The "CampusGarten"is a student project of the AStA's sustainability department, which has been set up in Haarentor on the grounds between buildings A10 and A07. Once a week, a group of students comes together here to garden together. The university supports the project not only with the space, but also financially. In return, it is permanently accompanied by a course.

Various nesting boxes hang on the university's sites to provide birds with a place to nest. For example, swifts or starlings find a home at Oldenburg University during the breeding season. A nesting box for kestrels has been hanging on the NeSSy research building since July 2017 - a project that was implemented together with NABU Oldenburger Land.

On 13 and 14 October 2023, a lot of drilling, screwing and shovelling took place in the inner courtyard of building A05. Following an initiative by the "Sustainability Economics and Management" Student Council, the courtyard was made more ecological by building numerous raised beds and planting them with insect-friendly perennials. The Student Council is also responsible for the further maintenance of the beds.

The project was financed by the Department of Economics and Law, with implementation supported by the University of Oldenburg's climate protection management team.

Initiated by the student initiative sneep two ballot bins were installed on the Haarentor campus in April 2019. These oversized ashtrays are intended to help reduce the number of cigarette butts that end up on the ground. The ballot bins are also an opinion monitor that encourages participation. They consist of two separate chambers - each one represents an answer option and has its own hole for voting by butt. The current voting status is visible at first glance, as the front of the bins is transparent.

There are a total of five bee hotels on the Wechloy campus, the Haarentor campus and in the university's Botanical Garden. They are the result of the "BeeScapes" project, which was funded by the European Regional Development Fund and aims to create more diverse habitats for insects and counteract the decline of the six-legged crawlers.

Since December 1, 2022, the Carl von Ossietzky University of Oldenburg has been a founding member of the global network of Nature Positive Universities - a program initiated by the United Nations Environment Programme and the University of Oxford. The University of Oldenburg is thus committed to the great importance of biodiversity and nature conservation and undertakes to take effective measures in this area. The network and the initiative were presented at COP15, the UN Conference on Biodiversity.