Science saves the planet, science destroys it; either concept is solely defined by human terms. What is it that defines positive and negative change in the planet when it is still just another form of "change", something that the planet is well associated with in many forms? If asked instead whether science can help maintain the planet's current form, then the answer would be "yes". But that is only if everyone agrees with the methods.
So what needs to be "saved" i.e. "kept the same" on the planet? After the last Ice Age it is warming up and raising sea levels as it goes in the natural process known as Global Warming. This process was fairly continuous until a miniature Ice Age occurred and people became used to a colder lifestyle. Since this colder spell the world has again continued to warm, even faster with human related by-products from industry and the burning of fossil fuels.
Aside from Global Warming, there are issues of pollution in the environment, the destruction of habitat of other species of animals, and general human wrongs or acts against the well-being of the planet and its other inhabitants. From this the general consensus appears to be the desire to erase visible negatives humanity has inflicted upon the planet and break a natural process of the planet to keep it at a standstill. On another stance, this very mentality seems to go against the concept of change and the natural process of evolution. Extinctions are also a natural process, but can science prevent this and keep everything under a glass? Of course it can, but it isn't easy, economically sound, or logical.
Already the steps against the negatives have been started across the face of the planet. The first form is the recognition of the problems and proposed solutions. The next step includes the regulations that start to affect the process of addition to the problem at hand. The following step after the stop of addition is the correction. It is with this correction that the world will be "saved" or transformed back to what it used to be. The final step after everything else is prevention, which effectively renders human influence zero. Whether prevention means harmony with nature, isolation from nature, or eradication from nature, it is up to science and the future generations to decide.
If people wonder where the process is right now, it is between the first and second steps. Already the problem has been noticed and steps that lead to its eventual halt are in effect. Also, governments and societies around the world are taking concerted effort to propose and enforce regulations of change that is needed to counter the contaminants that humanity continues to administer to the environment. At this time there is very little of the correction step included. This is why science is only in the beginning stages of "saving" the planet and people doubt in its success.
In order to get people to believe, the first two steps need to be dramatically enforced and the third step needs to start its action. People feel that correction is already in play with wind and solar energies, but that is in error with their philosophy. At the moment, while both green energies are very beneficial in their replacement of the fossil fuels, they themselves require power derived from negative system activities. Also, wind turbines have been known to negatively effect environments by creating low pressurization around their blades that kill bats from pressure damage and many various types of birds risk fatality as well from impact with blades. Although these are minor in the long run, in the near term it discourages those environmentalists that would otherwise favor the technology.
Apart from the green technologies, many more focus on the pollution and stability of the environments suffering from many various influences around the globe. Though everything helps, there are many solutions and activities that are left to be discovered as time moves forward. With every continued negative effect another chance to save what was begins to erode. If and when the planet can be saved by science and its technology, that time may very well disappear if there isn't a greater effort pushed forward. To erase what cannot be brought back is also a part of history. Even so, to save the planet as it will be when the technology is available? That is within the bounds of science.