52. NCERT Exemplar XXXIV

 

In the presence of sunlight, green plants convert carbon dioxide to fractoseglucosesucroselactose through photosynthesis, which is a food for plants and is then stored as starch. As a result, plants require carbon dioxide and fix it on a regular basis.

$CO_2$ is considered a pollutant because of its increased concentration in recent years. Due to the burning of liquid fuelsgaseous fuelssolid fuelsfossil fuels, deforestation and other human activities, large amounts of $CO_2$ and other greenhouse gases are released into the environment. These increased greenhouse gases trap the heat reflected by the earth. This heats up the atmosphere, which further leads to an increase in the earth’s average temperature. This phenomenon is called global warningglobal warmingglobal pollution.

 

Some of the harmful effects of global warming are:

(i). Increase in the temperature of the earth can lead to the melting of polar ice caps. This will result in a rise in the sea level, due to which forest regionsmidwest regionscoastal regions will be flooded or might even be submerged.

(ii). Increase in the temperaturepressurevolume of the earth due to the greenhouse effect will result in changes in weather and precipitation patterns.