Task 1：
About air pollution
Name: Air Protection Society

Task 2:
Question we are interested in:
(1) How many kinds of air pollution are there?
Aerosol(气溶胶) polluton like PM2.5 and some gas pollotion mainly including nitrogen, sulfur and carbon.
(2) What are the main reason of air pollution? Are they all caused by human activities?
They are not all caused by humans. Some caused by volcano eruption and forest fire. Human produce air pollution mainly by burning fuel, factory emissions, transportation emissions and some agricultural activities. According to some research, in some cases, natural emissions are more than human emissions.
(3) How the air pollution affect our world and how the effect come back to humans?
Some air pollution can reduce the sunlight arriving Earth and add the ammount of downward atmospheric radiation(大气逆辐射), which reduce the gap of temperature between the night and the day. It can also affect the environment and climate by other ways, like river drying up, forest reduction, animal extinction, ozone layer(臭氧层) destruction, greenhouse effect, acid rain.
It can also affect people's health. Like PM2.5, it can lead to some breathing illness.

Posible sollutions:
(1) Green travel.
(2) Reducing the use of some fuels like coals.
(3) Factory handle their pollution well.
(4) Some government policy.
(5) Call on people to protect the environment.