As we learned from the first Earth Day, the answer to that question may well depend on citizen action; when enough people make their voices heard, policymakers listen.

In 1970, as a 26 year-old, I joined in the effort in my home state of Massachusetts to organize for Earth Day. But what made the event so successful was that I was only one of about 20 million Americans of all ages and backgrounds who got involved. Congress even adjourned so that its members could attend rallies, “teach-ins” and marches in communities from coast to coast.

The result was a force that no American politician could ignore. Within months, President Nixon announced the creation of the U.S. Environmental Protection Agency. Congress followed quickly with landmark legislation to protect air quality and our threatened coasts.

Today, we need a similar effort, but on a global level.