Live Earth had announced shows on each inhabited continent for June 18 featuring more than 100 artists to raise pressure for a strong agreement at a UN-led climate conference in Paris at the end of the year.
Representatives however said Friday that no events would take place on June 18, and instead a free concert would be held near the Eiffel Tower in Paris sometime in the autumn.
Live Earth said that the change would "best reflect the global demand for climate action."
"We are excited to announce that this shift in timing allows us to host a free, public concert," it said in a statement.
Live Earth representatives said that they still planned events around the world but did not specify whether they would be full-fledged concerts.
Live Earth was initially intended to consist of concerts on June 18 in Australia, Brazil, China, South Africa and the United States, as well as Paris.
The MetLife Stadium in the New York suburbs had been expected to be the venue for the US concert.
Live Earth promised that it would still put on a major event, backed by Paris Mayor Anne Hidalgo, which would feature "countless artists."
"We will host an event which transcends social and cultural barriers, matches the scale of the challenge we face and enables us to maximise our impact on the issue," the statement said.
Gore, the former US vice president turned champion of action against climate change, had announced the June 18 concerts alongside pop star Pharrell Williams at the World Economic Forum in Davos, Switzerland, in January.
"The purpose is to have a billion voices with one message to demand climate action now," Gore said at the time.
The Paris talks are aimed at sealing a global agreement to keep global warming to within two degrees Celsius (3.6 Fahrenheit) over pre-industrial levels.
Scientists warn that the window for reaching the goal, and presenting the worst consequences of climate change, is fast narrowing.