Are we jumping the gun?

"It is not yet clear what the character of the fully developed Anthropocene will be, and it might be wise to let future generations decide, with hindsight, when the Anthropocene started, acknowledging only that we are in the transition towards it." 

The above quote from Wolff's (2014) paper strikes a chord with my own personal feelings. As I briefly touched on in my last post, how can we already determine (albeit with much contention...) a start date for a time period at epochal scale, which may only be in its early developmental stages? Unlike other geologic time periods, we have no idea what the Anthropocene will look like in 20, 200, 20,000 or 2,000,000 years time. As Wolff (2014) argues, atmospheric CO2 concentrations have risen significantly, but they are still rising and could easily reach somewhere between 500-1000 ppmv in the foreseeable future. Then again, if we mitigate emissions and impacts urgently, the current perturbation of Earth Systems might be the defining signature of the Anthropocene (Wolff 2014). I personally don't think mitigation of that magnitude would be likely, unless politicians could look back in retrospect at the 'human environment' and see the enormity of the changes caused to Earth because of it.

Zalasiewicz et al (2015) agree with Wolff in his conclusions that greater changes lie ahead, and that the Anthropocene's stratigraphic signature will likely differ from today when looking back in hindsight. However, Zalasiewicz et al (2015) argue that the scale of these future predicted changes (e.g. perturbations of the biosphere - see Barnosky et al 2012) may actually start to correspond more to period/era level changes in Earth Systems. One issue I have with this argument is that the Anthropocene epoch may barely come into fruition before it is argued that human impacts are instead on a period/era scale.

Do we argue that the onset of the Anthropocene is marked by the first instance of human alteration of Earth Systems, or by the time of greatest magnitude of change? How do we identify the moment when human impact on the Earth becomes so substantial that it warrants the beginning of a new interval of geologic time? Millions of years from now, what event would a geologist pinpoint as the start of the Anthropocene? Perhaps the Industrial Revolution? The Great Acceleration? Harnessing the Sun's power with nuclear fusion? Or colonising other planets, even solar systems? These are all big philosophical questions which I cannot answer objectively. I can, and will, however, weave these thoughts into posts throughout my remaining blogging journey.

I agree with Wolff (2014) that we need to acknowledge humanity's dominance over Earth Systems. BUT, were this proposed epoch to last tens of millions of years (as other epochs have done), we ought not to be too hasty in trying to pinpoint its starting point now. The current pace of change in technology, atmospheric chemistry, ocean dynamics, and biodiversity etc is so rapid that enormous change is inevitable in the near future. Perhaps, some future unknown-as-of-yet event or discovery would be a better signature of a human-dominated age than anything that has occurred to date. 

Some satirical humour for y'all on this rainy day. Does the Anthropocene mark the end of the Holocene? Should we hold off and let generations of the future decide? (Source)

In my next post, I'll be reviewing whether proposals for the start date of this epoch (see my previous post for the summary of onsets) meet GSSP criteria standards, or whether perhaps instead the Anthropocene should be defined by a GSSA. To keep your brains ticking over until then, sit down with a cuppa and consider this: have we already played the "human card" in the Holocene? Are we trying to play the same card again in the Anthropocene?

Let me hear your thoughts in the comments below!