Since 2009, the Academic Ranking of World Universities (ARWU), called the Shanghai Ranking, has published rankings in various academic subjects; this year's ranking comprises 54 subjects and more than 4,000 universities. Stockholm University is among the top 50 in the world in six subjects:
Geography (9)
Atmospheric Science (23)
Environmental Sciences & engineering (23)
Sociology (30)
Ecology (31), where the Swedish University of Agricultural Sciences is the best in Sweden in place six.
Oceanography (45)

The Shanghai Ranking is based, among other things, on research productivity, research quality and extent of international collaboration.
More about the 2019 subject ranking according to the Academic Ranking of World Universities (ARWU)