Question

CO${}_2$ content of atmosphere has increased in the last 150 years from

• A. 25 to 35 ppm
• B. 270 to 340 ppm
• C. 0.027 to 0.34 ppm
• D. 0.2 to 0.3 ppm

Answer 1

Answer: (B)

270 to 340 ppm

Usually, in nature, a constant mineral concentration is maintained due to continuous operation of biogeochemical cycles. The delicate balance of biogeochemical cycles is upset by anthropological activities like mining, industrialization, burning of fossil fuels etc. These activities lead to increased release of carbon dioxide into the atmosphere.

Carbon dioxide concentration was about 270 ppm in 1750 and 340 ppm in 2000. The rise has been due to large scale deforestation (for grazing land, cropland or urban estates), change in land use and large scale combustion of fossil fuels.