Unlike bryophytes, ferns a. utilize photosynthesis. b. have vascular tissue. c. exhibit alternation of generations. d. have to get water from the environment

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.