AIS will use a combination of direct marketing, advertising and online activity to raise awareness of The Climate Group's mission to reduce greenhouse-gas emissions. It will encourage businesses, governments and financiers to work together and share resources.
It has also developed its positioning and worked on the brand identity with the design agency Browns. Media is being handled by Davies Media.
Steve Howard, the chief executive of The Climate Group, said: "Our mission is to help preserve the world's climate systems. To achieve this, we will be looking to instigate momentum in the worlds of politics, trade and finance."
The AIS managing partner Stuart Archibald said: "We're passionate about the issues it is confronting, and are keen to help fight its corner. Howard and his team are also open to new ideas, so we've been given real freedom to push a few creative boundaries. It's an exciting challenge."
The launch is being supported by the Government and guests at the launch event will include the prime minister, Tony Blair, and the cabinet ministers for the environment and charity.
The Mayor of London, Ken Livingstone, is hosting a dinner on the evening of the event for The Climate Group board, which includes Archibald.
AIS will provide the communication strategy for The Climate Group's first conference, which is to be held in Toronto, Canada on 10 to 12 May.