Identify which of the following statements about the environmental movement in the 20th century are correct:
I. The Silent Spring by Rachel Carson, published in 1962, helped launch the modern environmental movement. 
II. The first Earth Day was held in 1970, primarily in the United States to raise awareness about environmental issues. 
III. The Montreal Protocol was signed in 1989 to address the issue of global warming by reducing carbon emissions. 

Statements I and II are correct. Rachel Carson's Silent Spring played a pivotal role in raising awareness about environmental degradation, particularly concerning pesticide use, helping to spark the modern environmental movement. The first Earth Day, indeed held in 1970, significantly increased environmental awareness. However, statement III is incorrect as the Montreal Protocol was actually aimed at addressing the depletion of the ozone layer, not global warming.