The study has yielded a prediction of the year when the mean climate of any given location on Earth will shift continuously outside the most extreme records experienced in the past 150 years, the researchers said.
Among the study's findings is that areas in the tropics are projected to experience unprecedented climates first -- within the next decade.
Under a business-as-usual scenario the index indicates the average location on Earth will experience a radically different climate by 2047, while under an alternate scenario with greenhouse gas emissions stabilization, the global mean climate departure will be 2069, the researchers said.
"The results shocked us. Regardless of the scenario, changes will be coming soon," lead author Camilo Mora of the College of Social Sciences at the University of Hawaii said. "Within my generation, whatever climate we were used to will be a thing of the past."
The predicted rapid changes will tamper with the functioning of Earth's biological systems and its species, scientists said.
"This work demonstrates that we are pushing the ecosystems of the world out of the environment in which they evolved into wholly new conditions that they may not be able to cope with," said Ken Caldeira of the Carnegie Institution for Science's Department of Global Ecology, who was not involved in this study. "Extinctions are likely to result."
The study highlights the need for ongoing efforts to slow climate change, Mora said.
"Scientists have repeatedly warned about climate change and its likely effects on biodiversity and people," he said. "Our study shows that such changes are already upon us.