The Anthropocene geological epoch began when human activity first had a GLOBAL impact on the planet’s environments. That was in late 1965, when the first evidence of a human-caused effect was detected EVERYWHERE, indicating a simultaneous global impact by human activity.
That evidence was the signature of radioactivity (Carbon-14) from nuclear bomb test fallout incorporated into tree rings for the year 1965 (within October to December) at all latitudes and longitudes. Atmospheric nuclear bomb explosions were set off from 1945 to, primarily, 1963. The peak of such activity was an orgy of bomb tests by the U.S. and USSR in 1962. 
Prior to 1965 many species had had geographically limited impact on altering environments, like pre-columbian humans in North America making pastures out of forests in Appalachian valleys, herd animals making permanent migration trails, and grazing animals nibbling bush down to grasslands.
But all previous geological epochs were set by planetary geophysics, such as with the coalescing of continents into the supercontinent Pangaea (335Mya) and then its breakup (from 175Mya), and the comings and goings of the Ice Ages, the last one starting 2.58Mya, and ending 11,700 years ago.
While we now know that human activity can have a simultaneous global impact for setting off a planetary geophysical process — global warming climate change with biodiversity losses — we do not yet know if human activity can set off a different planetary geophysical process to counter global warming climate change and biodiversity losses.
It is obvious that the only credible global climate stabilizing process available is the socio-economic revolution of abandoning nationalistic fossil-fueled capitalism, and replacing it with an international democratic socialism whose industrial and technological elements are powered by renewable energy, which does not emit greenhouse gases. 
Such a necessary transformation of organized human society is most definitely a challenge to the political processes of Earth’s 193-odd nations, and to the ambitions and prejudices of their political classes, their wealth elites, and their general populations. The practical problem facing climate stabilization activists is to overcome these political difficulties as soon as possible. Admittedly, this is a monumental task, and some fear it impossible. Even so, defeatism here is ignominious while engagement in this cause will at a minimum salvage personal honor, and most optimistically secure humanity’s long-term future.
So for now it is best to think of humans as in the driver’s seat of the Anthropocene Earth Car with the foot mashed down on the gas pedal connected to a powerful fuel-injected engine, but with the brake lines cut. Time of impact is unknown, but terminal speed will be high.
 The Anthropocene’s Birthday
 The Improbability of CO2 Removal from the Atmosphere