One of the factor is the Sun's elevation where the UV reaches us at a much lower frequency when the sun is more distant. Next is our ozone, with our ozone depleting as time goes by, the amount of solar energy it can diffuse is much lesser thus the heat is much more than the previous decades.
Answer:
rain is very important for life in certain areas, this is why you see little life in deserts and even they need rain occasionally. more rain will lead to more life, first, it will be the plants that move in, then once they grow, vegetation eaters will move in, then after that meat-eaters will move in to eat those creatures and the ecosystem will flourish.
Clues such as fossils such as bones, footprints, tar, etc, preserved underground helped inform scientists. You can also count how old a tree is when you cut it open and there are some alive for thousands of years so that is a possible way.
If you can connect air pollution leads to global warming and thus climate change.
So in order to decrease pollution levels
1. Lessen the usage of vehicles (motorised)
2. Industrial waste should be treated properly before releasing into the atmosphere
