Here's how much longer life on Earth has left, according to new research

Our Sun, the only star at the center of our solar system and the main source of energy that makes life on Earth possible, keeps getting brighter as the years go by. And, like all stars, it will eventually reach the end of its life. Even NASA estimates that in about 5 billion years, the Sun will run out of fuel in its core and eventually become a white dwarf. But what will happen to Earth?

Researchers estimate that life on Earth as we know it might not survive anywhere near that long. Instead, it could disappear way before. A new study takes a closer look at this timeline, and here's how much longer Earth may be able to sustain life.

In a study published in the journal JGR Atmospheres, researchers estimate that Earth's plant-based biosphere can actually keep going for roughly 1.8 billion more years. Before this, scientist James Lovelock and his colleagues shared that it could go on for 100 million years. 

Commenting on this, study co-author Jacob Haqq-Misra, an astrobiologist at Blue Marble Space, told Live Science, “We were trying to show that life on Earth — complex vegetation — could survive longer into the future than previous studies had shown.”

To get a more complete picture, researchers Haqq-Misra and Eric Wolf ran 29 different climate models covering a range of extreme conditions. They modeled a planet that’s too hot for life, but has stable carbon dioxide levels. Another one included stable temperatures as well as carbon dioxide too low to sustain plant life. 

By examining the details, which include scenarios where Earth efficiently took carbon from the air as it warmed, the team was able to study a range of possible conditions. The estimate got so much higher because the researchers factored in tough plants that can survive on very little carbon dioxide.

Andrew Rushby, an astrobiologist at Birkbeck University of London, called the new numbers "broad estimates." Even the study's authors also noted there's no real way of knowing how life will adapt to conditions billions of years from now. 

"It is not possible for us to predict or know the possible evolutionary adaptations that the photosynthetic biosphere may undergo in response to increasing solar output and lower [atmospheric CO2], especially over billions of years," added Andrew Rushby.

The researchers think this same modeling approach can also be used to figure out how long other planets around other stars might stay livable for life. So, if we build the physics right for Earth, we can do the same for different planets and stars.

Graham, who authored an earlier study on a similar topic, said, "Haqq-Misra and Wolf have used a sophisticated 3D climate model to show that Earth's climate may remain hospitable to plant life significantly longer into the future than predicted.” He added, "It's an advance over previous work and suggests that complex biospheres like that of Earth are more resilient to environmental change from stellar brightening than previously suggested."