When will Earth cease to exist? Humans might go extinct first

Many scientific theories suggest that our Sun will cause the Earth's end. As the central star of our solar system, the Sun's demise in a few billion years will likely spell doom for our planet. Meanwhile, experts from Live Science anticipate the extinction of the human species much earlier.

Due to the Sun's natural evolution, Earth is predicted to be uninhabitable for most organisms in about 1.3 billion years. In 4.5 billion years, as the Sun expands into a red giant, it is forecasted to engulf our planet.

"The Sun will swell to a size that surpasses Earth's orbit. Yet, Earth likely won't survive these 4.5 billion years and will definitely not be the Earth as we know it today. We don't have to wait for the outer layers of the Sun to touch Earth" - Ravi Kopparapu, a planetary scientist with NASA's Goddard Space Flight Center.

As the Sun's dying process progresses, Earth's temperatures will drastically increase. The oceans will evaporate and the Sun's gravity will shred our planet. In about 1.3 billion years, "humans will not be able to survive on Earth" due to persistently hot and humid conditions, Kopparapu predicts. He also suggests that in about 2 billion years, our Sun will shine almost 20% brighter than it does now.

Rodolfo Garcia, a Ph.D. candidate in astronomy and astrobiology at the University of Washington, suggests that humans could go extinct within just a few centuries. He cites global warming and rising temperatures worldwide as the main reasons.

Forecasts indicate that in a few years, temperatures in many places could soar past 95 degrees Fahrenheit. In most areas around the globe, 86 degrees Fahrenheit could become a common temperature.

"As for human existence, the next hundred years are going to be fascinating," Kopparapu points out.