America must lead the world in addressing the threat of climate change ("Climate change warnings," June 12). This is why Maryland Senators Ben Cardin and Barbara Mikulski must join Vermont Senator Bernie Sanders and California Senator Barbara Boxer to work for the passage of the Climate Protection Act of 2013, which will put a price on carbon and shift the United States away from dirty energy and toward clean power. This landmark legislation will send a clear signal to the rest of the world that the United States is willing to back up its rhetoric with firm action when it comes to reducing carbon emissions.

We must make sure that the Climate Protection Act of 2013 becomes law. The fate of present generations — not just future generations — depends on it.

D. R. Tucker, Brockton, Mass.