Rich nations urged to cut temperature rise targets

Rich nations urged to cut temperature rise targets

Senior scientist says voices of poorer nations must be heard in the political tussle over reducing the “utterly inadequate” global warming limit.

LONDON, 31 March, 2015 − The official target of limiting global warming to a 2˚C rise has been described by a senior scientist as “utterly inadequate” to protect the people most at risk from climate change.

That’s the conclusion reached by one of the authors of the recent Intergovernmental Panel on Climate Change (IPCC) assessment report, in an analysis of the political tussle between rich and poor nations at last December’s UN conference on limiting temperature rise.

Richer countries were happy to limit global average temperature rises to 2˚C, while middle and low-income nations would have preferred to contain warming within 1.5˚ C or lower.

Possibilities of calamity

But Dr Petra Tschakert, associate professor at Pennsylvania State University’s Earth and Environmental Systems Institute, reports in the journal Climate Change Responses that the agreed limit contains within it the possibilities of calamity for many people.

“The consensus that transpired during this [UN conference] session was that a 2˚C danger level seemed utterly inadequate, given the already observed impacts on ecosystems, food, livelihoods and sustainable development,” Dr Tschakert says.

“A low temperature target is the best bet to prevent severe, pervasive and potentially irreversible impacts, while allowing ecosystems to adapt naturally, ensuring food production and security, and enabling economic development to proceed in a sustainable manner.”

Her analysis is not of itself new, nor is it much disputed − other leading scientists have also warned that such an international agreed limit could be disastrous.

But her commentary in the journal reveals something of the debate among the government representatives and experts who must meet and prepare for global action.

Global average temperatures have been creeping up at fractions of a degree per decade for more than 30 years, and some degree of further global warming is now inevitable.

Scientists at the IPCC have from the start warned that – without steps to dramatically reduce the combustion of fossil fuels – the planet could warm by 4˚C or more, and sea levels could rise by up to a metre by 2100. In 2009, governments met in Copenhagen and settled on a limit of 2˚C.

“This should happen now, and not only when climate change hits the rich world”

But this target has always been contested. More than 100 poorer nations and small island states − such as Tuvalu, recently pounded by a tropical cyclone Pam − have repeatedly said that a 2˚C rise is unsafe, and called for a 1.5˚C limit.

The World Health Organisation argued at the December UN meeting that, as far as human health was concerned, there was no safe limit, and people already faced hazards from undernourishment, and from food and water-borne infections.

Heatwaves, such as the one that hit Russia in 2010, may have caused 10,000 additional deaths, while floods, hurricanes and other extreme weather events are likely to be more frequent and more severe hazards in a 2˚C world.

Climate impacts

Dr Tschakert’s argument is that a global average limit may be a convenient and compelling instrument for discussing climate change impacts, but nobody in the world actually faces a global average.

Such a notional limit is the average of extremes and variation across regions, all of which are subject to different hazards − ranging from glacial melting to coral bleaching − that could be disastrous for people in those regions, many of whom are among the world’s poorest.

Dr Tschakert says: “These implications emphasise what is truly at stake – not a scientific bickering of what the most appropriate temperature target ought to be, but a commitment to protect the most vulnerable and at-risk populations and ecosystems, as well as the willingness to pay for abatement and compensation..

“This should happen now, and not only when climate change hits the rich world.” – Climate News Network

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Changing climate causes weather chaos in Chile

Changing climate causes weather chaos in Chile

What is being described as an environmental catastrophe is hitting Chile as torrential rains batter the north while the south suffers prolonged drought and wildfires.

LONDON, 30 March, 2015 − The Atacama desert region of northern Chile, one of the driest areas on Earth, has been hit in recent days by torrential rains and floods that have caused deaths, swept away homes and left much of the region without power.

Meanwhile, in the usually lush southern parts of the country, wildfires are raging across lands and forests parched by the longest period of drought in living memory, endangering some of the world’s richest flora and fauna.

“We are witnessing a massive environmental catastrophe,” Luis Mariano Rendon, head of the Accion Ecologica environmental group, told the AFP news agency.

Irreparable loss

“There have been whole species lost, such as the Araucaria araucana (monkey puzzle tree). They are trees that take hundreds of years to reach maturity, so this is a practically irreparable loss for current generations.”

The trees, a distant relative of the pine, are considered sacred by indigenous Mapuche people, and have been declared part of Chile’s unique natural heritage.

Scientists say the drought in the southern region – which is the powerhouse of Chile’s multi-billion dollar agricultural sector, and site of many of its famous vineyards – is a long-term trend, linked to climate change.

“There is no choice but to assume that the lack of water resources is a reality that is here to stay”

Chile’s president, Michelle Bachelet, says millions of dollars will have to be invested in desalination plants and new reservoirs to cope with the continuing drought. Canals and irrigation systems will also have to be upgraded.

“Faced with this critical situation,” he says, “there is no choice but to assume that the lack of water resources is a reality that is here to stay, and that puts at risk the development of important regions of the country.”

The Maipo river basin − which includes Santiago, Chile’s capital − contains nearly 40% of the country’s population and is an important area for agriculture, mining, and for power generation, much of which comes from hydroelectric sources.

Researchers, led by the Centre for Global Change at the Pontifical Catholic University of Chile, have been mapping the impact that climate change is likely to have on the Maipo basin.

Projections so far indicate that rainfall is likely to drop by 10% in the area over the period up to 2040, and by up to 30% by the end of the century. Meanwhile, temperatures will rise by 1˚C above the historical average over the next 25 years, and by between 2.5˚C and 3.5˚C by 2100.

Power source

The researchers have also been investigating glacier mass and melt in the Andes − the source of the bulk of the country’s water supply for millions of people in the region, and a crucial power source.

Scientists say that accelerated melting of Andean glaciers is being caused by atmospheric warming.

Water shortages are hitting not only the agricultural sector, but also mining – one of Chile’s major industries. The country is the world’s biggest producer of copper, and mining companies say they are having to invest in costly desalination plants in order to get water for processing copper concentrate from milled rock.

A drop in river levels feeding hydroelectric facilities is also leading to an increase in coal-fired power plants – a major source of climate-changing greenhouse gases.

Despite the recent rains in the north of the country, scientists are warning of the dangers of desertification in the region, with the northern desert advancing further south each year. – Climate News Network

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Shrinking of ice shelves raises sea level concerns

Shrinking of ice shelves raises sea level concerns

Evidence of rapid reduction of West Antarctica’s shelf ice could have serious implications for global sea levels in a warming world.

LONDON, 29 March, 2015 – Scientists in the US report that the volume of Antarctic shelf ice is diminishing, and that there has been an 18% shrinkage in the mass of some ice floating on coastal waters over the last 18 years.

And because much of the loss has been off West Antarctica, where shelf ice helps to keep the ice sheet stable, it could mean that global sea levels will rise even faster as a result of increased glacial flow into the ocean.

The findings once again raise concern about the link between man-made emissions of greenhouse gases and the dangerous new world of global warming, climate change and sea level rise.

Fernando Paolo, a researcher at the Scripps Institution of Oceanography at the University of California, San Diego, and colleagues report in the journal Science that they used continuous radar altimetry measurements − taken from three European Space Agency satellites between 1994 and 2012 − to compose a high-resolution record of shelf ice thickness.

Declined swiftly

They found that the total volume of shelf ice – the thickness multiplied by the shelf area – around Antarctica stayed more or less the same from 1994 to 2003, but then declined very swiftly.

The ice shelves of West Antarctica lost ice during the entire period, and although East Antarctica had been gaining shelf ice, these gains ceased after 2003. Some shelves had lost 18% of their volume.

“Eighteen per cent over the course of 18 years really is a substantial change,” Paolo says. “Overall, we show not only that the total ice shelf volume is decreasing, but we see an acceleration in the last decade.”

Shelf ice is frozen sea, so when it melts, it makes no difference to sea levels. But there could be an indirect effect.

“The ice shelves buttress the flow from grounded ice into the ocean, and that flow impacts sea levels rise, so that’s a key concern from our new study,” says co-author Helen Fricker, a glaciologist at the Scripps Institution.

In climate science, one such study is never enough: such conclusions need support from other studies. But the ice volume measurements are likely to add to growing concern about West Antarctica.

“The ice shelves buttress the flow from
grounded ice into the ocean, and that
flow impacts sea levels rise”

One earlier study looked at the potential loss of ice from West Antarctica by examining the “grounding lines” of the terrestrial glaciers, and found evidence of continuous and accelerating retreat. In effect, the West Antarctic ice sheet could be approaching a point of no return, scientists reported.

And a second group used other satellite measurements to calculate that ice was being lost from the southern continent at an increasing rate – around 150 cubic kilometres a year from West Antarctica.

So the Scripps study indirectly backs up earlier findings. It calculates that most mass has been lost from ice shelves in the Amundsen and Bellingshausen seas, off the coast of West Antarctica. These account for less than 20% of the total West Antarctic ice-shelf area, but contribute more than 85% of the total ice-shelf volume loss from West Antarctica.

Slow process

Were the West Antarctic ice sheet to melt completely – a long, slow process at almost any temperatures – sea levels would rise by more than three metres worldwide.

At current rates, a couple of the ice shelves off the western coast of the continent could disappear completely within 100 years, the Scripps team says.

Although the Arctic is one of the fastest-warming places on the planet, and although this warming has been directly linked to man-made climate change, the pattern of temperature shifts in the southern hemisphere has been more ambiguous.

The Scripps team have now begun to think about possible reasons for the loss of shelf ice in the far south, and one factor might be the cycle of El Niño events – natural and periodic bubbles of Pacific ocean warmth that have waxed and waned at intervals and changed the prevailing weather patterns worldwide through history.

“We’re looking into connections between El Niño events in the tropical Pacific and changes in the Antarctic ice sheet,” Paolo says. “It’s very far apart, but we know these teleconnections exist. That may ultimately allow us to improve our models for predicting future ice loss.” – Climate News Network

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Eyes in the sky see seas rising alarmingly faster

Eyes in the sky see seas rising alarmingly faster

Scientists analysing sophisticated satellite data warn that rises in sea level more rapid than expected are increasing threats to coastal cities and food security.

LONDON, 27 March, 2015 − Satellite observations show that sea level rise may have been underestimated, and that annual rises are increasing.

A collaborative effort between maritime organisations and space agencies in measuring sea level rise has come to the conclusion that it has been increasing by 3.1 millimetres a year since 1993 – higher than previous estimates.

The evidence is growing from a number of recent studies of the ice caps that sea level rise is accelerating, posing a threat to many of the world’s largest and most wealthy cities − most of which are also important ports.

Many of these in the developing world have little or no protection against rising sea levels. Some in Europe – such as London and Rotterdam − already have flood barriers to protect areas below high tide or storm surge level, but  these will need to be replaced and raised in the next 30 years.

Delta areas in Egypt, Vietnam, Bangladesh and China – vital to each of the nation’s food supply – are already losing land to the sea.

Difficult to measure

One of the problems scientists have had in getting accurate worldwide data is that the sea does not rise evenly around the globe. This, added to the fact that in some places the land is sinking and in other places is rising, makes exact information difficult to measure from tide gauges.

Since 1991, it has been possible to measure the surface of the oceans across the entire globe by using satellite altimetry, whereby the satellite emits a signal towards the ocean’s surface and receives the reflected echo. The sea level is calculated from the round-trip time between the satellite and the sea surface and the position of the satellite along its trajectory.

While the data from tide gauges provides information about local changes relative to the land, the use of altimeter satellites enables the recording of data on a global basis.

Luciana Fenoglio-Marc, a scientist specialising in physical and satellite geodesy at the Technical University of Darmstadt, Germany, uses these and other satellite geodetic observation data in her research.

She is working with the European Space Agency and the European Organisation for the Exploitation of Meteorological Satellites, and in close consultation with the German Federal Institute of Hydrology and the Federal Maritime and Hydrographic Agency of Germany.

This lends credibility to the report that European coastal cities are not sufficiently prepared for the threats that climate change poses

The increase of around 3.1mm per year since 1993 indicates a marked rise in the average sea level when compared to previously recorded values, which show a sea level rise of between 1mm and 2mm per year in the 20th century.

In its fifth Assessment Report (AR5, 2013), the Intergovernmental Panel on Climate Change (IPCC) predicted a further increase in the global sea level of 30cm to 70cm by the end of the 21st century, based on a scenario involving a medium rate of global warming.

The report predicted that increases will not be even, but will have a greater impact on some regions than on others. The result could be coastal flooding and rising groundwater levels – an outlook that makes it essential to have a reliable data basis for dealing with the dangers this poses.

Protecting coasts from the rising seas will require considerable adaptations, particularly in such low-lying coastal regions as the North Sea coast of Germany and the many low-lying islands in the tropics.

Another aspect of the work with satellites is measuring ocean density to see how much water expansion − because of warming − is leading to sea level rise. A direct estimation of mass changes in the Mediterranean Sea show expansion to be the cause of an average sea level rise of about 2.1mm per year since 1993.

According to the IPCC, about 35% of the sea level increase between 1993 and 2010 was the result of thermal expansion, and the rest was due to melting ice and increasing run-off from land. But the latest observation shows this may not be true of the Mediterranean.

Too cautious

There is wide debate about whether the IPCC estimates of sea level rise have been too cautious, suggesting that the sea level will rise more than a metre this century – and some have even suggested that the rise could be two metres.

This is mainly because there has been uncertainty about how much of the huge icecap in Greenland, and most of all in Antarctica, would contribute to sea level rise by 2100 – if at all.

Research published since the IPCC estimates were made show that both icecaps will be large net contributors to sea level rise, and possibly much quicker than previously thought.

This lends credibility to the report last week that European coastal cities are not sufficiently prepared for the threats that climate change poses. The report − titled Underfunded, Unprepared, Underwater? Cities at Risk – is by the E3G non-governmental organisation, and it says governments across the European Union are leaving their major cities exposed to danger from climate change, including floods, heat waves and sea level rise.

Since it takes an average of 30 years from planning to complete construction of a major flood barrier to protect a city, the report warns that the problem needs to be given urgent consideration and funding. – Climate News Network

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Population increases flood and drought threat to cities

Population increases flood and drought threat to cities

As cities worldwide expand to cope with rising populations, scientists predict a huge increase in urban land vulnerable either to flooding or drought by 2030.

LONDON, 11 March, 2015 − Many of the great coastal cities of America, Asia and Africa will be at increased risk of damaging floods − even without the increasing effects of climate change.

And there will be problems with the other extreme, as scientists also predict that the urban area exposed to drought would double by 2013.

Burak Güneralp, a geographer at Texas A&M University, and colleagues report in the journal Global Environmental Change that by 2030 almost 5 billion people will live in cities, and coastal urban areas will spread out over danger zones of low elevation.

In 2000, about 30% of global urban land – 200,000 square kilometres – was in high-frequency flood zones. By 2030, this will have risen to 40%, or 700,000 square kilometres. And there could also be a growth in the urban extent of drylands 500,000 square kilometres.

Exposed area

So the city regions vulnerable to flood would increase 2.7 times, while the area exposed to drought would double.

The report’s authors says that disasters due to water-related hazards – floods, droughts and windstorms − made up nearly 90% of the 1,000 most catastrophic events between 1900 and 2006 − and because of increasing urbanisation, economic losses have soared.

In the 20 years from 1992-2012, flood and drought hazards caused $600 billion in damage, and in 2013, floods and drought accounted for more than a quarter of all global insured losses.

The message from the authors to tomorrow’s urban planners is: watch where you build new developments or permit new settlement.

“Potential future changes in the extent and layout of urban areas are typically ignored in resilience planning for these cities”

“Urban areas exposed to flood and drought hazards will increase considerably due to the sheer increase in their extents, primarily by socioeconomic forces,” Dr Güneralp says. “In particular, coastal megacities will house a majority of the urban populations, and they will increasingly be hubs of significant economic activity in the coming decades.

“Yet potential future changes in the extent and layout of the urban areas are typically ignored in resilience planning for these cities.”

The Texas team made their calculations with geographic information systems, existing urban maps and city growth forecasts. They did so without factoring in climate change, but they warn that all hazards will be amplified by rising average global temperatures.

Human numbers exposed to a once-a-century flooding event in 136 port cities across the world are expected to increase threefold by 2070, and their economic infrastructure –roads, houses, power and water services, offices and factories – will increase tenfold.

Water shortages

Meanwhile, the number of city-dwellers who could face perennial water shortages is expected to increase fivefold by 2050 − to around 160 million people.

The Texas scientists considered the great delta cities of China, Vietnam and India, but they also included the American megalopolises of New York, Baltimore, Houston and Miami, which are all vulnerable in their own ways.

Their research reinforces fresh reminders – on the eve of yet another disaster risk reduction conference, in Sendai, Japan − that global disasters of all kinds claimed 700,000 lives, changed the lives of 1.7 billion people, and cost cities and states at least $1.4 trillion in the last 10 years.

And 87% of these disasters were climate-related, according to the UN International Secretariat for Disaster Reduction. − Climate News Network

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Big cities head for water crisis as populations explode

Big cities head for water crisis as populations explode

With more than half the world’s population now in cities, scientists warn that inadequate surface water supplies will leave many at increasing risk of drought.

LONDON, 21 February, 2015 − More than 40% of the world’s great cities supplied by surface water could become vulnerable to shortages and drought by 2040, according to new research. And more than three out of 10 were already vulnerable in 2010.

Meanwhile, the vital array of satellites designed to monitor rainfall and to warn of potential flooding is reported to be coming to the end of its shelf life.

For the first time in history, more than half the world’s population is now concentrated in cities, and this proportion is predicted to increase to two-thirds. Cities grow up near plentiful water supplies − and as a population explodes, so does demand. But the flow remains much the same.

Some cities are already under drought stress. Chennai in southern India had to be supplied with tankers in 2004 and 2005, and São Paulo in Brazil is now at crisis point.

Supply analysis

Environmental scientist Julie Padowski and Steven Gorelick, director of the Global Freshwater Initiative at Stanford University in California, report in Environmental Research Letters that they analysed supplies to 70 cities in 39 countries, all of them with more than 750,000 inhabitants, and all of them reliant on surface water.

They defined vulnerability as the failure of an urban supply basin to meet demands from human, environmental and agricultural users, and they set the supply target as 4,600 litres per person per day – which factors in “virtual water”, defined as the total volume of water needed to produce and process a commodity or service.

They proposed three different kinds of measure of supply. If a city failed to meet one or two of these metrics, it was considered threatened. If it failed to meet all three, it was rated as vulnerable.

Importantly, the scientists did not factor in climate change, which is likely to make conditions worse. Instead, they simply considered current demand and supply, and then projected demand in 2040.

Of their 70 cities, they found that 25 (36%) could already be considered vulnerable by 2010. By 2040, this number had grown to 31 (44%).

The six cities that will begin to face water shortages are Dublin in Ireland, Charlotte in the US, Ouagadougou in Burkina Faso, and Guangzhou, Wuhan and Nanjing in China.

Most of the cities that are already vulnerable rely on reservoirs, and the study implies that urban planners will need to think about more reservoirs, deeper wells or desalination plants, or will have to contemplate the diversion of rivers from somewhere else.

Rainfall data

Meanwhile, they cannot rely on rainfall data because – as geological engineer Patrick Reed, professor of civil and environmental engineering at Cornell University, and colleagues report in Environmental Research Letters − the network of dedicated satellites “fails to meet operational data needs for flood management”.

Four of the 10 satellites have exceeded their design life − some by more than a decade. There are already weak spots in the network, especially in developing countries, which means that floods could take people by surprise.

Space-based instruments offer a way of monitoring rainfall and ground moisture upstream, in a way that gives authorities time to predict the moment when the rivers will start to rise and flood the cities. When four fail to deliver, the potential for catastrophe will be even worse.

So the scientists call for better international co-ordination of satellite replacement.

“It is important for us to start thinking as a globe about a serious discussion on flood adaptation and aiding affected populations to reduce their risks,” Professor Reed says. “We want to give people time to evacuate, to make better choices, and to understand their conditions.” – Climate News Network

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Arid areas of US face prospect of ‘megadroughts’

Arid areas of US face prospect of ‘megadroughts’

Scientists in the US predict droughts worse than the extreme conditions believed to have played a part in ending a once-flourishing medieval culture.

LONDON, 15 February, 2015The Central Plains and Southwest region of the US face “unprecedented” droughts later this century, according to new research.

While Midwest states have experienced ever more flooding over the last 50 years, the regions already suffering from extremes of aridity are being warned to expect megadroughts worse than any conditions in the last 1,000 years.

Climate scientist Benjamin Cook, of NASA’s Goddard Institute for Space Studies, New York, and colleagues report in a new journal, Science Advances, that they looked at historical evidence, climate projections and ways of calculating soil moisture.

They found that the drought conditions of the future American west will be more severe than the hottest, most arid extended droughts of the 12th and 13th centuries, which are thought to have played a role in ending the once-flourishing Pueblo culture of the American Southwest.

Computer predictions

The growth rings of trees provided the evidence for reconstructions of what climatologists call the warm Medieval period, and the researchers matched the picture from the past with 17 different computer model predictions of the climate later in the 21st century.

The conclusions were ominous: nearly all the models predicted that the Plains and the Southwest would become drier than at any time in the last 1,000 years.

Even though winter rain and snowfall could increase in parts of California – currently in the grip of calamitous drought – in the decades to come, overall there will be lower cold season precipitation and, because of higher temperatures, ever more evaporation and ever more water demand for the surviving vegetation.

The authors conclude: “Ultimately, the consistency of our results suggests an exceptionally high risk of a multidecadal megadrought occurring over the Central Plains and Southwest regions during the late 21st century, a level of aridity exceeding even the persistent megadroughts that characterised the Medieval era.”

“I was honestly surprised at just how dry the future is likely to be”

Co-author Toby Ault, head of the Emergent Climate Risk Lab at Cornell University, warned of future megadroughts only last year. He says: “I was honestly surprised at just how dry the future is likely to be.”

But to the north, in the American Midwest, conditions have begun to change in a different way. Iman Mallakour and Gabriele Villarini, of the Department of Civil and Environmental Engineering at the University of Iowa, collected evidence from 774 stream gauges in 14 states from 1962 to 2011.

Flood events

They report in Nature Climate Change that a third of them had recorded a greater number of flood events, and only one in 10 recorded a decrease.

The pattern of increase extended from North Dakota south to Iowa and Missouri, and east to Illinois, Indiana and Ohio.

The region was hit by economically-disastrous, billion-dollar floods in 1993, 2008, 2011, 2013 and 2014. The researchers wanted to see whether flooding was really on the increase, or whether perception of greater flooding was what they called “an artefact of our relatively short collective memory”.

The result is a confirmation of perceived increase. It was not an artefact.

“It’s not that big floods are getting bigger, but that we have been experiencing a larger number of big floods,” Dr Villarini says. – Climate News Network

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US coastal cities warned of daily high tide floods

US coastal cities warned of daily high tide floods

Scientists report that many cities near the coasts of the US should prepare for daily flooding at high tide by mid-century because of rising sea levels.

LONDON, 5 January, 2015 − Oceanographers have just identified the US coastal regions likely to experience 30 days or more of “nuisance” flooding every year. And the answer is that most of the American coast will experience high waters that are 30-60 cms above local high tides, at least 30 times a year.

Nuisance flooding means just that − somewhere between an inconvenience and modest damage. But climate change, and its attendant sea-level rise, will make them much more frequent, and possibly more damaging.

William Sweet and Joseph Park, scientists at the National Oceanic and Atmospheric Administration (NOAA), report in the journal Earth’s Future that sea level rise has accelerated from 1.7mm a year in the last century to 3.2mm a year in the last two decades, and flooding events that were once extreme could become the mean.

The oceanographers wanted to establish what they call “regional tipping points” – places where extra high waters would wash across streets and promenades normally above water and start to do so frequently.

Detailed picture

New York was inundated when Superstorm Sandy hit the city in 2012, and studies have repeatedly warned that coastal inundations will cost communities colossal sums each year by 2050, and even more by 2100. Nor is the US alone in this respect. There have been ominous calculations for the UK as well.

The NOAA scientists add detail to the big picture. They started with the projections for global sea level rise delivered by the Intergovernmental Panel on Climate Change and then included the more local factors such as land subsidence or settlement, and cyclic weather patterns that exacerbate the tidal highs. Such floods have already increased, and are now five to 10 times more likely than 50 years ago.

They looked at all those tidal stations with a continuous 50-year record of measurement. This does not include the city of Miami, where the tide stations were destroyed in 1992 by Hurricane Andrew.

Coastal changes

And they warn that Boston, New York City, Philadelphia, Baltimore and many other places along the Atlantic Coast, Galveston and Port Isabel in the Gulf of Mexico, and San Francisco Bay and San Diego along the Pacific Coast will all see a lot more seawater in city streets.

“Coastal communities are beginning to experience sunny-day nuisance flooding, much more so than in decades past,” said Dr Sweet. “This is due to sea level rise.

“Unfortunately, once impacts are noticed, they will become commonplace rather quickly. We find that in 30 to 40 years, even modest projections of global sea level rise – 1.5 feet by the year 2100 – will increase instances of daily high tide flooding to a point requiring an active and potentially costly response.

“And by the end of the century, our projections show that there will be near-daily nuisance flooding in most of the locations that we reviewed.” – Climate News Network

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US must face up to the dark side of climate change

US must face up to the dark side of climate change

As global temperatures rise, scientists warn that more cities in the US face the threat of power blackouts caused by fierce and frequent hurricanes.

LONDON, 29 December, 2014 − Climate change could leave more Americans in the dark as hurricanes become more intense or more frequent.

Researchers in the US have identified 27 cities that are likely to become more vulnerable to blackouts as a result of floods and high winds hitting the power grid.

They report in the journal Climatic Change that they matched evidence from the past – historic hurricane information – with scenarios for future storm behaviour throughout the US as global temperatures rise. And then they looked at those cities most vulnerable.

Big increase

Top of the list were New York, Philadelphia, Jacksonville, Virginia Beach and Hartford, which all could see a big increase in future risk of power cuts.

The cities most likely to keep the lights burning are Memphis, Dallas, Pittsburgh, Atlanta, and Buffalo.

In fact, there is no certainty about how global warming will affect hurricane patterns. As sea surface temperatures rise above 28°C, hurricanes tend to become more likely, and there is evidence that tropical cyclones in the Northern hemisphere are increasingly likely to threaten cities once considered beyond the hazard zone.

But hurricanes are capricious monsters, and how their characteristics will change with warmer atmosphere is still debated. So the scientists looked at a range of possibilities.

Cities already at risk – such as Miami and New Orleans – will remain at risk. But New York and Philadelphia, and even some inland urban areas, could become susceptible to increasing storm activity.

For New York – devastated by Superstorm Sandy in 2012 – and Philadelphia, the probability of the kind of storm previously considered a once-a-century event is likely to increase by 50%. More people would lose power more often, and the worst storms could be substantially more intense.

Future hazards

The point of the research is to make civic authorities more aware of potential future hazards.

“We provide insight into how power systems along the Gulf and Atlantic coasts may be affected by climate changes, including which areas should be most concerned and which ones are unlikely to see substantial change,” said Seth Guikema, a geographer at Johns Hopkins University in Baltimore.

“If I’m mayor of Miami, we know about hurricanes, we know about outages, and our system has been adapted for it. But if I’m mayor of Philadelphia, I might say: ‘Whoa, we need to be doing more about this.’” – Climate News Network

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Climate change’s threat of space centre invasion

Climate change's threat of space centre invasion

Rising sea levels and repeated storm damage to natural coastal defences pose an increasing threat to the famous Cape Canaveral rocket launch site in Florida.

LONDON, 15 December, 2014 − Climate change has begun to make its mark on one of America’s most iconic sites – the Kennedy Space Centre at Cape Canaveral in Florida.

Within a decade, according to geologists, the combination punch of rising sea levels and increasing wave energy could start to affect operations at the site where, more than five decades ago, astronauts were launched towards a landing on the Moon.

Peter Adams and John Jaeger, of the University of Florida, have since 2009 been studying the dunes and the beach at Cape Canaveral that historically screened the launch site from even the worst tropical storms.

These dunes were levelled in 2008 during Tropical Storm Fay, in 2011 during Hurricane Irene, and again in 2012 during Hurricane Sandy.

Washed away

Storm waves repeatedly covered a stretch of railroad track built by the US space agency NASA during the 1960s. The line is no longer used, and part of it has been removed to make room for a protective man-made dune. NASA’s own prediction in 2010 was that the line could be permanently breached by 2016.

Hurricane Sandy, the superstorm  that brought catastrophic flooding to New York and caused damage along almost all the US Atlantic seaboard, washed away a section of Cape Canaveral shoreline so close to a US Air Force launch pad that the surrounding fence was left near collapse.

“When you put immovable infrastructure right next to a dynamic environment, something has to give”

Coastal erosion is an enduring fact of life, but during the 1960s the Cape seemed a secure site for one of the great 20th-century adventures.

The two geologists, working as partners with NASA and the US Geological Survey, began looking at a problem that seemed to have been getting worse since 2004: chronic erosion of a six-mile stretch between the two launch pads used for the Apollo missions and space shuttle launches.

According to Dr Adams, the slow rise in sea levels and the increased energy of the ocean’s storm waves – both symptoms of global warming – are almost certainly to blame. He said: “Is it affecting NASA’s infrastructure? The answer’s yes.”

Although man-made dunes will protect the site for the immediate future, the space agency has already spoken of a “managed retreat”. And Dr Jaeger  said: “When you put immovable infrastructure right next to a dynamic environment, something has to give.”

Evidence of flooding

As a coastal facility, Cape Canaveral is naturally vulnerable to hurricanes, which tend to lose their energy as they hit the coasts. But University of Iowa scientists report in the Bulletin of the American Meteorological Society that they have found evidence of flooding by tropical cyclones as far inland as Iowa, in the Midwest.

Gabriele Villarini, a civil and environmental engineer, found the evidence in 30 years’ worth of discharge records from more than 3,000 US Geological Survey stream measurement stations.

Between 1981 and 2011, the US was hit by more than 100 tropical cyclones or hurricanes that did their worst damage at the coast, but could also be linked with major flooding far inland.

“Our results indicate that flooding from tropical cyclones affects large areas of the US and the Midwest, as far inland as Illinois, Wisconsin and Michigan,” Villarini said. – Climate News Network

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