Chinese Foreign Ministry spokeswoman Zhang Qiyue Thursday applauded the approval of the Kyoto Protocol by the lower house of Russian State Duma.

At a regular press conference in Beijing, Zhang called the ratification by Russian parliament "an important first step" for Russia to become a signatory country of the protocol.

It also signaled that the protocol, initiated in 1997, may soon be put to effect, she said.

The Kyoto Protocol will not go into effect until 55 countries representing 55 percent of industrial countries' carbon dioxide emissions in 1990 have approved it.

Analysts said the Russian Duma's ratification is essential for pushing the number of industrialized signatories over the threshold to activate the international treaty, as the country is responsible for 17 percent of the world's carbon dioxide emissions.

The protocol still needs the approval of the upper house of the Russian parliament and the signature of Russian President Putin to go into effect.

To quicken protocol's going into effect and curb greenhouse gase missions as fast as possible, Zhang called on countries having not approved the document to make active efforts to work together with the international community to protect the global environment.

Calling climate changes "a long-term challenge to humanity," Zhang said that China would like to team up with other countries and actively explore methods able to reverse the trend of global warming.

The Kyoto Protocol obliges industrialized signatory countries to reduce emissions of greenhouse gases by 2008-2012 from their 1990 levels.