SSC Staff Team

The SSC staff team is a small, dedicated group that help to support the programs and campaigns of the Sierra Student Coalition.

Karissa Gerhke

Karissa Gerhke, National Director

Karissa got her start in organizing through attending the SSC’s nationally-recognized summer grassroots leadership training program, called “Sprog”, which gave her the skills to organize a successful green fund campaign for her alma matter, University of South Florida. From there, Karissa went on to organize with the Sierra Club’s Beyond Coal campaign, where she successfully sought to prevent the construction of a proposed coal plant in rural West Texas. Most recently, she served as the Director of Member Engagement at the Progressive Change Campaign Committee (PCCC). At the PCCC, Karissa spearheaded the creation of ads targeting Senator Mitch McConnell and organized thousands of members in priority states on issues such as Social Security expansion and student loan rates. She's excited to bring her digital and electoral chops back to the SSC, and help build youth power for climate justice.
When Karissa isn't organizing, you'll likely find her in the woods, reading a book, or enjoying a cup of yerba mate. (Ideally all three at once.)

Tim Harlan-Marks


Tim Harlan-Marks, Trainings and Leadership Development Director

Tim has been a youth organizer since high school, working with other young people on issues of trade, immigration, human rights, and sustainability. Since graduating from Kalamazoo College in 2007, Tim has organized professionally with the Sierra Club, MPIRG, Transit for Livable Communities, and the Wilder Foundation, most recently winning a campaign against the last coal burning plant in Minneapolis. He is thrilled now to serve in the role of Trainings Director with the SSC, developing the capacity and leadership of the youth climate movement.  When not actively preventing catastrophic climate change Tim sings and plays bass in the Minneapolis music scene with two bands, Very Small Animal, and the Family Trade. Email Tim.


Randy Downs


Randy Downs, Representative 

Randy joins the SSC’s staff team from the ‘Show Me State’ of Missouri. He first got involved with the Sierra Student Coalition in 2005 when he attended his first Sprog. Randy transitioned from attendee to leader, serving volunteer leadership rolls, including: national trainer, Shindiger, and SSC chef. He was a standout within the SSC nation and in 2010 he was awarded the Sierra Student Coalition “Appetite for Change” Chef Award (which is now named after him!). Randy is also passionate about politics. He served in various political capacities including Campaign Manager of the Franklin County (MO) Democratic Party and Campaign manager for state representative candidates and county candidates. His passion also translated to success. In 2004 he was awarded the President’s Service Award and in 2011 was named the "Young Democrat of the Year" by the Missouri Democratic Party. Randy's education exemplifies his diverse talents, he attended East Central Community College in Union, MO then went on to earn a with a Bachelors of Science in Interdisciplinary Studies from Southeast Missouri State University with an emphases in Political Science, Communication, Theater, and Music. On his downtime, Randy enjoys food, running, the outdoors, and playing intramural softball and kickball.


Anaastasia Schemkes


Anastasia Schemkes, Campaigns Representative

Anastasia Schemkes is the national Campaign Representative for the Sierra Student Coalition. She directs Seize the Grid, the SSC’s campaign for 100% clean energy by 2030 on campuses nationwide. With the Sierra Student Coalition, she supported hundreds of students in retiring over half of the nation’s on-campus coal plants and developed the national “Seize the Grid” campaign to continue the essential work of transitioning to clean energy.

Anastasia got her start in organizing while on her own college campus. She knows first-hand the power of young people to transform their communities. She currently manages a growing campaign network of over thirty Seize the Grid campuses, mobilizing young people around clean energy and building the next generation of leaders for energy democracy. 



Rachel Shiozaki, National Online Organizer

Rachel's passion for organizing began after a summer of door-to-door canvassing for Environment California, working to pass AB32 (the California Global Warming Solutions Act of 2006). From there she got involved with many different campus sustainability initiatives including the Green Campus Program (now PowerSave Campus), Education for Sustainability Program (ESLP), and California Student Sustainability Coalition (CSSC). After graduating from UC Santa Cruz with a BA in Environmental Studies, she joined Green Corps, the field school for environmental organizing. During that year, she worked to launch the Sierra Club's and Sierra Student Coalition's Campuses Beyond Coal Campaign at the University of Colorado, Boulder, in addition to running three more campaigns throughout the year for Environment Texas, Corporate Accountability International, and the Fund for the Public Interest. After Green Corps, she worked as an organizing consultant for, Forecast the Facts (now Climate Truth), and yerdle. At yerdle, not only did Rachel get her first taste of start-up and B-Corp culture, but she also got to hone in on her online organizing skills, will working to launch the yerdle app, website, and blog, and manage the online organizing and community team.  


Contact Us

Sierra Student Coalition
50 F Street, NW | 8th Floor
Washington, DC 20001