Edward Norton appeared on the Today Show this morning to push tomorrow’s world-wide switch-off, Earth Hour. For one hour, people will make a statement that something needs to be done about climate change and that it is an issue worthy of world-wide recognition. Thus, millions of people across the globe will turn out their lights to raise awareness.

The purpose for the one-hour switch-off slated for March 28, from 8:30 to 9:30 p.m. local time, is to make a global statement of concern about climate change and to demonstrate commitment to finding solutions.

And the cause is gaining momentum. A total of 175 U.S. cities have now pledged to turn off their lights during the hour. National landmarks like the Empire State Building and many of Washington D.C.’s most notable buildings will go dark.

D.C.’s District Environment Director George Hawkins said Earth Hour was “a symbolic but important step in showing the world we’re serious about the climate.”