The most densely populated city in India is

How can global warming be controlled?

Choose the correct option for the following sentences:
$(1)$ Reducing deforestation
$(2)$ Reducing the use of fossil fuels
$(3)$ Planting trees
$(4)$ Slowing down the growth of the human population.

Which of the following is of more immediate concern regarding the carbon cycle?

The quantity of $CO_2$ in the atmosphere is about (in $\%$)

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