Known for advocating environmental activism and localism and as a former member of the Tsuen Wan District Council, Tam was charged with in 2021 with subversion in Hong Kong 47 case.

[4][5] Tam, as the President of Green Sense, was well known for several clashes with government on urban planning, including housing development over wetlands,[6] airport expansion,[7] and reclamation.

[11] However, Tam's environmental views was sometimes criticised as radical, such as recommending no escalators in metro stations and calling for boycotting World Wildlife Fund,[12] and was branded by pundit Choy Chi-keung as "environmentalism Taliban" after Tam urged to cancel television programme Hole in the Wall for wasting Styrofoam,[13][14] and by others for his objection to Ice Bucket Challenge.

[15] Tam ran in the 2008 legislative election in Kowloon West constituency under the slogan "vote for a green Hong Kong".

[20] Tam is also a supporter for Taiwan independence to preserve democratic institutions and defend local culture after he described Hong Kong's One Country, Two Systems as a failure.