Category Science

WHAT ARE FLUORINATED GASES?

Fluorinated gases or F-gases are a family of human-made fluorine-based gases. They are powerful greenhouse gases that trap heat and hasten global warming. Though they find wide applications in households and industries, many countries such as the UK have imposed regulations on their use as a step towards combating the climate crisis.

There are three main types of F-gases:

  • hydrofluorocarbons (HFCs)
  • perfluorocarbons (PFCs)
  • sulphur hexafluoride (SF6).

Main uses of F-gases F-gases are used in a number of ways:

  • Stationary refrigeration, air conditioning and heat pump (RAC) equipment are some of the largest sources of F-gas emissions.
  • Some stationary fire protection systems and portable fire extinguishers currently use HFCs.
  • Mobile air conditioning in cars and light vans currently uses HFCs. Other air-conditioned and refrigerated transport also uses F-gases.
  • Solvents containing F-gases are used to clean components, eg in the electronics and aerospace industries.
  • F-gases have many specialist uses such as in the production of magnesium, different types of foam and high voltage switchgear.

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WHAT IS MEAN BY EXTINCTION?

The dying out or extermination of a species is what is referred to as extinction. When species are diminished because of environmental factors or because of evolutionary changes in their members, extinction occurs. While rates of extinction have varied largely, human activities, deforestation, habitat loss, over-hunting, pollution and climate change have meant that the present-day extinction rate is many times more than what it was previously.

About 541 million years ago, a great expansion occurred in the diversity of multicellular organisms. Paleobiologists, scientists who study the fossils of plants and animals to learn how life evolved, call this event the Cambrian Explosion. Since the Cambrian Explosion, there have been five mass extinctions, each of which is named for the geological period in which it occurred, or for the periods that immediately preceded and followed it.

The first mass extinction is called the Ordovician-Silurian Extinction. It occurred about 440 million years ago, at the end of the period that paleontologists and geologists call the Ordovician, and followed by the start of the Silurian period. In this extinction event, many small organisms of the sea became extinct. The next mass extinction is called Devonian extinction, occurring 365 million years ago during the Devonian period. This extinction also saw the end of numerous sea organisms.

The largest extinction took place around 250 million years ago. Known as the Permian-Triassic extinction, or the Great Dying, this event saw the end of more than 90 percent of the Earth’s species. Although life on Earth was nearly wiped out, the Great Dying made room for new organisms, including the first dinosaurs. About 210 million years ago, between the Triassic and Jurassic periods, came another mass extinction. By eliminating many large animals, this extinction event cleared the way for dinosaurs to flourish. Finally, about 65.5 million years ago, at the end of the Cretaceous period came the fifth mass extinction. This is the famous extinction event that brought the age of the dinosaurs to an end.

In each of these cases, the mass extinction created niches or openings in the Earth’s ecosystems. Those niches allowed for new groups of organisms to thrive and diversify, which produced a range of new species. In the case of the Cretaceous extinction, the demise of the dinosaurs allowed mammals to thrive and grow larger.

Scientists refer to the current time as the Anthropocene period, meaning the period of humanity. They warn that, because of human activities such as pollution, overfishing, and the cutting down of forests, the Earth might be on the verge of—or already in—a sixth mass extinction. If that is true, what new life would rise up to fill the niche that we currently occupy?

Credit : National geographic 

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WHAT IS EL NINO WEATHER?

A climate pattern describing the unusual warming of surface waters in the easter tropical Pacific Ocean, El Nino corresponds to the warm phase of the larger phenomenon known as the El Nino-Southern Oscillation (ENSO). The pattern that describes the unusual cooling of the region’s surface waters, or the cool phase of ENSO, is referred to as La Nina. Ocean temperatures, the speed and strength of ocean currents, health of local fisheries, and the local weather of regions from Australia to South America and beyond are affected by the El Nino, which is not a regular cycle.

The El Nino phenomenon caused muddy rivers to overflow along the entire Peruvian coast in 2017.

El Nino can be understood as a natural phenomenon wherein the ocean temperatures rise especially in parts of the Pacific ocean. It is the nomenclature which is referred to for a periodic development along the coast of Peru. This development is a temporary replacement of the cold current along the coast of Peru.   El Nino is a Spanish word. The term El Nino basically means ‘the child’. This is due to the fact that this current starts to flow around Christmas and hence the name referring to baby Christ.

Another natural phenomenon, similar to El Nino is La Nina, which is also in news these days. The term La Nina literally means ‘ little girl’. It is termed as opposite to the phenomenon of El Nino as it results in the ‘cooling’ of the ocean water in parts of the Pacific ocean.   Both of them also result in changes in atmospheric conditions along with oceanic changes.

El Nino Effects

El Nino results in the rise of sea surface temperatures
It also weakens the trade winds of the affected region
In India, Australia, it can bring about drought conditions. This affects the crop productivity largely. It has been also observed certain times, that EL Nino may not bring drought but cause heavy rainfall. In both the cases, it causes heavy damage.
However, in some other countries it may result in a complete reversal, i.e., excessive rainfall.

Mitigation Of  Effects:

Keeping a check on the sea surface temperatures.
Maintaining sufficient buffer stocks of food grains and ensuring their smooth supply.
Ensuring relevant support to the farmer community including economic help.
Alternative ways to be promoted such as the practice of sustainable agriculture.

Credit : BYJUS.com

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WHAT IS A DEFINITION OF ECOSYSTEM?

A geographic area where plants, animals, and other organisms, along with weather and landscape, work together to form a sphere of life is known as an ecosystem. Ecosystems thus contain biotic or living parts like plants, animals and other organisms as well as abiotic factors like temperature, humidity and rocks. The interdependence of these various parts and factors. either directly or indirectly, is what makes ecosystems thrive.

Ecosystems are controlled by external and internal factors. External factors such as climate, parent material which forms the soil and topography, control the overall structure of an ecosystem but are not themselves influenced by the ecosystem. Internal factors are controlled, for example, by decomposition, root competition, shading, disturbance, succession, and the types of species present. While the resource inputs are generally controlled by external processes, the availability of these resources within the ecosystem is controlled by internal factors. Therefore, internal factors not only control ecosystem processes but are also controlled by them.

Ecosystems are dynamic entities—they are subject to periodic disturbances and are always in the process of recovering from some past disturbance. The tendency of an ecosystem to remain close to its equilibrium state, despite that disturbance, is termed its resistance. The capacity of a system to absorb disturbance and reorganize while undergoing change so as to retain essentially the same function, structure, identity, and feedbacks is termed its ecological resilience. Ecosystems can be studied through a variety of approaches—theoretical studies, studies monitoring specific ecosystems over long periods of time, those that look at differences between ecosystems to elucidate how they work and direct manipulative experimentation. Biomes are general classes or categories of ecosystems. However, there is no clear distinction between biomes and ecosystems. Ecosystem classifications are specific kinds of ecological classifications that consider all four elements of the definition of ecosystems: a biotic component, an abiotic complex, the interactions between and within them, and the physical space they occupy.

Ecosystems provide a variety of goods and services upon which people depend. Ecosystem goods include the “tangible, material products” of ecosystem processes such as water, food, fuel, construction material, and medicinal plants. Ecosystem services, on the other hand, are generally “improvements in the condition or location of things of value”. These include things like the maintenance of hydrological cycles, cleaning air and water, the maintenance of oxygen in the atmosphere, crop pollination and even things like beauty, inspiration and opportunities for research. Many ecosystems become degraded through human impacts, such as soil loss, air and water pollution, habitat fragmentation, water diversion, fire suppression, and introduced species and invasive species. These threats can lead to abrupt transformation of the ecosystem or to gradual disruption of biotic processes and degradation of abiotic conditions of the ecosystem. Once the original ecosystem has lost its defining features, it is considered “collapsed”. Ecosystem restoration can contribute to achieving the Sustainable Development Goals.

Credit : Wikipedia 

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WHAT IS DESERTIFICATION?

The process by which natural or human causes reduce the biological productivity of drylands (arid, semi-arid and dry sub-humid areas) is known as desertification, also referred to as desertization. Climate change, deforestation, overgrazing, unsustainable irrigation practices, political instability, poverty, or a combination of these factors generally result in declines in productivity of drylands. Africa has been the continent that is most affected by desertification.

Desertification, in short, is when land that was of another type of biome turns into a desert biome because of changes of all sorts. A huge issue that many countries have is the fact that there are large pockets of land that are going through a process that is known as desertification.

Desertification affects topsoil, groundwater reserves, surface runoff, human, animal, and plant populations. Water scarcity in drylands limits the production of wood, crops, forage, and other services that ecosystems provide to our community.

According to UNESCO, one-third of world’s land surface is threatened by desertification, and across the world, it affects the livelihood of millions of people who depend on the benefits of ecosystems that drylands provide.

Various Causes of Desertification

1. Overgrazing

Animal grazing is a huge problem for many areas that are starting to become desert biomes. If there are too many animals that are overgrazing in certain spots, it makes it difficult for the plants to grow back, which hurts the biome and makes it lose its former green glory.

2. Deforestation

When people are looking to move into an area, or they need trees in order to make houses and do other tasks, then they are contributing to the problems related to desertification. Without the plants (especially the trees) around, the rest of the biome cannot thrive.

3. Farming Practices

Some farmers do not know how to use the land effectively. They may essentially strip the land of everything that it has before moving on to another plot of land. By stripping the soil of its nutrients, desertification becomes more of a reality for the area that is being used for farming.

4. Excessive Use of Fertilizers and Pesticides

The use of excessive amounts of fertilizers and pesticides to maximize their crop yields in the short term often leads to significant damages for the soil.

In the long run, this may turn from arable into arid land over time, and it will no longer be suitable for farming purposes after a few years of excessive farming since the soil has been damaged too much over time.

5. Overdrafting of groundwater

Groundwater is the freshwater found underground and also one of the largest water sources. Over drafting is the process in which groundwater is extracted in excess of the equilibrium yield of the aquifer that is pumping or the excessive pulling up of groundwater from underground aquifers. Its depletion causes desertification.

6. Urbanization and Other Types of Land Development

As mentioned above, development can cause people to go through and kill plant life. It can also cause issues with the soil due to chemicals and other things that may harm the ground. As areas become more urbanized, there are fewer places for plants to grow, thus causing desertification.

7. Climate Change

Climate change plays a huge role in desertification. As the days get warmer and periods of drought become more frequent, desertification becomes more and more eminent.

Unless climate change is slowed down, huge areas of land will become desert; some of those areas may even become uninhabitable as time goes on.

8. Stripping the Land of Resources

If an area of land has natural resources like natural gas, oil, or minerals, people will come and mine it or take it out. This usually strips the soil of nutrients, which in turn kills the plant life, and eventually leads to the process of becoming a desert biome as time goes on.

There are some cases where the land gets damaged because of natural disasters, including drought. In those cases, there isn’t a lot that people can do except work to try and help rehabilitate the land after it has already been damaged by nature.

8. Soil Pollution

Soil pollution is a significant cause of desertification. Most plants are quite sensitive to their natural living conditions. When soil becomes polluted due to various human activities, the respective area of land may suffer from desertification in the long run. Higher the level of pollution more will be the degradation of soil over time.

9. Overpopulation and excessive consumption

Since our world population is continuously growing, the demand for food and material goods is also increasing at an alarming rate. Our overall level of consumption is also increasing at a steady rate.

Thus to fulfill our demand, we have to optimize our farming processes to harvest even higher crop yields. However, this excessive optimization of farming will hurt the soil and will eventually turn into the desertification of land in the long run.

10. Mining

Mining is another big reason for desertification. Large amounts of resources have to be extracted by industries to meet our demand for material goods. For mining, large areas of land have to be used, which causes deforestation as well as pollution of the nearby areas.

By the time most of the natural resources have been extracted, and mining practices are no more profitable, the soil gets damaged significantly, and the land becomes arid, which may not be recoverable, and desertification occurs.

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WHAT IS DEFORESTATION?


The intentional clearing of forested land is called deforestation. Throughout history and into current times, forests have been cleared in order to convert the forest land to farms, ranches, or urban uses. While deforestation has greatly changed the world’s landscapes, the greatest concentration of deforestation today is taking place in tropical rainforests. Deforestation not only results in more carbon dioxide being released into the atmosphere, but also threatens the world’s biodiversity as these forests are usually home to many species of plants and animals.

The Food and Agriculture Organization of the United Nations defines deforestation as the conversion of forest to other land uses (regardless of whether it is human-induced). “Deforestation” and “forest area net change” are not the same: the latter is the sum of all forest losses (deforestation) and all forest gains (forest expansion) in a given period. Net change, therefore, can be positive or negative, depending on whether gains exceed losses, or vice versa.

The removal of trees without sufficient reforestation has resulted in habitat damage, biodiversity loss, and aridity. Deforestation causes extinction, changes to climatic conditions, desertification, and displacement of populations, as observed by current conditions and in the past through the fossil record. Deforestation also reduces biosequestration of atmospheric carbon dioxide, increasing negative feedback cycles contributing to global warming. Global warming also puts increased pressure on communities who seek food security by clearing forests for agricultural use and reducing arable land more generally. Deforested regions typically incur significant other environmental effects such as adverse soil erosion and degradation into wasteland.

The resilience of human food systems and their capacity to adapt to future change is linked to biodiversity – including dryland-adapted shrub and tree species that help combat desertification, forest-dwelling insects, bats and bird species that pollinate crops, trees with extensive root systems in mountain ecosystems that prevent soil erosion, and mangrove species that provide resilience against flooding in coastal areas.] With climate change exacerbating the risks to food systems, the role of forests in capturing and storing carbon and mitigating climate change is important for the agricultural sector.

Credit : Wikipedia

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