TOKYO, Feb. 15 (Xinhua) -- Twelve globally famous companies signed a declaration here on Friday with the World Wide Fund for Nature (WWF), pledging to make joint efforts to fight against global warming.

    The Tokyo Declaration, endorsed by companies such as Sony Corp., Nokia Corp., Nike Inc. and Hewlett-Packard Co., calls for more than 50 percent cut of world's greenhouse gas emissions by 2050 to "limit the global average temperature increase to a maximum of 2 degrees Celsius compared to pre-industrial levels."

    The companies vowed in the declaration to try to widen the scope of emission reduction activities in cooperating with their business partners, to promote a low-carbon lifestyle to consumers and customers, and to serve as ambassadors of the industry by sharing proven successful approaches to more sectors and regions.

    The document, which was signed at the Climate Savers Summit 2008 sponsored by the WWF and Sony, envisions the start of decline in world's greenhouse gas emissions within the next one and half decades.