All C40 member cities have been invited to participate in the C40 Hong Kong workshop on November 5 and 6, Hong Kong's Secretary for the Environment Edward Yau said on Wednesday.

C40 is a group of large cities committed to tackling climate changes. The workshop is jointly organized by the city's Environmental Campaign Committee and Civic Exchange with the Environment Bureau's support, Yau told lawmakers Wednesday, adding that a steering committee has been formed to oversee the preparation work.

Reiterating Hong Kong will follow the national target to cut carbon intensity by 40 percent to 45 percent by 2020, Yau said a consultant will conduct additional modeling work and analysis.

The consultancy recommendations on Hong Kong's action blueprint for dealing with climate change will be made public upon completion of the analysis, Yau noted.

On greenhouse gas emissions, he said the government considers it inappropriate to legislate and stipulate emissions for the two power companies at this stage, as tightening their carbon emissions can only be achieved by changing the fuel mix.

"Changing the fuel mix for power generation involves important and complicated issues such as energy policy and security, stability in power supply and electricity tariff. It requires wider and more in-depth studies and assessments," he said.