On a day in early April, I was filming promotional material in Wheeler Hall for the Cool Campus Challenge, a high-profile competition between UC campuses to reduce our carbon footprints. As I walked down a first-floor hallway, I was popping my head into each classroom. It was 5 p.m. on a Wednesday, the sun was out, and every room was empty. Yet every single room had all of its lights turned on.

While crossing each room to flip the switch, I was troubled wondering exactly how many classrooms and offices at UC Berkeley stand completely empty and fully lit every day. In 2016, the operation of our campus was responsible for 151,650 metric tons of carbon dioxide, and the Office of Sustainability’s greenhouse gas inventories reveal that 75 percent of our emissions are associated with campus building energy use, much of this being lighting, ventilation and heating.

Our collective actions on our campus do not exist in a vacuum. Global climate disruption is impacting the planet in ways never experienced in human history. And in an attempt to do its part to respond to this rising environmental crisis and to lead by example, the University of California has committed to emitting net zero greenhouse gases from its buildings and vehicle fleet by 2025 — something no other major university system has done.

Every UC campus is taking a different approach to reaching carbon neutrality, and each is turning to a diversified portfolio to meet electricity and gas needs — the UC even built a giant solar farm in Central California that services some of the campuses and feeds into the grid as well. UC Berkeley has an extensive plan for expanding the use of low- and non-carbon energy supply for power and thermal needs. These energy supplies include directed biogas, green power options from utilities, on-site solar photovoltaics and other alternatives to natural gas use.

UC Berkeley’s carbon action plan, extensive though it is, focuses on infrastructure changes such as using on-site solar photovoltaics. The trajectories contained therein don’t account for much expectation that there will be reductions in energy demand, i.e., people on campus choosing to use less electricity. In my role as a student Carbon Neutrality Initiative Fellow, I focus on energy efficiency behavior change projects, because reductions can prove themselves an essential part of our 2025 goal.

In April, I ran the Cool Campus Challenge along with CNI Fellow Dante Gonzales, Director of Sustainability Kira Stoll, and a large team of students, engaging 4,331 Bears in carbon-saving pledges over the four-week period. We actually won the challenge, and have decided to reinvest the prize money into further emission reductions with a new behavior change campaign this fall.

Through a project with Stoll starting in August, a new, small sticker is going to be posted on every light switch in every room on campus reminding you to turn the lights off as you exit. To accompany this, the Office of Sustainability and the Student Environmental Resource Center’s Carbon Crew will be creating and aggressively advertising a short educational YouTube series, using a variety of outreach methods such as social media, tabling and faculty outreach to engage students. We really want reducing energy usage to be at the forefront of campus conversation this semester.

The last time the campus offered an energy saving behavior program, it saw a 3 percent reduction in electricity use as a result of people choosing conservation options — what I’m aiming for is a culture change large enough to achieve at least a 10 percent reduction. Over winter break each year, the lighting, ventilation and heating are turned down for about a week and a half. Last year, the campus saved $112,000 during curtailment. As students, why not do our part to make every week curtailment?

So, Bears, all I’m asking you to do is to start turning off lights, computers, projectors and any other electronics when you leave any room (on campus and elsewhere!). Talk to your friends and classmates, share this article, point out the new stickers when you see them, and convince those around you to do the same. Such small actions on your behalf will collectively have a huge impact on the carbon footprint of our campus and will advocate for the responsible use of your tuition money. After all, why should our carelessness have a carbon impact? Who is benefiting from brightly-lit, empty classrooms? Climate action cannot take place if we all continue to wait for the government, big corporations or the university to “do something about it.” It’s time for all of us to stop simply caring and to start moving. Let’s start with the first step: Flip a switch on your way out the door.

Sage Lenier is a rising senior who works for the UC Berkeley Office of Sustainability as a Carbon Neutrality Initiative Fellow.