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Rising ocean waters from global warming could cost trillions of dollars

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Ocean waters are rising because of global warming. They are rising for two reasons. First, and perhaps most obvious, ice is melting. There is a tremendous amount of ice locked away in Greenland, Antarctica, and in glaciers. As the world warms, that ice melts and the liquid water flows to the oceans.

The other reason why water is rising is that warmer water is less dense – it expands. This expansion causes the surface of the water to rise.

Rising oceans are a big deal. About 150 million people live within 1 meter (3 feet) of sea level. About 600 million live within 10 meters (33 feet) of sea level. As waters rise, these people will have to go somewhere. It is inevitable that climate refugees will have to move their homes and workplaces because of rising waters.

In some places, humans will be able to build sea walls to block off the water’s rise. But, in many places, that won’t be possible. For instance, Miami, Florida has a porous base rock that allows sea water to permeate through the soils. You cannot wall that off. In other places, any sea walls would be prohibitively expensive.

It isn’t just the inevitable march of sea level that is an issue. Rising waters make storm surges worse. A great example is Superstorm Sandy, which hit the US East Coast in 2012. It cost approximately $65 bn of damage. The cost was higher because of sea level rise caused by global warming.

Climate scientists do their best to project how much and how fast oceans will rise in the future. These projections help city planners prepare future infrastructure. My estimation is that oceans will be approximately 1 meter higher in the year 2100, that is what our infrastructure should be prepared for. What I don’t know is how much this will cost us as a society.

A very recent paper was published that looked into this issue. The authors analyzed the cost of sea level if we limit the Earth to 1.5°C or 2°C warming. They also considered the future cost using “business as usual” scenarios.

What the authors found was fascinating. If humans take action to limit warming to 1.5°C, they estimate sea level will rise 52 cm by the year 2100. If humans hold global warming to 2°C, sea levels will rise by perhaps 63 cm by 2100.

The difference (11 cm) could cost $1.4 tn per year if no other societal adaptation is made. This is a staggering number and in itself, should motivate us to take action.

But the authors went further, they considered an even higher future temperature scenario (one that is essentially business as usual). With that future, global annual flood costs would increase to a whopping $14 tn per year.

In the study, the authors considered which countries and regions would suffer most. It turns out upper middle income countries will be worse off, particularly China. Higher-income countries have a slightly better prognosis because of their present flood protection standards. But make no mistake about it, we will all suffer and the suffering will be very costly.

There are four important takeaways from this study. First, while the economic costs are large, there is some range of projections. The actual costs may be lower or higher than the median predicted in the study. This is largely due to the fact that we don’t know how fast Greenland and Antarctica will melt. If they melt faster than projected, things will be worse than what I’ve described here.

Second, adaptation will help. By adaptation I mean making our societies less susceptible to sea level rise. For example, building sea walls when possible, building new infrastructure away from coasts, putting in natural breaks to limit storm surge during large storms, and making infrastructure more water-resistant.

Third, what we do now matters. If we can get off the high-emissions business as usual scenarios – if we can increase investment in clean and renewable energy – we can reduce the future costs.

Finally, while scientists often use 2100 as a benchmark year, it isn’t like oceans will stop rising then. In fact, we are committing ourselves to hundreds of years of rising oceans. The ocean has a lot of climate inertia. Once it starts rising, you cannot stop it. So, by focusing only on the year 2100, we are deluding ourselves into underestimating the long term costs.

This research shows it’s important to connect climate science with economic science. Too often, social scientists and economists with very little climate science understanding have tried to tell us that climate change is not a problem. Whenever you hear an economist or a social scientist give you a rosy future prediction, take it with a grain of salt. Their opinion is worthless without being backed by physical understanding. And the loudest economists and social scientists often have very little of this physical understanding.

Source: theguardian.com

(Dipla Aikaterini)

Baltic Sea oxygen levels at ‘1,500-year low due to human activity’

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The coastal waters of the Baltic have been starved of oxygen to a level unseen in at least 1,500 years largely as a result of modern human activity, scientists say. Nutrient run-off from agriculture and urban sewage are thought to be to blame.

“Dead zones” – areas of sea, typically near the bottom, with a dearth of oxygen – are caused by a rise in nutrients in the water that boosts the growth of algae. When these organisms die and sink to the seafloor, bacteria set to work decomposing them, using up oxygen in the process.

The resulting lack of oxygen not only curtails habitats for creatures that live on the seafloor, but also affects fish stocks and can lead to blooms of toxic cyanobacteria.

But it is not a problem confined to the Baltic. Earlier this year a study revealed that ocean dead zones have quadrupled in size since the 1950s, and are found the world over in coastal regions of high population, from Europe to North America and China.

Researchers behind the latest study say that while nations are taking action to help waters rebound, individuals can help.

“In terms of the general public, one of the main things to do in the future may be to reduce the proportion of meat in the diet. Livestock agriculture generates higher nutrient losses per kilogram of food produced,” said Sami Jokinen, a PhD student at the University of Turku, and Tom Jilbert, an assistant professor of the University of Helsinki, who are co-authors of the research.

At present, the Baltic Sea dead zone extends across 70,000 km2 – an area almost twice the size of Denmark, Jokinen says. The team say the lack of oxygen in the waters at the bottom is seasonal, related to layering of the water resulting from summer heating of the surface.

While previous studies have revealed that oxygen depletion has occurred in the central Baltic at various points in time in the past several thousand years, the latest study looks at how oxygen levels have changed in coastal waters.

Writing in the journal Biogeosciences, the team, from Finland and Germany, describe how they probed the issue by removing two four-metre-long cores from a site between the coasts of Sweden and Finland.

The team used a host of measures to analyse one of the cores, including looking at the grain sizes of the sediment layers and ratios of different types of elements. They also used both cores to hunt for trace fossil burrows from organisms that lived in the sediment.

Among the findings, they found clear layers of sediment dating back to just over 100 years, suggesting that animals including bivalves and annelids disappeared from the bottom of the sea from this point.

The upshot was that the researchers were able to reconstruct how oxygen levels at the seafloor have changed over the past 1,500 years, revealing that while the degree of oxygen depletion in coastal areas has varied over the period – largely due to changes in the climate – there has been a marked depletion in the past 100 years or so.

The researchers say they were surprised to find that the steep drop in oxygen levels began before the postwar peak in urbanisation and intensive agriculture in the region in the 1950s. They say a combination of factors is likely to blame, including an uplift of the Baltic area as well as human activity – the latter a factor that appears to have become increasingly important.

“Our evidence of deoxygenation at the beginning of the 20th century suggests that the human influence was felt earlier – in other words, that the system is more sensitive than we thought previously,” Jokinen and Jilbert told the Guardian.

The pair note that since 2007, coastal nations around the Baltic Sea have attempted to improve the situation with an action plan to reduce nutrients flowing into the waters, and that oxygen levels are on the rise in waters off Stockholm. But, they add, global warming might be hindering progress, with no evidence of recovery seen in the regions examined.

“It is likely delaying the recovery process, because oxygen dissolves less easily in warm water,” they said.

Callum Roberts, professor of marine conservation at the University of York, who was not involved in the research, welcomed the study.

“Its great strengths are the fine-scale resolution of the timing of changes in conditions, and its ability to take us back all the way to Europe in the dark ages, long before the industrial revolution and modern population growth,” he said. “By doing so, the researchers can separate human from environmental forces shaping the Baltic, to show that Baltic dead zones are the responsibility of those who live along its shores.”

But, he said, the study also raised concerns.

“One troubling finding is that recent efforts to reduce pollution have not yet led to recovery,” said Roberts. “The Baltic is stuck in a vicious cycle in which low oxygen at the seabed releases nutrients trapped in bottom sediments to fuel yet more plankton bloom and bust that causes the dead zones to get bigger.”

Source: theguardian.com

(Dipla Aikaterini)

Most of Europe’s rivers and lakes fail water quality tests – report

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The vast majority of Europe’s rivers, lakes and estuaries have failed to meet minimum ecological standards for habitat degradation and pollution, according to a damning new report.

Only 40% of surface water bodies surveyed by the European Environmental Agency (EEA) were found to be in a good ecological state, despite EU laws and biodiversity protocols.

England was one of the poorer performers to emerge from the State of Our Waters report, which studied 130,000 waterways.

The EU’s environment commissioner, Karmenu Vella, said there had been a slight improvement in freshwater quality since 2010. “But much more needs to be done before all lakes, rivers, coastal waters and groundwater bodies are in good status,” he added. “Tackling pollution from agriculture, industry and households requires joint efforts from all water users throughout Europe.”

Scotland dramatically outperformed England in the clean water stocktake which covers the 2010-15 period, with water standards similar to much of Scandinavia.

Precise comparisons are difficult as reporting methodologies vary across Europe but water quality in England was in the bottom half of the European table, and had deteriorated since the last stocktake in 2010.

Peter Kristensen, the report’s lead author told the Guardian that higher population densities, more intensive agricultural practices, and better monitoring of waterways had all contributed to the result.

England is comparable to countries in central Europe with a high proportion of water bodies failing to reach good status,” he said. “The situation is much better in Scotland, where only around 45% of sites failed [to meet minimum standards].”

“It would be advisable for England to continue with legislation similar to the water framework directive after Brexit,” he added.

The directive aims to protect human health, water supply, ecosystems and biodiversity and was supposed to oblige EU countries to achieve a good ecological status for their waterways by 2015.

But they have not, and their failure to do so threatens the bloc’s 2020 biodiversity goals, according to Andreas Baumueller, WWF Europe’s head of natural resources.

“This report shows that we are nowhere [near] halting biodiversity loss by 2020,” he said. “It is just another symptom that we will miss the targets set by heads of states. The legislation is there in the form of the EU’s Water Framework Directive, but the political will is clearly lacking to make it work on the ground.”

The EEA survey revealed a divide between chemical pollution in ground and surface water sites. Three-quarters of groundwater samples were of good quality; 62% of rivers, estuaries and lakes were not.

Mercury contamination was one of the most common problems, with overuse of pesticides, inadequate waste treatment plants and tainted rainfall all contributing to the results.

Hans Bruyninckx, the EEA’s executive director said: “We must increase efforts to ensure our waters are as clean and resilient as they should be – our own wellbeing and the health of our vital water and marine ecosystems depend on it.”

Source: theguardian.com

(Dipla Aikaterini)

2017 Was a Really Bad Year for Tropical Forests

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Tropical forests suffered some of their worst losses in history last year, according to a new report from the monitoring group Global Forest Watch.

About 39 million acres, or 61,000 square miles, of forest cover disappeared in 2017—an area approximately the size of Bangladesh. That makes it the second-worst year on record, topped only by losses in 2016.

It’s discouraging news for global climate mitigation efforts. Healthy tropical forests store vast amounts of carbon, while deforestation can release that carbon back into the atmosphere.

And research suggests declines in tropical forest cover are taking their toll: Last year, a blockbuster study in Science concluded that tropical forests—because of their widespread destruction—are actually a net source of carbon to the atmosphere, rather than a carbon sink, as many experts had previously assumed.

The new data present “an alarming story of the situation for the world’s rainforests”, Andreas Dahl-Jørgensen, deputy director of Norway’s International Climate and Forest Initiative, said during a teleconference announcing the findings. “We simply won’t meet the climate targets that we agreed [to] in Paris without a drastic reduction in tropical deforestation and restoration of forests around the world.

The findings were released yesterday morning as representatives from around the world convened in Oslo, Norway, for an international forum on conserving tropical forests. A major focus of the conference includes the role of forests in global climate action.

Several recent estimates have underscored the significant contributions of deforestation to global carbon output—both the 2017 Science paper and a more recent estimate from the Global Carbon Project have suggested that forest losses and degradation may account for more than 10 percent of the world’s emissions.

But while the potential of forests to store or emit carbon remains their most substantial role in global climate efforts, some scientists note that forest losses may influence climate in other ways, as well. A new report from the World Resources Institute, also released this week to coincide with the Oslo forum, points out that deforestation can affect local temperatures and even alter the local water cycle. The report cites a range of recent studies on these effects.

Tree cover, for instance, has the potential to either warm or cool a local climate, depending on a combination of factors. On the one hand, trees tend to be darker in color than their surroundings, meaning they absorb more sunlight and more heat. On the other hand, they also release water into the air through their leaves, and they help to break up landscapes in ways that can disperse heat—both factors that may cool the local climate. Trees also release certain chemical compounds into the atmosphere that can have either cooling or warming effects.

But some recent research suggests that the cooling effect of trees may win out—meaning deforestation can drive local temperatures up and exacerbate the influence of ongoing climate change. A paper published in Nature Climate Change in April, for instance, links deforestation in the Northern Hemisphere to an increase in the intensity of hot days throughout the year.

Overall, the study suggests that deforestation probably accounted for more than half the warming that occurred over North America between 1920 and 1980. This effect has now been outstripped by the growing influence of human-caused climate change, but the researchers say deforestation may still account for nearly a third of the region’s warming (Climatewire, April 24).

2016 paper in Science had a similar message, suggesting forest losses around the world generally drive local temperatures higher. In fact, on a global average, it suggests the warming they produce may be the equivalent of about 18 percent of the influence from human-caused greenhouse gas emissions.

Other research suggests that deforestation could affect regional precipitation patterns. Trees lose water through their leaves, putting moisture back into the air—so tree cover losses can lead to drier local climates.

The effect may be particularly pronounced in tropical rainforests. One 2015 study found that deforestation in the Amazon basin reduces the region’s rainfall—and suggests that if the current deforestation rate continues, average rainfall throughout the Amazon basin could decline by more than 8 percent by 2050.

The point, the WRI report notes, is that “tropical forest loss is having a larger impact on the climate than has been commonly understood.”

Deforestation and degradation contribute substantially to global carbon emissions, thus helping fuel the progression of human-caused climate change. And at the same time, other non-carbon climate effects of deforestation may also be compounding the influence of global warming.

“When you add up these impacts of forest loss, one thing is clear: People living closest to deforested areas face a hotter, drier reality,” said Nancy Harris of WRI, who co-authored the report with Michael Wolosin of Forest Climate Analytics.

The new findings from the Global Forest Watch add renewed urgency to the global conversation on forest conservation and its role in international climate mitigation.

“A lot is hinging on our success in reversing these trends,” Dahl-Jørgensen said.

Source: scientificamerican.com

(Dipla Aikaterini)

The Climate Change Solution Under Our Noses

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Our planet’s outermost surface is so important, it bears its name: earth. It’s the foundation of forests, grasslands and other natural habitats and the medium that gives us food, medicine, clothes, fuel, and livelihoods. Unfortunately, our use and misuse of land accounts for a significant proportion of our total annual greenhouse gas emissions, yet it accounts for a paltry amount of climate funding. We cannot prevent the worst effects of climate change without improving the ways we use land.

Every minute, about 27 football pitches’ worth of forests are lost. Their destruction — and that of grasslands, mangroves and other habitats — emits huge amounts of greenhouse gases into the atmosphere, where they heat the planet. At the same time, habitat loss diminishes the earth’s capacity to pull those gases back into the ground.

Fortunately, there is a growing movement among farmers, executives, policymakers, financiers, consumers, voters, and more to fight climate change by conserving and restoring the earth and making it more resilient.

This September, thousands of these climate leaders are coming to San Francisco for the Global Climate Action Summit. The event will bring together governors, mayors, legislators, CEOs, investors, researchers, and more from around the world to demonstrate progress, set more ambitious and measurable goals, and encourage national governments to go further faster.

As part of the Summit, we are issuing the 30X30 Forests, Food and Land Challenge: calling on businesses, states, city and local governments, and global citizens to take action for better forest and habitat conservation, food production and consumption, and land use, working together across all sectors of the economy to deliver up to 30% of the climate solutions needed by 2030.

While many businesses and local leaders have committed to scale up their use of renewable energy or set energy-use targets in line with the Paris Agreement’s temperature goals, fewer have factored land stewardship into their climate action plan. As a result, we’re challenging all businesses and local leaders to ensure that conserving and restoring lands — everything from eliminating deforestation in supply chains to reducing food waste — is factored into their strategies for addressing climate change.

Rainforests can seem an abstract concept to someone sitting in a city with no trees in sight, but even urbanites can take concrete actions right now to save land. Indeed, food production drives deforestation, most often to raise livestock and produce animal feed. Yet about a third of the food we produce is never eaten, representing the waste of an estimated 14 million square kilometers of land. Further, when food rots in landfills, it emits methane, a potent greenhouse gas that traps 25 times more heat than carbon dioxide. Thus, by eating a balanced diet and wasting less food, anyone can alleviate pressure on land and reduce emissions directly.

Those closer to the land — farmers, ranchers, Indigenous Peoples, and local communities with support from financial institutions, governments, and businesses along the supply chain — can restore degraded lands while boosting their productivity, which alleviates the need to clear forests and other habitats for production. Research funded by WWF in Latin America estimates that rehabilitating land that has already been cleared of natural habitats, used, and abandoned in Brazil’s Cerrado savannah and Amazon rainforest can provide enough land to meet projected demand for beef and soy through 2040 without having to fell one more tree.

These stakeholders can also integrate practices on farms, ranches and commercial forests that reinvigorate soil. Soil is a habitat unto itself, replete with microbial fauna and flora that serve as its engine. The more life in the soil, the more fertile it is, and the more effectively it can pull greenhouse gases out of the atmosphere and turn them into food, fiber, and fuel.

Shifting production practices takes a lot of time and money, however, and farmers are more likely to be poor and hungry than any other profession. That leaves it to governments, financial institutions, and large multinational commodity buyers to support the rehabilitation of land and the transition of practices. Through innovative financing mechanisms, lenders, investors and large buyers can diffuse risk and foster investment in more sustainable practices. State and local governments should set and enforce habitat conservation laws and work with businesses to set a fair and level playing field for producers.

In addition, it’s critical to engage Indigenous Peoples and local communities and protect their rights, as they are both some of the most effective stewards of the land and among those most directly harmed by habitat loss and degradation. Indeed, World Resources Institute has reported that indigenous and community lands store about 25 percent of the world’s aboveground carbon.

We also need innovative technology to foster conservation. Today, paper-based systems and lax oversight create blind spots in supply chains so big that they’re visible from space, literally. Satellites can monitor protected areas and distributed ledgers can move bills of lading into the cloud. Working together, these systems can enable any company or consumer to verify where and how their food, paper, clothing or other goods were produced.

Finally, the scientific community, NGOs, and businesses can develop science-based targets against which companies can measure how much greenhouse gas they’ve saved by conserving and restoring land and making it more resilient.

In 2015, national governments took a stand against climate change in Paris, but those commitments, if fully met, will only deliver one third of the emissions reductions needed to avoid catastrophic climate change. We need to do more.

This September, businesses, state and local leaders, NGOs and citizens around the world will have that opportunity. Together, we can spur national governments to accelerate their efforts by taking a stand to protect what we all stand on — earth.

Source: medium.com/@WWF

(Dipla Aikaterini)

The deadliest volcanic eruptions of the past 25 years

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After Guatemala’s Fuego volcano erupted, killing at least 25 people, here is a list of the most deadly volcanic eruptions over the last quarter century.

2014: Japan

The sudden of Mount Ontake kills more than 60 in Japan’s worst volcanic disaster in nearly 90 years. The 3,067 metre (10,121 feet) Ontake is packed with hikers when it erupts without warning in September.

Also in Japan, the Unzen volcano kills 43 people when it erupts in 1991.

2014: Indonesia

At least 16 people are killed on the island of Sumatra in February by a spectacular eruption of Mount Sinabung, which had lain dormant for 400 years before roaring back to life five months earlier. In 2016 villages are scorched and farmland devastated after another eruption kills seven.

2010: Indonesia

One of the world’s most dangerous volcanoes, Mount Merapi, explodes on the densely populated central Java island, killing more than 300 people in its most powerful eruption since 1872. Some 280,000 people are evacuated. Another eruption in 1930 killed 1,300 people, while yet another killed more than 60 in 1994.

2002: DR Congo

The eruption of Mount Nyiragongo in the eastern Democratic Republic of Congo destroys the centre of Goma town, along with several residential areas, and kills more than 100 people.

1999: Peru

At least 34 people go missing after a sudden volcanic eruption causes mudslides that bury five Andean villages northeast of Lima.

1997: Montserrat

The capital of the small British colony, Plymouth, is wiped off the map and 20 are killed or left missing in avalanches of hot rock and ash clouds when its volcano erupts.

1996: The Philippines

At least 70 are killed and another 30 missing after the crater of the Parker volcano in the south of the island of Mindanao collapses. Five years earlier the eruption of Mount Pinatubo, 80 kilometres (50 miles) north of the capital Manila, kills more than 800.

Worst ever

The explosion of Indonesia’s Krakatoa in 1883 is considered the worst ever seen. The eruption sent a jet of ash, stones and smoke shooting more than 20 kilometres (12 miles) into the sky, plunging the region into darkness, and sparking a huge tsunami that was felt around the world. The disaster killed more than 36,000 people.

The most famous eruption in history is that of Mount Vesuvius in modern-day Italy in 79 AD, which destroyed the towns of Herculaneum, Stabiae, and Pompeii, wiping out an estimated 10 percent of the population of the three cities.

Source: phys.org

(Dipla Aikaterini)

Climate Change Could Lead to Major Crop Failures in World’s Biggest Corn Regions

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Climate change will increase the risk of simultaneous crop failures across the world’s biggest corn-growing regions and lead to less of the nutritionally critical vegetables that health experts say people aren’t getting enough of already, scientists warn.

Two new studies published in Proceedings of the National Academy of Sciences look at different aspects of the global food supply but arrive at similarly worrisome conclusions that reiterate the prospects of food shocks and malnutrition with unchecked global warming. While developing tropical countries would likely be hardest hit, the destabilizing financial effects could reach all corners of the globe, the authors say.

One paper analyzed corn—or maize—the world’s most produced and traded crop, to project how climate change will affect it across the major producing regions. Much of the world’s corn goes into feeding livestock and making biofuels, and swings in production can ripple through global markets, leading to price spikes and food shortages, particularly for the 800 million people living in extreme poverty.

The researchers found significant differences in corn yield depending on how high global temperatures rise.

An increase of 4 degrees Celsius—close to where the current greenhouse gas emissions trajectory would take us by the end of this century—could cut U.S. corn production by nearly half. If global warming is instead held to 2°C (the goal of the Paris climate agreement is to stay below that level) the projected loss in U.S. production would be closer to 18 percent, the researchers found.

Chart: Global warming increases risks to corn yields

Risk of Simultaneous Crop Failures Rises

While those numbers are pretty dramatic, the researchers find that the chances of the top-producing regions suffering extreme yield losses at the same time rises, too.

When the researchers looked at the four biggest corn exporters—the U.S., Brazil, Argentina and Ukraine—they found that the likelihood of all four suffering yield losses of 10 percent or more at the same time rises from about 7 percent at 2°C warming to 86 percent at 4°C warming.

Such simultaneous shocks in the top-producing regions, which are rare now, could have significant impacts on global markets and drive up the price of food.

“Global grain prices have been going up because of demand and biofuels,” said Michelle Tigchelaar, the lead author of the study and a researcher with the University of Washington. “That has made markets tighter, so when you have a yield shock, that has really big implications for the market.”

And for global stability. During the last global food crisis, in 2007 and 2008, rising costs triggered riots and unrest in countries around the world.

Vegetables also at Risk from Global Warming

The second study published Monday looked at how environmental changes brought on by climate change could impact the production and quality of vegetables and legumes—foods that government nutrition guidelines and nutritionists urge people to eat more of.

Researchers led by the London School of Hygiene & Tropical Medicine looked at 174 studies, across 40 countries, published since 1975. The authors say it is the first attempt to systematically examine how climate-induced environmental changes could impact yields of vegetables and legumes around the world.

While previous research has shown that increased levels of carbon dioxide could boost some vegetable and legume yields, the new study finds that any benefits will be offset by the negative effects of increased ozone, less water availability and increased salinity.

Nutritionally important vegetables and legumes can be particularly sensitive to temperature increases and more vulnerable to heat stress than staple or cereal crops. The researchers found that without efforts to reduce emissions, a lack of water and increased ozone would cut yields of vegetables by about 35 percent in the second half of this century.

Result: People Lose Key Sources of Nutrition

Globally, about 2 billion people suffer from micronutrient deficiencies linked to a lack of vegetable and legume consumption, while worldwide per capita consumption of vegetables and fruits is between 20 and 50 percent below recommended levels.

Vegetables and legumes are vital components of a healthy, balanced and sustainable diet and nutritional guidelines consistently advise people to incorporate more vegetables and legumes into their diet,” said Pauline Scheelbeek, the lead author of the study. “Our new analysis suggests, however, that this advice conflicts with the potential impacts of environmental changes that will decrease the availability of these important crops unless action is taken.”

Another recent study that analyzed the impact of climate change on rice, a primary food source for 2 billion people, found that rising carbon dioxide levels will also diminish its nutrient levels.

Source: insideclimatenews.org

(Dipla Aikaterini)

New study examines impacts of fracking on water supplies worldwide

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Using hydraulic fracturing to extract oil and natural gas from shale is a common technique used worldwide. Because the technique requires large amounts of water, however, it raises the question of whether it could lead to water shortages or competition with other water uses, especially agriculture.

In a new paper in the AGU journal Earth’s Future, Lorenzo Rosa and his colleagues evaluated the impacts of on local availability for food production and other human and environmental needs globally.

They found that 30 percent of shale deposits are located in arid regions where aquifers are already being heavily tapped for irrigating crops and 31 percent to 40 percent of shale deposits are in areas where water-stress would emerge or be exacerbated by fracking.

The researchers conclude that in such places water management plans would be needed to ensure that fracking would not affect other human and environmental water needs.

The map shows water stress within shale deposits. In water stressed areas, water is consumed at greater rates than the local water supply is replenished. Green, yellow, orange or red pixels represent areas where there are shale deposits and where freshwater is already being used at unsustainable rates. Areas with water stress indexes greater than one are where consumption for human activities is unsustainable.

Source: phys.org

(Dipla Aikaterini)

‘Water is life’: Ivory Coast city struggles with crippling drought

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“All that comes out of the tap right now is cockroaches,” said Honorine Babalou, a 20-year-old textile worker.

In Bouake, Ivory Coast’s second city, the regular supply trickled to a halt three months ago—a shortage that officials blame on a drought inflicted by global warming.

Like many other Bouake residents, Babalou balanced on her head a giant basin of fresh water drawn from a tanker truck which had trundled down sun-scorched clay tracks to make a delivery in a poor part of town.

The city of about 800,000 people, as estimated by the mayor, has long depended on the nearby Loka dam for around three-quarters of its water supply.

But the lake behind the dam has shrivelled to almost nothing. Hundreds of metres (yards) behind a sign that sternly declares “Fishing and Bathing Forbidden” lies a sad, muddy puddle.

This is . It rains a lot less often, the sun has been stronger for several years,” states Yeboue Ouffoue, 85, chief of the small village of Angoua-Yaokro, near the site where the dam was built in the late 1970s.

“Here we live off agriculture, but with the water shortage we can no longer plant the way we want. Income has dropped, that’s for sure,” Ouffoue said, expressing concern for some 300 villagers in his charge. “Times are hard.”

“We’ve entered a time of water rationing in Bouake,” said Mayor Nicolas Djibo, who also blames climate change, along with people who diverted waterways to exploit sand quarries in the region.

Young Ivorian women carrying precious water in the city where the taps have run dry

‘Greeted like the Messiah’

Located in the centre of Ivory Coast, Bouake is known as a centre for “white gold”, referring to the once lucrative cotton industry, and now “grey gold”, the thriving cashew nut business.

The city formerly served as headquarters for rebels who helped bring President Alassane Ouattara to power in 2011 after a disputed election and a violent political crisis.

Today, faced with an existential threat, the city is looking at a scheme to pipe in supplies from Lake Kossou, about 100 kilometres (60 miles) away.

This operation would take two years and cost an estimated 45 million euros ($53 million), said Djibo, who hopes the World Bank will help finance it.

At the Alassane Ouattara 2 University in Bouake, the lack of water has forced many students to leave their rooms on campus to return home, some geography students told AFP.

Tanker trucks now provide emergency supplies, after attempts to drill into groundwater faltered. In a bid to ease the shortage, authorities sank wells in several parts of Bouake, but the water pumped fell far short of basic requirements.

“We’re greeted like the Messiah, or something like that,” joked driver Mohamed Lamine Diakite, whose truck carries 10,000 litres (2,500 gallons) of water. He announces his arrival in a district by pumping his horn to bring local residents running.

A supplier distributes water from a tanker truck to residents of Bouake at the start of July 2018

In the Sokoura district, women set out hundreds of basins and buckets on the ground, waiting for the water distribution under a broiling sun. There are few men around. Women carry away the heavy load for the family.

‘Water is like treasure’

“We cannot live like this,” said Mariam Kone, a trading woman with three children who also cares for her sick mother.

“You can go two or three days without washing yourself. Before this, we drank water straight from the tap. Today, we adults hold back but the children don’t understand. We have to pay for mineral water. The price has risen by 400 (CFA francs) to 800 (1.20 euros, $1.40). We’re spending more and more—we’ll go broke,” Kone said.

People in the 2 Bodjo district make similar protests. “This is too hard. This doesn’t suit us. We have no water to wash or to drink. When the truck doesn’t come, we have to take water from the well or swamps,” said Chigata Soro, 30, who sells hot food at the roadside. “We need water. It’s not too much to ask.”

Others are angry at officialdom, accusing it of mismanaging both the problem and the solution.

“They tell us ‘It’s emergency measures’ or ‘Wait a couple of years’ but the dam didn’t go dry from one day to the next. The government, the authorities, the (water distribution company) SODECI—somebody handled this really badly,” one resident said.

Awaiting her turn in line, Sabine Kone yelled at a neighbour: “Hands off my water!”

Explaining her sharp words, the young student said: “Water is like treasure now. And what’s more, she wanted to fill her dirty flask from my bowl. This water we get is drinking water. She was going to make it dirty. Water is life!

Source: phys.org

(Dipla Aikaterini)

International Environment Day: Plastic in Africa

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This year, plastic pollution is the main theme of International Environment Day, celebrated on June 5.

In Africa, 4.4 million tonnes of plastic are found in oceans and seas every year, according to United Nations figures from 2010.

Plastic, and in general, is a very big problem in Africa,” said Mohamed Atani, regional information officer for the UN environmental agency UNEP.

Discarded plastic is a biohazard that can take decades to degrade. But at this site in Kampala, Uganda, women clean plastic bags

He described the problem of , which is gaining attention globally as it kills and blankets swathes of the ocean surface, as “a danger for human health”.

“Most of the plastic disposed in the ocean comes from the daily use of single-use plastics,” said Atani.

Spoiled seas: Plastic comprises most of the debris washed up on a beach near the South African city of Cape Town, whose fabled T

The European Union this month proposed a ban on items such as plastic straws and cutlery.

While many western nations still dole out plastic bags in supermarkets, several African countries have taken the lead and banned them entirely, such as Morocco, Rwanda and Kenya.

Source: phys.org

(Dipla Aikaterini)