Conversations on Climate: Paul Wignall says climate crisis is nothing new

NEW climate pic

Climate Change: We’ve Been Here Before
by Paul Wignall

The world’s climate is always changing and always has. Even during the past few centuries we have seen substantial variations, but only recently have we begun to blame ourselves for them. But how much natural variability is there, and just how extreme can climate change be? To gain some longer-term perspective on the climate’s variability we can look back through geological time, particularly at catastrophic events known as mass extinctions. In my recent book, The Worst of Times, I focus on an 80 million year interval when life on Earth suffered one disaster after another. These catastrophes included the Permo-Triassic mass extinction, the worst crisis that life has ever faced. It is not very reassuring to find that these extinctions all coincide with intervals of rapid global warming.

rocks from Permian-Triassic boundary in Guizhou

Sedimentary rocks from the Permian-Triassic boundary in Guizhou Province, SW China that record evidence for the greatest of all mass extinctions.

So, are we all going to hell in a hand basket? Well, probably not just yet. The story from the past is much more nuanced than this and I believe there is substantial hope that all is not so bad today. The reason is that the worst 80 million years happened a long time ago and more recently (in the past 100 million years) things have got a lot better. At one time all the world’s continents were joined together into a single supercontinent called Pangea. This seems to have created a global environment that was very fragile. Every time there was a phase of giant volcanic eruptions in Pangea, climates changed rapidly, the oceans stagnated and life began to suffer. The cause seems to be not the actual lava flows themselves, although these were very large, but the gases that bubbled out of them, especially carbon dioxide, everyone’s (not so) favorite greenhouse gas. As I explain in my book the effects of these gases on climate and oceans changed global environments in a disastrous way. Rapid increases in global temperature were part of the story and the results were some of the hottest climates of all time. The results for life were profound; dominant groups went extinct and new groups appeared only to have their brief hegemony terminated by the next disaster. By the time these waves of extinction were over the dinosaurs were the newest kids on the block. They went on to thrive and get very large whilst scurrying around at their feet were a group of small furry creatures. These were the mammals and they would have to wait a long time for their turn.

basalt flows

A landscape entirely made of giant basalt flows from the Permian Period, Yunnan Province, SW China.

Dinosaurs were the dominant animals on Earth for over 140 million years and it is often thought that they were somehow competitively successful but I think they were just very lucky. They appeared at a time when the Earth was rapidly getting better at coping with climatic changes caused by giant volcanism. There were plenty of episodes of large-scale eruptions during the time of the dinosaurs and none caused major extinctions. The key thing was that Pangea was splitting up and separate continents were forming – the familiar continents of today’s world. Such a world seems better able to cope with rapid increases in atmospheric gases because feedback mechanisms are more effective. In particular rainfall is more plentiful when the continents are small and nowhere is too far away from the sea. Rain scrubs the atmosphere and thus alleviates the problems.

However, the $64,000 question is how quickly this feedback can happen. The world seems better at doing this today than it was in deep time but maybe we are adding the carbon dioxide too fast to our atmosphere, maybe we are swamping the system? This is a hard question to answer, we’re not sure how much gas came out during the giant eruptions of the past and so it’s hard to directly compare with the present day pollution rates. What we do know is that past mega-eruptions have been remarkably damage-free. For over 100 million years, our world has been a benign place.

Oh, except for a remarkably large meteorite impact that was bad news for the dinosaurs, but that’s another story.

Wignall jacketPaul B. Wignall is professor of palaeoenvironments at the University of Leeds. He has been investigating mass extinctions for more than twenty-five years, a scientific quest that has taken him to dozens of countries around the world. The coauthor of Mass Extinctions and Their Aftermath, he lives in Leeds.

New Earth Science Catalog

We invite you to scroll through our new Earth Science catalog:

 

Planet Oliver Morton explores the uses of geoengineering in addressing the problems posed by climate change in The Planet Remade. This is necessary reading for all those concerned with the health of our planet.
Rules In The Serengeti Rules, Sean B. Carroll describes how the rules of regulation apply to all of life, from the number of zebras in the African savanna to the amount of cells in our organs. Read it to understand how life works!
Life Be sure to check out Life’s Engines. Paul G. Falkowski explains how life is supported by microbes, organisms that have existed on Earth for billions of years.

For more information on these and many more new titles in Earth Science, look through our catalog above. If you would like updates on new titles emailed to you, subscribe to our newsletter.

Finally, if you’re going to be at the American Geophysical Union Fall Meeting from December 14 to December 18, visit PUP at booth #920 and/or join the conversation using #AGU15.

New Earth Science Catalog!

Be among the first to browse and download our new earth science catalog!

Of particular interest is Stephen R. Palumbi and Anthony R. Palumbi’s The Extreme Life of the Sea. The ocean teems with life that thrives under difficult situations in unusual environments. The Extreme Life of the Sea takes readers to the absolute limits of the aquatic world—the fastest and deepest, the hottest and oldest creatures of the oceans. It dives into the icy Arctic and boiling hydrothermal vents—and exposes the eternal darkness of the deepest undersea trenches—to show how marine life thrives against the odds. This thrilling book brings to life the sea’s most extreme species, and reveals how they succeed across the wide expanse of the world’s global ocean.

Also be sure to note Donald E. Canfield’s Oxygen: A Four Billion Year History. The air we breathe is twenty-one percent oxygen, an amount higher than on any other known world. While we may take our air for granted, Earth was not always an oxygenated planet. How did it become this way? Oxygen is the most current account of the history of atmospheric oxygen on Earth. Donald Canfield—one of the world’s leading authorities on geochemistry, earth history, and the early oceans—covers this vast history, emphasizing its relationship to the evolution of life and the evolving chemistry of the Earth. With an accessible and colorful first-person narrative, he draws from a variety of fields, including geology, paleontology, geochemistry, biochemistry, animal physiology, and microbiology, to explain why our oxygenated Earth became the ideal place for life.

And don’t miss out on Gillen D’Arcy Wood’s Tambora: The Eruption That Changed the World. When Indonesia’s Mount Tambora erupted in 1815, it unleashed the most destructive wave of extreme weather the world has witnessed in thousands of years. The volcano’s massive sulfate dust cloud enveloped the Earth, cooling temperatures and disrupting major weather systems for more than three years. Amid devastating storms, drought, and floods, communities worldwide endured famine, disease, and civil unrest on a catastrophic scale. On the eve of the bicentenary of the great eruption, Tambora tells the extraordinary story of the weather chaos it wrought, weaving the latest climate science with the social history of this frightening period to offer a cautionary tale about the potential tragic impacts of drastic climate change in our own century.

Even more foremost titles in earth science can be found in the catalog. You may also sign up with ease to be notified of forthcoming titles at http://press.princeton.edu/subscribe/. Your e-mail address will remain confidential!

If you’re heading to the annual American Geophysical Union meeting in San Francisco, CA December 9th-13th, come visit us at booth 632, and follow #AGU13 and @PrincetonUPress on Twitter for updates and information on our new and forthcoming titles throughout the meeting. See you there!

Paleoclimate

Bender_Paleoclimate “Michael Bender, a giant in the field, fits the excitement, rigor, and deep insights of paleoclimatology into a succinct text suitable for a semester-long course introducing this indispensable branch of environmental science.”–Richard B. Alley, Pennsylvania State University

Paleoclimate
Michael L. Bender

In this book, Michael Bender, an internationally recognized authority on paleoclimate, provides a concise, comprehensive, and sophisticated introduction to the subject. After briefly describing the major periods in Earth history to provide geologic context, he discusses controls on climate and how the record of past climate is determined. The heart of the book then proceeds chronologically, introducing the history of climate changes over millions of years–its patterns and major transitions, and why average global temperature has varied so much. The book ends with a discussion of the Holocene (the past 10,000 years) and by putting manmade climate change in the context of paleoclimate.

The most up-to-date overview on the subject, Paleoclimate provides an ideal introduction to undergraduates, nonspecialist scientists, and general readers with a scientific background.

Endorsements

Watch Michael Bender discuss Paleoclimate at the Fundamentals of Climate Science Symposium at Princeton University

Request an examination copy.