Tag: extinction

Guy McPherson and the end of humanity (not)

Is climate change going to wipe out humanity over the next 10 years? Prof Jim Renwick doesn’t think so…

Ecologist Guy McPherson has been touring New Zealand for the past couple of weeks, explaining why humanity has only 10 years to live (a kind-of Ziggy message that has immediate appeal to me). After his appearance on the Paul Henry breakfast show, I was called by TV3/Newshub for comment. Based on my understanding of climate change science I said that though the situation is very serious — dire even — extinction in 10 years is not going to happen. When I gave my remarks to Newshub, I knew little about McPherson but I understood that he is a very knowledgeable biologist who should not be dismissed lightly.

So, what’s the story? Is McPherson right? Is the IPCC woefully conservative and keeping the truth from us all? I had the opportunity to hear Prof McPherson speak in Paraparaumu on Saturday (Dec 10th) to get more insight into what his views really are. It was a very interesting presentation, and a very interesting discussion with the audience of 50-odd Kāpiti coasters who showed up to hear him. As the old saying goes, extraordinary claims require extraordinary evidence. What we heard was extraordinary for sure, but was not too convincing in terms of evidence.

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The Sixth Extinction

Elizabeth Kolbert’s recent book The Sixth Extinction: An Unnatural History is science journalism of a high order. As with her earlier notable book on climate change, Field Notes from a Catastrophe, she includes lively narrative accounts of her visits to places around the world where scientists are at work and communicates the import of their work with clarity and intelligence. Well-informed background discussions on the general topic of extinction are woven into these narratives, in passages well pitched to the understanding of the general reader. Foreboding though the subject may be the book is a pleasure to read.

The phenomenon of species extinction has only begun to be understood in relatively recent times. Kolbert traces the discussions of the 19th century from the ground-breaking conclusion of Cuvier to the doubting Lyell and finally Darwin, whose theory of evolution necessarily involved the disappearance as well as the emergence of species.

In evolutionary terms the mass extinctions of the distant past are a special case, arising from relatively sudden events for which natural selection over long periods of time had not prepared many of the species which disappeared under the stress of a rapidly changed environment. Kolbert comments on the fact that just as we have recovered the story of these past events and identified five of them we have discovered that we are causing another. Whether it will reach the proportions of the Big Five is not yet known, but the indications are significant enough for it to be called the Sixth Extinction. She notes the estimation that one-third of all reef-building corals, a third of all freshwater mollusks, a third of sharks and rays, a quarter of all mammals, a fifth of all reptiles , and a sixth of all birds are headed toward oblivion. It’s no small matter.

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The state of the ocean (dire)

Alex Rogers, Professor of Conservation Biology at the Department of Zoology at Oxford, and scientific director of the International Programme on the State of the Ocean describes the main problems affecting the global ocean — and discusses some of the things we could do to address them in this new video. The IPSO has just launched the summary of its forthcoming report on the state of the oceans ((Rogers, A.D. & Laffoley, D.d’A. 2011. International Earth system expert workshop on ocean stresses and impacts. Summary report. IPSO Oxford, 18 pp)) — PDF here. The key findings make sobering reading:

  • Human actions have resulted in warming and acidification of the oceans and are now causing increased hypoxia.
  • The speeds of many negative changes to the ocean are near to or are tracking the worst case scenarios from IPCC and other predictions. Some are as predicted, but many are faster than anticipated, and many are still accelerating.
  • The magnitude of the cumulative impacts on the ocean is greater than previously understood.
  • Timelines for action are shrinking.
  • Resilience of the ocean to climate change impacts is severely compromised by other stressors from human activities, including fisheries, pollution and habitat destruction.
  • Ecosystem collapse is occurring as a result of both current and emerging stressors.
  • The extinction threat to marine species is rapidly increasing.

The bottom line is not pretty:

[…] we now face losing marine species and entire marine ecosystems, such as coral reefs, within a single generation. Unless action is taken now, the consequences of our activities are at a high risk of causing, through the combined effect of climate change, over exploitation, pollution and habitat loss, the next globally significant extinction event in the ocean.

The report recommends immediate action on reduction of CO2 emissions, calls for a long list of actions to restore and protect marine ecosystems, and the formation of a new Global Ocean Compliance Commission to establish rules and regulations for the protection of the “high seas” — the ocean beyond national jurisdictions.

This is a cri du coeur from the world’s ocean scientists. We ignore it at our peril…

[See also Climate Progress, and the NZ Herald. The IPSO site also has more videos from workshop participants, and a great ocean cycles graphic.]