Some branches of science are truly making the world a safer place. Meteorology, with its Doppler weather radar and satellites, complex computer models and hurricane trackers, has greatly reduced the loss of life from severe weather. Research into better ways for building homes and apartments in storm prone areas deserves a tip of the hat to science. Earthquake proof buildings mean the 800,000 deaths from a 1556 Chinese temblor are unlikely to happen today, even in the largest and most congested cities of the world.
On the flip side, it has given us toxic waste, weapons of mass death, mercury leaching into water supplies, automobile-fostered ozone pollution, and the like.
So "science" is both the curse of our planet and its potential "savior". We are progressing slowly but surely in widely diverse areas: cloning (good or bad, you decide), curing of diseases, incredible computer technologies, clean energy, etc.
Without science, we might really (still) believe that mental illness is caused by evil spirits, that the stars are just little points of light stuck in the roof of Heaven, and that the brain's main function is to create mucus (the Egyptians believed this and that's why they disposed of it when burying their kings).
Plagues were routine until less than a hundred years ago, and they wiped out large segments of the population each time. The Spanish Flu epidemic just after World War I killed 50 million, for instance. Before the discovery of vitamin C, scurvy was a constant threat especially at sea. A leg infection might easily have meant an amputated limb whereas today a bottle of penicillin does the trick. Just surviving was a daunting task in the "old days".
So in many ways science is "saving the planet" by making it a safer and friendlier place to live. Life expectancies have increased while early deaths by natural causes have decreased, even though the population is more than six times what it was in 1800. Of course birth control, which is a responsible idea today, is also the result of good science.
It seems that science will "save the planet" if anything can. Perhaps our duty is to make sure we don't wield science as a sword of persecution or entitlement. Science is a way of thinking, not simply memorizing facts out of a book or off of a website. It is a platform of total equality without regard to race, gender, or any other human trait. True progress demands we implement all the elements of what science is.
It's the best hope we have for learning and growing as a civilization. It could also allow us to destroy ourselves if we don't temper it with compassion and wisdom as well as logic.