Burning of fossil fuels is the main cause of increasing carbondioxide concentration in the environment which results in air pollution. This increase in carbondioxide concentration absorbed more heat energy from reflected solar radiation which increases the temperature of earth surface causes global warming. Due to this global warming, snow melting occurs on the poles of the earth which increases sea level.
An environment high in carbon dioxide and high in oxygen induce oxygen to bind to hemoglobin. Another factors are an environment under high pressure and an environment under low pressure.
