Question

Match the columns and choose the correct combination.

	I		II
a	$C{O}_2$	$1$.	$292$ ppt
b	$C{H}_4$	$2$.	$316$ ppb
c	$N_{2}O$	$3$.	$368$ ppm
d	$CFC+HFC$	$4$.	$1750$ ppb

• A. a-$3$, b-$4$, c-$2$, d-$1$
• B. a-$1$, b-$4$, c-$2$, d-$3$
• C. a-$4$, b-$3$, c-$2$, d-$1$
• D. a-$2$, b-$3$, c-$4$, c-$1$
• E. a-$1$, b-$2$, c-$3$, d-$4$

Answer 1

The correct option is A a-$3$, b-$4$, c-$2$, d-$1$

• Various reports have mentioned that the atmospheric CO2 concentrations have increased from around 280 ppm to 368 ppm over the past 200 years, contributing up to 50% to the global temperature increase known as greenhouse effects.
• Globally averaged concentration of methane in Earth's atmosphere increased by about 150 percent from 722 ± 25 ppb in 1750 to 1803.2 ± 1.2 ppb in 2011.
• The concentration of nitrous oxide in the atmosphere has increased from about 270 ppb in pre-industrial time (i e., 1750 AD.) to about 316 ppb (parts per billion) in year 2000 AD.

So, the correct answer is 'A'.