Posts

Soil erosion and degradation: a global problem – Effects (Part 2)

drought-mud-feather-dry-nature-soil-erosion

The consequences of soil erosion are primarily centered on reduced agricultural productivity, as well as soil quality. But also, water ways may be blocked, and it may affect water quality. This means, most of the environmental problems the world face today, arises from soil erosion.

Particularly, the effects of soil erosion go beyond the loss of fertile land. In other words, it has led to increased pollution and sedimentation in streams and rivers, clogging these waterways and causing declines in fish and other species. And degraded lands are also often less able to hold onto water, which can worsen flooding.

So, the effects of soil degradation include:

  1. Loss of arable land: Lands used for crop production have been substantially affected by soil erosion. Soil erosion eats away the top soil which is the fertile layer of the land and also the component that supports the soil’s essential microorganisms and organic matter. In this view, soil erosion has severely threatened the productivity of fertile cropping areas as they are continually degraded. Because of soil erosion, most of the soil characteristics that support agriculture have been lost, causing ecological collapse and mass starvation.
  1. Water Pollution and Clogging of Waterways: Soils eroded from agricultural lands, carry pesticides, heavy metals, and fertilizers which are washed into streams and major water ways. This leads to water pollution and damage to marine and freshwater habitats. Accumulated sediments can also cause clogging of water ways and raises the water level leading to flooding.
  1. Increased flooding: Land is commonly altered from its natural landscape when it rids its physical composition from soil degradation. In other words, soil degradation takes away the soil’s natural capability of holding water thus contributing to more and more cases of flooding.
  1. Drought and Aridity: Drought and aridity are problems highly influenced and amplified by soil degradation. As much as it’s a concern associated with natural environments in arid and semi-arid areas, the UN recognizes the fact that drought and aridity are anthropogenic induced factors especially as an outcome of soil degradation. Hence, the contributing factors to soil quality decline such as overgrazing, poor tillage methods, and deforestation are also the leading causes of desertification characterized by droughts and arid conditions.
  1. Destruction of Infrastructure: Soil erosion can affect infrastructural projects such as dams, drainages, and embankments, reducing their operational lifetime and efficiency. Also, the silt up can support plant life that can, in turn, cause cracks and weaken the structures. Soil erosion from surface water runoff often causes serious damage to roads and tracks, especially if stabilizing techniques are not used.
  1. Desertification: Soil erosion is also responsible for desertification. It gradually transforms a habitable land into deserts. The transformations are worsened by the destructive use of the land and deforestation that leaves the soil naked and open to erosion. This usually leads to loss of biodiversity, alteration of ecosystems, land degradation, and huge economic losses.

Finally, we all understand that the erosion of the soil is a very serious issue, especially in our days. That is why we need to take action and prevent the unpleasant effects.

Dipla Aikaterini (Arid Zone Afforestation)

Sources:

 

 

Soil erosion and degradation: a global problem – Causes (Part 1)

soil-degradation-and-conservation-5-638

Soil degradation, defined as lowering and losing of soil functions, is becoming more and more serious worldwide in recent decades, and poses a threat to agricultural production and terrestrial ecosystem.

Particularly, soil degradation simply means the decline in soil quality, which comes about due to aspects such as improper land use, agriculture and pasture, urban or industrial purposes. It involves the decline of the soil’s physical, biological and chemical state. In other words, it is a process that leads to decline in the fertility or future productive capacity of soil, as a result of human activity.

It is well known that all soils undergo soil erosion, but some are more vulnerable than others, due to human activities and other natural causal factors. The severity of soil erosion is also dependent on the soil type and the presence of vegetation cover.

Here are few of the major causes of soil degradation:

  1. Physical factors: There are several physical factors contributing to soil degradation, distinguished by the manners in which they change the natural composition and structure of the soil.  Rainfall, surface runoff, floods, wind erosion, tillage, and mass movements result in the loss of fertile top spoil thereby declining soil quality. All these physical factors produces different types of soil erosion (mainly water and wind erosion) and soil detachment actions, and their resultant physical forces eventually changes the composition and structure of the soil by wearing away the soil’s top layer as well as organic matter.
  1. Chemical factors: The reduction of soil nutrients because of alkalinity or acidity or water logging, are all categorized under the chemical components of soil degradation. In the broadest sense, it comprises alterations in the soil’s chemical property that determine nutrient availability.
  1. Biological factors: Biological factors refer to the human and plant activities that tend to reduce the quality of soil.  Some bacteria and fungi overgrowth in an area can highly impact the microbial activity of the soil through bio-chemical reactions, which reduces crop yield and the suitability of soil productivity capacity. Also, human activities such as poor farming practices may also deplete soil nutrients thus diminishing soil fertility.
  1. Deforestation: Deforestation causes soil degradation on the account of exposing soil minerals by removing trees and crop cover, which support the availability of humus and litter layers on the surface of the soil. When trees are removed by logging, infiltration rates become elevated and the soil remains bare and exposed to erosion and the buildup of toxicities.
  1. Improper cultivation practices: There are certain agricultural practices that are environmentally unsustainable and at the same time, they are the single biggest contributor to the worldwide increase in soil quality decline. For example, due to shortage of land, increase of population and economic pressure, the farmers have adopted intensive cropping patterns of commercial crops in place of more balanced cereal-legume rotations.
  1. Misuse and Extensive cultivation: The excessive use and the misuse of pesticides and chemical fertilizers kill organisms that assist in binding the soil together. In other words, it increases the rate of soil degradation by destroying the soil’s biological activity and builds up of toxicities through incorrect fertilizer use. We all know that due to tremendous population increase, the use of land is increasing day by day.
  1. Overgrazing: The rates of soil erosion and the loss of soil nutrients as well as the top soil, are highly contributed by overgrazing. Overgrazing destroys surface crop cover and breaks down soil particles, increasing the rates of soil erosion. As a result, soil quality and agricultural productivity is greatly affected.
  1. Industrial and Mining activities: Soil is chiefly polluted by industrial and mining activities. For example, mining destroys crop cover and releases a myriad of toxic chemicals such as mercury into the soil thereby poisoning it and rendering it unproductive for any other purpose. Industrial activities, on the other hand, release toxic effluents and material wastes into the atmosphere, land, rivers, and ground water that eventually pollute the soil and as such, it impacts on soil quality. Altogether, industrial and mining activities degrade the soil’s physical, chemical and biological properties.
  1. Roads and Urbanization: Urbanization severely affects the erosion process. Land denudation by removing vegetation cover, changing drainage patterns, soil compaction during construction and then covering the land by impermeable layers of concrete or asphalt, all of them contribute to increased surface runoff and increased wind speeds.

Finally, taking into consideration all the above, we understand that soil erosion is a continuous process and may occur either at a relatively unnoticed rate or an alarming rate contributing to copious loss of the topsoil. So, we have to be careful and avoid all the above problems.

Dipla Aikaterini (Arid Zone Afforestation)

Sources:

 

 

 

Greenland: how rapid climate change on world’s largest island will affect us all

DGyVy3LVoAAJ5ot

The largest wildfire ever recorded in Greenland was recently spotted close to the west coast town of Sisimiut, not far from Disko Island.  The fire has captured public and scientific interest not just because its size and location came as a surprise, but also because it is yet another signpost of deep environmental change in the Arctic.

Greenland is an important cog in the global climate system. The ice sheet which covers 80% of the island reflects so much of the sun’s energy back into space that it moderates temperatures through what is known as the “albedo effect”. And since it occupies a strategic position in the North Atlantic, its meltwater tempers ocean circulation patterns.

But Greenland is especially vulnerable to climate change, as Arctic air temperatures are currently rising at twice the global average rate. Environmental conditions are frequently setting new records: “the warmest”, “the wettest”, “the driest”.

The ice sheet is melting

Between 2002 and 2016 the ice sheet lost mass at a rate of around 269 gigatonnes per year. During the same period, the ice sheet also showed some unusual short-term behaviour.

The 2012 melt season was especially intense – 97% of the ice sheet experienced surface melt at some point during the year. Snow even melted at its summit, the highest point in the centre of the island where the ice is piled up more than 3km above sea level. 

In April 2016 Greenland saw abnormally high temperatures and its earliest ever “melt event” (a day in which more than 10% of the ice sheet has at least 1mm of surface melt). Early melting doesn’t usher in a period of complete and catastrophic change – the ice won’t vanish overnight. But it does illustrate how profoundly and rapidly the ice sheet can respond to rising temperatures.

Despite its icy image, the margins of Greenland are actually quite boggy, complete with swarms of mosquitoes. This is the “active layer”, made up of peaty soil and sediment up to two metres thick, which temporarily thaws during the summer. The underlying permafrost, which can reach depths of 100m, remains permanently frozen.

If thawing continues, it’s estimated that by 2100 permafrost will emit 850-1,400 billion tonnes of CO₂ equivalent (for comparison: total global emissions in 2012 was 54 billion tonnes of CO₂ equivalent). All that extra methane and carbon of course has the potential to enhance global warming even further.

With this in mind, it is clear to see why the recent wildfire, which was burning in dried-out peat in the active layer, was especially interesting to researchers. If Greenland’s permafrost becomes increasingly degraded and dry, there is the potential for even bigger wildfires which would release vast stores of greenhouse gases into the atmosphere.

Learn more here: https://theconversation.com/greenland-how-rapid-climate-change-on-worlds-largest-island-will-affect-us-all-82675

The US cities at risk of flooding – and how they deal with it

3000

Tropical storm Harvey may have bared its teeth at Houston, but other cities in the US have felt the pangs of nervousness. Several cities are vulnerable to the fiercer storms and sea level rise that are being fueled by climate change.

Cities, by their very nature, struggle during flood situations. Water that would have been soaked up by grass and other vegetation washes off the concrete and asphalt of urban areas and, if not properly diverted away, can inundate homes.

Add in, as in Houston’s case, lax rules around property zoning and a federal flood insurance system that repeatedly pays out for damage to poorly situated houses, and it’s clear cities have much work to do to cope with the changes upon them.

Harvey brought a huge amount of rainfall, but cities now face flooding threats even without a major storm. “Rare events are going to become more common in the future strictly due to sea level rise,” said William Sweet, an oceanographer at the National Oceanic and Atmospheric Administration (Noaa).

“We are already seeing flooding in property and the streets in Charleston, Norfolk and Miami on sunny days, driven by the tides. That is a looming crisis that is only going to grow more severe over time.”

The nightmare of a Harvey (or Katrina or Sandy) has led to many cities opt for huge sea walls and other expensive engineering fixes. But there is no easy solution – a sea wall simply pushes the water elsewhere, perhaps on to a neighbor’s head. The water has to go somewhere and decades of development on flood-prone land has left little space to maneuver for some municipalities.

“There are coastal cities at risk from an extreme event and they have giant sea walls or houses on stilts,” said Sweet. “But then there are communities that don’t face a big hurricane threat but water is bubbling up from underneath them. They can’t defend against this sort of flooding. You can’t build a wall everywhere.”

Some progressive cities have started to look at alternative approaches, most notably from the Netherlands, where communities “live” with the water, allowing certain areas to flood while aggressively defending critical infrastructure. Natural sponges such as parklands, wetlands and dunes are now also in vogue with city planners.

But as attitudes to flooding slowly shift, the problem is escalating. Scientists are now confident that hurricanes will become more powerful, fed by a warming, moisture-laden atmosphere, while more common “nuisance” flooding will become so frequent along parts of the US east coast that they will occur once every three days by 2045. By around this time, a majority of US coastal areas are likely to be threatened by 30 or more days of flooding each year.

So which cities are at risk and what are they doing about the threat?

Follow the link to learn more about that serious problem, and how climate change is responsible for this situation: https://www.theguardian.com/environment/2017/aug/31/us-risk-flooding-harvey-boston-new-york-miami-beach

World has missed chance to avoid dangerous global warming – unless we start geo-engineering the planet

planet-earth

The world has missed the chance to avoid dangerous global warming – unless we start geo-engineering the atmosphere by removing greenhouse gases, according to new research.

Scientists used computer models to assess what needs to be done to restrict global warming to between 1.5 and 2 degrees Celsius, the limits adopted by the Paris Agreement on climate change. They found that the world was likely to overshoot this temperature but could bring it back down to 1.2C by the end of this century by using techniques to remove carbon dioxide from the air.

Giant biological machines could be created to do this by growing vegetation which absorbs carbon, then burning the resulting biomass in power stations that capture the emissions.

The researchers also said other techniques to remove carbon from the atmosphere would need to be developed. Another team of researchers reached similar conclusions last month, finding that geo-engineering would be required to restrict warming to 1.5C but 2C could be achieved without it.

Scientists previously thought limiting global warming to 2C would avoid the most dangerous effects, but there is increasing evidence that allowing it to go much above 1.5C could lock in considerable sea level rise for the next few centuries. So far the world has warmed by just under 1C in little over a century.

The world would have to bring about a “complete shift” to an energy system based on renewables, nuclear, hydrogen, and bio-energy with carbon capture and storage.

Follow the link to learn more about the research: http://www.independent.co.uk/environment/world-global-warming-avoid-geo-engineering-planet-climate-change-man-made-a7904966.html

Global warming doubles growth rates of Antarctic seabed’s marine fauna – study

2781

Marine life on the Antarctic seabed is likely to be far more affected by global warming than previously thought, say scientists who have conducted the most sophisticated study to date of heating impacts in the species-rich environment.

Growth rates of some fauna doubled – including colonising moss animals and undersea worms – following a 1C increase in temperature, making them more dominant, pushing out other species and reducing overall levels of biodiversity, according to the study published  in Current Biology.

The researchers who conducted the nine-month experiment in the Bellingshuan Sea say this could have alarming implications for marine life across the globe as temperatures rise over the coming decades as a result of manmade greenhouse gases in the atmosphere.

Gail Ashton of the British Antarctic Survey and Smithsonian Environmental Research Center said she was not expecting such a significant difference. “The loss of biodiversity is very concerning. This is an indication of what may happen elsewhere with greater warning.”

Sub-zero conditions near the south pole mean there are comparatively few species on the usually frozen land, but below the ice, the relative lack of pollution, traffic and fishing has left an abundance of marine life that divers and biologists compare to coral reefs.

Previous studies of warming impacts have focused on single species, but the latest research examines an assemblage of creatures. Twelve identical 15cm sq heat plates were set in concrete on the seabed. Four were warmed by 1C, four by 2C and four left at ambient temperature as a control.

Until recently, most of the coverage of temperature rises has focused on the north pole, where the shrinking of arctic ice has been most visibly dramatic. But concerns are growing about the impact of global warming on the far bigger southern ice cap.

Follow for more information: https://www.theguardian.com/environment/2017/aug/31/global-warming-doubles-growth-rates-of-antarctic-seabeds-marine-fauna-study

13 Graceful Pictures of Rare Sea Turtles

01_sea_turtle.ngsversion.1497627245389.adapt.676.1

Sea turtles are one of a small number of species alive today that once roamed with dinosaurs, as far back as 150 million years ago. But despite their long history on this planet, sea turtles are now facing an existential crisis.

Of the seven species that swim in our oceans today, all face potential threats. The hawksbill sea turtle and the Atlantic Ridley sea turtle have the most uncertain future—the International Union for Conservation of Nature classifies both as critically endangered.

Sea turtles feel the brunt of human influence on the environment. These animals inhabit both marine and beach ecosystems, and experts warn their extinction could harm seagrass beds and other ecosystems on which people also depend.

The world’s most vulnerable sea turtles face threats at all stages of their life. Sea turtle eggs are frequently harvested and consumed as a delicacy. The beaches upon which they depend to lay eggs and hatch their young are also disappearing or being degraded.

Of the seven sea turtles found around the globe, six travel through U.S. waters and are therefore protected under the Endangered Species Act. Because sea turtles can migrate as many as 10,000 miles across multiple oceans, multilateral agreements have been established internationally to ensure that each turtle is protected across all the regions it inhabits.

Follow the link to see some graceful pictures of rare sea turtles: http://news.nationalgeographic.com/2017/06/world-sea-turtle-day-photos/

 

Just 100 companies responsible for 71% of global emissions, study says

4240

Just 100 companies have been the source of more than 70% of the world’s greenhouse gas emissions since 1988, according to a new report.

The Carbon Majors Report “pinpoints how a relatively small set of fossil fuel producers may hold the key to systemic change on carbon emissions,” says Pedro Faria, technical director at environmental non-profit CDP, which published the report in collaboration with the Climate Accountability Institute.

Traditionally, large scale greenhouse gas emissions data is collected at a national level but this report focuses on fossil fuel producers. Compiled from a database of publicly available emissions figures, it is intended as the first in a series of publications to highlight the role companies and their investors could play in tackling climate change.

The report found that more than half of global industrial emissions since 1988 – the year the Intergovernmental Panel on Climate Change was established – can be traced to just 25 corporate and state-owned entities. The scale of historical emissions associated with these fossil fuel producers is large enough to have contributed significantly to climate change, according to the report.

ExxonMobil, Shell, BP and Chevron are identified as among the highest emitting investor-owned companies since 1988. If fossil fuels continue to be extracted at the same rate over the next 28 years as they were between 1988 and 2017, says the report, global average temperatures would be on course to rise by 4C by the end of the century. This is likely to have catastrophic consequences including substantial species extinction and global food scarcity risks.

While companies have a huge role to play in driving climate change, says Faria, the barrier is the “absolute tension” between short-term profitability and the urgent need to reduce emissions.

Click here, to learn more about that serious problem: https://www.theguardian.com/sustainable-business/2017/jul/10/100-fossil-fuel-companies-investors-responsible-71-global-emissions-cdp-study-climate-change

“The problem of Deforestation: causes, effects and possible solutions”

deforestation_2074483b

Deforestation, clearance or clearing is the removal of a forest or stand of trees, often resulting in damage to the quality of the land. Through agriculture and logging, mining and climate change, humans are wiping out irreplaceable forests – and the life that depends on them, face a lot of problems. We are losing not only our primeval forests, which regulate our climate and water resources, but also the amazing range of species that call them home.

For example, the biggest driver of deforestation is “agriculture”, where the farmers cut forests to provide more room for planting crops or grazing livestock. Also, “logging operations”, which provide the world’s wood and paper products, cut countless trees each year. As a result, the problem is becoming more and more serious and the people are not trying to do something, in order to deal with it.

It is very important to understand “how serious the problem is”, especially in terms of the environment.  To make it clear, it is widely accepted that one of the most dramatic impacts is the loss of habitat for millions of species. Eighty percent of Earth’s land animals and plants live in forests, and many cannot survive the deforestation that destroys their homes. They lose their habitat and are forced to move to a new location, while some of them are even pushed to extinction. So, our world has lost so many species of plants and animals in last couple of decades.

In addition to the loss of habitat, the lack of trees also allows a greater amount of greenhouse gases to be released into the atmosphere.  In other words, with constant deforestation, the ratio of green house gases in the atmosphere has increased, adding to our global warming woes. As a result, not only the humans are facing a lot of health problems, but also we observe a deterioration of the problem of global warming.

Further effects of deforestation include soil erosion, because with the clearance of tree cover, the soil is directly exposed to the sun, making it dry. Here, we have to add also the problem of “floods”. In particular, when it rains, trees absorb and store large amount of water with the help of their roots. When they are cut down, the flow of water is disrupted and leads to floods in some areas and droughts in other. 

So, the question is “what we can do to prevent deforestation”?

Some possible solutions:

  • Law and regulations

The best solution to deforestation is to curb the felling of trees, by employing a series of rules and laws at governmental and organizational levels. Laws on timber, wood fuel, farming, and land use among other forest resources must be advanced and enforced to limit deforestation.

  • Replanting – Reforestation

People, communities, governments, and organizations are all active actors. Reforestation involves selecting and dedicating large tracts of land mainly for the purpose of cultivating forests. For instance, in local communities and urban centers, it can be done around market areas, or within city parks.

  • Green Business

Green methods of production and utilization of resources can immeasurably reduce deforestation. Particularly, it’s the focus on re-using items, reducing the use of artificial items, and recycling more items.  By focusing on recycling paper, plastics, and wood products, it means there will be less dependence on the natural resources and trees.

  • Sensitization and Educative Campaigns

By organizing a campaign so as to inform the public, we can achieve positive results. In this way, people will be able to detect the causes, effects, and ways of counteracting deforestation. In addition, sharing information with people including family, friends, colleagues, and the entire community on deforestation and its effects, is an appropriate measure of standing up in unison to combat the clearing of forests.

So, it is very important to understand the seriousness of the problem and, by extension, to take action. It is not obligatory to follow the above ways of dealing, but you can alone discover new methods and contribute in a better future.

Take action! Be positive! Change the world! 

Dipla Aikaterini (Arid Zone Afforestation)

Millions of native oysters to be returned to the Solent

5409

New project aims to restore what was once Europe’s largest oyster fishery, off the south coast of England. Millions of native oysters are to be put into the Solent, once the site of Europe’s largest oyster fishery.

The five-year project aims first to restore a thriving oyster population to the waters between the south coast and Isle of Wight. Oyster beds provide habitat for many other species and the shellfish filter vast volumes of water – 200 litres per oyster – helping to clean up pollution. Once re-established, significant oyster fishing could resume.

A million young oysters will be put into the Solent in 2017, in places where they cannot be legally fished. A further 10,000 are being put in special cages in harbours, from where they can send out larvae.

Oysters have been fished in the UK since at least Roman times and at its peak in the 1920s 40 million oysters were eaten each year, with the abundance leading to the mollusc being known as a poor man’s food. But by the 1960s this had fallen to 3 million oysters a year.

The population in the Solent crashed again recently, with the annual catch falling from 200 tonnes in 2007 to just 20 tonnes in 2011 – about 250,000 shells – and oyster fishing was banned in the Solent in 2013. “It’s a perfect storm of overfishing, habitat destruction, dredging, climate change, disease, invasive species and quite possibly pollution,” said Preston, a marine biologist at the University of Portsmouth who is monitoring the project.

Read more here: https://www.theguardian.com/environment/2017/apr/20/millions-of-native-oysters-to-be-returned-to-the-solent