In celebration of Earth Day this coming Sunday, Apple will be hosting two special Today at Apple sessions at their Union Square store in downtown San Francisco.

Apple has a long tradition of raising awareness of environmental issues in the days surrounding Earth Day, and this year is no exception. The first of the two events will be held on April 22nd at 2 PM, where photographer Oscar Nilsson will lead a 1.5-mile photo walk in San Francisco. Apple describes the event in more detail on their reservation page:

Beyond photography, Nilsson’s work extends into short documentary filmmaking and partnerships with other major brands in the creative community like Adobe and 500px. More of Nilsson’s work can be found on his website and Instagram page.

Find the color, even in the dullest of days.

A post shared by Oscar Nilsson • San Francisco (@oscarwastaken) on Dec 17, 2017 at 7:19pm PST

Apple’s second special event will be held four days after Earth Day on April 26th at 6:30 PM. Speaking at the session will be Apple’s VP of environment, policy and social initiatives Lisa Jackson, and National Geographic explorer, filmmaker, and water advocate Alexandra Cousteau. Last year, Jackson and former Vice President Al Gore headlined a similar event in San Francisco for Earth Day. Apple details the one hour session:

Cousteau has been traveling the globe since she was a young child, advocating on the importance of protecting our environment. In 2008, she was honored as a National Geographic Emerging Explorer, and later led Expedition Blue Planet, a series that chronicled the interconnectivity of water.

In addition to the two Today at Apple Events, Apple will once again offer an Activity Challenge for Earth Day, inviting Apple Watch owners to complete a 30-minute workout on April 22nd. Earlier this month, Apple touted that all of their operations now run off 100% renewable energy. If you’re planning to attend either Today at Apple session, sign up is required and space is limited, so you’ll want to act soon.