Quick Questions for Richard Karban, author of How to Do Ecology: A Concise Handbook (Second Edition)

Richard KarbanDr. Richard Karban is a professor of entomology at the University of California, Davis. He is a recipient of the George Mercer Award, presented by the Ecological Society of America for outstanding research (1990) and was a 2010 Fellow in the American Association for the Advancement of Science.

Dr. Karban received a B.A. in Environmental Studies from Haverford College (1977) and completed his Ph.D. in Ecology at the University of Pennsylvania (1982). He is the recipient of nearly a dozen research grants, whose focuses range from population regulation to plant resistance of insects and pathogens. He is the author of How to Do Ecology: A Concise Handbook (Second Edition).

Now, on to the questions!

PUP: What inspired you to get into your field?

Richard Karban: I grew up in an ugly and dangerous neighborhood in New York City. Natural history and natural areas were highly romanticized in my mind. Being an ecologist seemed like an exciting way to escape this life.

What is the book’s most important contribution?

Doing ecological research successfully requires a considerable amount of insider knowledge. We don’t teach these tips in academic classes. This book attempts to provide a simple set of guidelines for navigating the process of generating hypotheses, testing them, analyzing your results, and communicating with an interested audience. In my opinion, this is what we should be teaching ecology students, but aren’t.


“Indeed, confidence and persistence are the most important attributes that separate successful projects from failures.”


What was the biggest challenge with bringing this book to life?

The biggest challenge getting this book to happen was not allowing myself to get discouraged. I teach a graduate-level course in which each student develops an independent field project. The book started as a series of handouts that I gave my students. Each year, I revised my pile of materials. After a decade or so of revisions, I submitted a manuscript but was told that it was too short and lacked interesting visuals and other tools that would make the material accessible. Okay, so much for that, although I continued to add and tweak the content for my class. My wife, Mikaela Huntzinger, read what I had and convinced me that it would be useful to students; she also volunteered to add figures and boxes. Most of all, she encouraged me not to give up on the thing. Indeed, confidence and persistence are the most important attributes that separate successful projects from failures.

Why did you write this book?

I had a terrible time in grad school. I didn’t attend a large research university as an undergrad and I arrived with little sense of how to do research or thrive in an environment that valued research, publications, and grants above all else. Figuring out the culture was a painful process of trial and error. My experiences made me acutely aware of the “game” and made me want to share what I had learned to spare others the same pain.

Who is the main audience?

This book is intended primarily for young ecologists who can use some help posing interesting questions, answering them, and communicating what they find. Undergrads who want to do research and grad students doing a thesis are the two populations who will find the book most useful, although we hope that our colleagues will also get something from it.

How did you come up with the title and cover?

The title is a little presumptuous, but also conveys what we hope to provide in a few clear words – perfect.

The cover reflects my long-standing interest in streams that cut gently through landscapes. The first edition had a photo taken by my collaborator, Kaori Shiojiri, at our field site along Sagehen Creek. This edition features an abstraction of that image that I painted. If we write future editions, they will have further abstractions of that same theme done as a mosaic (Mikaela’s favorite medium) or as a stained glass (one of Ian’s).

Check out Chapter 1 of the book, here.

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Richard Karban is the author of:

6-6 Ecology How to Do Ecology: A Concise Handbook (Second Edition) by Richard Karban, Mikaela Huntzinger, & Ian S. Pearse
Paperback | May 2014 | $24.95 / £16.95 | ISBN: 9780691161761
200 pp. | 5 x 8 | 8 line illus. | eBook | ISBN: 9781400851263 |   Reviews Table of Contents Chapter 1[PDF]

Princeton at Hay Festival


Hay on Monday evening
Blackburn at Hay
Simon Blackburn talks to Rosie Boycott
Mitton at Hay
Jacqueline Mitton broadens our knowledge of the solar system
Bethencourt at Hay
Francisco Bethencourt discusses “Racisms”

Last week was an important week in the British literary calendar–the week of Hay Festival! Set in beautiful Hay-on-Wye on the Welsh Borders, and running since 1988, the festival attracts thousands of book and culture enthusiasts from around the world every year. This year’s line-up was as strong as ever: with names such as Toni Morrison, Richard Dawkins, Stephen Fry, Mervin King, Jeremy Paxman, Simon Schama, Sebastian Faulks, William Dalrymple, Benedict Cumberbatch, Bear Grylls, Max Hastings, Rob Brydon, Bill Bailey and Dame Judi Dench (to name but a few to catch my eye in the jam-packed programme), 2014′s Festival could not fail to enthrall and delight anyone who walked its muddy paths.

And of course, Princeton University Press authors have been gracing the Hay stages this year, with a variety of wonderful events. From Diane Coyle, explaining GDP to us in plain English (and lo0king very stylish in her Hay wellies) to Michael Wood (translator of Dictionary of Untranslatables) discussing words that defy easy–or any–translation from one language and culture to another, to Ian Goldin’s talk about globalization and risk (The Butterfly Defect), last weekend got off to a great start.

Then, earlier in the week, Jacqueline Mitton (author of From Dust to Life) took a gripped audience on a journey through the history of our solar system in her “John Maddox Lecture”.  On Tuesday, Rosie Boycott spoke to Simon Blackburn about his book Mirror, Mirror–a fascinating conversation which covered everything from psychopathic tendencies displayed in senior management to whether Facebook is really that damaging to the young. Francisco Bethencourt, meanwhile, managed to squeeze a history of racisms into an hour and gave us lots to ponder.

If all this leaves you wishing you’d been there, there is still more to envy! Later in the week, Roger Scruton, Will Gompertz and others discussed the value of a Fine Art degree – does contemporary art celebrate concept without skill? On a parallel stage, renowned historian Averil Cameron (author of Byzantine Matters) convinced us that an understanding of the Byzantine era is just as important as studying, say, Rome or Greece. Finally, Michael Scott (author of Delphi), whom it is almost impossible to miss on the BBC these days, delivered a talk about Delphi: A History of the Center of the Ancient World on Friday.

Whether you swoon for science are potty for poetry, whether you want to dance the night away in a frenzy of jazz or are hoping to meet your favourite on-screen star, Hay Festival offers something new and exciting every year.

It’s Getting Hot in Here: Eric H. Cline’s New York Times Op-Ed on the Perils of Climate Change

5-28 Bronze Age CollapseIn the eye of the storm – that is to say, in the unrelenting public discussion that is climate change – author Eric H. Cline’s latest Op-Ed for The New York Times packs quite a gale force.

Holding both ancient and contemporary society up to the proverbial light, Cline asks if we’re really all that different from our forebears and whether or not we’re capable of avoiding a similarly abrupt end.

Eric H. Cline, a Professor of classics and anthropology at George Washington University and the Director of the Capitol Archaeological Institute,  doesn’t hesitate to present these very early, and very scary repercussions of environmental catastrophe. He reminds readers that these events have acted as catalysts of warfare and harbingers of destruction since the days of old, or, more specifically, since the tail-end of the Late Bronze Age.

In his new book, 1177 B.C.: The Year Civilization Collapsed, Cline reveals that the thriving cultures within Egypt, Greece, and Mesopotamia didn’t necessarily succumb to the military prowess of the ‘Sea Peoples’ alone, but rather, fell victim to Mother Nature herself: earthquakes, changes in water temperature, drought, and famine hearkened in a period of rebellion, followed by complete ruin.


“We still do not know the specific details of the collapse at the end of the Late Bronze Age or how the cascade of events came to change society so drastically. But it is clear that climate change was one of the primary drivers or stressors, leading to the societal breakdown.”


The real question Cline seems to be getting at is: “Why not us?” We’re no more able to control the weather than they were – or are we? Recent debates about global warming suggest that we might just be able to put off our own demise, at least temporarily.

What happens if we don’t change our habits, however, is less certain; but Cline is fairly convinced, based on the evidence from his book, that it won’t be good. For him, the possibility of total collapse is far from the realm of the ridiculous, and his article is not so much a threat as it is a warning. Maybe if we know what brought our ancestors into the Dark Ages, we can stay in a light for just a little while longer.

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Eric H. Cline is the author of:

5-28 Cline 1177 B.C.: The Year Civilization Collapsed by Eric H. Cline Hardcover | 2014 | $29.95 / £19.95 | ISBN: 9780691140896
264 pp. | 6 x 9 | 10 halftones. 2 maps. | eBook | ISBN: 9781400849987
Reviews Table of Contents Prologue[PDF]

Happy Darwin Day!

We’re celebrating with Steve Palumbi, co-author of The Extreme Life of the Sea.

In 1837 Charles Darwin first speculated that atolls, ring-shaped coral reefs that encircle lagoons, formed by growing around volcanic islands that eventually sunk. It took 100 years to prove Darwin’s theory of atoll formation correct. Why? Steve Palumbi explains in this video at his Stanford-based Microdocs site.

The Extreme Life of the Sea highlights other fascinating facts about these delicate yet enduring creatures.  Black corals, Steve and his co-author Anthony Palumbi explain in their chapter “The Oldest”, can be smashed to bits by the smallest waves yet have been known to live up to 4,600 years and are likely the oldest living organisms on the planet. Instead of becoming frail as they age like many other species, the longer black corals live the more likely they are to survive and reproduce.

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Photo by Steve Palumbi.

The book is just now shipping to stores, but we’ve made the book’s prologue available online to tide you over until you can get your hands on a copy.

Join us from February 3 – 8 as we celebrate UnShark Week

What is UnShark Week, you ask?

A birthday held six months away from the real one, is an UnBirthday. So, for the thousands of ocean species that are just as interesting and sometimes more extreme than sharks, we propose the week of Feb 3-8, 2014 as UnSharkWeek.

UnSharkWeek will introduce fans of Shark Week to other extreme forms of life in the sea. There are all sorts of really cool things happening in the harshest environments on Earth, so join Steve Palumbi, one of the world’s leading marine biologists, as he celebrates some of the deepest, fastest, oldest, and just plain strangest creatures found in the ocean.

Follow along here: http://unsharkweek.tumblr.com/

For more information about The Extreme Life of the Sea by Steve and Anthony Palumbi or to read an excerpt from the book, please visit this web site: http://press.princeton.edu/titles/10178.html

The Extreme Life of the Sea by Stephen & Anthony Palumbi (#ExtremeLifeOTC)

This book officially publishes in March 2014 and will be available in three formats: Print, standard eBook, and enhanced eBook (featuring a dozen exclusive videos that are beautifully produced and informative).

For more about the book, please visit our web site: http://press.princeton.edu/titles/10178.html

“The oceans are our most precious treasure, full of creatures and stories more fantastic than any science fiction. The Extreme Life of the Sea is a fascinating exploration of this vast mysterious universe. Wonderfully written, it will grab you from page one and carry you all the way through. A must-read for everyone.”–Philippe Cousteau

“This book brims with fascinating tales of life in the sea, told with freshness, wit, and verve. Simply wonderful.”–Callum Roberts, author of The Ocean of Life: The Fate of Man and the Sea

Hurricane Sandy and Global Warnings, an original article by Ian Roulstone and John Norbury

Hurricane Sandy and Global Warnings

Ian Roulstone and John Norbury

There are many heroes in the story of Hurricane Sandy, but we arguably owe the greatest debt of gratitude to mathematicians who wrangle massive amounts of data to improve the accuracy of our weather predictions. Two devastating storms, decades apart, provide a fantastic snapshot of how weather prediction has improved thanks to the introduction of computational mathematics over the last century.

Just over 75 years ago, on September 9th 1938 above the warm tropical waters near the Cape Verde islands, a storm gathered. As the weather system intensified, it was ushered westward by the prevailing larger-scale ridge of high pressure over the Atlantic. By the 16th the storm had become a hurricane, and the captain of a Brazilian freighter caught sight of the tempest northeast of Puerto Rico. He radioed the U.S. Weather Bureau to warn them of the impending danger – no satellites or sophisticated computer models to help the forecasters in those days.

A deep trough of low pressure over Appalachia forced the storm northward, avoiding the Bahamas and Florida, and towards the north-eastern seaboard of the United States. The forecasters were relying on real-time reports of the storm’s progress, but it advanced at an incredible pace, moving northward at nearly 70mph. By the time the Weather Bureau realised it was on a collision course with Long Island it was too late. The death toll from the Great New England Hurricane approached 600, with over 700 injured, and the damage was estimated at $308 million – or around $4.8 billion at today’s prices.

History very nearly repeated itself on October 29 and 30th last year, when Hurricane Sandy slammed into New Jersey. Meteorologists referred to Superstorm Sandy as a “multi-hazard event”, with major damage resulting from wind gusts, from high seas, from a tidal surge, from heavy rain, and even from driving snow. The number of fatalities in the U.S., attributed either directly or indirectly to Hurricane Sandy, were around 160: a tragedy, but mercifully fewer than the number killed by the Great Hurricane of 1938.

It is almost certain that timely warnings averted greater catastrophe last year. Unlike the storm of 1938, which caught forecasters by surprise, one of the most remarkable features of the forecast of Hurricane Sandy from the European Centre for Medium-Range Weather Forecasts (ECMWF) was the prediction made on October 21st, 36 hours before Sandy even formed, of a one-in-four chance of a severe storm, centred on New York, on October 30th.

ECMWF routinely produce two types of forecast for 10 days ahead. As they state in a recent newsletter “The ECMWF global medium-range forecast comprises a high-resolution forecast (HRES) and an ensemble of lower-resolution forecasts (ENS)”, and it was the ENS that helped forewarn of Sandy.

To calculate a forecast we use supercomputers to solve seven equations for the seven basic variables that describe weather: wind speed and direction (3 variables), pressure, temperature, air density, and humidity. The equations governing weather are highly nonlinear. This means that the ‘cause and effect’ relationships between the basic variables can become ferociously complex. To deal with the potential loss of predictability, forecasters study not one, but many forecasts, called an ensemble. Each member of the ensemble is started from a slightly different initial state. These different initial states reflect our ignorance of exactly how weather systems form. If the forecasts predict similar outcomes, we can be reasonably confident, but if they produce very different scenarios, then the situation is more problematic.

In the figure below the ensemble of forecasts for Sandy, starting at midday on October 23rd indicates the high probability of the ‘left turn’ and the most probable landfall – information that helped save lives. The inset at top right shows the strike probability chart that highlights the region around New York within which there is 25% chance of a severe storm by midnight on October 30th. This forecast was computed from an earlier ensemble starting at midday on October 21st and gave forecasters the vital “heads-up” of severe weather striking a highly populated area.

Forecasting Superstorm Sandy: The ensemble of forecasts covering the 10 days from the formation of the cyclone on October 23; the dotted black line is the actual track of the storm. Top right inset shows the storm strike probability from midday October 21. Bottom right inset shows the ensemble predictions of Sandy’s central pressure. © ECMWF

Forecasting Superstorm Sandy: The ensemble of forecasts covering the 10 days from the formation of the cyclone on October 23; the dotted black line is the actual track of the storm. Top right inset shows the storm strike probability from midday October 21. Bottom right inset shows the ensemble predictions of Sandy’s central pressure. © ECMWF

The science of weather and climate prediction was utterly transformed in the second half of the 20th Century by high-performance computing. But in order to fully exploit the computational power, and the information gathered by weather satellites and weather radar, we need mathematics.  As we explained in our article in Scientific American [hyperlink] math quantified the choreography of Hurricane Sandy. And to account for the ever-present uncertainties in the science of weather forecasting, math delivers the tools to analyse the predictions and to highlight the dangers.

Lives were saved because of the quality of our weather forecasts, which are made possible by an international group of mathematicians and weather prediction centers. The math that helps us quantify uncertainty in weather forecasting is being used to quantify uncertainty in climate prediction. It is easy to underestimate the value of this research, but investing in this science is vital if we are to stave off future billions in damages.

 


For further insights into the math behind weather and climate prediction, see Roulstone and Norbury’s new book Invisible in the Storm: The Role of Mathematics in Understanding Weather.

 

Climate Change: a Movie and the Math by Ian Roulstone and John Norbury

Climate Change: a Movie and the Math

By Ian Roulstone and John Norbury

Next week the Intergovernmental Panel on Climate Change (IPCC) will release the first of three reports that constitute their Fifth Assessment Report on climate change. This first report, The Physical Science Basis, will cover a huge range of topics from the carbon cycle to extreme weather. But climate prediction also relies heavily on mathematics, which is used to quantify uncertainties and improve the models.

The role of math is illustrated by a remarkable video of our ever-changing weather. Last month the National Oceanic and Atmospheric Administration (NOAA) decommissioned Geostationary Operational Environmental Satellite 12 (GOES-12), which monitored our weather for the past 10 years from its isolated vantage point 36,000 kilometers above America and the Atlantic Ocean.

GOES-12 had seen it all – from wildfires, volcanic ash, and landscape parched by drought, to Hurricanes Ike, Katrina and Sandy, and the blizzards that gripped the central United States in the winter of 2009-10. NOAA created a video – 187 seconds and 3641 images – one snapshot from each day of its operational life, which amounts to 10 years’ weather flashing before our eyes in just over 3 minutes. It’s dramatic and amazing:

In Scientific American, Evelyn Lamb commented on how this video highlights “a tension between the unpredictability of the weather and its repetitiveness”. Even after a few seconds it becomes clear that the patterns revealed by clouds differ from one part of the globe to another. Great towering cumulonimbus bubble up and unleash thunderstorms in tropical regions every day, while in more temperate mid-latitudes, the ubiquitous low pressure systems whirl across the Atlantic carrying their warm and cold fronts to Europe. The occasional hurricane, spawned in the tropics, careers towards the United States (Hurricane Sandy can be seen at about 2’50’’). But the mayhem is orchestrated: the cyclones almost seem like a train of ripples or waves, following preferred tracks, and the towering storms are confined largely to the tropics.

CaptureThis image of water vapour in the atmosphere (taken by GOES-13) reveals the swirling cyclones and the tropical storms. While the detail varies from hour to hour and from day to day, there are recurring patterns. Image courtesy of NEODAAS/University of Dundee.

In fact, this movie is affording us a glimpse of a remarkable world – it is a roller-coaster ride on the ‘weather attractor’.

An ‘attractor’ is a mathematician’s way of representing recurring behavior in complex systems, such as our atmosphere. A familiar illustration of an attractor can be seen in the figure below, and it is named after one of the fathers of chaos, Edward Lorenz.

Capture
The Lorenz attractor: every point within the space delineated by the coordinate axes represents a possible state of a circulating fluid, such as the ascent of warm air and the temperature difference of the warmer rising air to the cooler descending air. The points on the ‘butterfly wings’ are the attractor: they represent the set of states through (or around) which such a system will evolve. Even if the system begins from a state that does not lie on the attractor, it tends towards the states that do. The transition from one wing of the attractor to the other (which might represent a change in the ‘weather’) can be difficult to predict, due to inherent chaos in the system. But the overall pattern captures the repetitiveness.

It is impossible to illustrate the weather attractor for the atmosphere in terms of a simple three-dimensional image: Lorenz’s very simple model of a circulating cell had only three variables. Our modern computer models used in climate prediction have around 100 million variables, so the attractor resides in a space we cannot even begin to visualise. And this is why the movie created by NOAA is so valuable: it gives us a vivid impression of the repetitiveness emerging from otherwise complex, chaotic behaviour.

Weather forecasters try to predict how our atmosphere evolves and how it moves around the attractor – a hugely difficult task that requires us to explore many possible outcomes (called an ensemble of forecasts) when trying to estimate the weather several days ahead. But climate scientists are faced with a very different problem: instead of trying to figure out which point on the 100 million-dimensional attractor represents the weather 100 years from now, they are trying to figure out whether the shape of the attractor is changing. In other words, are the butterfly wings ‘folding’ as the average weather changes? This is a mathematician’s way of quantifying climate change.

If 100 years from now, when a distant successor of GOES-12 is retired, our descendants create a movie of this future weather, will they see the same patterns of recurring behaviour, or will there be more hurricanes? Will the waves of cyclones follow different tracks? And will tropical storms be more intense? Math enables us to “capture the pattern” even though chaos stops us from saying exactly what will happen, and to calculate answers to these questions we have to calculate how the weather attractor is changing.

 


This article is cross-posted with the Huffington Post: http://www.huffingtonpost.com/ian-roulstone/climate-prediction-mathematics_b_3961853.html

For further insights into the math behind weather and climate prediction, see Roulstone and Norbury’s new book Invisible in the Storm: The Role of Mathematics in Understanding Weather.

David Vogel, author of The Politics of Precaution, is crowned winner of the 2013 Levine Prize

David Vogel, author of The Politics of Precaution: Regulating Health, Safety, and Environmental Risks in Europe and the United StatesDAVID VOGEL - The Politics of Precaution: Regulating Health, Safety, and Environmental Risks in Europe and the United States

Winner of the 2013 Levine Prize, Research Committee on the Structure of Government (SOG) of the International Political Science Association

The Prize is awarded to a book that makes a contribution of considerable theoretical or practical significance in the field of public policy and administration, takes an explicitly comparative perspective, and is written in an accessible style.

Committee statement about the award:

“In recent decades, the politics of risk regulation has played a growing role all round the world. In his carefully crafted and compelling book The Politics of Precaution: Regulating Health, Safety, and Environmental Risks in Europe and the United States (Princeton University Press, 2012), David Vogel explores the changing transatlantic policy divergence in risk regulation. Dealing with an impressive number of issues, ranging from food safety and agriculture to air pollution, consumer safety and chemicals and hazardous substances, this well-written and policy-relevant book formulates an original framework to explain the regulatory and perception gap between Europe and United States.

“This historically-minded book also covers more than a half century of policy development, from the late 1950s to the present, a period during which the United States lost its status of regulatory leader at the expense of the European Union, where the precautionary principle has become prevalent. This is a convincing and illuminating book on a broad topic that students of risk regulation, environmental policy, and comparative public policy should find most helpful. The Award Committee is pleased to select this excellent book as the 2013 recipient of the Levine Award.”

View the Levine Award information on the GOVERNANCE Blog: http://governancejournal.net/levine-book-prize/

The Politics of Precaution: Regulating Health, Safety, and Environmental Risks in Europe and the United States by David VogelThe Politics of Precaution examines the politics of consumer and environmental risk regulation in the United States and Europe over the last five decades, explaining why America and Europe have often regulated a wide range of similar risks differently. It finds that between 1960 and 1990, American health, safety, and environmental regulations were more stringent, risk averse, comprehensive, and innovative than those adopted in Europe. But since around 1990, the book shows, global regulatory leadership has shifted to Europe. What explains this striking reversal?

David Vogel takes an in-depth, comparative look at European and American policies toward a range of consumer and environmental risks, including vehicle air pollution, ozone depletion, climate change, beef and milk hormones, genetically modified agriculture, antibiotics in animal feed, pesticides, cosmetic safety, and hazardous substances in electronic products. He traces how concerns over such risks–and pressure on political leaders to do something about them–have risen among the European public but declined among Americans. Vogel explores how policymakers in Europe have grown supportive of more stringent regulations while those in the United States have become sharply polarized along partisan lines. And as European policymakers have grown more willing to regulate risks on precautionary grounds, increasingly skeptical American policymakers have called for higher levels of scientific certainty before imposing additional regulatory controls on business.

David Vogel is professor at the Haas School of Business and in the Department of Political Science at the University of California, Berkeley.

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.

 

Toby Tyrrell, author of On Gaia, explains how he came to question the Gaia Hypothesis

We interviewed Toby Tyrrell about his new book “On Gaia” last week. This week, we’re proud to link to this article in which he details some of the research that led him to view the Gaia Hypothesis with a critical eye:

Nitrogen is exceptionally abundant in the environment, it makes up 78 per cent of air, as dinitrogen (N2). N2 is also much more plentiful in seawater than other dissolved forms of nitrogen. The problem is that only organisms possessing the enzyme nitrogenase (organisms known as nitrogen-fixers) can actually use N2, and there aren’t very many of them. This is obviously a less than ideal arrangement for most living things. It is also unnecessary. Nitrogen starvation wouldn’t happen if just a small fraction of the nitrogen locked up in N2 was available in other forms that can be used by all organisms; yet biological processes taking place in the sea keep nearly all that nitrogen as N2. If you think about what is best for life on Earth and what that life can theoretically accomplish, nitrogen starvation is wholly preventable.

This realisation led me to wonder what other aspects of the Earth environment might be less than perfect for life. What about temperature? We know that ice forming inside cells causes them to burst and that icy landscapes, although exquisite to the eye, are relatively devoid of life. We can also see that ice ages – the predominant climate state of the last few million years – are rather unfortunate for life as a whole. Much more land was covered by ice sheets, permafrost and tundra, all biologically impoverished habitats, during the ice ages, while the area of productive shelf seas was only about a quarter of what it is today. Global surveys of fossil pollen, leaves and other plant remains clearly show that vegetation and soil carbon more than doubled when the last ice age came to an end, primarily due to a great increase in the area covered by forests.

Although the cycle of ice ages and interglacials is beyond life’s control, the average temperature of our planet – and hence the coldness of the ice ages – is primarily determined by the amount of CO2 in the atmosphere. As this is potentially under biological control it looks like another example of a less than perfect outcome of the interactions between life on Earth and its environment.

Look further and you find still more examples. The scarcity of light at ground level in rainforests inhibits growth of all but the most shade-tolerant plants. There’s only really enough light for most plants at canopy height, often 20 to 40 metres up, or below temporary gaps in the canopy. The intensity of direct sunlight does not increase the higher you go, so having the bulk of photosynthesis taking place at such heights brings no great advantage to the forest as a whole. Rather the contrary, trees are forced to invest large amounts of resources in building tall enough trunks to have the chance of a place in the sun. This arrangement is hard to understand if you expect the environment to be arranged for biological convenience, but is easily understood as an outcome of plants competing for resources.

Source: “Not Quite Perfect”, Planet Earth Online: http://planetearth.nerc.ac.uk/features/story.aspx?id=1492&cookieConsent=A

 

Read a sample chapter from On Gaia: A Critical Investigation of the Relationship between Life and Earth [PDF].

Q&A with Toby Tyrrell, author of “On Gaia”

 

tyrell_toby_au photo

Toby Tyrrell is professor of Earth system science at the National Oceanography Centre Southampton (University of Southampton). His new book On Gaia: A Critical Investigation of the Relationship between Life and Earth publishes at the end of July.

He kindly answered some questions from our UK Director of Publicity Caroline Priday.

Q: Why did you write this book

A: My aim was to determine whether the Gaia hypothesis is a credible explanation of how life and environment interact on Earth.

 

Q: What is the Gaia hypothesis?

A: James Lovelock’s Gaia hypothesis, first put forward in the 1970’s, proposes that life has played a critical role in shaping the planetary environment and climate over ~3 bil­lion years, in order to keep it habitable or even optimal for life down through the geological ages. Life has not been merely a passive pas­senger on a fortuitously habitable Earth, it is claimed, but rather has shaped the environment and helped to keep it comfortable.

 

Q: Why has there been so much interest in the Gaia hypothesis?

A: In part because it suggests answers to some fundamental questions of widespread interest, such as how it is that Earth remained continuously habitable for so long, how did our planet and the life upon it end up the way they are, and how does the Earth system work?

 

Q: Lots of scientists have considered Gaia before – what is different about this book?

A: Previous books have been mostly reviews of the scientific debates over Gaia, collections of scientific papers, or congratulatory restatements of Gaia by supporters. This book is the first to submit the Gaia hypothesis to detailed sceptical scrutiny, subjecting each of three main arguments put forward in support of Gaia to close analysis, and comparing them to modern evidence collected in the more than 30 years since the Gaia hypothesis was first proposed. It is the first book containing a hard-nosed and thorough examination of the Gaia hypothesis.

 

Q: What are the three main arguments that have been advanced in support of Gaia?

A: Firstly, that the Earth is very comfortable for life. Secondly, that the presence of life on Earth has profoundly altered the nature of the planetary environment. And thirdly, that the environment has remained fairly stable over geological time.

bookjacket

Q: What is the main conclusion of the book?

A: That the Gaia hypothesis does not “hold up in court”: it is not consistent with modern scientific evidence and understanding and should therefore be rejected.

 

Q: What are the reasons given for rejecting the Gaia hypothesis?

A: Firstly because there are no facts or phenomena that can be explained only by Gaia (no ‘smoking gun’). Secondly because there is no proven mechanism for Gaia (no accepted reason for why it should emerge out of natural selection). And thirdly because the key lines of argument that Lovelock and others advanced in support of Gaia either give equally strong support to alternative hypotheses or else are mistaken. For instance the planet is not excessively favourable for life: it has been colder than optimal during the ice ages that have occupied the majority of the last few million years, and unnecessary nitrogen starvation is ubiquitous. Its environmental history has not been all that stable: we now have abundant evidence of past environmental instability, from ice age cycles to seawater Mg/Ca variation to Snowball/Slushball Earths.

 

Q: If life and its environment do not interact in the way suggested by Gaia (life moulding the environment towards its own convenience) then how do they interact?

A: Through ‘coevolution’. Stephen Schneider and Randi Londer put forward the idea of a coevolution between life and its environment: biological processes such as oxygen production by photosynthesis shape the environment, and, clearly, the environment also strongly influences life through evolution of organisms to fit their environments. Coevolution recognises that both affect the other. Unlike Gaia, however, coevolution does not claim any emergent property out of the two-way interaction between life and environment. It is neutral with regards to predictions about the resulting effect on the environment. It does not suggest that the interaction tends to improve living conditions on Earth.

 

Q: If the Gaia hypothesis is not the reason, then why did the Earth remain habitable for such an enormously long interval of time?

A: This may relate partly to the weak Anthropic Principle, whereby we logically cannot observe any facts that preclude our own existence. So however infrequent it may be in the universe for a planet to remain continuously habitable over billions of years, we happen to be on just such a planet. According to this way of thinking, Earth may just have been lucky, with no sentient observers having evolved on other planets which were not so lucky, i.e. where conditions became sterile at some point. Another possible explanation for extended habitability in the absence of Gaia is a predominantly inorganic thermostat, such as has been suggested for silicate weathering.

 

Q: Why would people be interested in this book?

A: It considers some of the great questions about the nature of our planet, its history, and how it came to give rise to us. Many fascinating topics are covered, often from little-known corners of the natural world. Examples include: hummingbirds in the High Andes and the similarity of their beaks to the flowers they extract nectar from, the wonderfully-named Walsby’s square archaeon in the Dead Sea, the ever-lasting durability of the waste that coral reefs generate (not everything in nature is recycled), changes in the nature of the saltiness of seawater over geological time, and differences in the way Australian snakes bear young depending on climate (they don’t always lay eggs).

 

Q: Are there any implications for the current era of global change?

A: Yes, it is suggested that belief in the Gaia hypothesis can lead to excessive complacency about the robustness and resilience of the natural system. Gaia emphasizes stabilising feedbacks and protective mechanisms that keep the environment in check. If Gaia is rejected, however, we are left with a less comforting view of the natural system. Without Gaia it is easier to appreciate that the natural system contains lines of weakness and other susceptibilities. One such line of weakness that has already been demonstrated is the ozone layer depletion by CFC’s. I have argued in the book that there is no over-riding Gaia to protect our planet’s life support system. Maintaining the Earth’s environment is up to us.

 

Read a sample chapter from On Gaia: A Critical Investigation of the Relationship between Life and Earth [PDF].