Today's edition of the Washington Post has an article with interviews addressing the human-engineered great extinction event known as the Anthropocene, with a focus on the ocean.
The article notes that large mammals are dying off first in this great extinction event in a pattern that is historically anomalous.
It also notes that CLIMATE CHANGE is not the most important factor driving current extinctions, although it is expected to be in the future.
Rather, the most important factors driving current extinctions are human predation and habitat destruction:
Chris Mooney. Sep. 14, 2016. What the ‘sixth extinction’ will look like in the oceans: The largest species die off first. The Washington Post, https://www.washingtonpost.com/news/energy-environment/wp/2016/09/14/what-the-sixth-extinction-will-look-like-in-the-oceans-the-largest-species-die-off-first/?utm_term=.8e32fb19a59d&wpisrc=nl_headlines&wpmm=1
“What to us was surprising was that we did not see a similar kind of pattern in any of the previous mass extinction events that we studied,” said geoscientist Jonathan Payne of Stanford University, the study’s lead author. “So that indicated that there really is no good ecological analogue…this pattern has not happened before in the half billion years of the animal fossil record.” ...
...The researchers conducted the work through a statistical analysis of 2,497 different marine animal groups at one taxonomic level higher than the level of species — called “genera.” And they found that increases in an organism’s body size were strongly linked to an increased risk of extinction in the present period — but that this was not the case in the Earth’s distant past....
...Thus, as previous work has also suggested, the current study underscores that ecosystem risks are not being principally driven by a changing climate — yet. Rather, they’re being driven more directly by which species humans hunt and fish, and where they destroy ecosystems to build homes, farms, cities, and much more
Human predation is easy to understand but "habitat destruction" is rather abstract. In my book, Crisis Communication, Liberal Democracy and Ecological Sustainability ((here), I make the argument that habitat destruction results in large part (albeit not exclusively) from catastrophic "accidents" arising from gross negligence and disregard.
You can ask your local library to obtain a copy (either purchase or through inter-library loan) if you are interested in reading my empirical account of how human negligence in risk management leads to catastrophic environmental contamination.
Here is a brief excerpt from the introduction of this book where I introduce my argument:
Environmental crises emerge without end or resolution, as illustrated most recently by the 2010 BP oil spill and the 2011 Fukushima nuclear crisis, both catastrophic accidents, capstones of decades of similar disasters.
Crude is toxic because it contains many chemicals capable of adversely impacting cell biology and DNA, while nuclear contamination by radionuclides presents significant chemical and radiation damage to biological life. Contamination of the planet by radionuclides, crude, and other chemicals threatens the world’s fresh water, soil, oceans, and DNA.
How much ecological damage is necessary before irreparable tipping points are reached, resulting in escalating systems disintegration? The answer is unknown, but the scale of ecological damage magnifies with each new disaster.
In 2013, an international panel of marine scientists urged that immediate efforts be taken to mitigate severe ocean degradation[i] as marine species experience alarming mass mortality events. [ii] Ocean degradation results from human activities, including direct habitat destruction, routine industrial emissions and effluents, and catastrophic accidents such as Fukushima and the BP oil spill, among myriad other human externalizations.
Biodiversity is currently collapsing at a rate comparable to previous mass extinctions, causing some scientists to predict that 75 percent of species will be gone over the next few centuries if present trends continue.[iii] More specifically, “the average rate of vertebrate species loss over the last century is up to 100 times higher than the background rate.”[iv]
Scientists have named our present period the “Anthropocene” to highlight human influence over the planet. For some scientists, the first atomic blast, the Trinity atomic explosion in New Mexico, ushered in the new age.[v] Recent work on the Anthropocene[vi] and ecological tipping points circulate across the popular media, but appear to have little-to-no lasting impact on the risk-seeking conduct of the most powerful complexes of corporations and government agencies.
[i] “Latest Review of Science Reveals Ocean in Critical State from Cumulative Impacts,” International Programme on the State of the Ocean, October 3, 2013, accessed October 3, 2013, http://www.stateoftheocean.org/research.cfm.
[ii] Douglas McCauley, Malin Pinsky, Stephen Palumbi, James Estes, Francois Joyce and Robert Warner, “Marine Defaunation: Animal loss in the Global Ocean,” Science 347 (2015): accessed November 2, 2015, doi: 10.1126/science.1255641.
[iii] Richard Monastersky, “First Atomic Blast Proposed as Start of Anthropocene,” Nature (January 16, 2015): Accessed January 20, 2015, doi:10.1038/nature.2015.16739.
[iv] Gerardo Ceballos, Paul Ehrlich, Anthony Barnosky, Andrés García, Robert Pringle and Todd Palmer, “Accelerated Modern Human–Induced Species Losses: Entering the Sixth Mass Extinction,” Science Advances 1 (2015): accessed June 23, 2015, doi: 10.1126/sciadv.1400253.
[v] Richard Monastersky, “First Atomic Blast Proposed as Start of Anthropocene,” Nature (2015): Accessed January 20, 2015, doi:10.1038/nature.2015.16739.
[vi] Anthony Barnowsky, Nicholas Matzke, Susumu Tomiya, Guinevere Wogan, Brian Schwartz, Tiago Quental, Charles Marshall, Jenny McGuire, Emily Lindsey, Kaitlin Maguire, Ben Mersey and Elizabeth Ferrer, “Has the Earth’s Sixth Mass Extinction Already Arrived,” Nature 471 (2011): 51–57, accessed November 10, 2011, doi:10.1038/nature09678.