To take mastery of climate as we once took mastery of fire, then of genetics (agriculture), then of communication (music, writing, math, maps, images, printing, radio, computers) will require mathematics we don't have, physics and biology we don't have, and governnance we don't have.
Our climate models, sophisticated and muscular as they are (employing more teraflops than any other calculation), still are just jumped-up weather prediction models. The real climate system has more levels and modes of hyper-connected nonlinearity than we can yet comprehend or ask computers to replicate, because so far we lack the math to represent climate dynamics with the requisite variety to control it. Acquiring that math will change everything.
Materials scientist and engineer Saul Griffith estimates that humanity must produce 13 terawatts of greenhouse-free energy in order to moderate global warming to a just-tolerable increase of 2° Celsius. (Civilization currently runs on about 16 terawatts of energy, most of it from burning fossil fuels.) Griffith calculates that deploying current clean technologies — nuclear, wind, geothermal, biofuels, and solar technology — to generate 13 terawatts would cover an area the size of Australia. It is imaginable but not feasible. Just improving the engineering of nuclear and solar won't get us what we need; new science is needed. The same goes for biofuels: the current state of genetic engineering is too crude to craft truly efficient organisms for sequestering carbon and generating usable energy. The science of molecular biology has to advance by leaps. Applied science that powerful will change everything.
Climate change is a global problem that cannot be fixed with global economics, which we have; it requires global governance, which we don't have. Whole new modes of international discourse, agreement, and enforcement must be devised. How are responsibilities to be shared for legions of climate refugees? Who decides which geoengineering projects can go forward? Who pays for them? Who adjudicates compensation for those harmed? How are free riders dealt with? Humans have managed commons before — fisheries, irrigation systems, fire regimes — but never on this scale. Global governance will change everything.
Of course, these radical adjustments may not happen, or not happen in time, and then climate will shift to either a chaotic mode or a different stable state with the carrying capacity for just a fraction of present humanity, and that will really change everything.