Hellmann was one of the first to identify that living with climate change is "just as crucial to the future of humanity and Earth’s ecosystems as slowing and stopping greenhouse gas emissions".

[3] Hellmann has said she chose a career in ecology after being inspired by space camp, her grandfather's farm and her father who worked as a mechanical engineer at General Motors.

[17] She delivered the 2012 Reilly Forum Lecture, "Fixing the global commons: what humans can and should do to help nature live and thrive through climate change".

[20][21] She was worried about being labelled a "butterfly person", as she studied them extensively as proxy for how climate change impacts insects in general.

[12] In 2015, Hellmann joined the University of Minnesota as the director of the Institute on the Environment.,[22] where she delivered a keynote talk, "Can we save biodiversity from climate change?

[26] She is on the Board of Directors of the Great Plains Institute, the Science Advisory Council for the Environmental Law and Policy Center and the governing committee of the Natural Capital Planet.

[36] Hellman regularly contributes to the following scientific journals: Proceedings of the National Academy of Sciences, Frontiers in Ecology and the Environment, BioScience and PLOS ONE.

She serves on the editorial board of the journal Evolutionary Applications and is an associate editor with both Conservation Biology and Elementa.