Thermal power plants can lead to:

Which of the following industries is the best source of increasing $CO$ levels in the atmosphere?

Which of the following molecules is present in photochemical smog?

Which of the following is not a common component of photochemical smog?

When the biosphere becomes an environment useful to humans,what is it called?

Polar stratospheric clouds were observed over Antarctica some time ago. How might they have formed,and what happens if some of these clouds break down due to heat in the presence of sunlight?