box of environmental problems for forest species,” says Laurance. The problems include fragmentation, hunting, logging, deforestation and illegal mining. In the Amazon, 95 per cent of all deforestation occurs within 5.5 kilometres of a legal or illegal road.

Many of these roads will be poorly built, so they will be washed away in heavy rainfall, or become riddled with holes. Rather than having a positive impact on development, maintaining them may be a financial drain on these nations.

Roads, and forest fragmentation in general, may also affect us – in a dramatic way. “Tropical forest edges are much more susceptible to wildfires,” says Jos Barlow of Lancaster University, UK. A 2015 study found that fires occur more often at forest edges, such as beside roads or clearings, striking there every 11 years compared with every 82 years in dense jungles. According to Barlow, preventing the fragmentation of forests may be a vital step in reducing the incidence of wildfires.

Journal reference: Nature, DOI: 10.1038/nature24457

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Europe and the US were most responsible for deadly heatwave

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A severe heatwave has been attributed to man-made climate change – and for the first time we can also identify the countries whose emissions are most responsible.

Friederike Otto of the University of Oxford, UK and her colleagues studied a heatwave that struck Argentina in 2013/14. The heatwave brought some of the highest temperatures ever recorded in the nation’s capital Buenos Aires, killing many and collapsing the city’s power grid.

In a 2015 study, Otto examined whether climate change made the heatwave more likely. She simulated temperatures in Argentina with and without humanity’s greenhouse gas emissions and found that heatwaves like the one from 2013/14 were significantly more likely when our emissions were included.

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“Anthropogenic climate change made the Argentinian heatwave approximately five times more likely,” says Otto.

The next step was to determine which countries were responsible.

Climate justice

Otto’s team calculated how much carbon dioxide each country had emitted between 1850, the dawn of the industrial era, and 2013. They found that the European Union (including the UK) contributed the most to making the heatwave more likely. The EU was followed by the US, China and the rest of Asia. South America, where the heatwave occurred, came in fifth.

This arguably underplays the role of Western nations. That is because the emissions from manufacturing a product are attributed to the country where the product was made, rather than where it was consumed. While emissions from countries like China and India are increasing, the goods manufactured there are often consumed in affluent countries.

Many climate activists argue that developed countries, which have historically contributed the most to climate change, should be held most responsible for stopping it.

“The aim of the study was to explore what science could contribute to the debate about climate justice,” says co-author Ragnhild Bieltvedt Skeie of the Center for International Climate and Environmental Research in Oslo, Norway.

However, it is unlikely that Western nations will be made to pay up to pay damages for fouling the atmosphere anytime soon. The Paris climate change agreement of 2015, which almost all countries have now signed up to, focuses primarily on cutting greenhouse gas emissions. As the study observes, the agreement “ruled out the possibility that addressing loss and damage associated with the adverse effects of climate change should provide a basis for liability or compensation”.

Instead, co-author Myles Allen, also at the University of Oxford, wants to take the world’s biggest emitters to court for their role in causing climate change.

“The ability to look at individual extreme events and assess if climate change played a role is quite significant for climate change litigation,” says Heidi Cullen of Climate Central in Princeton, New Jersey. “Now for the first time, we may be able to hold those who create the emissions responsible for the damage that they do.”

Journal reference: Nature Climate Change, DOI: 10.1038/nclimate3419

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The latest science reads remind us why we really do need experts

Gazing into the crystal ball

Gazing into the crystal ball

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Politics, extreme weather events, international crises: all instances in which you might feel you’d want an expert handling things at the top. Someone experienced and with reasoned judgement would, you might hope, anticipate, or at least be able to handle, the unforeseen.

In Forewarned: A sceptic’s guide to prediction (Biteback), Paul Goodwin reveals just how far the forecasting industry has become entwined with our everyday lives. It keeps supermarket shelves full, ensures that call centres are adequately staffed and anticipates demand on the electricity grid. Yet prediction is far from an exact science. Walking us from the financial crisis of 2007-2008 to the perilous consequences of predicting elections, Goodwin provides a compulsively readable account of both the fallibility and necessity of human forecasters. We are still more likely to judge electoral candidates on appearance than competence, and even those experienced in prediction impart their own bias to algorithmic projections. Forewarned is a fascinating book – and not at all a reassuring one.

Minding the Weather: How expert forecasters think (MIT Press) is an altogether more academic exploration of the forecasting we are most familiar with. Despite striking advances in meteorology, Robert Hoffman and his co-authors argue that forecasts are most likely to improve not with the arrival of software that can replicate the cognitive processes of human forecasters, but with programs that can model the weather itself with greater accuracy. Forecasting, they insist, remains very much the domain of human reasoning operating in the face of vast volumes of data.

Surgery and geology from the past

In the 19th century, although meteorology

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Alligators, rulers of the swamps, link marine and freshwater ecosystems

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Transmitters similar to those that track space mission orbiters are being used here on Earth to follow alligators, rulers of the swamps. The transmitters are allowing scientists to learn about alligator movements between freshwater and saltwater ecosystems. Ecologists at the National Science Foundation (NSF) Georgia Coastal Ecosystems Long-Term Ecological Research (LTER) site, one of 28 NSF LTER sites in the U.S. and around the world, used radio or GPS transmitters to track alligators’ wanderings for as long as four months, placing the instruments on the alligators’ backs. The scientists discovered that the amount of time alligators spend in fresh or salt water depends on factors such as tide range and water temperature. Alligators move back and forth between marine and freshwater ecosystems to rebalance their salt levels — and to feed.

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System for performing 'tensor algebra' offers 100-fold speedups

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We live in the age of Big Data, but most of that data is “sparse.” With sparse data, analytic algorithms end up doing a lot of addition and multiplication by zero, which is wasted computation. Programmers get around this by writing custom code to avoid zero entries, but that code is complex, and it generally applies only to a narrow range of problems. Researchers have developed a new system that automatically produces code optimized for sparse data. That code offers a 100-fold speedup over existing, non-optimized software packages. Also, its performance is comparable to that of meticulously hand-optimized code for specific sparse-data operations while requiring far less work on the programmer’s part. The system is called Taco, for tensor algebra compiler. In recent years, the mathematical manipulation of tensors — tensor algebra — has become crucial to big-data analysis and machine learning. It has been a staple of scientific research since Einstein’s time.

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Freeloading mites are squatting on spider webs and stealing food

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Professor Rodrigo Lopes Ferreira

In caves in Brazil, there lives a newly-discovered mite that is a freeloader. Groups of these mites live on a spider’s web and steal its food. They are the first mites known to do this.

Leopoldo Ferreira de Oliveira Bernardi at the Federal University of Lavras in Minas Gerais first saw live mites dotting a spider web by the entrance of Brazil’s Lapa Nova cave in 2007. The relationship between mites and spider immediately intrigued him.

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After observing the same thing in another cave, Bernardi and his colleagues designed an experiment. They placed live bait – a cave moth – on the web of a recluse spider where mites were present.

The spider immediately attacked the moth and began feeding. But in the next 5 to 40 minutes, mites, which were previously scattered all over the web, gathered to feed on the moth.

The team has named the newly-discovered mite Callidosomacassiculophylla: “cassiculus” means “spider web” and “phylla” means “friend”.

Take what you want

“Spiders and their webs are predictable sources of food, and many animals regularly exploit this resource,” says zoologist Lidianne Salvatierra at the National Institute of Amazonian Research in Manaus, Brazil. “These ‘thieves’ are specialised spiders, scorpion flies, flies, plant bugs, gnats and also hummingbirds.”

However, until now mites have never been reported stealing from spiders.

“The fact that the mites involved in the relationship are adult is interesting,” says Robert Pape at the University of Arizona Insect Collection. Adult mites in the family to which C. cassiculophylla belongs are usually free-living predators, which eat small invertebrates and their eggs. “In this regard, Callidosomacassiculophylla is unusual.”

What’s more, these mites only eat their host spider’s freshly-killed prey, and do not scavenge on dead decaying insects.

In turn, the spider is very tolerant of mites sharing its meal. The researchers never saw any signs of aggression towards them. “I saw a mite walk under the spider’s legs and nothing happened,” says Bernardi.

It may be that the mites are too tiny to bother their host. They are about 0.14 centimetres long and 0.08cm wide, while the spider is about 5cm in size, says Bernardi.

“The mites are too small to be useful prey for the spiders, and are not large enough to be a potential predator,” says Pape. “I suspect the spiders are not adversely affected by the small amount of nutrients consumed by the mites.”

Journal reference: Zootaxa, DOI: 10.11646/zootaxa.4338.3.3

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Rivers and forests need the same legal rights we grant to people

Colorado river

The once-mighty Colorado

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Does a river have rights? A coalition of US environmental groups thinks so. They have filed a lawsuit in Denver that says the Colorado river’s “right to exist, flourish, regenerate, be restored, and naturally evolve” has been violated by its namesake state.

Controversially, they want to represent it as a “person” in court and list it as a plaintiff.

The Colorado provides water to 36 million people in seven arid US states and north-west Mexico. Thanks to irrigation, it greens thousands of square kilometres. But the river, which is severely overused for agriculture

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