The Curiosity rover was sent up the Mount Sharp, the biggest sediments stack on Mars. On the way, it collected samples that indicated a portion of carbon dioxide in the Martian atmosphere might have been sequestered in the sedimentary rocks, just as it happens with limestone on Earth. This would have drawn carbon dioxide out of the atmosphere, reducing the greenhouse effect that warmed the planet.
Based on these findings, a team of scientists led by Benjamin Tutolo, a researcher at the University of Calgary, used this data to conclude Mars had a carbon cycle that could explain the presence of liquid water on its surface. Building on that earlier work, a team led by Edwin Kite, a professor of planetary science at the University of Chicago (and member of the Curiosity science team) has now built the first Martian climate model that took these new results into account. The model also included Martian topography, the luminosity of the Sun, latest orbital data, and many other factors to predict how the Martian conditions and landscape evolved over the span of 3.5 billion years.
Their results mean that any Martian life would have had a rough time of it.