Question

The ozone layer reduces due to co2 and that is produced more due to human activities and with motorcars and bikes . Then why do the poles have a bigger hole than any other place were there are no motorcars or bikes which produce gas

Answer 1

Ozone depletion is due to chlorofluorocarbons (CFCs) in the stratosphere above the Antarctica and to some degree the Arctic. Under the right conditions, CFCs can undergo a reaction that releases chlorine ions, which break up ozone molecules. For a couple of reasons, this is most dramatically observed above Antarctica:

Meteorologically, the atmosphere above Antarctica is largely isolated from the rest of the world, a phenomenon called the 'polar vortex.' It’s essentially a persistent, giant cyclone over the Antarctic continent. Therefore, the loss of ozone there isn't replaced quickly with influx from the surrounding atmosphere.The reaction that breaks CFCs up to release chlorine ions occurs under very, very cold conditions and when high energy (ultraviolet) photons are present. During the winter in the Antarctica, the stratosphere becomes cold enough for the reaction to occur and in the early spring when the stratosphere starts to receive sunlight again, UV light causes the reaction.

Another phenomenon of the Antarctica stratosphere, and sometimes the Arctic stratosphere, is that it becomes cold enough for ice to crystallize out (approximately -80 degrees), creating polar stratospheric clouds (PSCs). Reactions on these ice crystals speed up the chlorine ion production which depletes the ozone faster, so there is a correlation between PCSs and ozone depletion thus PSC monitoring is part of the data collected when assessing ozone depletion.

CFCs are everywhere in the atmosphere and ozone depletion due to CFCs occurs worldwide, but in the Antarctic and Arctic, where the stratosphere becomes cold enough for PSCs, ozone depletion is most severe.

Also If you rotate the globe to the north and south poles you can see that at all times there are a ring of weather systems around the south pole, isolating it, while no such thing exists around the north pole.