LOS ANGELES – First the good news: In the last 11,300 years, humans have endured a planet warmer than today’s, even as they set about building their earliest civilizations.

Now the bad news: That will no longer be true 87 years from now, according to scientists who have conducted a comprehensive analysis of the planet’s climate history since the world’s ice sheets began their most recent retreat from North America and Europe.

New research into the Earth’s ancient climate is providing a clearer, more detailed view of how the planet’s average surface temperature fluctuated over the period known as the Holocene epoch, which continues through to the present day. It’s the time in which humans truly began making their mark on the planet, abandoning their hunting and gathering traditions and adopting a settled, agricultural lifestyle.