Minister for Forest C P Yogeshwar told reporters here that though the state had opposed the proposal, the Centre has gone ahead with the notification.
Development efforts will be hit if these places were declared as world heritage spots and people living there would face hardship, he said.
Yogeshwar said he would discuss the issue with the Chief Minister later in the day.
BJP MLA D N Jeevaraj, who hails from Chikmagalur district, located in the Malnad region of the state, which passes through the western ghats, also opposed the UNESCO decision.
The state had last year written to the Centre that the spots falling in western ghats in Karnataka should not be declared as heritage centres.
UNESCO's World Heritage Committee included India's 1600-km Western Ghats mountain chain in its list of world heritage sites recently for being one of the eight "hottest hotspots" of biological diversity.
