Over the past 50 years, humans have changed the world’s ecosystems more rapidly and extensively than in any other comparable period in human history.

What researchers in a new Ambio paper are calling 'The Great Acceleration', stage 2 of the Anthropocene epoch, leads to questions how humankind will react in stage 3 - defined as the recognition that human activities are indeed affecting the structure and functioning of the Earth System as a whole.

Increased research and understanding, the Internet, and more free and open societies have influenced humanity to become a self-conscious, active agent in the operation of its own life support system. The new study discusses the three known broad philosophical approaches that address the Earth System; the business-as-usual approach, mitigation, and geo-engineering options.

The business-as-usual approach is based on three assumptions. First, global change will not be severe or rapid enough to cause major disruptions. Second, the existing market-oriented economic system can deal autonomously with any required adaptations. And third, resources required to mitigate global change proactively would be better spent on more pressing human needs.

By the time humans realize that a business-as-usual approach may not work, the world will be committed to further decades of environmental change.

The second approach, mitigation, is an alternative pathway based on the notion that the threat of further global change is serious enough that it must be dealt with immediately and by curbing greenhouse gases. Technology will play a strong role in reducing the pressure on the Earth System. The critical question is whether the trends of dematerialization and shifting societal values become strong enough to trigger a transition of a globalized society toward a much more sustainable one.

The third approach, geo-engineering, involves purposeful manipulation by humans of global-scale processes with the intention of counteracting human-driven environmental change. Geo-engineering solutions raise serious ethical questions and intense debate, such as when unintended and unanticipated side effects of the solutions have severe consequences.

According to the report, The Great Acceleration is reaching criticality. Enormous challenges confront humanity in the next few decades as we pass through the bottleneck of continued population growth, excessive resource use, and environmental deterioration. In most parts of the world, the demand for fossil fuels overwhelms the desire to significantly reduce greenhouse gas emissions. Whatever unfolds, the next few decades will surely be a tipping point in the evolution of the Anthropocene.

Article: The Anthropocene: Are Humans Now Overwhelming the Great Forces of Nature?, Will Steffen, Paul J. Crutzen and John R. McNeill, Ambio, Volume 36, Issue 8 (December 2007)