Environmental degradation is the deterioration of the environment through depletion of resources such as air, water and soil; the destruction of ecosystems and the extinction of wildlife. It is defined as any change or disturbance to the environment perceived to be deleterious or undesirable.
Environmental degradation is of many types. When natural habitats are destroyed or natural resources are depleted, environment is degraded.
Environmental Destruction
The planet's natural ecosystems and regenerating bio-capacity are being severely degraded and, as a result, this compromises the ability of the planet to sustain life. Forests, fisheries, oceans, rangeland, fresh water systems (lakes, wetlands, rivers) and other natural ecosystems are all threatened while many are on the verge of collapse. Water, land and air are getting increasingly polluted, water tables are falling, soil erosion is leading to desertification, global warming is well underway, and species are dying out 1000 times faster than their natural rate of extinction.
Facts
Forests
We are losing forestland at a rate of 375 km2 each day. This is more than the total area of New Hampshire, Vermont, Massachusetts, Rhode Island, Connecticut, New Jersey and Delaware combined!
The world has already lost 80% of its original forests.
1.1 billion acres of tropical forest were cleared in just thirty years, between 1960 and 1990.
Brazil lost 91.4 million acres of its tropical forest between 1980 and 1990. This is almost the total area of North and South Dakota combined.
At the world's current rates, 5-10% of tropical forest species will become extinct every decade.
Fisheries
75% of all the fish stocks in the world are already either: exploited, over-exploited or recovering. 27% of coral reefs have already been and 70% of Earth's coral reefs will cease to exist within the next forty years. The world has lost half of its coastal wetlands, including mangrove swamps and salt marshes.
In the next 30 years, as many as one-fifth of all species alive today will become extinct. 23% of all mammals and 12% of all birds’ species were considered "threatened" in 2003.
assalamualaikum & good day :))
from the facts shared above..it's well said that this topic is all about what's our globe up to nowadays.
it's so unfortunate that we have to see things happening around us helplessly.
as a matter of a fact, WE CAN HELP BY AT LEAST STOP BEING SELFISH
realizing the important roles can be played by everyone in the society,there's a strong reason of including this topic in Science for Standard 6.
i decided to make my students come out with their own presentation which were great ones as the outcome.
enjoy the videos recorded throughout the whole session and hopefully will be giving all of you some clear ideas about the whole topic.
above : diagrams of SERIES CIRCUIT(on the left) & PARALLEL CIRCUIT(on the right)
assalamualaikum all my readers.
today's topic of the entry is ELECTRICITY
subtopic is SERIES CIRCUIT & PARALLEL CIRCUIT
this lab activity was carried out on 25th April 2012.
the students are from my Primary 5 class.
above : SERIES CIRCUIT
above : PARALLEL CIRCUIT
above : SERIES CIRCUIT (added with dynamo)
There are two basic ways in which to connect more than two
circuitcomponents:seriesandparallel.
Components of an electrical circuit or electronic circuit can be connected in many different ways. The two simplest of these are calledseries and parallel and occur very frequently. Components connected in series are connected along a single path, so the same current flows through all of the components. Components connected in parallel are connected so the same voltage is applied to each component.
A circuit composed solely of components connected in series is known as a series circuit; likewise, one connected completely in parallel is known as a parallel circuit.
In a series circuit, the current through each of the components is the same, and the voltage across the components is the sum of the voltages across each component.In a parallel circuit, the voltage across each of the components is the same, and the total current is the sum of the currents through each component.
