For Animals, Plastic Is Turning the Ocean Into a Minefield

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On a boat off Costa Rica, a biologist uses pliers from a Swiss army knife to try to extract a plastic straw from a sea turtle’s nostril. The turtle writhes in agony, bleeding profusely. For eight painful minutes the YouTube video ticks on; it has logged more than 20 million views, even though it’s so hard to watch. At the end the increasingly desperate biologists finally manage to dislodge a four-inch-long straw from the creature’s nose.

Raw scenes like this, which lay bare the toll of plastic on wildlife, have become familiar: The dead albatross, its stomach bursting with refuse. The turtle stuck in a six-pack ring, its shell warped from years of straining against the tough plastic. The seal snared in a discarded fishing net.

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But most of the time, the harm is stealthier. Flesh-footed shearwaters, large, sooty brown seabirds that nest on islands off the coasts of Australia and New Zealand, eat more plastic as a proportion of their body mass than any other marine animal, researchers say: In one large population, 90 percent of the fledglings had already ingested some. A plastic shard piercing an intestine can kill a bird quickly. But typically the consumption of plastic just leads to chronic, unrelenting hunger.

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“The really sad thing about this is that they’re eating plastic thinking it’s food,” says Matthew Savoca, a marine biologist with the National Oceanic and Atmospheric Administration. “Imagine you ate lunch and then just felt weak and lethargic and hungry all day. That would be very confusing.” Fish such as anchovies, Savoca has found, eat plastic because it smells like food once it’s covered with algae. Seabirds, expending energy their malnourished bodies don’t have, roam farther in search of real food, only to drag back plastic waste to feed their young.

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What makes plastic useful for people—its durability and light weight—increases the threat to animals. Plastic hangs around a long time, and a lot of it floats. “Single-use plastics are the worst. Period. Bar none,” Savoca says, referring to straws, water bottles, and plastic bags. Some 700 species of marine animals have been reported—so far—to have eaten or become entangled in plastic.

We don’t fully understand plastic’s long-term impact on wildlife (nor its impact on us). We haven’t been using the stuff for very long. The first documented cases of seabirds ingesting plastic were 74 Laysan albatross chicks found on a Pacific atoll in 1966, when plastic production was roughly a twentieth of what it is today. In hindsight, those birds seem like the proverbial canaries in a coal mine.

Source: nationalgeographic.com

(Dipla Aikaterini)

 

 

WWF: Majority of Greek Islanders Open to Renewable Energy Systems

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The residents of 15 Greek islands want to revert to renewable energy sources, according to a study carried out by WWF Greece as part of the ongoing TILOS (Technology Innovation for the Local Scale Optimum Integration of Battery Energy Storage) project.

Of those surveyed, 41 percent said they think RES (renewable energy systems) will have a positive impact on tourism.

The survey was carried out on the islands of Agios Efstratios, Astypalea, Anafi, Donoussa, Kastellorizo, Amorgos, Symi, Nisyros, Chalki, Milos, Sifnos, Rhodes, Santorini, Skyros and Ikaria – which due to size and location can benefit from the experience gained on Tilos, which was the first in Greece and the Mediterranean – in May last year – to run completely on a renewable energy-based battery station and smart micro-grid.

The majority of islanders – 73.7 percent – said they prefer RES for their needs. Respondents also said they would install photovoltaic (42 percent) or battery systems (49.3 percent) at their homes. At the same time, 32 percent said they do not consider wind turbines to be disturbing.

The aim of the study was to look into the possibility of applying the Tilos energy model – a hybrid energy production and storage station covering 85 percent of the island’s energy needs while also providing neighboring Kos with 400kW in power five hours a day – to other Aegean islands.

The Dodecanese island of Tilos won out of 12 nominees the EU Sustainable Energy Award in the Energy Islands category and the Citizens’ Award via public online vote last year for the TILOS application.

Source: news.gtp.gr

(Dipla Aikaterini)

Streams may emit more carbon dioxide in a warmer climate

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Streams and rivers could pump carbon dioxide into the air at increasing rates if they continue to warm, potentially compounding the effects of global warming, a new worldwide analysis has shown.

To reach that conclusion, an international research team conducted the first continental-scale study of flows into and out of streams across six major climatic zones. They collected data in watersheds from Puerto Rico and Oregon to Australia and Alaska. In each one, scientists analyzed the balance between photosynthesis—which uses atmospheric CO2 to generate plant material such as roots and leaves—and respiration, which pumps CO2 back into the air.

The scientists published their results this week in the journal Nature Geoscience.

The issue is important because the world’s rivers and streams exchange carbon with the atmosphere at rates that are comparable with land-based ecosystems and the oceans. If continues, an increase in stream-based carbon emissions could add to the concentration of heat-trapping CO2 in the atmosphere.

“This paper is the first to look at the effects of climate change on stream metabolism at the continental scale using field observations,” said Alba Argerich, co-author who monitored McRae Creek and Lookout Creek in the H. J. Andrews Experimental Forest east of Eugene, Oregon. “This approach takes into consideration the complexity of an ecosystem, as opposed to controlled experiments where you recreate simplified versions of an ecosystem.”

Argerich and other scientists monitored streams for water temperature, dissolved oxygen and sunlight at the water surface. The researchers also simulated the balance between net primary production (the product of photosynthesis by all organisms in the stream) and respiration under a 1-degree Celsius rise in stream temperature.

The net result of the simulations, they reported, was a 24 percent shift toward more respiration and CO2 emissions. However, not all streams are projected to respond in the same manner. The shift toward more CO2 emissions appears to be more pronounced in warmer streams, the scientists found, while colder streams might actually see an increase in net primary production. Carbon cycling in streams can also be affected by other factors such as the plants and microbes in the stream ecosystem and nutrients flowing into the water from surrounding lands.

Argerich conducted her work as a researcher in the College of Forestry at Oregon State University. She is now an assistant professor in the School of Natural Resources at the University of Missouri.

In previous work at the H.J. Andrews Forest, Argerich showed that small streams can export surprising amounts of carbon both downstream and to the atmosphere. “This paper confirms the role of streams as an active source of CO2 to the atmosphere, which can be even become more important as global temperatures increase,” she said.

Source: phys.org

(Dipla Aikaterini)

New research reveals ocean waves play greater role in trapping carbon dioxide

For decades scientists have investigated the influence of the world’s oceans in trapping greenhouse gasses. But a groundbreaking new study involving an academic from Heriot-Watt University has found waves play a greater role in this process than previously understood.

The research, published in Scientific Reports, shows that when waves break on the surface, such as in high winds, a substantial number of bubbles are injected to depths of at least one metre. These bubbles tend to partially dissolve, releasing into the water. The discovery means an increase in the current global estimates of the oceanic sink of carbon dioxide and rates of ocean acidification.

Led by the University of Southampton, the study was published in collaboration with UK-based scientists including Dr. David Woolf at Heriot-Watt’s Orkney Campus. He applied his expertise in modelling the processes of air-sea gas exchange for the project and said: “The role of bubbles in the air-sea exchange of gases has been of interest for decades, but firm conclusions have been prevented by a lack of adequate data. Participation in this project has been very rewarding since measurements are finally giving us the information we need.”

The results of the study, titled ‘Asymmetric transfer of CO2 across a broken sea surface’, indicate a much larger imbalance of carbon dioxide than previously suggested, contradicting an assumption inherent in most existing estimates of ocean atmosphere gas transfer.

The research could help the science community gain a stronger understanding of the influence of the ocean in contributing to global climate control.

Professor Tim Leighton, Principal Investigator for the study from the University of Southampton, said: “If the amount of carbon dioxide dissolving into the seas from the atmosphere exactly balanced the amount leaving the seas and entering the atmosphere, we would have a steady state situation.

“However, our data suggests that in stormy seas the bubble-induced asymmetry in dissolving into the oceans, as compared to previously dissolved carbon dioxide being released back into the atmosphere, is many times greater than scientists currently estimate.

“The excess Co2, which gas dissolves into stormy seas through bubbles, will increase as the proportion of CO2 in the atmosphere increases.

The study was published in collaboration between Professor Tim Leighton, his Ph.D. student Dr. David Coles, Professor Paul White at the University of Southampton’s Institute of Sound and Vibration Research, Professor Meric Srokosz from the National Oceanography Centre and Dr. David Woolf.

The research team have passed on all of their methods, equipment, computer codes and findings to other groups around the UK for further investigation.

Source: phys.org

(Dipla Aikaterini)

Another extreme heat wave strikes the North Pole

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In four of the past five winters, the North Pole has witnessed dramatic temperatures spikes, which previously were rare. Now, in the lead up to summer, the temperature has again shot up to unusually high levels at the tip of the planet.

Scientists say this warming could hasten the melt of Arctic sea ice, which is already near record low levels.

In just the past few days, the temperature at the North Pole has soared to the melting point of 32 degrees, which is about 30-35 degrees (17-19 Celsius) above normal.

Much of the entire Arctic north of 80 degrees latitude is abnormally warm. The temperature averaged over the whole region appears to be the warmest on record for the time of year, dating back to at least 1958. It is about 18 degrees (10 Celsius) above the normal of 4 degrees (minus 16 Celsius).

As the warm air intruded the Arctic, sea ice melted suddenly. The Norway Ice Service tweeted the sea ice area near Svalbard, the small island chain between Norway and the North Pole, fell by about 32,000 square miles (82,000 square kilometers) to the second lowest area on record. The amount of ice lost is enough to cover the entire state of South Carolina.

Zachary Labe, a climate scientist at University of California in Irvine, said that such a pulse of warm, moist air into the Arctic can “have a long-lasting fingerprint” that preconditions the ice to melt more rapidly in the summer.

Indeed, a study published last year in the Journal of Geophysical Research found that these spring intrusions of warm, moist air can “can initiate sea ice melt that extends to a large area” through the summer and fall.

Already, Arctic sea ice is near its lowest extent on record. The Bering and Chukchi seas have never had so little ice in recorded history.

Interestingly, while much of the Arctic has turned abnormally warm, the cold air normally entrenched over the region has had to move somewhere. In recent days, it has parked over south central Greenland where temperatures are 30 to 35 degrees colder than normal.

Jesper Eriksen, a meteorologist with the Danish Meteorological Institute, tweeted that the temperature at Summit Station, near the top of the Greenland ice sheet, plummeted to minus 47 degrees (minus 44 Celsius), very close to the coldest temperature on record for the month of May of minus 50 (minus 45.6 Celsius).

The contrast between frigid air over interior Greenland and unusually mild air over the Arctic is leading to very stormy conditions over the Canadian Arctic Archipelago.

The warming of the Arctic and loss of ice are likely strongly connected to the buildup of greenhouse gases in the atmosphere from human activities. On Friday, a NOAA study was published that found that the “extraordinary heat” that affected the Arctic in 2016 “could not have happened without the steep increases in greenhouse gas concentrations.”

Source: washingtonpost.com

(Dipla Aikaterini)

The Sahara Desert Is Growing. Here’s What That Means

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The Sahara — the world’s biggest hot desert — is getting even bigger. In fact, it is currently about 10 percent larger than it was nearly a century ago, and scientists suggest that climate change is partly responsible.

In a new study, researchers examined rainfall data gathered across Africa, consulting records dating back to 1920 and noting how changing conditions affected regions around the boundaries of the great desert.

They discovered that while some natural climate cycles could partly explain reduced rainfall and desert expansion southward, human-driven climate change is also playing a part. And if climate change continues unchecked, the Sahara’s slow growth will likely continue, the study authors reported. [The Sahara: Facts, Climate and Animals of the Desert].

Previously, scientists had explored the Sahara’s expansion by examining satellite data dating back to the 1980s. This study, which was supported by the U.S. National Science Foundation, is the first to analyze long-term trends in rainfall and surface air temperature over a timescale of nearly an entire century, the study’s lead author, Natalie Thomas, a doctoral candidate in atmospheric and oceanic science at the University of Maryland, told Live Science.

Deserts are defined as places on Earth that receive less than 10 inches (25 centimeters) of rainfall per year, according to the U.S. Geological Survey (USGS). With a surface area of about 3.6 million square miles (9.4 million square kilometers), the Sahara is the third-largest desert in the world. Only the cold deserts are bigger: icy Antarctica’s frozen desert spans about 5.5 million square miles (14.2 million square km), and the Arctic desert covers around 5.4 million square miles (13.98 million square km), USGS reported.

“A strong expansion”

The study authors originally set out to examine seasonal cycles of temperature and rainfall across Africa, consulting data spanning 1920 to 2013. But their attention was quickly drawn to trends of decreasing precipitation in the Sahel, a semiarid region linking the Sahara to the savannas of Sudan. By looking at this more closely, they hoped to discover how rainfall trends might be linked to the Sahara’s growth over time, according to Thomas.

To a certain extent, many deserts’ boundaries expand and contract seasonally, as conditions fluctuate between wetter or drier. But the researchers found that there has been “a strong expansion” of the Sahara within the 20th century, Thomas said.

Depending on the season, the Sahara experienced growth of at least 11 percent, and it grew by as much as 18 percent during the driest summer months, according to data collected over roughly 100 years. Over the course of a century, it steadily expanded to become about 10 percent bigger than it was in 1920, the study authors reported.

Much of the Sahara’s overall size increase can be explained by climate cycles driven by anomalies in sea-surface temperatures. These cyclical changes in turn affect surface temperatures and precipitation on land, and their impact can last for decades, according to the study.

“Decades of drought”

One such cycle, the Atlantic Multidecadal Oscillation (AMO), entered what is known as a “negative phase” — with cooler-than-average sea-surface temperatures — in the 1950s, bringing heat and dry conditions to the Sahel region and fueling a drought that lasted until the 1980s, Thomas said.

Using statistical methods, the scientists compensated for the effects of the AMO on average rainfall, and thereby calculated how much of the Sahara’s growth could be explained by the dryness that the cycle’s negative phase produces. They estimated that the AMO accounted for about two-thirds of the desert’s expansion — but one-third of the Sahara’s remaining growth was likely the result of climate change.

The researchers’ findings point to changes that occur over decades rather than in a single year, and that makes it hard to predict exactly how the Sahara’s continued growth could affect the wildlife and people near its changing borders. But as the places where humans grow food become increasingly drier, some areas could become more vulnerable to drought, bringing a greater risk of famine to the people who live there, Thomas said.

The findings were published online (March 29) in the Journal of Climate.

Source: livescience.com

(Dipla Aikaterini)

In Energy Breakthrough, India Added More Renewable Than Fossil Fuel Capacity for the First Time Last Year

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India added more energy capacity from renewable energy sources last year than from conventional sources like coal for the first time, an important breakthrough for a country that struggles with high greenhouse gas emissions and deadly air pollution.

Not only did renewables exceed conventional sources, they exceeded them by more than two times. Between April 2017 and March 2018, the subcontinent added about 11,788 megawatts of renewable energy capacity and only 5,400 megawatts of capacity from fossil fuels or large hydropower projects, Quartz India reported Thursday.

The vast majority of that that added capacity—9,009 megawatts—came from ground solar power. A total of 1,766 megawatts came from wind power, 352 came from rooftop solar and 657 megawatts came from biomass, small-scale hydropower and waste-to-energy.

The added capacity reflects an increased commitment by India’s government to add 175,000 megawatts of renewable energy capacity by 2022. However, while last year’s progress was impressive, it actually fell behind government targets for wind and rooftop solar. The government had set an added wind power capacity target of 4,000 megawatts and a rooftop solar capacity target of 1,000 megawatts.

Still, pushing past fossil fuels, which currently supply more than 70 percent of India’s power, is a good sign for the global fight against climate change. In 2016, India’s greenhouse gas emissions rose by 4.7 percent, more than any other major emitter’s, The Hindustan Times reported in September 2017.

It is also a positive move for a country with two of the world’s most polluted mega-cities, according to the latest World Health Organization (WHO) data released Tuesday. Delhi is the most polluted mega-city in the world, with pollution levels 10 times worse than WHO guidelines.

Pollution levels have gotten so bad that they are impacting one of the country’s most famous landmarks. The Indian Supreme Court warned on Tuesday that the Taj Mahal is turning brown and green due to air pollution and to excrement from insects attracted to the polluted Yamuna river nearby, The Independent reported Wednesday.

“It is very serious. It seems you are helpless. It has to be saved. You can get help from experts from outside to assess the damage done and restore it,” Supreme Court judges Madan Lokur and Deepak Gupta said, ordering the state government to fix the problem.

Source: ecowatch.com

(Dipla Katerina)

How valuable are trees?

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Megacities are on the rise. There are currently 47 such areas around the globe, each housing more than 10 million residents.

More than half the global population now lives in urban areas, comprising about 3 percent of the Earth. The ecological footprint of this growth is vast and there’s far more that can be done to improve life for urban residents around the world.

When it comes to natural spaces, trees are keystone species in the urban ecosystem, providing a number of services that benefit people. My research team has calculated just how much a tree matters for many urban areas, particularly megacities. Trees clean the air and water, reduce stormwater floods, improve building energy use and mitigate climate change, among other things.

For every dollar invested in planting, cities see an average of $2.25 return on their investment each year.

Measuring trees

Our team, led by Dr. David Nowak of the USDA Forest Service and Scott Maco of Davey Institute, develops the tree benefits software i-Tree Tools.

These tools simulate the relationship between trees and ecosystem services they provide. These services can include food, clean air and water, climate and flood control, pollination, recreation and noise damping. We currently don’t simulate many services, so our calculations actually underestimate the value of urban trees.

Volunteers Dalia Elbihi and her father, Faycal Elbihi, dig holes for new trees at Milby Park in Houston. Photo: Leslie Plaza Johnson, Freelancer / For The Chronicle / Freelance

Our software can simulate how a tree’s structure – such as height, canopy size and leaf area – affects the services it provides. It can estimate how trees will reduce water flooding or explore how trees will affect air quality, building energy use and air pollution levels in their community. It can also allow users to inventory trees in their own area.

Our systematic aerial surveys of 35 megacities suggest that 20 percent of the average megacity’s urban core is covered by forest canopy. But this can vary greatly. Trees cover just 1 percent of Lima, Peru, versus 36 percent in New York City.

We wanted to determine how much trees contribute to human well-being in the places where humans are most concentrated, and nature perhaps most distant. In addition, we wanted to calculate how many additional trees could be planted in each megacity to improve the quality of life.

How tree density affects a city

We looked in detail at 10 megacities around the world, including Beijing, Cairo, Mexico City, Los Angeles and London. These megacities are distributed across five continents and represent different natural habitats. Cairo was the smallest, at 1173 square kilometers, while Tokyo measured in at a whopping 18,720.

For most cities, we looked at Google Maps aerial imagery, randomly selecting 500 points and classifying each as tree canopy, grass, shrub and so on. We calculated that tree cover was linked to significant cost savings. Each square kilometer saved about $0.93 million in air pollution health care costs, $20,000 by capturing water runoff and $478,000 in building energy heating and cooling savings.

What’s more, the median annual value of carbon dioxide sequestered by megacity tree cover was $7.9 million. That comes out to about $17,000 per square kilometer. The total CO2 stored was valued at $242 million, using a measure called the social cost of carbon.

The sum of all annual services provided by the megacity trees had a median annual value of $505 million. That provides a median value of $967,000 per square kilometer of tree cover.

Trees in your city

An entire urban forest can provide services for a good life.

All the cities we studied had the potential to add additional trees, with about 18 percent of the metropolitan area on average available. Potential spots included areas with sidewalks, parking lots and plaza areas. The tree’s canopy could extend above the human-occupied area, with the trunk positioned to allow for pedestrian passage or parking.

New trees are planted in the Eastern Glades of Memorial Park in April 2018. Photo: Michael Ciaglo, Houston Chronicle / Houston Chronicle / Michael Ciaglo

Want to conserve forests and plant more trees in your area? Everyone can take action. City and regional planners can continue to incorporate the planning for urban forests. Those who are elected to office can continue to share a vision that the urban forest is an important part of the community, and they can advocate and support groups that are looking to increase it.

The ConversationIndividuals who cannot plant a tree might add a potted shrub, which is smaller than a tree but has a leafy canopy that can contribute similar benefits. For the property owner wanting to take charge, our i-Tree software can assist with selecting a tree type and location. A local arborist or urban forester could also help.

Theodore Endreny is Professor of Water Resources & Ecological Engineering at the State University of New York College of Environmental Science and Forestry

Source: houstonchronicle.com

(Dipla Katerina)