Environmental Science

The biosphere is the biological component of earth systems, which also include the lithosphere, hydrosphere, atmosphere and other spheres (e.g. cryosphere, anthrosphere, etc.). The biosphere includes all living organisms on earth, together with the dead organic matter produced by them.

Components of Environment:
At the top of the hierarchy is the planet’s entire living environment, known as the biosphere. Within this biosphere are several large categories of living communities known as biomes that are usually characterized by their dominant vegetation, such as grasslands, tropical forests, or deserts. The biomes are in turn made up of ecosystems. The living or biotic parts of an ecosystem, such as the plants, animals, and bacteria found in soil, are known as a community. The physical surroundings or abiotic components, such as the minerals found in the soil, are known as habitat.

Biomagnification, also known as bioamplification or biological magnification, is the increase in concentration of a substance that occurs in a food chain. It occurs as a consequence of:
• Persistence (can't be broken down by environmental processes)
• Food chain energetics
• Low (or nonexistent) rate of internal degradation/excretion of the substance (often due to water-insolubility)

Incineration is a waste treatment process that involves the combustion of organic substances contained in waste materials. Incineration and other high temperature waste treatment systems are described as "thermal treatment". Incineration of waste materials converts the waste into ash, flue gas and heat.

Ocean acidification is the name given to the ongoing decrease in the pH of the oceans, caused by the uptake of anthropogenic carbon dioxide (CO₂) from the atmosphere.

Stockholm Convention on Persistent Organic Pollutants is an international environmental treaty, signed in 2001 and effective from May 2004, that aims to eliminate or restrict the production and use of persistent organic pollutants (POPs).
Montreal Protocol, Kyoto Protocol and Vienna Protocol are international treaties signed to protect the ozone layer.

The major greenhouse gases are water vapour, which causes about 36 - 70% of the greenhouse effect (excluding clouds); carbon dioxide (CO₂), which causes 9 - 26%; methane (CH₄), which causes 4 - 9%; and ozone, which causes 3 - 7%.

The biosphere is the largest organisational grouping in ecology. It includes every place where life is found on the earth. A population is all of one species in one area at one time, a community is all of the species in one area at one time and a biome is a specific climactic community established by the climate, which controls the plants living there, which in turn, control the animals living there.

In ecology, a biome is a major regional group of distinctive plant and animal communities best adapted to the region's physical natural environment, latitude, altitude and terrain. A biome is made up of communities at stable steady state and all associated transitional, disturbed, or degraded, vegetation, fauna and soils, but can often be identified by the climax vegetation type.
A fundamental classification of biomes is into:
Terrestrial (or continental) biomes, and Aquatic biomes.
The criteria used for classification of biomes are:

1. Availability of soil
2. Availability of water
3. Availability of vegetation cover

Nitrous oxide traps heat about 300 times more effectively than carbon dioxide and can stay in the atmosphere for a century.
One molecule of methane is 20 times more efficient at trapping infrared radiation radiated from the Earth’s surface than a molecule of carbon dioxide.

All the above given statements are perfectly correct.
Use of a series of mirrors is indispensable for harnessing solar power.
Solar energy can be tapped for generating electricity, heating homes, providing hot water, etc.
Wind mills have been used by man for grinding food grains.
Geothermal energy can be used for generation of electricity.

The trophic level of an organism is the position it occupies in the food chain. Green plants make up the first trophic level and are known as primary producers. Plants are able to convert energy from the sun into food through a process known as photosynthesis. In the second trophic level, the primary consumers - known as herbivores - are animals and insects that obtain their energy solely by eating the green plants. The third trophic level is composed of the secondary consumers, flesh-eating or carnivorous animals that feed on herbivores. At the fourth level are the tertiary consumers, carnivores that feed on other carnivores. Finally, the fifth trophic level consists of the decomposers, organisms such as fungi and bacteria that break down dead or dying matter into nutrients that can be used again.

United Nations Environment Programme is headquartered at Nairobi, Kenya.

Nitrogen fixation is a process by which nitrogen (N₂) in the atmosphere is converted into ammonia (NH₃).
Nitrogen fixation, natural and synthetic, is essential for all forms of life because nitrogen is required to biosynthesize basic building blocks of plants, animals and other life forms, e.g. nucleotides for DNA, RNA and amino acids for proteins.
Nitrogen fixation also refers to other biological conversions of nitrogen, such as its conversion to nitrogen dioxide.
Biological nitrogen fixation (BNF) occurs when atmospheric nitrogen is converted to ammonia by an enzyme called nitrogenase.

Nitrogen fixation is a process by which nitrogen (N₂) in the atmosphere is converted into ammonia (NH₃).
Nitrogen fixation also refers to other biological conversions of nitrogen. Biological nitrogen fixation (BNF) occurs when atmospheric nitrogen is converted to ammonia by an enzyme called nitrogenase.
All the given microorganisms can fix atmospheric nitrogen.