Spread cultural traits because they bring cultural traditions with them to their new homeland.
a. traders
b. explorers
c. migrants
d. native americans

burning of wood and coal

explanation:

the panel also concluded there's a better than 95 percent probability that human-produced greenhouse gases such as carbon dioxide, methane and nitrous oxide have caused much of the observed increase in earth's temperatures over the past 50 years.

genetic variation will increase because of a new habitat and food source.

explanation:

burning fossil fouls really decrease the carbon in the atmosphere so b