How have approaches to environmental issues changed over the years?

Over the years, greater controversy has arisen over environmental issues as the issues addressed have become more complex and less easily identifiable.

the answer is 1. photosynthesis. glad to

for  example, forests have higher evapotranspiration than other ecosystems,  such  as grasslands, because of their deeper roots and greater leaf area. thus forests have a net moistening effect on the atmosphere and become a moisture source for downwind ecosystems.