Green house gases – are those gases which allow short wave radiations to pass through but absorb long wave heat radiations:
eg: CO2, CH2, N2O, CFCs.
They cause green house effect and increases surface temperature making earth. Sustainable or life
Question Downward flux of long waves by green house gases is called green house reflux. It keep earth warm at 15°C, without it earths temperature would dropto-18°C.
But enhanced green house effect causes global warning that is leading to deleterious changes in environment and resulting in odd climate changes.
(b) Catalytic Converter :
It is a method to reduce emissions from automobiles. The device has a platinum – palladium and Rhodium as catalyst. Exhaust emissions passes through it; nitric oxide splits into nitrogen and oxygen, Carbon monoxide into carbon dioxide, unburned hydrocarbons get burned to form CO2 and H2O. It is useful only is unleaded petrol because lead inactivates catalyst of the convertor.
(c) Ultraviolet B (UVB) –
They normally do not reach earth surface as ozone layer reflects it back. But due to ozone hole, UVB reaches earth surface these days.
They cause:
- Skin cancer
- Blinding – Corneal damage .
- Immune system is partially suppressed
- Larval stages die
- Photosynthesis – is impaired so crop yield falls.
- Nucleic acids – Mutations
- Phytoplankton – their function is disturbed so productivity falls.
- Global warning.
