What is the year associated with the Chipko movement?

Assertion : The concentration of methane in the atmosphere has more than doubled in the last $250$ years.
Reason : Wetlands and rice fields are the major sources of methane.

Eutrophication is caused by

The limit of $BOD$ prescribed by the Central Pollution Control Board $(CPCB)$ for the discharge of industrial and municipal wastewater into natural surface waters is

During the past century,the temperature of the Earth has increased by: (in $^{\circ}C$)

What did Chernobyl,Three Mile Island,the Love Canal,and Bhopal,India all have in common?