At 5pm on the dot, we’ll all be setting off the alarms on our smartphones or tablets to send a signal: it’s time for Congress to wake up and take action on climate change,” according to Whitehouse’s website. “If you can’t be here in person, you can participate from home by setting your own alarm, and by tweeting along at #SoundTheAlarm4Climate.”

He and Boxer will be leading an event inside Congress at 5pm to “bring climate change to center stage in our country.” You can follow it on Twitter using the hashtag #SoundtheAlarm4Climate. And Whitehouse is livestreaming the event on his website here.