Final answer:
True. Environmental issues have undergone changes since the 1970s.
Step-by-step explanation:
True.
The environmental issues and concerns have indeed undergone changes since the 1970s. In the 1950s and 1960s, there was a growing awareness about environmental problems, such as pollution, deforestation, and climate change. This led to the rise of the modern environmental movement in the 1970s, with organizations and activists advocating for environmental preservation and protection. Since then, international agreements, such as the 2015 Paris Agreement, have been made to address these issues.