Yes terraforming.

The former paper was produced by Aaron Berliner from the University of California, Berkeley, and Chris McKay from the Space Sciences Division at NASA Ames Research Center. In their paper, the two researchers present a timeline for the terraforming of Mars that includes a Warming Phase and an Oxygenation Phase, as well as all the necessary steps that would precede and follow. As they state in their paper's Introduction: "Terraforming Mars can be divided into two phases. The first phase is warming the planet from the present average surface temperature of -60° C to a value close to Earth's average temperature to +15° C, and recreating a thick CO² atmosphere. This warming phase is relatively easy and quick, and could take ~100 years. The second phase is producing levels of O² in the atmosphere that would allow humans and other large mammals to breath normally. This oxygenation phase is relatively difficult and would take 100,000 years or more, unless one postulates a technological breakthrough." Before these can begin, Berliner and McKay acknowledge that certain "pre-terraforming" steps need to be taken. These include investigating Mars' environment to determine the levels of water on the surface, the level of carbon dioxide in the atmosphere and in ice form in the polar regions, and the amount of nitrates in Martian soil. As they explain, all of these are key to the practicality of making a biosphere on Mars. So far, the available evidence points towards all three elements existing in abundance on Mars. While most of Mars water is currently in the form of ice in the polar regions and polar caps, there is enough there to support a water cycle – complete with clouds, rain, rivers and lakes. Meanwhile, some estimates claim that there is enough CO² in ice form in the polar regions to create an atmosphere equal to the sea level pressure on Earth. Nitrogen is a also fundamental requirement for life and necessary constituent of a breathable atmosphere, and recent data by the Curiosity Rover indicate that nitrates account for ~0.03% by mass of the soil on Mars, which is encouraging for terraforming. On top of that, scientists will need to tackle certain ethical questions related to how terraforming could impact Mars. For instance, if there is currently any life on Mars (or life that could be revived), this would present an undeniable ethical dilemma for human colonists – especially if this life is related to life on Earth. As they explain: "If Martian life is related to Earth life – possibly due to meteorite exchange – then the situation is familiar, and issues of what other types of Earth life to introduce and when must be addressed. However, if Martian life in unrelated to Earth life and clearly represents a second genesis of life, then significant technical and ethical issues are raised." To break Phase One – "The Warming Phase" – down succinctly, the authors address an issue familiar to us today. Essentially, we are altering our own climate here on Earth by introducing CO² and "super greenhouse gases" to the atmosphere, which is increasing Earth's average temperature at a rate of many degrees centigrade per century. And whereas this has been unintentional on Earth, on Mars it could be re-purposed to deliberately warm the environment. "The timescale for warming Mars after a focused effort of super greenhouse gas production is short, only 100 years or so," they claim. "If all the solar incident on Mars were to be captured with 100% efficiency, then Mars would warm to Earth-like temperatures in about 10 years. However, the efficiency of the greenhouse effect is plausibly about 10%, thus the time it would take to warm Mars would be ~100 years." Once this thick atmosphere has been created, the next step involves converting it into something breathable for humans – where O² levels would be the equivalent of about 13% of sea level air pressure here on Earth and CO² levels would be less than 1%. This phase, known as the "Oxygenation Phase", would take considerably longer. Once again, they turn towards a terrestrial example to show how such a process could work. Here on Earth, they claim, the high levels of oxygen gas (O²) and low levels of CO² are due to photosynthesis. These reactions rely on the sun's energy to convert water and carbon dioxide into biomass – which is represented by the equation H²O + CO² = CH²O + O². As they illustrate, this process would take between 100,000 and 170,000 years: "If all the sunlight incident on Mars was harnessed with 100% efficiency to perform this chemical transformation it would take only 17 years to produce high levels of O². However, the likely efficiency of any process that can transform H²O and CO² into biomass and O² is much less than 100%. The only example we have of a process that can globally alter the CO² and O² of an entire plant is global biology. On Earth the efficiency of the global biosphere in using sunlight to produced biomass and O2 is 0.01%. Thus the timescale for producing an O² rich atmosphere on Mars is 10,000 x 17 years, or ~ 170,000 years." However, they make allowances for synthetic biology and other biotechnologies, which they claim could increase the efficiency and reduce the timescale to a solid 100,000 years. In addition, if human beings could utilize natural photosynthesis (which has a comparatively high efficiency of 5%) over the entire planet – i.e. planting foliage all over Mars – then the timescale could be reduced to even a few centuries. Finally, they outline the steps that need to be taken to get the ball rolling. These steps include adapting current and future robotic missions to assess Martian resources, mathematical and computer models that could examine the processes involved, an initiative to create synthetic organisms for Mars, a means to test terraforming techniques in a limited environment, and a planetary agreement that would establish restrictions and protections. Quoting Kim Stanley Robinson, author of the Red Mars Trilogy, (the seminal work of science fiction about terraforming Mars) they issue a call to action. Addressing how long the process of terraforming Mars will take, they assert that we "might as well start now".