Which of the following conferences obtained commitments from different countries for reducing overall greenhouse gas emissions to a level $5\%$ below $1990$ levels by $2008-2012$?

In which year was the Joint Forest Management $(JFM)$ scheme introduced in India?

What is the raw material for polyblend?

Match the following columns:

Column-$I$	Column-$II$
$(a)$ Biomagnification	$(1)$ Nitrates and Phosphates
$(b)$ Eutrophication	$(2)$ Chlorine
$(c)$ Global warming	$(3)$ $DDT$
$(d)$ Ozone depletion	$(4)$ Greenhouse gases

In this soil conservation method,several grasses are left out in the soil after the crop is harvested.

$A$ large number of fish suddenly die in a lake near a village. Which of the following could be the reason for this?
$(a)$ Excessive use of urea and phosphate fertilizers in nearby fields.
$(b)$ Spraying of $DDT$ in the entire area.
$(c)$ The lake water has turned green and murky.
$(d)$ The population of phytoplankton in the lake has decreased,reducing the photosynthetic capacity.
Which two of the above reasons are responsible?