In 1984, I headed off to Berkeley – a hot bed of activism. Not to demonstrate or protest, but to study applied math and physics among some of the world’s leading experts.

Ironically that path turned out to be the one that led me to become a combatant in a fierce political fight.

I went on to study physics in graduate school and then into climate research. My path of discovery led me to publish the now iconic “Hockey Stick” graph two decades ago, on Apr 22 (“Earth Day”) 1998.

The “Hockey Stick” tells a visual story that the current warming spike is unprecedented as far back as we can go. Our continued burning of fossil fuels is the culprit. Fossil fuel interests who find this message inconvenient, along with front groups and politicians doing their bidding, attacked it—and me.

I was initially reluctant to be at the center of the fractious public debate over human-caused climate change. But I ultimately came to embrace that role. I’ve become convinced there’s no more noble pursuit than seeking to ensure that policy is informed by an objective assessment of scientific evidence.

So, while I continue to do scientific research, I spend much of my time these days communicating the reality and threat of climate change to the public and to our policymakers.

Unfortunately, my efforts and those of other scientists and communicators have not been sufficient. This past summer we saw the true face of climate change, as unprecedented extreme weather events made worse by climate change—floods, droughts, heat waves and wildfires—wreaked havoc across the Northern Hemisphere. We witnessed, in real time, the devastation wrought by heat waves in Europe and the U.S., record flooding in Japan. In California, heat and drought combined to yield unprecedented wildfire.

Climate scientists like myself predicted decades ago that this is what we would see if we didn’t act. And now our predictions are coming true because politicians have NOT acted to the extent necessary. Too often our politicians do the bidding of powerful vested interests rather than what is in our interest.

As a result, we are still continuing to pollute the atmosphere with billions of tons of carbon pollution every year from the burning of fossil fuels—oil, coal, natural gas. Yet we can still prevent the worst impacts of climate change if we act now. We must rapidly transition away from fossil fuels toward renewable energy if we are to avert truly catastrophic climate change. We need policymakers who will supports measures to incentivize clean energy and put a price on the emission of carbon pollution.

So what can college students do today? I think back to my first semester at UC Berkeley in Fall 1984. I was not politically active in high school. And my choice to go to UC Berkeley had nothing to do with its legacy as a fount of political activism, that is, the key role it played in the protests of McCarthyism in the ‘40s/’50s, the civil rights and free speech movements in the ‘60s, and the Vietnam War protests in the late ‘60s and early ‘70s. It had much more to do with the 11 Nobel Prize-winning science faculty the institution boasted, and the knowledge that I had an opportunity to learn from some of the world’s leading scientists.

The mid 1980s marked the “Reagan Revolution”. In Fall 1984 I witnessed the Berkeley College Republicans march triumphantly across campus the night that Ronald Reagan was elected to his second term as president. Complacency had replaced activism even at Berkeley.

But college activism wasn’t dead. It was simply dormant. A nascent movement– the Anti-Apartheid movement opposing the South African apartheid system discriminating against non-whites—was brewing and soon bubbled over in 1985. Students demanded that their universities divest of holdings in companies doing business with the discriminatory government of South Africa. In July of 1986, the UC Regents voted to divest $3.1 billion from companies doing business with the apartheid government, the largest university divestment in the country.

Students at Berkeley—and all across the nation—had not only found their voice again but used it—to change the world. We are seeing a reawakening of student involvement and activism not unlike that I witnessed back in my days at UC Berkeley. Today’s students, too, are finding their voice and changing the world—in a positive way.

The fossil fuel divestment movement asks colleges, universities and other institutions to divest of holdings in fossil fuel companies who, like Tobacco companies in the past, have used their immense wealth and power to poison the public dialogue when it comes to the problems created by their product—in this case, fossil fuels and dangerous planetary warming. Spearheaded by Bill McKibben’s organization 350.org, the divestment campaign has spread across college campuses. More than $6 Trillion dollars in holdings have been pulled out by nearly a thousand institutions and more than 50,000 people.

Students are making their voices heard.

And there are many other ways to make your voice heard: writing about the climate crisis, talking with your friends and family, supporting organizations focused on climate action. And then there is voting.

My first semester at UC Berkeley was the first election I was able to vote in. My preferred presidential candidate did not win, but it was empowering nonetheless. I felt the agency of directly participating in the political process. ­You all have the same opportunity this Fall.

If you do not like the direction that we are headed, with a president and congress that is seeking to overturn a half century of environmental protections and scuttle international cooperation in acting on climate change, then you can communicate your dissatisfaction with your vote. It is not an exaggeration to say that the mid-term election this November may determine the future course of climate action.

You have an opportunity to, as my friend Bill Nye says, change the world.

Do it, my friends

About the Author:

Dr. Michael E. Mann is Distinguished Professor of Atmospheric Science at Penn State University, with joint appointments in the Department of Geosciences and the Earth and Environmental Systems Institute (EESI). He is also director of the Penn State Earth System Science Center (ESSC). Dr. Mann received his undergraduate degrees in Physics and Applied Math from the University of California at Berkeley, an M.S. degree in Physics from Yale University, and a Ph.D. in Geology & Geophysics from Yale University. His research involves the use of theoretical models and observational data to better understand Earth’s climate system. He is the recipient of numerous awards and accolades including the Hans Oeschger Medal of the EGU, the National Conservation Achievement Award of the National Wildlife Foundation, the Friend of the Planet Award from the NCSE, and the Stephen H. Schneider Award for Outstanding Climate Science Communication. He made Bloomberg News‘ list of fifty most influential people in 2013. He has authored more than 200 publications, and four books including Dire Predictions, The Hockey Stick and the Climate Wars, The Madhouse Effect, and The Tantrum that Saved the World.