In 2020, Hansen had his election results challenged, but a judge dismissed the case for failing to state a claim and lack of subject-matter jurisdiction.

[20][21][22] Hansen has pushed for increasing state funding to deal with invasive species such as emerald ash borer, and restoration programs for wildlife habitats and wetlands.

[29][30][31] Hansen supports increased research into sources of pollinator decline, especially due to neonicotinoid chemical pesticides and their use in the agricultural industry.

[32][33][34] In 2019, Hansen authored a bill that designated the native rusty patched bumblebee as Minnesota's state bee, providing it with endangered species protections.

[39] Hansen supported the Minnesota Department of Agriculture's decision to ban chlorpyrifos pesticides in 2021 after it was found to pose risks to children and fetuses.

[40] Hansen, a hunter, has sponsored legislation to deal with the spread of chronic wasting disease in Minnesota's wild and farmed deer populations.

[44] He has been critical of Minnesota's Board of Animal Health, saying it was failing in its oversight of the state's deer farms, calling for a legislative audit, and accusing it of regulatory capture.

[50][13][51] Hansen supported Governor Mark Dayton's efforts to establish buffer strips between farmland and waterways to protect from agricultural runoff.

[55][56] Hansen, a member of the Legislative-Citizen Commission on Minnesota Resources, has opposed efforts by Republicans to use that funding to include local wastewater treatment projects.

[57] He has drafted legislation to clean up Saint Paul's Pig's Eye Regional Park of harmful contaminants due to a nearby landfill, and supported using solar panels and wind turbines at wastewater treatment plants.

[70] Hansen has supported grants included in the 2020 Tax Bill to help meat processing plants in his district of South St. Paul relocate and grow.