America’s Atlantic coast set to take a worse battering

America’s Atlantic coast set to take a worse battering

Scientists say the eastern seaboard of the US faces more frequent storms and flooding as sea levels continue to rise with climate change.

LONDON, 3 October 2015 −Sea level rise and global warming spell danger for New York as average flood heights have risen by 1.25 metres along that part of the US coast − and new research warns that the devastating flood that arrived with Superstorm Sandy in 2012 could happen again.

A flood height of 2.25 metres would once have happened only every 500 years. Now scientists say it could recur every 25 years.

And a second study finds that almost the entire US Atlantic coast is increasingly at risk from the combined hazards of storm surge and sea level rise, and that this risk rises dramatically with time. According to one scenario, it could increase 350-fold.

The two studies are based on different approaches, but they reinforce each other’s conclusions.

Historic approach

Andra Reed, a researcher in the Department of Meteorology at Pennsylvania State University in the US, and colleagues report in the Proceedings of the National Academy of Sciences that the devastation of Sandy prompted them to take the historic approach.

They did this by using fossil evidence to reconstruct the history of flooding along the coast where New York City now stands.

The 2012 hurricane breached the sea walls at Battery Park on the southern tip of Manhattan, and flooded the city’s subway tunnels, but the city’s record of such surges goes back only to 1850.

So the researchers used a mix of climate models and evidence from sediments and tiny marine organisms to build up a picture of sea level change between AD 850 and 2005.

“In the pre-anthropogenic era, the return period for a storm producing a surge of 2.81 metres or greater, like Sandy at the Battery, would have been about 3,000 years,” Reed said. “We found that, in the anthropogenic era, the return period for this same storm surge height has been reduced to about 130 years.”

“A storm that occurred once in seven generations is now occurring
twice in a generation”

Her co-author, Benjamin Horton, professor of marine and coastal sciences at Rutgers University, put the same findings another way. “A storm that occurred once in seven generations is now occurring twice in a generation,” he said.

The 1,200-year reconstruction of sea level change showed that sea level rise had risen at its steepest rate in 1,000 years in the last century. This meant that “an extra 100,000 people flooded in the region during Hurricane Sandy who would not have been flooded if sea level had not been rising”.

Sandy caused an estimated $50 billion worth of damage and destroyed 600,000 houses. But concern about storms and floods – especially along densely populated coasts – is not new.

In the last three years, researchers have warned that maritime cities could by 2050 face an annual toll of $1 trillion in flood defences and damage, and this may have risen to $100 trillion by 2100.

America’s eastern seaboard already experiences sea level rises above the global average, and routine high tide flooding presents an increasing hazard.

But the unholy mix of rising seas and more intense coastal storms presents special dangers, according to Christopher Little, a climate scientist at Atmospheric and Environmental Research in Lexington, Massachusetts.

Climate models

He and colleagues report in Nature Climate Change journal that they analysed 15 climate models at five locations – Atlantic City in New Jersey, Charleston in South Carolina, Key West and Pensacola in Florida, and Galveston in Texas – to see not just what would happen to sea level rise, and to the frequency and intensity of hurricanes, but also the chances that the two could coincide.

They calculated what might happen if the planet greatly reduced the emissions of greenhouse gases − produced by the combustion of coal, oil and natural gas − and what could be expected if the humans went on burning them in the “business-as-usual” scenario.

Even if the planet voted for severe cuts in fossil fuel use, the combined heights and durations of future floods could increase at least fourfold, and perhaps as much as 75-fold. If humans carry on pumping oil and shovelling on the coal, this “flood index” could increase by 35 to 350 times.

“When you look at hazards separately, it’s bad enough, but when you consider the joint effects of two hazards together, you can get some surprises,” says one of the report’s co-authors, Radley Horton, a climate systems researcher at Columbia University’s Earth Institute. “Sometimes one plus one can equal three.” – Climate News Network

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Climate threatens Pacific with seesaw sea levels

Climate threatens Pacific with seesaw sea levels

Scientists say coasts and communities in the Pacific region face more extreme weather hazards as climate change magnifies the devastating El Niño effect.

LONDON, 28 September, 2015 − El Niño, that periodic bubble of heat that hits the tropical Pacific every few years, has nothing to do with climate change – but the phenomenon could be made much more devastating by climate change, according to two new studies.

And that is bad news for a region where vulnerable coastlines are already at risk from serious storms, floods and rising sea levels.

One set of researchers reports in Science Advances that, in response to El Niño, Western Pacific sea levels will fall and rise more frequently by 2100. When they fall, they threaten the corals with a foul-smelling tide; when they rise, they threaten to flood the atolls.

And another group reports in Nature Geoscience that the alternating impact of a blistering El Niño and its chillier sister, La Niña, could bring more extreme flooding and more damaging erosion to the entire Pacific region.

Scientists have already warned once this year that a periodic cycle of warming and cooling in the Pacific could increase in frequency.

Bubble of heat

El Niño is a cyclic phenomenon that tends to manifest itself at Christmas time, which is why, long ago, Peruvian fishermen started giving it the name that means “The Child” in Spanish.

A great bubble of ocean heat moves eastward across the Pacific, causing sea levels in one place to rise, in another to fall, bringing floods and storms to the normally dry west coasts of the Americas, and bringing drought and even forest fires to the rainforests of Indonesia.

A notorious El Niño in 1998 helped make that year one of the hottest ever recorded, and since then meteorologists and climate scientists have been puzzling about what will happen to this natural cycle as carbon dioxide levels rise − in response to human combustion of fossil fuels − and in turn raise average global temperatures.

Matthew Widlansky, a climate researcher at the International Pacific Research Centre in Hawai’i, and colleagues report in that global warming will enhance El Niño-linked sea-level extremes.

This, in turn, will mean very low sea levels in the western Pacific, followed six months later by a seesaw in north-south sea levels, in which the seas drop by as much as 30 centimetres, to expose vulnerable coral ecosystems. And these could double in frequency.

“Utilising many years of data enabled us to definitively identify how the major climate drivers affect coastal hazards across the Pacific”

“The possibility of more frequent flooding in some areas and sea level drops in others would have severe consequences for the vulnerable coastlines of Pacific islands,” Dr Widlansky says.

Patrick Barnard, a coastal geologist at the US Geological Survey in Santa Cruz, California, and colleagues report that they took a different line of approach to arrive at a similar conclusion.

Thirteen research institutions looked at data from 48 Pacific beaches in the US, Canada, Japan, Australia, New Zealand and Hawai’i from 1979 to 2012 to see if patterns in coastal change could be linked to climate cycles such as El Niño and La Niña. They too found that climate change was likely to make such events worse.

“Shoreline behaviour can be controlled by so many different factors, both locally and regionally, that it’s been difficult to isolate the signal until now,” Dr Barnard says.

Predict impacts

“However, utilising the many years of data we were able pull together in this study enabled us to definitively identify how the major climate drivers affect coastal hazards across the Pacific. This will greatly enhance our ability to predict the broader impacts of climate change at the coast.”

C o-author Mitchell Harley, a civil and environmental engineer at the University of New South Wales, Australia, says: “Coastlines of the Pacific are particularly dynamic as they are exposed to storm waves generated often thousands of miles away.

“This research is of particular importance as it can help Pacific coastal communities prepare for the effects of changing storm regimes driven by climate oscillations like El Niño and La Niña.

“To help us complete the puzzle, for the next step we would like to look at regions of the Pacific like South America and the Pacific Islands, where very limited shoreline data currently exists.” – Climate News Network

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Harder rains set to fall as the world warms

Harder rains set to fall as the world warms

Scientists pinpoint when global warming emerged – and predict increasingly greater climate extremes in hot, cold and wet weather trends.

LONDON, 26 September, 2015 – In not quite the words of the singer Bob Dylan, a hard rain is going to fall. Australian scientists predict that precipitation extremes with large variability will emerge in the Northern Hemisphere in the coming decades as part of a “wettening trend”.

In other words, an even harder rain will fall − and then you’ll really know that the climate has changed.

Andrew King, a climate system scientist at the Climate Change Research Centre at the University of New South Wales and at the University of Melbourne, is lead author of a report in the journal Environmental Research Letters.

He and colleagues say they have pinpointed the moment when global warming, as a result of human influences, emerged in the historic record in some parts of the world. They can now also predict when it will become even clearer in places so far untouched.

Story of warming

Although climate change can be predicted, it can only be identified after the event. That is because, while climate is the average of all the extremes of weather, the weather can get pretty extreme, even within a stable climate.

From the late 1980s onwards, global average temperatures began to tell a consistent story of warming.

But if those temperatures are now on the increase because of the continual rise in carbon dioxide concentrations in the atmosphere, as a consequence of the human exploitation of fossil fuels, then there must have been some moment in the past when the signs of change could have been detected, and when a new climate trend developed.

Such questions sound academic, but the better humans understand the past, the more likely they are to be prepared for the future.

“It is likely to bring pronounced precipitation events, on top of the already existing trend
towards increasingly wet winters”

So Dr King and his colleagues used state-of-the-art computer models to simulate not just climate change, but the way that extreme events have begun to change. “Both hot and cold extremes have already emerged across many areas,” they say.

The scientists examined average and extreme temperatures because these would, of course, be most sensitive to global warming − and therefore evidence should show in historic records.

“Remarkably, our research shows you could already see clear signs of global warming in the tropics by the 1960s, but in parts of Australia, south-east Asia and Africa it was visible as early as the 1940s,” Dr King says.

Changing pattern

First the scientists saw a rise in average temperatures; then the changing pattern of extremes of climate began to confirm the picture.

There are exceptions: the continental US, especially on the East Coast, has yet to show any obvious warming signals, but these could appear in the next decade.

And although greater warming means more evaporation and more precipitation, in many places this heavier rainfall is still so far within the range of “normal” extreme weather.

“We expect the first heavy precipitation events with a clear global warming signal will appear during winters in Russia, Canada and northern Europe over the next 10 to 30 years,” says Ed Hawkins, a meteorologist at the University of Reading in the UK, and one of the report’s co-authors.

“It is likely to bring pronounced precipitation events, on top of the already existing trend towards increasingly wet winters in these regions.” – Climate News Network

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Risk of new Katrinas rises as climate warms

Risk of new Katrinas rises as climate warms

Climate change may drastically increase the risk of simultaneous cyclones and storm surges striking populous coastlines around the world.

LONDON, 1 September, 2015 – Perfect storms are by definition improbable. But climate scientists now think that the devastating combination of extreme tropical cyclone and unprecedented storm surge is going to get a whole lot less improbable by the end of the century.

The chances that the city of Tampa, in Florida, will be hit by a devastating hurricane and an 11-metre wall of ocean water by 2100 could have increased by up to fourteen-fold, they report in Nature Climate Change.

All climate modelling involves a calculation of probabilities. Ning Lin, a civil engineer at Princeton University in New Jersey in the US, and Kerry Emanuel, a climate scientist at Massachusetts Institute of Technology in Cambridge, Massachusetts, started exploring the idea of events that are highly improbable, but worth trying to predict anyway because their consequences could be so calamitous.

If storms that could not be expected are “black swan” events, then they have identified a second category: “grey swan” events that are worse than any in recorded history, but are nevertheless foreseeable, using knowledge of atmospheric physics, topography and the climate record.

So – on the tenth anniversary of Hurricane Katrina’s assault on New Orleans, the most costly disaster in American history – they decided to see how bad things could really get.

Advance warnings

The horror of Katrina was that although it was a storm surge without precedent, engineers and meteorologists had repeatedly warned that New Orleans could be vulnerable. And when it arrived, New Orleans, the state of Louisiana and the Washington Administration were all taken by surprise.

For their study, the two scientists selected three vulnerable bits of coastline and set about modelling the worst that could happen, and the probabilities that it might happen. They chose Dubai in the Persian Gulf – an area never before hit by a tropical cyclone – Cairns on the coast of Australia, and Tampa in Florida.

They found that a “grey swan” cyclone right now could cause a storm surge of six metres in Tampa, Cairns 5.7 metres and Dubai four metres. The chances of such a thing happening in any one year, however, were as low as one in 10,000. That is, not very likely.

And then they factored in continuing climate change, driven by global warming as a consequence of prodigal fossil fuel combustion by humankind, and started to consider the long-term consequences.

By the end of the century, the hazard to Dubai had increased to seven metres, and to Tampa to 11 metres. And the probabilities had increased too: the likelihood of a devastating storm and an overwhelming wall of water in the Persian Gulf had become “non-negligible”: the extreme in Tampa’s case was one in 700.

“The ocean conditions that led to a severe hurricane season in 2005 also reduced atmospheric moisture flow to South America, contributing to a once-in-a-century dry spell in the Amazon”

But such research is based only on known hazards now and projections for the future. In fact, hurricane conditions in one region can be matched by awful hazards in places far away according to a team from the University of California, Irvine, and the US space agency Nasa.

They report in Geophysical Research Letters that they have identified a link between catastrophic wildfires in the Amazon and hurricanes such as Katrina that devastate the northern hemisphere coasts.

Yang Chen, an earth system scientist from UC Irvine, and colleagues looked at years of sea surface temperature and other climate data to find the connection. In years of high numbers of hurricanes and high fire risk, warm waters in the North Atlantic help hurricanes develop and gather strength and speed on their way to North American shores.

These same warm waters drag rainfall away from the southern Amazon, leaving the rainforests increasingly vulnerable to fire. Since the Amazon forests are a vital repository of stored carbon, any fires there can only fuel global warming still further, increasing sea surface temperatures and stepping up yet more the probability of tropical cyclones, typhoons or hurricanes.

“Hurricane Katrina is, indeed, part of this story”, said UCI earth system scientist James Randerson, senior author of the paper. “The ocean conditions that led to a severe hurricane season in 2005 also reduced atmospheric moisture flow to South America, contributing to a once-in-a-century dry spell in the Amazon. The timing of these events is perfectly consistent with our research findings.” – Climate News Network

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Extreme weather puts Africa’s food security at risk

Extreme weather puts Africa's food security at risk

A British government scientific panel says increasingly frequent heat waves, droughts and other extreme weather threaten more – and more severe – global food crises.

LONDON, 15 August, 2015 – Developing countries in sub-Saharan Africa which depend heavily on food imports will be worst hit by the increasingly extreme global weather, a report says, with the Middle East and North Africa also threatened, in this case by social unrest.

In contrast, the authors say the impact on the world’s biggest economies is likely to be muted. But they think a serious crisis could occur as soon as 2016, with repercussions in many countries.

They write: We present evidence that the global food system is vulnerable to production shocks caused by extreme weather, and that this risk is growing…preliminary analysis of limited existing data suggests that the risk of a 1-in-100 year production shock is likely to increase to 1-in-30 or more by 2040.”

The report was jointly commissioned by the UKs Foreign and Commonwealth Office and its Government Science and Innovation Network, with a foreword by the countrys former chief government scientist, Sir David King.

He writes: We know that the climate is changing and weather records are being broken all the time…The food system we increasingly rely on is a global enterprise. Up to now its been pretty robust and extreme weather has had limited impact on a global scale. But…the risks are serious and should be a cause for concern…

Likely scenarios

We should be looking carefully at even very low probability situations, and the likelihood of the scenarios suggested in this report are far too significant to ignore.”

The report says the UN’s Food and Agriculture Organisation estimates that by 2050 global food demand will be 60% above todays, with per capita demand also growing, and more meat-eating.

In 2007/8 a small weather-related production shock, coupled with historically low stock levels, led to rapid food price inflation in the main internationally traded grains, as measured by the FAO Food Price Index.

Prices rose by over 100%. A similar price spike occurred in 2010/11, partly driven by the weather in eastern Europe and Russia.

In 2012, the worst drought to hit the American Midwest for half a century triggered comparable spikes in international maize and soya prices. There is good evidence, the report says, that extreme weather events, from intense storms to droughts and heat waves, are increasing significantly.

Food production of the globally most important commodity crops (maize, soya, wheat and rice) comes from a small number of major producing countries.

Multiple failure

Simultaneous extreme weather events in two or more of these regions – creating a multiple bread basket failure – would represent a serious production shock. There is an urgent need to understand the driving dynamics of linked problems such as the El Niño effect – which may be becoming more extreme – the report says.

By examining production shocks in the recent past, the authors devised what they call a plausible worst case scenario” – a simultaneous drought affecting maize and soya production, and another which damages wheat and rice harvests.

More topically, they also describe what they say is a plausible worst case scenario for 2016. This involves a complex sequence, starting with a disappointing 2015 Indian monsoon, the loss of much of 2016s Black Sea winter wheat crop, and then Russian and Ukrainian export bans.

International wheat prices rise fast, prompting similar measures in south and central Asia and Argentina, and repercussions as far afield as China, Iran, Saudi Arabia and Morocco.

In late spring a persistent drought starts in North America, affecting soya and maize forecasts and prices. Then a heatwave and drought hit the European wheat crop, leading to further rises across all cereals.

Panicked markets

In early summer a second failure of the Indian monsoon unleashes panic in the rice market, where Asian households have been steadily hoarding. Myanmar, Sri Lanka, Egypt and Nepal impose export restrictions.

Major importers such as Nigeria, Malaysia and the Philippines place orders far above normal levels in a bid to calm domestic markets. The scenario ends with still more countries
– Vietnam, Cambodia and Indonesia – imposing export bans.

One of the reports recommendations is that agriculture should adapt to a changing climate.

That, it says, means productivity must be increased by reversing declines in yield growth and closing the gap between actual and attainable yields in the developing world, while also reducing agricultures environmental impact, including the depletion of fresh water and the increase in greenhouse gas emissions.

However, it says, given the increasing risk of extreme weather, this cannot come at the expense of production resilience. – Climate News Network

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Record torrential rainfall linked to warming climate

Record torrential rainfall linked to warming climate

Scientists show that devastating increases in extreme rainfall over the last 30 years fit in with global temperature rise caused by greenhouse gases.

LONDON, 13 July, 2015 – If you think you’re getting an unusually hard soaking more often when you go out in the rain, you’re probably right.

A team of scientists in Germany says record-breaking heavy rainfall has been increasing strikingly in the last 30 years as global temperatures increase.

Before 1980, they say, the explanation was fluctuations in natural variability. But since then they have detected a clear upward trend in downpours that is consistent with a warming world.

The scientists, from the Potsdam Institute for Climate Impact Research (PIK), report in the journal Climatic Change that this increase is to be expected with rising global temperatures, caused by greenhouse gas emissions from burning fossil fuels.

High-impact flooding

Short-term torrential rains can lead to what the team calls “high-impact” flooding. For example, extreme rainfall in Pakistan in 2010 brought devastation that killed hundreds of people and led to a cholera outbreak.

In the same year, rainstorms in Texas caused dozens of flash floods. And no fewer than three “once-in-a-century” floods in Germany all happened in just a couple of years from 1997.

“In all of these places, the amount of rain pouring down in one day broke local records – and while each of these individual events has been caused by a number of different factors, we find a clear overall upward trend for these unprecedented hazards,” says the lead author, Jascha Lehmann, a PIK researcher into climate impacts and vulnerabilities.

Statistical analysis of rainfall data from 1901 to 2010, derived from thousands of weather stations around the globe, shows that from 1980 to 2010 there were 12% more of these intense events than would be expected in a climate without global warming. In the last year of the period the team studied, there were 26% more record-breaking daily rainfall events globally.

“One out of 10 record-breaking rainfall events in the past 30 years can only be explained if
the long-term warming is taken into account”

Not all parts of the world are experiencing a similar pattern of soaking. The PIK scientists found that − possibly not surprisingly − wet regions generally saw a bigger increase in deluges and drier regions a smaller one.

In southeast Asia, the observed increase in record-breaking rainfall events is as high as 56%, in Europe 31%, and in the central US it is a more modest, but still worrying, 24%.

In marked contrast, some regions have experienced significantly fewer record-breaking daily rainfall events. In the Mediterranean, the reduction is 27%, and in the western US it is 21%. Both regions are at risk from severe droughts.

The team says there is a simple scientific explanation for what they report. They compared their findings with existing knowledge about how much more water the atmosphere can store when temperatures rise, described by what they call the well-known Clausius-Clapeyron equation.

Put simply, warmer air holds more moisture, which can be released during short-term heavy rainfall.

The scientists show that the observed increase in unprecedented heavy rainfall generally fits with this thermodynamically expected increase under global warming.

Upward trend

“One out of 10 record-breaking rainfall events observed globally in the past 30 years can only be explained if the long-term warming is taken into account,” says co-author Dim Coumou, a PIK researcher into the links between atmospheric circulation and extreme weather events. “For the last year studied, 2010, it is even one event out of four, as the trend is upward.”

There are, of course, qualifications to the broad picture. For instance, the scientists allowed for the fact that the quality of historic weather data differs from one place to another. Unsurprisingly, rainfall measurements from the Sahara desert are scarce, so the team avoids drawing conclusions for the region.

But rainfall in regions such as Europe and the US has been carefully monitored for over a century, allowing the authors to draw conclusions with high levels of confidence

“The pronounced recent increase in record-breaking rainfall events is, of course, worrying,” Coumou says. “Yet since it is consistent with human-caused global warming, it can also be curbed if greenhouse gas emissions from fossil fuels are substantially reduced.” – Climate News Network

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Deaths mount as Pakistan heatwave is linked to climate

Deaths mount as Pakistan heatwave is linked to climate

More than 1,200 people have died as the result of an intense heatwave in southern Pakistan, and experts warn of more hot weather to come.

ISLAMABAD, 6 July, 2015 − Pakistan’s lack of preparedness in the face of increasingly intense weather events is being blamed for a growing death toll following what has been one of the most sustained heatwaves in the country since records began.

And weather experts say that the extreme heat – which lasted for much of the second half of June, and was felt most in the southern province of Sindh – is linked to climate change.

Ghulam Rasul, director general of the Pakistan Meteorological Department (PMD), told Climate News Network that the intense heat was caused by an unusually persistent area of low pressure over the Arabian Sea off Pakistan’s coast.

“Usually, in summer, cool winds blow from the sea to land, and in winter the situation is the opposite,” he said. “This moderates temperatures in the port city of Karachi, but this summer, this didn’t happen.”

Climate taskforce

Pervaiz Amir, formerly a member of a special taskforce on climate change set up by Nawaz Sharif, Pakistan’s prime minister, said: “The mortality from heatstroke could have been avoided had the Sindh provincial government responded to a heatwave forecast issued by the Pakistan Meteorological Department.”

Karachi, a city of nearly 20 million, was worst hit, with bodies piling up in the city’s morgues, and hospitals crammed with people suffering from severe heatstroke as daytime temperatures climbed to well over 40°C for extended periods.

About 65,000 heatstroke patients were treated at the city’s hospitals, and the death toll in southern Pakistan climbed above 1,200.

“This is leading to more extreme weather events, with floods and heatwaves becoming more intense and frequent in recent years”

Chronic energy shortages – a common occurrence in Pakistan – added to the problem, and the heatwave came during Ramadan, the Muslim fasting period when people do not eat or drink during daylight hours.

Experts say Karachi has also suffered from what’s known as the urban heat island effect, with poor urban planning and a lack of green spaces making conditions even hotter.

Social workers say the majority of those who have died have been the poor and homeless. At one stage, Karachi’s cemeteries ran out of space for burying the dead.

Mohsin Iqbal, a climate scientist at the state-owned Global Change Impact Study Centre in Islamabad, says temperature increases in Pakistan are above the rise in average global temperatures.

Extreme events

“This is leading to more extreme weather events, with floods and heatwaves becoming more intense and frequent in recent years,” he says.

Climate experts say weather patterns throughout the Asian sub-continent are changing, with more intense periods of heat, delays in the monsoon season and a greater incidence of drought conditions.

In April and May this year, many parts of India were hit by an intense heatwave, causing the death of more than 2,000 people.

AccuWeather, a global forecasting service, says delays in the arrival of monsoon rains and further hot periods are likely to exacerbate drought conditions in Pakistan and northwest India in July and August, threatening crop production across a wide swathe of land. – Climate News Network

  • Saleem Shaikh is a freelance climate change and science journalist, based in Islamabad, Pakistan.

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Scientists detect mysterious warming in US coastal waters

Scientists detect mysterious warming in US coastal waters

Unprecedented ocean temperature rises off the Atlantic and Pacific coasts of the US may be linked to sea level rise or the recent pattern of “weird” weather.

LONDON, 28 June, 2015 − Oceanographers are puzzled by an accelerated burst of warming sea that threatens the fisheries of the American Atlantic coast.

Meanwhile, off the US West coast, scientists report that they have been baffled by a mysterious “blob” of water up to 4°C warmer than the surrounding Pacific, linked to weird weather across the entire country.

Jacob Forsyth and research colleagues from the Woods Hole Oceanographic Institution (WHOI) in Massachusetts report in the Journal of Geophysical Research: Oceans that the ocean off the US north-east continental shelf has been warming at unprecedented levels for 13 years.

Their findings came after analysis of data from sensors − called bathythermographs − dropped 14 times a year from the container ship Oleander, which for 37 years has travelled between New Jersey and Bermuda. Each detector takes the temperature of the water column as it sinks up to 700 metres.

Startling discovery

What they were startled to discover was an unexplained, and unprecedented, rise in the water temperatures that may be linked with an equally mysterious sea level anomaly: sea levels are going up, but they are going up faster off the north-east coast of the US than almost anywhere else.

“The warming rate since 2002 is 15 times faster than from the previous 100 years,” says Glen Gawarkiewicz, a WHOI senior scientist and one of the authors of the report.

“There’s just been this incredible acceleration to the warming, and we don’t know if it’s decadal variability or if this trend will continue.”

“It’s producing conditions that we think are going to be more common with global warming”

To make sure of their perspective, the authors compared their analysis with surface data from the Nantucket lightship and other such installations along the coast, from 1880 to 2004. The new study shows that the warming is not just confined to surface waters.

Although there must be some link with the steady rise in atmospheric temperatures because of global warming as a result of human-made carbon dioxide emissions, the oceanographers suspect there may also be another explanation, so far undiscovered.

Off the Pacific coast, meteorologists have been scratching their heads over the appearance in 2014 of a “remarkably” warm patch −  1,500 kilometres across in every direction and 100 metres deep − that could be linked to “weird” weather across the continental US that has seen heat and drought in the west and blizzards and chills in the East.

High pressure ridge

Nicholas Bond,  a research meteorologist at the University of Washington in Seattle, and colleagues report in Geophysical Research Letters that what they have called “the blob” was linked to a persistent high pressure ridge, linked in turn to a calmer ocean during the last two northern hemisphere winters.

The blob plays a sure role in the West Coast weather. Air sweeping across it picks up heat, and this results in warmer temperatures and lower snowpack in coastal mountains − which certainly stoke up the conditions for drought.

A second study in Geophysical Research Letters links the warm Pacific puzzle to the big freeze in the eastern states in 2013 and 2014.

Once again, there doesn’t seem to be a direct connection with climate change, but it raises the spectre of changes to come.

“This is a taste of what the ocean will be like in future decades,” Dr Bond says. “It wasn’t caused by global warming, but it’s producing conditions that we think are going to be more common with global warming.” − Climate News Network

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Prospect of warmer winters doesn’t mean fewer deaths

Prospect of warmer winters doesn’t mean fewer deaths

New scientific study pours cold water on the theory that mortality rates will drop in winter months as the climate warms.

LONDON, 26 June, 2015 − Global warming is unlikely to mean that fewer people in northern latitudes will die from cold during the winter, according to a study by scientists in the US.

Despite arguments that an increase in death rates caused by global warming and increased summertime temperatures will be offset by a matching drop in mortality as winter temperatures also rise, the study cautions against assuming any such link as research suggests otherwise.

The study, carried out over several years, looked at temperature-related seasonal mortality rates, particularly among elder people, in a total of 39 cities – the majority in the US, and three in France.

It concludes: “Our findings suggest that reductions in cold-related mortality rates under a warming climate may be much smaller than some have assumed.”

The research, carried out by a team led by Professor Patrick Kinney, a specialist in public health at the Columbia University Earth Institute in the US, is published in the Environmental Research Letters journal.

Temperature range

“We found that excess winter mortality did not depend on seasonal temperature range and was no lower in warmer vs colder cities, suggesting that temperature is not a key driver of winter excess mortality,” the study says.

Although the researchers acknowledge that seasonal temperature patterns can have an effect on health, many other factors influence mortality rates in winter among elderly people.

Diseases such as influenza – often transmitted when younger generations of families meet up with their elders at family celebrations – play a far greater role in mortality than the cold.

“Most older people who die over the winter don’t die from cold – they die from complications related to ’flu and other respiratory diseases,”  Kinney says.

Most previous studies investigating the links between temperature rises and death rates have focused on the impact of summer heat.

“Most older people who die over the winter don’t die from cold – they die from complications
related to respiratory diseases”

A prolonged heatwave across Europe in 2003 – which many scientists say can be attributed to climate change – is believed to have caused between 30,000 and 50,000 deaths. Elderly people in urban areas – often left stranded in their baking apartment blocks – were particularly badly hit.

A lot of media attention has also been given recently to the high rates of death among migrant workers from Nepal working in high temperatures in Qatar and other countries in the Gulf region.

The Columbia study looked at winter death rates among elderly people in cities in different climate zones and with differing demographics – from Paris and New York to Miami and Marseilles.

Opposite effect

It found that most of the elderly people living in the cities from which data was gathered were not exposed to the winter cold for long periods as the majority had access to a warm indoor environment.

Kinney says that rather than decreasing mortality, warmer winters could have the opposite effect.

“We see mosquito-borne diseases emerging in new territories because warmer winter temperatures enable the insects to over-winter in more northerly regions,” he says.

“Warmer temperatures can also enable an insect-borne virus to replicate inside the insect vector to be transmitted and cause disease in a human or animal.

“Sadly, this research tells us that an increase in summer deaths due to climate change is unlikely to be counteracted by a reduction in winter deaths.” – Climate News Network

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India blames heatwave deaths on climate change 

India blames heatwave deaths on climate change 

Fierce temperatures in India doubled the heat-related deaths normally recorded in May − and the government insists natural causes are not to blame.

CHENNAI, 19 June, 2015 − India, one of the key players in the efforts to reach an international agreement on global warming, has no doubt of its malign effects. It was, says a government minister, the warming climate that caused last month’s devastating heatwave.

From mid-April till the end of May, nearly 2,200 people were killed by the heat − 1,636 of them in Andhra Pradesh, the worst-affected state. The normal May figure for the whole of India is about 1,000 heat-related deaths.

Dr Harsh Vardhan, India’s Minister of Science and Technology and Earth Sciences, has blamed the heat deaths squarely on climate change.

Improve understanding

Launching a supercomputer at the National Centre for Medium Range Weather Forecasting to improve understanding of climatic changes, he said: “It’s not just another unusually hot summer − it is climate change.

“Let us not fool ourselves that there is no connection between the unusual number of deaths from the ongoing heatwave and the certainty of another failed monsoon.”

Dr Vardhan said that May’s heatwave, followed by the delay to the start of the monsoon, on which nearly half of India’s farmlands depend, was a definite manifestation of climate change.

Jejabba, a 63-year-old farmer in Andhra Pradesh state, was one of those who lost their lives because of this year’s scorching heat.

He took his cows out to graze in a mango grove near his house around 11am, but was tired and dehydrated when he returned home four hours later. After he began vomiting, and then fainted, he was rushed to the small government hospital 5km from his village, but died on the way.

“In my 17 years of service, I have not
come across such an alarming number
of deaths due to a heatwave”

“Summer is severe, and many people have been affected by the heatwave in our village,” says Jejabba’s distant cousin, Pindigi Ramamurthi, who runs a grain store in the village. “Just the previous day, we took our two children to hospital after they began vomiting. The doctor admitted them for a few hours to administer fluids, and luckily that revived them.”

Local officials recorded Jejabba as “the latest of the summer deaths”. But when his widow asked for compensation − the state government pays 100,000 rupees (US$1,570) to the family of a victim − the local panchayat (civic) official, who has to recommend the payment, told her she must get a certificate from the hospital doctor.

“The doctor told the family he could not give the certificate because Jejabba did not die in his hospital,” Ramamurthi recalls. “Why couldn’t the poor fellow have stayed alive just an hour or so longer till we reached the hospital? Now the widow must suffer this red tape.”

In parts of southern India, daytime temperatures reached between 45° and 47°C during this year’s heatwave − up to 7°C above normal.

Alarming number

Dr Srihari Rao, resident medical officer at the government general hospital in Tirupati, about 45km from Jejabba’s home, says: “In my 17 years of service, I have not come across such an alarming number of deaths due to a heatwave.

“Almost every day in May there was a death in the district from sunstroke. The majority of the dead were in the 65 to 80 age group, but there was also a case of a 19-year-old girl dying from dehydration.”

Dr Rao said infants, aged people and farmers had been particularly severely affected.

The Intergovernmental Panel on Climate Change reported last year that there would be significant changes in the frequency and intensity of extreme weather events, including heatwaves in India. Its report was based on weather records from 1906 to 2005.

Researchers at the India Meteorological Department, after conducting a study of heatwaves over the last 50 years, have called for public information campaigns to be launched on the dangers, and also stressed the importance of using social care networks to reach vulnerable sections of the population. − Climate News Network

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