Under a Green Sky

[mariusromanus@aol.com]

I don't completely subscribe to Ward's conclusions in his book _Out of 
Thin Air_ concerning dinosaurs, mammals and oxygen levels... but his 
most recent book, _Under a Green Sky_, in my humble opinion, is right 
on the money.

All of the work I've been doing lately in climate science (Arctic 
climate change, in particular) pretty much hammers home his book's 
message.... especially when you consider the second article I have 
copied below which is about a study recently published in the 
Proceedings of the Royal Society B, and which also discusses an 
additional study that was presented by Ward at GSA's meeting in Denver 
a few weeks ago. The gist of it is that there is a natural 60 
million-year cycle of climate that moves between warm and cool periods. 
Right now, the current state of the climate follows suit as it warms 
from its recent glacial state. If these studies holds true, then we are 
on track to see the same level of extinctions brought about by climate 
warming in the past sometime in the next 100 years, unless greenhouse 
gas emissions are curbed, and curbed fast. What's interesting is that 
this is nearly the same conclusion announced yesterday by the 
Nobel-Prize winning U.N. scientific panel which met in Spain last week.

It's interesting how over the past couple of years, the climate 
modeling community has become less skeptical about just how bad 
conditions were, for example, 250 mya, even though the evidence is 
clearly laid out in the rocks. Climate models have become sophisticated 
enough to reproduce past climate systems with enough fidelity to 
re-create conditions like those seen preserved in the rocks... even for 
those conditions that defy belief as in severe greenhouse worlds which 
cooked the planet 4 times over the past 520 million years.

Of course, how can you trust models of past and future climate if the 
models of current climate can't get it right? Well, here's the thing... 
models of current climate DO get it reasonably right. They are not as 
far out to lunch as the media would lead you to believe. And speaking 
from my own personal experience, the main problem for climate change 
models is one of temporal resolution. And by that I mean, the changes 
in the current climate system that we are seeing are produced, but not 
soon enough; e.g. ALL models forecast Arctic ice loss, but not as fast 
as the observed conditions. They lag by an average of 50-100 yrs.

In the grand scheme of things... that is pretty freakn' scary.

Kris
Saurierlagen@gmail.com

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Global Warming Linked to Worst Mass Extinctions in Earth History
By Rosanne Skirble
Washington, DC
09 October 2007

http://www.voanews.com/english/archive/2007-10/2007-10-09-voa24.cfm?CFID=221110350&CFTOKEN=19133481

A new book explores how global warming is linked to the worst mass 
extinctions in earth's history. In Under a Green Sky, paleontologist 
Peter Ward recounts how a sharp CO2 rise accelerated dramatic 
environmental changes in the past, and what that can tell us about our 
future. Rosanne Skirble reports.

Picture this: "Shorelines encrusted with rotting organic matter. From 
shore to horizon â as far as the eye can see there is an unending 
purple color, a vast flat oily purple. We are under a pale green sky, 
and it has the smell of death and poison."

This is a scene from the book Under A Green Sky: Global Warming, the 
Mass Extinctions of the Past and What They Can Tell Us About Our 
Future.

The author, Peter Ward, has spent a career studying fossils. He 
specializes in catastrophic mass extinctions from the earth's ancient 
past â what scientists call the 'Big Five.' "[Those] that killed off at 
least 50 percent of the species on earth, and one of them, the Permian, 
may have killed off 90 percent of the species on earth," he explains.

Ward, a University of Washington paleontologist, details the causes and 
consequences of these events in Under A Green Sky. He says most 
scientists embrace the idea that a giant asteroid hit the earth around 
65 million years ago, hastening the demise of the dinosaurs. He 
describes the earth as it goes through a global blackout. "We have 
falling meteors coming back from the impact sites setting all the 
forests on fire. We have sulfur going into the atmosphere coming back 
as sulfuric acid, acidifying the ocean, acid rain in the lakes."

But asteroids do not explain the other mass extinctions. For that, Ward 
and others have found evidence in the fossil record that prolonged 
volcanic activity spewed huge amounts of carbon dioxide and other gases 
into the atmosphere. As he points out, "There was a short-term rapid 
increase in carbon dioxide. High C02 increases greenhouse temperatures 
on the planet."

Over thousands of years, that spike in CO2 and the resulting worldwide 
heat wave had nasty consequences. Winds ceased, ocean currents died and 
most marine life vanished from too much heat and too little oxygen.

Ward says things got even worse. "These warm anoxic oceans produced 
[surface] blooms of hydrogen sulfide-producing bacteria. Enough of that 
went into the atmosphere to kill land animals and land plants and cause 
the ozone to disappear as well."

Records show that environmental change began to accelerate when 
atmospheric CO2 hit 1,000 parts per million. Today's levels are 
one-third of that and rising.

Looking at the ancient evidence, Ward notes that ice caps began to 
shrink. "Melting all the ice caps causes a 75-meter increase in sea 
level. [That] will remove every coastal city on our planet." It will 
also cover earth's most productive farmland, the author warns, adding, 
"It will happen if we do not somehow control CO2 rise in the 
atmosphere."


Ward does see some positive signs in the fight against global warming. 
"Most people are now educated as to what it is and most everyone knows 
that it has to do with carbon dioxide and that we have to slow that 
down. There is half the battle right there."

Ward is also encouraged that people are beginning to make changes in 
their daily lives and demanding action from their leaders. He hopes his 
book helps readers put the current state of the earth into historical 
perspective. "[Recognizing] that we are on a planet that has violent 
convulsions, and that we humans are playing with nature in such a way 
that we could recreate what were some really awful times in earth's 
history, that we really tinker with the earth's atmosphere at our 
peril."

As Peter Ward writes in Under a Green Sky, "This moment on this Earth 
truly is a precious gift, to be savored and appreciated. If we 
needlessly destroy this world, it is unlikely we will find another to 
replace it."

---------------------------------------------


Wednesday, October 24, 2007 - Page updated at 01:04 AM

http://seattletimes.nwsource.com/html/nationworld/2003970889_extinctions24.html

Mass-extinction study casts cloud on future
By SETH BORENSTEIN

The Associated Press

WASHINGTON â Whenever the world's tropical seas rose several degrees, 
Earth experienced mass extinctions over millions of years, according to 
a first-of-its-kind statistical study of fossil records.

And scientists fear it may be about to happen again â but in a matter 
of several decades, not tens of millions of years.

Four of the five major extinctions over 520 million years of Earth 
history have been linked to warmer tropical seas, something that 
indicates a warmer world overall, according to the new study published 
today.

"We found that over the fossil record as a whole, the higher the 
temperatures have been, the higher the extinctions have been," said 
University of York ecologist Peter Mayhew, co-author of the 
peer-reviewed research published in the Proceedings of the Royal 
Society B, a British journal.

Earth is on track to hit that same level of extinction-connected 
warming in about 100 years, unless greenhouse-gas emissions are curbed, 
according to top scientists.

A second study, to be presented Sunday, links high carbon-dioxide 
levels, the chief man-made gas responsible for global warming, to past 
extinctions. The study was conducted by a University of Washington 
scientist.

In the British study, Mayhew and his colleagues looked at temperatures 
in 10 million-year chunks because fossil records aren't that precise in 
time measurements. They compared those to the number of species, the 
number of species families, and overall biodiversity. They found more 
biodiversity with lower temperatures and more species dying with higher 
temperatures.

The researchers examined tropical-sea temperatures â the only ones that 
can be determined from fossil records and go back hundreds of millions 
of years. They indicate a natural 60 million-year climate cycle that 
moves from a warmer "greenhouse" to a cooler "icehouse." The Earth is 
warming from its current colder period.

Every time the tropical-sea temperatures were about 7 degrees warmer 
than they are now and stayed that way for enough years, there was a 
die-off.

The study linked mass extinctions with higher temperatures but did not 
try to establish a cause and effect. For example, the most recent mass 
extinction, the one 65 million years ago that included the die-off of 
dinosaurs, probably was caused by an asteroid collision as scientists 
theorize and Mayhew agrees.

But extinctions were likely happening anyway as temperatures were 
increasing, Mayhew said. Massive volcanic activity, which releases 
large amounts of carbon dioxide, has also been blamed for the dinosaur 
extinction.

The author of the second study, which focuses on carbon dioxide, said 
he sees a cause and effect between warmer seas and extinctions.

Peter Ward, a University of Washington biology and paleontology 
professor, said natural increases in carbon dioxide warmed the air and 
ocean. The warmer water had less oxygen and spawned more microbes, 
which in turn spewed toxic hydrogen sulfide into the air and water, 
killing species.

Ward examined 13 major and minor extinctions in the past and found a 
common link: rising carbon-dioxide levels in the air and falling oxygen 
levels. Ward's study will be presented Sunday at the Geological Society 
of America's annual convention in Denver.

Mayhew also found increasing carbon-dioxide levels in the air 
coinciding with die-offs.

Those higher temperatures that coincided with mass extinctions are 
about the same level forecast for a century from now if the world 
continues its growing emissions of greenhouse gases, according to the 
Intergovernmental Panel on Climate Change.

In April, the same climate panel of thousands of scientists warned that 
"20 to 30 percent of animal species assessed so far are likely to be at 
increased risk of extinction" if temperatures rise by about 3 to 4 
degrees Fahrenheit.

"Since we're already seeing threshold changes in ecosystems with the 
relatively small amount of climate change already taking place, one 
could expect there's going to be severe transformations," said 
biologist Thomas Lovejoy, president of the H. John Heinz Center for 
Science, Economics and the Environment in Washington, D.C.

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