The $CO_2$ content of the atmosphere has increased in the last $150$ years from:

Match the columns :

Column - $I$	Column - $II$
$(1)$ Nitrous oxide	$(a)$ Secondary pollutant from car exhaust.
$(2)$ Chlorofluorocarbons	$(b)$ Combustion of fossil fuels,wood etc.
$(3)$ Methane	$(c)$ Denitrification
$(4)$ Ozone	$(d)$ Refrigerators,aerosols,sprays
$(5)$ Carbon dioxide	$(e)$ Cattle,rice fields,toilets

The Wildlife Protection Act was introduced in:

Write critical notes on the following:
$(a)$ Eutrophication
$(b)$ Biomagnification
$(c)$ Groundwater depletion and ways for its replenishment

Match the following important dates/events related to environmental issues in India:
$A$. $2002$
$B$. $1$ April $2005$
$I$. Bharat Stage $II$ applicable to all automobiles in the country.
$II$. All buses of Delhi were converted to run on $CNG$.

The Chernobyl tragedy occurred in