The increased use of wind turbines and solar
collectors to generate electric power will
(1) negatively affect ecosystems by increasing
biodiversity
(2) negatively alter the chemical composition of
soil and water
(3) reduce the amount of pollution that comes
from the burning of fossil fuels
(4) increase oil consumption for business and
industry

It is number 3 since wind turbines are used to replace chemical energy which causes carbon to be released into the atmosphere

I think that it is 4.5 million years. It does not end there though because other people would just say it and go. The reason we know this is because there is some people who lose teeth in those areas when mankind started then they took it to a lab and they found their results after continuous testing.