Coastal cities in the United States could experience "once in a lifetime" extreme flood events almost daily by the end of the century if sea levels continue to rise at current rates, new research published in Scientific Reports showed on Thursday.

Emissions from burning fossil fuels have already warmed Earth more than one degree Celsius above pre-industrial times, melting polar ice sheets and boosting global sea levels.

With oceans predicted to rise by one to two metres by 2100, researchers in the US looked at the frequency of extreme water levels measured by 202 tide gauges along the US coastline.

They combined this data with various modelled pathways of sea-level rise to predict the rate at which flooding events may increase in future.

The results were stark: at nearly three-quarters of the gauge locations the difference between average high tide and a once-in-50-years flooding event was less than a metre.

Most temperature scenarios predict sea-level rises higher than that.

The team also found that the risk of extreme flood events will double every five years on average as seas get ever higher.

This likely means profound impacts on major US cities including Miami, Atlantic City and Charleston in the decades to come, the authors concluded.

"In the absence of adaptation measures, the rate of coastal hazard impacts will likely double every five years, and this is indeed quite problematic," lead study author Sean Vitousek, from the United States Geological Survey, told AFP.​

Researchers say the apparent accelerated impact from climate change on estuaries could adversely affect economic activity and ecological biodiversity in rivers and lakes worldwide.
Dr. Elliot Scanes from the University of Sydney said: "Our research shows that estuaries are particularly vulnerable to a warming environment. This is a concern not only for the marine and bird life that rely on them but the millions of people who depend on rivers, lakes and lagoons for their livelihoods around the world."

The researchers say that changes in estuarine temperature, acidity and salinity are likely to reduce the global profitability of aquaculture and wild fisheries. Global aquaculture is worth $US243.5 billion a year and wild fisheries, much of which occurs in estuaries, is worth $US152 billion. More than 55 million people globally rely on these industries for income.

Professor Pauline Ross, who leads the research group in the School of Life and Environmental Sciences, said: "Estuaries provide services of immense ecological and economic value. The rates of change observed in this study may also jeopardise the viability of coastal vegetation such as mangroves and saltmarsh in the coming decades and reduce their capacity to mitigate storm damage and sea-level rise."

The results are based on 12 years of recording temperatures in 166 estuaries along the entire 1100-kilometre stretch of the New South Wales coast in south-eastern Australia. In that time more than 6200 temperature observations were taken.

The data, which are publicly available, were taken by field officers of the NSW Department of Planning, Industry and the Environment and used in a marine research collaboration with the University of Sydney.

On average, the estuary systems experienced a 2.16-degree temperature increase, about 0.2 degrees each year.

Dr. Elliot Scanes said: "This is evidence that climate change has arrived in Australia; it is not a projection based on modelling, but empirical data from more than a decade of investigation."

Studies on specific lake and river systems have found evidence of warming, such as along the North Sea, in Germany, in the Hudson River in New York and Chesapeake Bay, Maryland. This is the world's first long-term study that has considered a diverse range of estuary types on such a large scale.

It is published today in Nature Communications.

"This increase in temperature is an order of magnitude faster than predicted by global ocean and atmospheric models," Dr. Elliot Scanes said.

According to the Australian Bureau of Meteorology, air and sea temperatures in Australia have increased by about 1 degree since 1910. And over the past decade, air temperatures have increase 1.5 degrees as compared to the 1961 to 1990 average.

NSW environment officer collecting data at Bengello near Batemans Bay. Credit: NSW DPIE"Our results highlight that air or ocean temperatures alone cannot be relied upon to estimate climate change in estuaries; rather, individual traits of any estuary need to be considered in the context of regional climate trends," Dr. Elliot Scanes said.

"New models will need to be developed to help predict estuarine changes."

The study also found that acidification of estuaries was increasing by 0.09 pH units a year. There was also changes to the salinity of estuary systems: creeks and lagoons became less saline while river salinity increased.

Temperature increases in estuaries were also dependent on the type, or morphology of the system, the study found.

Professor Ross said: "Lagoons and rivers increased in temperature faster than creeks and lakes because they are shallower with more limited ocean exchange."

She said that this suggests industries and communities that rely on shallow estuaries for culture, income and food could be particularly vulnerable during global warming.

"This is of concern in other dry temperate zones like the Mediterranean and South Africa where many of the estuaries are similar to those studied here," she said.

The study suggests that estuaries that remain open may also soon begin to "tropicalise", and estuarine ecosystems could become colonised by tropical marine species and reflect a warmer environment.
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Professor Ross said: "This research will help local fisheries and aquaculture to develop mitigation strategies as the climate changes."

This region contains a vast concentration of living plants with fossil records from tens of millions of years ago, according to Peter Wilf.

In a letter in the March issue of Science, Wilf, an Institutes of Energy and the Environment co-funded faculty member, and two colleagues explain the importance of these regions and make an appeal to readers to conserve the land. Wilf's coauthors were Robert Kooyman, the letter's lead author and rainforest researcher at Macquarie University, Australia, and James Watson, professor of conservation science at University of Queensland, Australia.

"You may think of the Amazon when you think of rainforests, but Australia has just a few little pockets that are still wet year-round," Wilf said. "The areas are so small that climate change could just wipe them out in a geologic second and with it, wipe out more than 40 million years of rainforest history. The area of Nightcap National Park, about half of which was affected by the recent fires, is a World Heritage site because it is a living museum of paleo-Antarctic plants that are found nowhere else."
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Wilf, a professor of geosciences in the College of Earth and Mineral Sciences, examines the time period of 70–45 million years ago, a period that he describes as a time of "immense global change." It includes the last great mass extinction (66 million years ago), which suddenly killed off the dinosaurs and 70% of living things. This time period also saw the recovery of the Earth's ecosystems followed by millions of years of global warming, starting around 60 million years ago.

"Many types of living things on the planet evolved very rapidly after the dinosaurs were gone," he said. "Then with the warming, there was more evolution and a lot of movement of plants and animals across the Arctic and the Antarctic because the poles were so warm."

The movement of plants and animals in response to past climate change is one facet of Wilf's research. He has found many fossil plants that "aren't supposed to be there." For example, he and his team found fossils of the Asian chinquapin, part of the beech, oak and chestnut family, in southern Argentina. This discovery was notable because all previous fossils from this whole family had only been found in the northern hemisphere.

According to Wilf, the wildfires around the world are threatening to destroy some of the last ancient living-fossil forests on the earth and their living evolutionary history, like in the rainforests in Australia and Southeast Asia. It is these ancient forests that hold the connection to the history Wilf searches for.

"There is very little rainforest in Australia," Wilf said. "Those areas are home to plants that date back to when Australia, Antarctica and South America were part of the same land mass."
He and his colleagues have found abundant fossil evidence of diverse plants that survive in the Australian rainforest. Some of these fossils come from rocks that are 50 million years old or older and from as far away as Argentina.

#ClimateChange; #UNEP; #GreenhouseGasEmissions; #COVID19

New York, Apr 6 (Canadian-Media): Greenhouse gas emissions are down and air quality has gone up, as governments react to the COVID-19 pandemic. However, the head of the UN Environment Programme (UNEP), Inger Andersen, has cautioned against viewing this as a boon for the environment. In this First Person editorial, Ms. Andersen calls instead for a profound, systemic shift to a more sustainable economy that works for both people and the planet, UN reports said.

Farmers, who gatherer flowers in the Southern Espinhaço Mountain Range in Brazil, enhance biodiversity and preserve traditional knowledge. Image credit: FAO/João Roberto Ripper

“The global coronavirus pandemic, which has already caused unimaginable devastation and hardship, has brought our way of life to an almost complete halt. The outbreak will have profound and lasting economic and social consequences in every corner of the globe. In the face of such turmoil, as the Secretary-General has indicated, COVID-19 will require a response like none before – a “war-time” plan in times of human crisis.

And as we inch from a “war-time” response to “building back better”, we need to take on board the environmental signals and what they mean for our future and wellbeing, because COVID-19 is by no means a “silver lining” for the environment.

Visible, positive impacts – whether through improved air quality or reduced greenhouse gas emissions – are but temporary, because they come on the back of tragic economic slowdown and human distress.

Visible, positive impacts come on the back of tragic economic slowdown and human distress Inger Andersen, Executive Director, UNEP

The pandemic will also result in an increase in the amounts of medical and hazardous waste generated. This is no one’s model of environmental response, least of all an environmentalist’s. And indeed, the Scripps Institute of Oceanography has highlighted that fossil fuel use would have to decline by about 10 percent around the world, and would need to be sustained for a year to show up clearly in carbon dioxide levels.

A healthy planet means fewer diseases

Any positive environmental impact in the wake of this abhorrent pandemic, must therefore be in our changing our production and consumption habits towards cleaner and greener. Because only long-term systemic shifts will change the trajectory of CO2 levels in the atmosphere. So, in the aftermath of the crisis, when economic stimulus packages composed of infrastructure are designed, there is a real opportunity to meet that demand with green packages of renewable energy investments, smart buildings, green and public transport, etc. 

The Executive Director of the UN Environment Programme, Inger Andersen, addresses a meeting in Nairobi, Kenya., by UNEP/Cyril VillemainWith respect to the disease itself, part of the challenge ahead is understanding where such diseases come from, because the health of our planet plays an important role in the spread of zoonotic diseases, i.e. disease originating from pathogens that transfer from animals to humans. As we continue to encroach on fragile ecological ecosystems, we bring humans into ever-greater contact with wildlife. Further, illegal wildlife trade and illegal wet markets are not infrequent causes of such diseases. Around 75 per cent of new and infectious diseases are zoonotic and, in fact, about 1 billion cases of illness and millions of deaths occur every year from these diseases.
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The wild must be kept wild

Humanity’s expansion on the terrestrial earth surface means that, today, human activity has altered almost 75 per cent of the earth’s surface, squeezing wildlife and nature into an ever-smaller corner of the planet. And yet, nature is critical to our own survival: nature provides us with our oxygen, regulates our weather patterns, pollinates our crops, produces our food, feed and fibre, but it is under increasing stress. 

As we continue our relentless move into natural habitats, contact between humans and reservoir hosts increases, whether as a result of urbanization, habitat loss and fragmentation, or live animal markets – all of which increases the likelihood of interaction between these vectors and humans. According to IPBES, we have seen 100 million hectares of agricultural expansion in the tropics between 1980 and 2000, roughly equal to the size of France and Germany combined. 

The “wild” must be kept “wild.” It is time to restore our forests, stop deforestation, invest in the management of protected areas, and propel markets for deforestation-free products. Where the legal wildlife trade chain exists, we need to do a far better job of improving hygiene conditions. And of course, there is the urgent need to tackle the illegal wildlife trade, the fourth most common crime committed worldwide.  

Building a ‘different economy

’The better we manage nature, the better we manage human health. This is why the post-2020 biodiversity framework that countries around the world are expected to agree on this year matters greatly. An important pillar in our post-COVID recovery plan must be to arrive at an ambitious, measurable and inclusive framework, because keeping nature rich, diverse and flourishing is part and parcel of our life’s support system. Even more important when you consider that between 25-50 per cent of pharmaceutical products are derived from genetic resources. 

And as the engines of growth begin to rev up again, we need to see how prudent management of nature can be part of this “different economy” that must emerge, one where finance and actions fuel green jobs, green growth and a different way of life, because the health of people and the health of planet are one and the same, and both can thrive in equal measure."