The Chipko movement was successfully launched by

Soil conservation is a practice in which soil:

Inhabitants living close to very busy airports are likely to experience health hazards.

Contour farming is usually employed in

Assertion : Methane,a component of greenhouse gases,contributes about $20$ percent to global warming.
Reason : The introduction of multi-point fuel injection engines in automobiles has decreased methane content in the exhausts.

Increase in the percentage of fauna and decrease in flora may be dangerous because it enhances