Ch 16Environmental Issues — Class 12 Biology, concept-first.

Clean air is essential for every living organism, and once it becomes contaminated with pollutants it can injure plants, slow crop growth and yield, and damage the respiratory systems of humans and an…

Delhi has one of the largest vehicle populations of any Indian city — at one point it had more registered vehicles than the states of Gujarat and West Bengal combined — and by the 1990s it ranked amon…

Across the world, human beings have long treated rivers, lakes and other water bodies as convenient places to dispose of waste, on the mistaken assumption that flowing water simply "washes everything…

Wastewater from homes carries away everything we wash down our drains, yet it takes only about 0.1 per cent impurity by mass to make domestic sewage unfit for human use — a striking illustration of ho…

Wastewater treatment does not have to rely purely on engineered, artificial processes — it can also combine artificial treatment with natural, ecosystem-based processes, and the town of Arcata on the…

Solid wastes are, quite simply, everything that ends up in the trash. Municipal solid waste is the waste generated by homes, offices, shops, schools and hospitals that a municipality collects and disp…

A Bangalore-based manufacturer of plastic sacks found a practical answer to the growing problem of plastic waste piling up in the city.

The Green Revolution brought a large rise in the use of inorganic (chemical) fertilisers along with pesticides, herbicides and fungicides, all aimed at boosting crop yields.

Integrated organic farming is a cyclical, essentially zero-waste approach to agriculture, in which the waste generated by one process becomes the input — the nutrient supply — for another.

Nuclear power was originally welcomed as a clean, non-polluting way of generating electricity. Over time, however, two serious problems associated with it became clear: the risk of accidental leakage…

The term borrows its name from an actual greenhouse — a small glass structure used to grow plants, especially through winter.

Ozone formed near the ground, in the troposphere, is a harmful pollutant that damages plants and animals — this is the "bad" ozone studied earlier in chemistry.

Natural resources can be degraded not only by pollution but also simply by using and managing them poorly.

Deforestation is the conversion of forested land into land that no longer carries forest cover. Globally, an estimated 40 per cent of tropical forest has already been lost, compared with only about 1…

People's involvement in forest protection in India has deep historical roots. In 1731, the king of Jodhpur in Rajasthan sent his minister and workers to fell trees near a village inhabited by the Bish…