Question

In the absence of greenhouse gases, the temperature of earth's surface will fall to

• A. $0^o$C
• B. $-5^o$C
• C. $-{10}^o$C
• D. $-{20}^o$C

Answer 1

The correct option is D $-{20}^o$C

Without the Greenhouse gases, the average temperature of earth would be 0${}^o$ F or -20${}^o$ C. The naturally present Greenhouse gases allow most of the incoming solar radiations to warm the earth surface and do not let the thermal radiations to escape into the space. However, anthropogenic contribution to the Greenhouse gases increase the level of solar radiations trapped and thus increase the overall temperature leading to global warming.

Hence, the correct answer is '-20${}^o$ C'.