[1] Following her Ph.D. she joined the United States Geological Survey where she became a scientist emeritus in 2013.
[2] In 2015, Harden was elected a fellow of the American Geophysical Union who cited her "for fundamental contributions to quantitative understanding of soils in global change and carbon cycling".
[10] The connections between fire in boreal forests and carbon is another focus of Harden's research.
[15][16] Harden has also quantified the amount of carbon and nitrogen that would be released under different future climate scenarios from Gelisols, soils impacted by permafrost.
[17][18] Through collaborative research projects, Harden has quantified the amount of soil organic carbon stored in permafrost[19] and the release of this organic carbon under warming climate conditions.