The effect of pollution is first and most marked on:

$A$: $El$ $Nino$ is a climatic change which causes deleterious environmental changes.
$R$: Increased tropospheric ozone due to $El$ $Nino$ causes a shift of climatic regions.

When did the worst environmental nuclear power plant accident and the $MIC$ gas tragedy occur,respectively?

The most common pesticide used in India is

Human activities interfere with the carbon cycle. List any two such activities.

The $UN$ Conference of Parties on climate change in the year $2011$ was held in