Anthropocene: Turning Point In Human History

Anthropocene

Human brains are wired for categorization, thought by many to be an evolutionary advantage and a condition for rational thought. It is no surprise then, that humans have classified the history of time on Earth into eras of clearly defined periods marked by some characteristic. Some eras are shorter while others span much longer time frames. A person can have eras of their own, viewing their own personal lifetime in various periods, such as being a teenager or married. Or we can view the categorization of something much larger like the timeline of the origins of our universe. In any case, what happens in the eras of any timescale defines the uniqueness of that time.

The usage of chronology for life makes sense since everything alive is evolving into something different from what it was in a prior state. In looking at the life span of the planet Earth, the home to all who are reading this, it is estimated to be 4.5-billion years old since it was birthed from a nebula of particles from our Sun during the Hadean era. Immediately after was the beginning of the Archean era, 4-billion years ago, when the Earth's first continents were formed, then shortly after, our oceans. It was this blessing of water that created the first signs of life 3.5-billion years ago. Photosynthetic life eventually developed after falling in love with the energy of the sun and produced oxygen 2-billion years ago during the Paleoproterozoic Era. Water and oxygen together created the atmosphere 1-billion years ago during the Proterozoic era leading to complex multicellular life forming in the Cambrian era 580-million years ago.

As these complex multicellular life forms developed, events with sudden climatic changes such as an ice age, shifted the scale of physical evolution of all species of life existing at that time. Diverse hard-shelled animals first appeared 250-million years ago in the Mesozoic Era spawning the dinosaurs. When the dinosaurs became extinct, birds survived helping to develop the next set of life along with great change in the terrestrial vegetation leading up to the Cenozoic period about 65-million years ago. This time marked the proliferation of insects, and fish joining the birds in this process of proliferation. Periods of global heating and cooling over the next several million years created tectonic shifts in Earth's continental plates and the development of land animals and their eventual migration around the globe marking the Pliocene Era 5-million years ago. Eventually animal migration allowed for the intermingling of species giving rise to a diverse set of mammals from horses to cats and homo habilis during the Pleistocene Era 2-million years ago. As homo erectus spread throughout the world 150,000 years ago, they contributed to the extinction of the large animals that they hunted. Since then, small scale climate shifts and continued migration evolved homo erectus into the humans we are today, homo sapiens. This gives our current Era of the last 11,700 years the name Holocene, dubbed "The Age of Man" as it plays spectator to most of humanity's recorded history and the rise and fall of all its civilizations since then.

Anatomically, modern homo sapiens evolved within the last 150,000 years defining only 0.004% of Earth's whole geographic history. While all organisms influence their environments to some degree, few have ever impacted Earth as much, or as fast, as our species has done during our short 0.004% stay. Modern humans are changing the world, ushering in a new era in geologic time, currently proposed to be called Anthropocene. This concept of a new era has been discussed and debated as the time in history where human influences became so great, that it changed the future of Earth and humanity all together. This is the first time that an era is credited to a particular species, the human.

But is this really something so dramatic? The impetus for leaps of growth in life on Earth usually include destruction then recovery. The changes currently being observed in our ecosystem are parallel with major events of past eras that developed the landscape we see today and the photosynthetic organisms that released oxygen into our atmosphere for us to breathe. The only distinction this time around is how quickly our impact has been and who is doing it. Humans have wandered the Earth for thousands of years but never has our capacity to alter the Earth's ecosystem at a larger scale been more prominent than it is today.