NEW YORK (Reuters) - Former Vice President Al Gore on Thursday urged people worldwide to pressure their governments to cut global warming pollution by 90 percent in developed countries and by more than half worldwide by 2050.

Al Gore smiles at a news conference to introduce a "7 Point Pledge" in conjunction with the Live Earth Concerts in New York, June 28, 2007. REUTERS/Jeff Zelevansky

Gore said the July 7 Live Earth concerts -- to be held in Johannesburg, London, New Jersey, Rio de Janeiro, Shanghai, Sydney and Tokyo -- will ask people around the globe to sign the climate change pledge.

Organizers have said the concert, which is being broadcast in more than 100 countries, could be watched and heard by 2 billion people worldwide.

“This is a global challenge,” Gore told a news conference in New York. “We will need a tougher global treaty, we will need every nation to be a part of the solution and we will need individuals all around the world to be part of the solution.”

“The Live Earth concerts represent an unprecedented opportunity to ask for the world’s attention long enough to deliver an SOS and then to begin delivering information about the solutions to every single person,” he said.

The seven-point Live Earth pledge demands governments agree and sign within two years an international treaty to fight climate change. It also asks people to cut their own pollution, to make their homes, business, schools and transport more energy efficient, and to plant new trees and preserve forests.

The pledge also asks people to fight for a halt on any new coal burning generators without the capacity to trap and store carbon dioxide gases, for laws and policies that expand the use of renewable energy sources, and to buy from businesses and support leaders committed to solving the climate crisis.

“We have to get all nations involved, but in order to accomplish that we have to bring about a sea change in public opinion,” said Gore, whose documentary “An Inconvenient Truth” about global warming won two Academy Awards this year.

Scientists say smokestack and tailpipe emissions of heat-trapping gases cause global warming, which could lead to more deadly floods, droughts and heat waves.

The Intergovernmental Panel on Climate Change has found that global carbon dioxide emissions must fall 50 to 85 percent by 2050 to stop the planet from heating up more than 2 degrees Celsius.

Gore said Madonna and the Black Eyed Peas had each written original songs for Live Earth, while a third original song would be unveiled on the day. Concert organizer Kevin Wall also promised a surprise event in Antarctica.