Otellini and the other signers of the letter, which include business leaders, academics and scientists, are members of the Copenhagen Climate Council. The group was created to build awareness for the U.N. Climate Change Conference, scheduled to be held in Copenhagen in December.
"We believe that this year we are at an historic crossroads. Either we establish a new more effective global climate treaty to tackle the climate problem, or we jeopardize our common future," the group wrote in the letter, which was also published in the International Herald Tribune newspaper.
G-20 members will convene in London today. The issues topping their agenda include stabilizing financial markets and to map out a sustainable economic recovery.
"Either decision-makers lay the foundation for sustainable, economic recovery -- or we will hand huge risks to our children," the Copenhagen Climate Council said.
