Climate change: ‘human fingerprint’ found on global extreme weather

Global warming makes temperature patterns that cause heatwaves, droughts and floods across Europe, north America and Asia more likely, scientists find.

The fingerprint of human-caused climate change has been found on heatwaves, droughts and floods across the world, according to scientists.

The discovery indicates that the impacts of global warming are already being felt by society and adds further urgency to the need to cut carbon emissions. A key factor is the fast-melting Arctic, which is now strongly linked to extreme weather across Europe, Asia and north America.

Rising greenhouse gases in the atmosphere have long been expected to lead to increasing extreme weather events, as they trap extra energy in the atmosphere. But linking global warming to particular events is difficult because the climate is naturally variable.

The new work analysed a type of extreme weather event known to be caused by changes in “planetary waves” – such as California’s ongoing record drought, and recent heatwaves in the US and Russia, as well as severe floods in Pakistan in 2010.

Planetary waves are a pattern of winds, of which the jet stream is a part, that encircle the northern hemisphere in lines that undulate from the tropics to the poles. Normally, the whole wave moves eastwards but, under certain temperature conditions, the wave can halt its movement. This leaves whole regions under the same weather for extended periods, which can turn hot spells into heatwaves and wet weather into floods.

This type of extreme weather event is known to have increased in recent decades. But the new research used observations and climate models to show that the chances of the conditions needed to halt the planetary waves occurring are significantly more likely as a result of global warming.

“Human activity has been suspected of contributing to this pattern before, but now we uncover a clear fingerprint of human activity,” said Prof Michael Mann, at Pennsylvania State University in the US and who led the study published in the journal Scientific Reports.

Large scale wind patterns are largely driven by the temperature difference between the poles and the tropics. But global warming is altering this difference because the Arctic is heating up faster than lower latitudes and because land areas are heating up faster than the oceans.

Recent changes in the Arctic are particularly striking, with record low levels of ice cover and extremely unusual high temperatures. “Things in the Arctic are happening much faster than we expected,” said Prof Stefan Rahmstorf, also at PIK.

“It is not just a problem of nature conservation or polar bears, it is about a threat to human society that comes from these rapid changes,” he said. “This is because it hits us with increasing extreme events in the highly populated centres in the mid-latitudes. It also affects us through sea level rise, which is hitting shores globally. So these changes that are going on in the Arctic should concern everyone.”

Other climate research, called attribution, is increasingly able to calculate how much more likely specific extreme weather events have been made by global warming. For example, the heatwave in south-eastern Australia in February was made twice as likely by climate change, while Storm Desmond, which caused heavy flooding in the UK in 2015, was made 40% more likely.

Scientist pioneers new technology, maps giant virus

In a laboratory at Michigan State University, scientists took a DIY approach to build a retrofitted cryo-electron microscope that allowed them to map a giant Samba virus -- one of the world's largest viruses.

"If the common cold virus is scaled to the size of a ladder, then the giant Samba virus is bigger than the Washington Monument," said Kristin Parent, assistant professor of biochemistry and molecular biology and co-author of the paper featured on the cover of the journal Viruses. "Cryo-EM allowed us to map this virus' structure and observe the proteins it uses to enter, or attack, cells."

It seems counterintuitive that bigger organisms are harder to see, but they are when using cryo-electron microscopy. That's because these microscopes usually are used to look at thin specimens and can't decipher larger organisms to reveal their biological mechanisms. For thick samples, scientists see only dark gray or black blobs instead of seeing the molecular framework.

Cryo-EM allowed Parent's team to image the giant Samba virus and understand the structures that allow it to enter an amoeba. Once inside, Samba opens one of its capsid layers and releases its nucleocapsid -- which carries the genetic cargo that sparks an infection. While Samba isn't known to cause any diseases in humans, its cousin, the mimivirus, may be a culprit for causing some respiratory ailments in humans.

"If you scoop up a handful of water from Lake Michigan, you are literally holding more viruses than there are people on the planet," said Parent, who published the paper with Jason Schrad and Eric Young, MSU biochemistry and molecular biology graduate students. "While scientists can't study every virus on Earth, the insights we glean from viruses like the giant Samba can help us understand the mechanisms of other viruses in its family, how they thrive and how we can attack them."

As bacteria become more resistant to antibiotics, looking for new ways to fight diseases will continue to grow in importance. Parent's lab also studies how bacteria-infecting viruses enter cells using this method, which could potentially lead to new antibacterial treatments. Yet the world's best cryo-EM microscope costs more than $5 million. Limited by funds but not drive, Parent was able to upgrade an existing microscope at MSU to do cryo-EM -- one that is a tinkerer's dream.

This traditional transmission electron microscope was retrofitted with a cryostage, which keeps viruses frozen in liquid nitrogen while they're being studied. Parent and her team then added a Direct Electron DE-20 detector, a powerful camera -- the mighty microscope's piece de resistance.

Parent didn't invent cryo-EM, but establishing it on campus serves as a viable proof-of-concept for MSU, opening the door for many interdisciplinary partnerships. This cutting-edge microscopy has applications across many fields, from those addressing a single protein to others studying entire cells. Virtually anyone studying complex molecular machines can advance their work with this tool, Parent added.

Parent has earned an AAAS Marion Milligan Mason Award for Women in the Chemical Sciences. This award, her paper in Viruses and being the co-author who performed cryo-EM work in a recent Nature Communications paper, lays the groundwork to some day have a more advanced cryo-EM microscope housed at MSU to be able to perform high-resolution structural studies.

"We've done quite a bit with our limited resources, but we're primed to do more," Parent said. "I think MSU could serve as a cryo-EM center and to increase the prevalence of this technology in the Midwest and beyond."

As one example, scientists from Universidade Federal de Minas Gerais (Brazil) and Universidade Federal do Rio de Janeiro (Brazil) also contributed to this study and benefitted from the technology MSU has to offer.

Global warming: Humans responsible for 60% loss of sea ice, study shows

That human activity is a cause of global warming and changing temperatures is a fact that cannot be debated, but until now, scientists had little clue as to what was the extent of damage due to human intervention.

That human activity is a cause of global warming and changing temperatures is a fact that cannot be debated, but until now, scientists had little clue as to what was the extent of damage due to human intervention. A paper published in Nature, based on model simulations of different climate conditions, shows that humans may be responsible for 50-70% change in climate conditions, leading to melting of ice at the Arctic sea. Although the study absolved humans for air flow changes, 70% of which, it said, is due to natural variability, it pointed that 60% of sea ice decline since 1979 was caused by summer-time changes in atmospheric circulation.

While the study is expected to change how we observe climate change, it will also get us to alter our future predictions. With Arctic ice depleting fast—in January it was 1.26 million square kilometres, which was 8.6% below the 1981–2010 average—global warming would need coordinated action from governments. Policy turns in the US—Republicans have presented a bill in the Congress to do away with the country’s Environmental Protection Agency—will end up harming the environment. With global warming accompanying industrialisation, countries would need a concerted approach to tackle its ill-effects.

Sperm swimming technique 'all down to simple maths'

How an individual sperm swims, against all the odds, through fluid to reach the fallopian tubes has been revealed - and it's all about rhythm.

Researchers from the UK and Japan found that the head and tail movements of sperm made patterns similar to the fields that form around magnets.

And these help to propel sperm towards the female egg.

Knowing why some sperm succeed and others fail could help treat male infertility, the researchers said.

More than 50 million sperm embark on the journey to fertilise an egg when a man and woman have sex.

About 10 reach the finish line - but there can only be one winner.

The journey is treacherous, says study author Dr Hermes Gadelha.

"Every time someone tells me they are having a baby, I think it is one of the greatest miracles ever - but no-one realises," says Dr Gadelha, a lecturer in applied mathematics at the University of York.

http://ichef.bbci.co.uk/news/624/cpsprodpb/3145/production/_95231621_1bb2f474-1030-42f0-9633-b826b3f568aa.pngThe swimming technique is all based on a simple maths formula Kenta Ishimoto, Kyoto University

He and his team measured the beat of individual sperm cells' tails to try to understand the flow of fluid around the sperm.

It turns out that a "simple mathematical formula" explains the rhythmical patterns created, Dr Gadelha says.

And these movements help selected sperm cells move forward towards their holy grail - the female egg.

The study, published in the journal Physical Review Letters, says the next step is to use the model to predict how large numbers of sperm move.

Prof Allan Pacey, a sperm expert from the University of Sheffield, says a successful sperm is more than just about swimming prowess.

"The more we know about sperm the better. This might help infertility treatment in some small way but there are lots of other factors to consider too."

They include the number of sperm available, getting them to the right place at the right time and the DNA present in the head of the sperm.

http://ichef.bbci.co.uk/news/624/cpsprodpb/B084/production/_95188154_c0174119-sperm_lm-spl.jpg Science Photo Library

Race to the egg - what sort of journey do sperm face?

When a man has ejaculated, 50 million to 150 million sperm are produced, and these cells immediately start swimming upstream towards a woman's fallopian tubes.

But it's not an easy journey - there are lots of hurdles to overcome for the male sex cells, which are just 0.065mm in length.

Only one sperm can penetrate the woman's egg and fertilise it, so the race is on.

First, they have to survive the vagina, where conditions mean most die. Then they have to avoid dead ends and being trapped before reaching the uterus.

On the way there are marauding white blood cells ready to kill them.

Finally, the remaining sperm arrive at the fallopian tubes, where they are fed and nourished.

But has an egg been released at exactly the right time to welcome the winning sperm? If not, the journey has all been in vain.

Vaccines do work for pandemic flu, says study

Vaccines are successful in preventing pandemic flu and reducing the number of patients hospitalised as a result of the illness, a study led by academics at The University of Nottingham has found.

However, the research -- the most comprehensive review undertaken in this area -- also found that the effectiveness of vaccines can vary depending on the age of the patient.

The work, published in the journal Vaccine, was led by Professor Jonathan Van Tam and Dr Louise Lansbury in the University's Health Protection and Influenza Research Group in collaboration with other scientists in the UK, Japan, Bosnia and the Netherlands.

Professor Van Tam said: ""The 2009 swine flu pandemic was the first in human history when pandemic vaccines have been available worldwide. It's therefore really important to pull all of these data together and ask the question: did these vaccines really work?

"We found that the vaccines produced against the swine flu pandemic in 2009 were very effective in both preventing influenza infection and reducing the chances of hospital admission due to flu. This is all very encouraging in case we encounter a future pandemic, perhaps one that is more severe. Of course, we recognise that it took five to six months for pandemic vaccines to be ready in large quantities; this was a separate problem. However, if we can speed up vaccine production times, we would have a very effective strategy to reduce the impact of a future flu pandemic."

In early 2009, a novel influenza A(H1N1) virus appeared in humans, containing a unique combination of influenza genes which had not previously been identified in animals or people. The first cases were reported in the United States in March 2009 but the new virus spread rapidly to other countries and in June 2009 the WHO declared a pandemic caused by this strain, known as influenza A(H1N1)pdm09, or 'swine flu'.

An estimated 61 million people were infected worldwide. Vaccines against the new strain were developed and rolled out across the world from September to December 2009. The majority of vaccines available contained inactivated A(H1N1)pdm09 influenza virus rather than live virus. Some formulations also contained an 'adjuvant' to strengthen the body's immune response to the vaccine and allow smaller doses of antigen to be used (adjuvanted vaccines).

Many individual studies have looked at how effective the available vaccines were at preventing illness and hospitalisation caused by the pandemic influenza strain but up until now no-one has summarised all the available data. This systematic review and meta-analysis is the most comprehensive summary and offers insight into the relative effectiveness of both adjuvanted and non-adjuvanted vaccines in different age groups.

The researchers found 38 studies published between June 2011 and April 2016 that measured the effectiveness of the inactivated pandemic influenza vaccines, covering a population of more than 7.6m people. Twenty-three of these studies reported results that were suitable for meta-analysis -- a statistical method used to combine the results from multiple individual studies that are broadly similar in terms of vaccine used and types of people in the study and which is statistically more powerful and can provide a more precise estimate of the effect of vaccination than any individual study contributing to the analysis.

Overall, pandemic influenza vaccines were found to be 73 per cent effective at preventing laboratory-confirmed influenza illness and 61 per cent effective at preventing hospitalisation in the population as a whole. However, when the vaccines' effectiveness was examined in different age groups, they were shown to be less effective in adults over 18 years than in children, and effectiveness was lowest in adults over 50 years of age. Adjuvanted vaccines in particular were found to be more effective in children than in adults against laboratory confirmed illness (88 per cent in children versus 40 per cent in adults) and hospitalisation (86 per cent in children versus 48 per cent in adults).

Overall the inactivated pandemic influenza vaccines used in the 2009 pandemic were effective in preventing laboratory-confirmed illness and hospitalisation. Adjuvanted vaccines tended to be more effective than non-adjuvanted vaccines but only in children. The lower effectiveness in older people may be due to them having pre-existing antibodies against A(H1N1)pdm09 from previous exposure to a similar virus, with corresponding lower incidence of the infection in this age group.

The results showed that pandemic influenza vaccines produced globally during the 2009-10 pandemic were largely effective in reducing illness and hospitalisation. The results from the study could be used to help public health officials to plan a more effective response to future pandemics, such as rolling out vaccines at a much earlier time and targeting specific types of vaccines at different age groups.

Antibiotics not effective for clinically infected eczema in children

Estimates suggest that 40 percent of eczema flares are treated with topical antibiotics, but findings from a study led by Cardiff University suggest there is no meaningful benefit from the use of either oral or topical antibiotics for milder clinically infected eczema in children.

Eczema is a common condition, especially in young children, and affects around 1 in 5 children in the UK. Eczema sometimes gets worse, or 'flares', and having particular bacteria on the skin may contribute to causing some of these flares. Quite often eczema flares are treated with antibiotics, although there was very little research to show whether antibiotics are helpful or not.

The CREAM study was designed to find out if oral (taken by mouth) or topical (creams and ointments applied to the skin) antibiotics help improve eczema severity in children with infected eczema. All children also received standard eczema treatment with steroid creams and emollients (moisturiser) from their doctor.

Results from the analysis of data from 113 children with non-severely infected eczema, published in the Annals of Family Medicine journal, showed no significant difference between the groups in the resolution of eczema symptoms at two weeks, four weeks or three months.

Researchers found rapid resolution in response to mild-to-moderate strength topical corticosteroids and emollient treatment, and ruled out a clinically meaningful benefit from the addition of either oral or topical antibiotics.

Dr Nick Francis, Clinical Reader at Cardiff University and practicing GP, who led the study said: "Topical antibiotics, often in combination products with topical corticosteroids, are frequently used to treat eczema flares. Our research shows that even if there are signs of infection, children with milder eczema are unlikely to benefit from antibiotics, and their use can promote resistance and allergy or skin sensitization."

"Providing or stepping up the potency of topical corticosteroids and emollients should be the main focus in the care of milder clinically infected eczema flares."

Archaeologists in Egypt discover massive statue in Cairo slum

Archaeologists in Egypt discovered a massive statue in a Cairo slum that may be of Pharaoh Ramses II, one of the country's most famous ancient rulers.

The colossus, whose head was pulled from mud and groundwater by a bulldozer and seen by the Associated Press on Friday, is around 26 feet high and was discovered by a German-Egyptian team.

Egyptologist Khaled Nabil Osman said the statue was an "impressive find" and the area is likely full of other buried antiquities.

"It was the main cultural place of ancient Egypt. Even the Bible mentions it," he said. "The sad news is that the whole area needs to be cleaned up. The sewers and market should be moved."

Ramses II ruled Egypt more than 3,000 years ago and was a great builder whose effigy can be seen at a string of archaeological sites across the country.

Massive statues of the warrior-king can be seen in Luxor, and his most famous monument is found in Abu Simbel, near Sudan.

Osman said the massive head removed from the ground was made in the style that Ramses was depicted and likely was him. The site contained parts of both that statue and another.

Egypt is packed with ancient treasures, many of which remain buried. The sites open to tourists often are empty of late as the country has suffered from political instability that has scared off foreigners since its Arab Spring uprising in 2011.

  • Published in World

Arctic circle could become completely free of sea ice even if global warming limited to two degrees Celsius

Loss of sea ice could have 'catastrophic' effects on the weather in much of the northern hemisphere and speed up global warming.

The Arctic Ocean could become free of sea ice for the first time in 100,000 years even if action is taken to keep global warming to within two degrees Celsius, scientists have warned.

The region has experienced much sharper rises in temperature in recent decades that the rest of the world with temperatures in winter in Spitsbergen an astonishing 8 to 11C higher than the average between 1961 and 1990.

And this is believed to be having a significant effect on the weather in much of the northern hemisphere, increasing the number of dangerous storms. One leading expert has warned it could have a “catastrophic” effect on the Earth’s climate.

The loss of sea ice, which reflects much of the energy from sunlight, will also increase the rate of global warming.

In a paper in the journal Nature Climate Change, Dr James Screen and Dr Daniel Williamson, of Exeter University, looked at the likelihood of the ice disappearing almost completely if temperatures rose by 1.5C or 2C.

The Paris Agreement on climate change spoke of keeping global warming below 2C and as close to 1.5C as possible – in order to avoid levels considered particularly dangerous – but the world is currently on track to hit anything from 2.6C to 3.1C by the end of the century.

The researchers wrote: “We estimate there is less than a one-in-100,000 chance of an ice-free Arctic if global warming stays below 1.5C, and around a one-in-three chance if global warming is limited to 2C. 

“We suppose then that a summer ice-free Arctic is virtually certain to be avoided if the 1.5C target of the Paris Agreement is met. 

“However, the 2C target may be insufficient to prevent an ice-free Arctic.”

The Arctic will be considered ice-free if it falls to below a million square kilometres. This would mean the sea around the North Pole would be clear with the remaining ice found mainly in the small islands and inlets off the north coasts of Russia and Canada, where the effect of the land, which gets colder than the sea, is more pronounced.

In September last year, Arctic sea ice fell to about 4.1 million square kilometres, the second lowest figure, compared to about 3.4 million in 2012, according to the US National Snow & Ice Data Centre.

Antarctic sea ice is currently at record low levels with 2.14 million square kilometres, compared to the average of 3.16 million between 1981 and 2010.

In December, the US National Oceanic and Atmospheric Administration (NOAA) said the situation was changing so quickly it was “outpacing our ability to understand and explain” what was happening.

They suggested the word “glacial” should not be used to mean something happening slowly but as a term for something that was “rapidly diminishing”.

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