In a lake polluted with pesticides, water fowls will contain the maximum amount of pesticides. Waterfowl are members of the family Anatidae. They are strong swimmers with medium to large bodies. They have historically been an important food source, and continue to be hunted as game, or raised as poultry for meat and eggs. 

Smog is fog + smoke. 

A natural phenomenon that becomes harmful due to pollution is greenhouse effect. 

Abiotic factors describe factors like moisture, oxygen, carbon dioxide, light, and minerals that are needed by a plant for survival. Abiotic factors are non-living chemical and physical factors in the environment, which affect ecosystems. It explains such factors needed for the plant survival. 

Primary reason for targeting 'biodiversity hotspots' for conservation is the number of species threatened far exceeds our capacity to protect them and we can, therefore, only concentrate on areas of highest species diversity. The biodiversity hotspots hold especially high numbers of endemic species, yet their combined area of remaining habitat covers only 2.3 percent of the Earth's land surface. Each hotspot faces extreme threats and has already lost at least 70 percent of its original natural vegetation. Over 50 percent of the world's plant species and 42 percent of all terrestrial vertebrate species are endemic to the 34 biodiversity hotspots. 

A common disease which develops among the coal mine workers is silicosis. Exposure to coal mine dust and crystalline silica results in pneumoconiosis with initiation and progression of pulmonary fibrosis.

The Carnivores is a biotic factor directly operating in an ecosystem. A carnivore meaning 'meat eater' is an organism that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of animal tissue, whether through predation or scavenging. 

Helium is not a major greenhouse gas. It is a greenhouse gas because it can absorb and re-emit the Sun's energy, but it is not a major greenhouse gas. 

Trapping of sun rays by the atmosphere causes greenhouse effect. A greenhouse gas is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. 

Many scientists believe that the greenhouse effect is predominantly the result of using large amounts of gasoline, oil and coal in developed nations. The use of these products releases carbon dioxide, which is believed to destroy the ozone layer, which protects Earth from harmful solar radiation. 

One third of land surface is used for agriculture and grazing by the world's 6 billion people. This method of raising livestock is known as intensive rotational grazing or management-intensive grazing. It may be a very non-productive method but it reduces pollution, improves water quality and reduces erosion. 

North America is the largest source of carbon dioxide emissions from the burning of fossil fuels.  North America’s 3,000 fossil fuel-burning power plants continue to produce two-thirds of the region’s electricity and, at the same time, generate the majority of certain harmful air pollutants and emit more greenhouse gases than any other industrial sector. 

Common cold is not caused by air pollution. Some of the causes of common cold are transmission of common cold viruses via airborne droplets, i.e. aerosols, direct contact with infected nasal secretions or contaminated objects. 

The amount of carbon dioxide in the atmosphere has increased in recent years. Environmentalists suggest this change is a direct result of the overcutting of forests and the increased use of fossil fuels. Deforestation and the use of fossil fuels are both suspected of increasing the amount of carbon dioxide in the atmosphere. This is of worldwide concern because of its potential effects on the environment, such as global warming due to the weakening of the ozone layer which protects the earth from harmful solar radiation. 

The age of earth is estimated to be 4.5 billion years. This age is based on evidence from radiometric age dating of meteorite material and is consistent with the ages of the oldest-known terrestrial and lunar samples. 

Man made pollution is causing the increase in temperatures being observed around the world. Man made pollution causes causes acid rain, ozone problems, and global warming. And these are the main reasons for increase in temperatures around the world. 

The centre of a cyclone is known as Eye of the storm. Eye of the Storm refers to a region of mostly calm weather found at the center of strong tropical cyclones. 

The percentage of carbon dioxide in the atmosphere is .03% .04%. In 2009, the CO₂ global average concentration in Earth's atmosphere was about 0.0387% by volume, or 387 parts per million by volume. 

The swift movement of falling water droplets along with the rising air that creates lightning and sound is called thunderstorm. A thunderstorm is also known as an electrical storm, a lightning storm, thundershower which  is a form of weather characterized by the presence of lightning and its acoustic effect on the Earth's atmosphere known as thunder. 

Ozone gas absorbs ultra-violet radiation. It absorbs ultraviolet rays from the sun. Ozone is capable of absorbing infrared radiation coming from the planet and releases it during the evening hours. It is a greenhouse gas. 

Carnivores are totally dependent upon other animals for their food. Carnivorous animals are meat-eaters, meaning that they only eat other animals in order to get their nutrition. Carnivores usually have sharp teeth and strong jaws, which they need to successfully, catch and eat their prey. Lions, crocodiles, sharks, otters and weasels are all carnivorous animals.

Rising global temperatures will lead to regional climatic changes and a rise in sea level. Global warming is the rise in the average temperature of Earth's atmosphere and oceans since the late 19th century, and its projected continuation. 

The percentage of oxygen in the atmosphere is 21%. The atmosphere of Earth is a layer of gases surrounding the planet Earth that is retained by Earth's gravity. Even if the atmosphere today has only 21 percent oxygen, today is still regarded as a period with rapid development of animals because of a high amount of oxygen in the atmosphere. 

Reduce, reuse and recycle is the mantra to help conserve water. The water waste hierarchy refers to the three R's of reduce, reuse and recycle which classify water waste management strategies according to their desirability. 

All of Earth's water, land, and atmosphere wherein life exists are called the biosphere. The biosphere is the global sum of all ecosystems. It can also be called the zone of life on Earth, a closed and self-regulating system.