(CNN) -- It's that time of year when colleges around the country show off the people who will offer the last lesson to soon-to-be graduates: the commencement speakers.
This year, some universities drew on famous alumni: The University of New Hampshire featured 1992 New Hampshire graduate Jennifer Lee, the Oscar-winning screenwriter and director of Disney's hit film "Frozen." Shonda Rhimes, creator of "Grey's Anatomy" and "Scandal," told graduates of her alma mater, Dartmouth College, that it's impossible to do it all, but it's still worth doing as much as they can.
"Volunteer some hours. Focus on something outside yourself. Devote a slice of your energies towards making the world suck less every week," Rhimes said. "Some people suggest doing this will increase your sense of well-being. Some say it's good karma. I say that it will allow you to remember that, whether you are a legacy or the first in your family to go to college, the air you are breathing right now is rare air. Appreciate it."
Other schools competed for high-profile speakers like President Barack Obama, who spoke at University of California-Irvine in June after receiving 10,000 postcards from the community asking him to attend. First lady Michelle Obama spoke at Dillard University in New Orleans, as well as a high school senior recognition ceremony in Topeka, Kansas, and a college access program in Washington.
President Obama used part of his speech at University of California-Irvine to address climate change, calling lawmakers and pundits who deny manmade climate change a "fairly serious threat to everybody's future."
"Progress won't always be flashy. It will be measured in disasters averted, and lives saved, and a planet preserved -- and days just like this one, 20 years from now, and 50 years from now, and 100 years from now," he said. "But can you imagine a more worthy goal -- a more worthy legacy -- than protecting the world we leave to our children?"
The gallery above shows some high-profile commencement speakers that grads are hearing from this spring.