Book Review: The Whole Story of Climate: What Science Reveals About
the Nature of Endless Change by E. Kirsten Peters (Prometheus Books 2012)
Hot off the presses, this very readable book delves into the
history and implications of climate science. The potential implications of
climatology go way beyond just man-made global warming and this book does an
excellent job of presenting much of the developmental picture of climate
science as we know it, without being overly biased regarding predictions and
policy. The author is a geologist too and provides a wonderful geological
history of climate science. Although this book is a great and valuable read it
is in no way the “whole” story of climate. It is a great history of climate
science from a predominantly geological perspective but it neglects much
meteorological and atmospheric data and is not in great detail as some climate
studies are. Her conclusions regarding the immediate threat of climate change
are a bit more muted than the detailed data suggest in my opinion. Nonetheless
she does paint a nice picture of the development of climatology as well as some
ideas for the future.
Geological evidence reveals multiple massive climate change
events. The author notes that many of these happened very quickly (in geologic
time terms) although the pace of anthropogenic climate change seems likely far
quicker than any of these.
She suggests that climate scientists rely too much on
computer models and should rely more on geological studies of past climate
events. This may be true but it does not offer any evidence to the contrary
that man-made climate problems could be in a precarious position in danger of
feed-backing out of control as evidence suggests. In fact, studies of the
geologic past may be supporting the alarmist position. She talks about rapid
climate change events (RCCE) such as one that is thought to have occurred in
ancient Egypt around 2300 BC where there are records of drought, crop failures,
and subsequent famine to the extent that people were said to have eaten their
own children. She does point out that we have been remarkably fortunate for the
climate stability since the last Ice Age since natural climate change can be
extreme, especially on a local scale.
We have a very good geologic picture of the extent and
conditions of Pleistocene glaciation that began about 1.8 million years ago
(mya) and ended about 10,000 years ago. The general pattern has been about
100,000 years of cold Ice Age conditions followed by about 10,000 years of warm
conditions so logically one could assume that we are due for another Ice Age
soon. The Holocene Era (dubbed so due to the influence of humans) begins after
the last Pleistocene ice recedes and humans very soon make jumps such as
agriculture, animal domestication, pottery, cloth-weaving, and eventually
writing. The implications of a new Ice Age are potentially as bad or worse than
current scenarios of global warming. The world’s foremost grain agricultural
regions would be under ice and famine could kill billions. The author notes
that such a change could occur rapidly, in the space of a few generations, and
indeed this was more of a concern before the data about industrial greenhouse
gases was discovered and tracked to show that it was causing climate to warm.
There is also the possibility that humans have increased greenhouse gas emissions
since the advent of agriculture through such methods as slash and burn. This,
along with industrial greenhouse gases may have actually held off the Ice Age
that was due in the current solar minimum. Even the foremost climate scientist
and global warming alarmist champion Dr. James Hansen has implied that that
might be the case.
The author gives a nice history of the development of
glacial geology in the early 1800’s in the story of the Swiss scientist Louis
Agassiz’s work beginning in the Alps . This is
a story of the development of glaciology as a science. He convinced the famed
naturalist/geologist Charles Lyell of his theory of Ice Ages and mounting
evidence brought it into the mainstream. Geology as a profession led to
detailed observations and terrain mapping that further confirmed mechanisms and
multiple periods of glaciation. The glacial extents of the various periods are
now well mapped. Water wells revealed multiple layers of glacial debris called
till, with layers containing wood in between, which indicates changing climatic
conditions through time. Reading the vertical record through geologic time
became established and thus stratigraphy was born. Beach strands indicated sea
level fluctuations through time. In terms of climate, sea level is low when ice
is thick and high when temps warm back up. It was also discovered that land
surfaces flexed upward, or “rebounded” through time after heavy weights of ice
were removed. Such is happening now around the Great Lakes and in Scandinavia . The author gives stories of other early
geologists such as Whittlesey, T.C. Chamberlain, and G.K. Gilbert. Gilbert
unraveled the mystery of the Lake Bonneville Salt Flats in Utah ,
the massive lake that was breached and emptied into the Snake River Canyon
and on to the Columbia River Gorge to the Pacific. It is now well-known that
catastrophic flooding accompanied the retreating and melting of glaciers.
The proliferation of religion and observations of an ordered
world led many in the past – such as Thomas Jefferson – to infer an ‘intelligent
design-like’ theory of nature where everything has its place, created by God,
and so the idea of extinction was rather alien. Examination of fossils in the
stratigraphic record confirmed that many species had gone extinct. The
connection between climate events and extinction events gradually became clear.
Many Ice Age mammals became extinct during or after the Pleistocene ice
retreated but many are still around today.
The accurate study of the geologic past (Historical Geology)
requires relative timing and dating of events. Fortunately, nature records
prevailing conditions through time in various ways. For instance, one can study
current rates of erosion and extrapolate back. The study of “varves”, which are
alternating thin layers of clay-mud and silt along the shores of what were once
bodies of water, indicate annual conditions. Several hundred years of varves
are accessible at the bottom parts of glacial lakes that once existed in Sweden and Denmark . The contrast between
summer and winter conditions of such northern lakes bounded by glaciers is
enough to create these contrasting layers. Gerhard Jakob de Geer and his
students surmised that it had taken about 800 years for the Swedish glaciers to
melt.
Another method of unraveling the earth’s recent regional
climate history year by year is the study of layers of pollen in peat bogs.
Pollen is stable and can reveal the local vegetation and thus suggest climatic
conditions. The pollen record, later confirmed through coring, has given us a
good picture of the climate variation of the late Pleistocene and into
historical times so that more detailed knowledge of this climate variation is
now available. Much of this evidence has been corroborated through ice core
data and even tree ring data. Pollen data has been especially good at mapping
regional climate variability so that comparisons of conditions in different
parts of the world at the same time could be made.
The author also gives the history of the unraveling of local
and regional climate history through tree ring variability and dating. This is
called dendrochronology. One could even say that anything that grows or
accumulates also records – even if it is just changes in the growth or
accumulation rates that are recorded. The author details the development of
dendrochronology through the work of Andrew Ellicott Douglass in the American
Southwest in the early 1900’s. Douglass was also an astronomer and remarkably
discovered the relationships between tree rings (and thus weather variations)
and sunspot cycles. During his retirement in the 1930’s and 40’s Douglass
worked out that the sunspot cycle was affected by the planetary orbits of the
larger planets – Jupiter and Saturn.
Although the relationships between planetary motions and alignments and sunspot
cycles and weather patterns are complex and not reliably predictable, the
relationship seems likely, even if controversial.
Next she describes the development of radiocarbon dating and
the great implications of this more precise form of dating. This has done much
to corroborate and date climate evidence from other sources such as tree ring
data and the pollen record.
The story of the ice record is next told, beginning with the
expedition of Ernst Sorge and Alfred Wegener to Greenland
in 1930. Wegener, the first purveyor of the radical “continental drift” theory,
died there, but Sorge came back with evidence for the detailed yearly recording
of climate variations by the layers in the ice. The annual layers of variable
summer and winter snowfall amounts are called “firns” and can be compared
to the seasonally alternating varves.
The Greenland ice sheet was eventually found
to be close to 2 miles thick which represents quite a time period. After World
War II the ability to core the ice sheets was developed. Trapped air bubbles in
the ice layers give detailed data about atmospheric composition. Traces of
salts, dust, and volcanic ash can also give information such as wind speeds.
Temperatures of the ancient past can be deduced from the ice record through
analysis of oxygen isotope ratios. The ice record gives the most complete and
detailed picture of the climate past from the middle of the Pleistocene
glaciation to the present. The ice cores collected in the 1980’s and 1990’s
were key to unraveling this detail. The Vostok ice data records the last
420,000 years. These are where our CO2 and temperature graphs of the past come
from. Temperature variations up to about 20 deg F occur at the onset of warm
periods such as the Eemian period about 125,000 years ago which was warmer than
today. Some of this data was suggested from other sources, such as the pollen
record, varves, the glacial till record, and fossilized tree ring data. The
reason for the 100,000 year cold/10,000 warm general cycles was unknown but in
the early 1900’s a Serbian engineer – Milutin Milankovitch built upon the work
of Scottish geologist James Croll who suggested that differences through time
of the power of sunlight could be a factor. Croll also suspected the earth’s
elliptical rather than circular orbit to be a factor in sunlight intensity
variation. Croll’s work did not reveal close correlations to the data, however.
Milankovitch added to it in various ways, demonstrating several planetary
cycles that could affect solar intensity. One was the change in the angle of the
earth’s tilt on its axis, its wobble, which also accounts for the apparent
phenomena known as the precession of the equinoxes. Another cyclic variation
due to earth’s orbit is its distance from the sun in winter relative to summer
through time which can either enhance or suppress temperature. Milankovitch
calculated the cumulative effect of the three orbital cycles and got a closer
match to the geological data but there is still variability due to other
factors such as clouds, the amount of open sea, and the amount of ice cover.
Since reflection or absorption of solar energy is dependent on color, there can
be much variability in the feed-backing mechanisms. The three cycles that make
up the overall Milankovitch cycle occur at intervals of 100,000 years, 40,000
years, and 23,000 years. I believe another affect is that of the larger planets
whose orbits can also affect the elliptical-ness of the earth’s orbit so it can
change through time as well. The author mentions other cycles in the ice record
of climate, one a 6000 year cycle, the other a 1500 year cycle, which are
covered below. This underscores her theme throughout the book that climate change
is complex with many variables and low overall predictability. Many other
climate scientists, such as James Hansen, would agree that there is complexity,
but they think there is more than enough information to begin mitigating
anthropogenic greenhouses gases immediately.
The climatic evidence from sea floor sediments is an
important subject. The rocks, debris, and silt from glaciers and icebergs end
up in the sea when they melt. These layers of glacial sediment were found at
6000-7000 year intervals in tune with climatic cycles. These are called Heinrich events, named after geologist
Harmut Heinrich’s work in the 1980’s. The changes are linked to the
complexities of ocean circulation which can strongly affect climate. The 1500
year cycles are called Dansgaard/Oeschger
events, named after the Danish and Swiss researchers. While Heinrich events
lead to colder temperatures, Dansgaard/Oeschger events lead to warmer temps.
British geologist Gerald Bond, who studied Cambrian cycles as well, discovered
variations in these 6000 and 1500 year cycles. The Bond cycles may mute or
enhance the other cycles and all three cycles are thought to have been muted in
their intensity in the Holocene. It is not yet clear why this is so.
Fortunately (or maybe not) for us this climate stability helped us develop our
civilization.
A significant climate event occurred about 8000 years ago
(6000 B.C.) that had a negative effect on humans. This is a cooling event not
as severe as the Younger Dryas that occurred at the end of the Pleistocene as a
millennium of Ice Age relapse. The climate event mentioned earlier, around 2300
BC, may have helped bring about the collapse of the Egyptian Old Kingdom, the
Akkadian civilization, and the Harappan civilization. Other extreme climate
events are recorded in history as well: the Roman Warming, the Medieval
Warming, and the Little Ice Age. The Medieval Warming may have helped the Norse
to settle Iceland and Greenland . The so-called Little Age may have led the
Norse to abandon their long-held settlements in Greenland
as the climate cooled too much. It should be noted that these were overall
trends with some variation in successive years – but crop failures and famines
are both reported and seen in the archaeological record.
She mentions the possible effects on sunspot cycles in these
warmings and coolings, not just the 11-year cycle but other longer-termed
cycles. There is much debate about this and some think their increase since
about 1850 has had an effect on current global warming. While this may be true,
the effect is surely nothing like that of man-made greenhouse gases. Many
scientists, however, do not see a correlation between sunspot cycles and
climate.
The author gives the Little Ice Age dates from 1300-1850.
Incidentally, she says, climate records began to be kept, esp. temperature as
thermometers became available, around 1850. However, she notes, most or all of
these records were in populated areas with none in the Arctic
and remote regions so graphs of avg. global temps from the mid-1800’s. esp. the
early ones, have been statistically manipulated, and should not be seen as
definitely accurate.
The hypothesis of William Ruddiman, that humans have been
affecting climate for millennia, is next examined. I am mot sure how plausible
or accepted this is, although Ruddiman is considered to be a distinguished
scientist. In examining the ice core record Ruddiman thinks he sees evidence
for CO2 and methane increases due to the advent of widespread human
agriculture. Ruddiman suggests that this early modest increase of greenhouse
gases helped stave off the increase of glaciation here in the Holocene.
Ruddiman noticed an anomaly in the regular atmospheric methane cycles (from the
ice cores) that began about 5000 years ago. This anomalous rise in methane
would have been predicted to be a drop. He looked to the expected sources of
increased methane: tropical swamps and peat bogs, but both were known to
decline in these periods. Ruddiman noticed that the timing of rice farming in East Asia through the making of rice paddies, ie.
man-made swamps, corresponded to the increase in atmospheric methane.
Extrapolating back from 1700 CE, the time when hydrocarbons began to be burned
and utilizing known population then and suspected population 5000 years ago, Ruddiman
determined that the data from methane concentrations could be explained by rice
farming. Other farming methods, land clearing, and slash-and-burn agriculture
could also contribute to the increased methane concentrations seen in the ice
core record. Increased domestication of propagation of livestock in settled agricultural
societies with growing populations could also have contributed. The author also
emphasizes the complexity and complicated nature of the carbon cycle. The
unexpected increase in CO2 beginning about 6000 BC (8000 years ago) also
perplexed Ruddiman. He also thought this could be attributable to clearing and
burning of land and wood. He also thinks this rise in temperature due to a rise
in CO2 and methane could be why the retreating glaciers in North America did
not begin to re-grow after the optimum which may have led to a runaway feedback
where more light was reflected of the ice cooling things down making more ice,
more cooling, more reflection, and on and on. Nowadays with man-made global
warming the danger seems to of a runaway feedback in just the opposite way.
Ruddiman thinks the overall 1.5 deg F rise in global temperature over the
millennia since agriculture began may be attributed to it and may have warded
off the scheduled return to increased glaciation. Ruddiman does point out that
his theory in no way denies that global warming is occurring at present due to
industrial greenhouse gases. The author does acknowledge the uncertainty of
Ruddiman’s hypothesis. She also points out that eventually catastrophic climate
change of some sort is inevitable:
“… scientists know from a variety of evidence that Earth’s
climate changes naturally, rapidly,
repeatedly, and drastically.”
There is a discussion of early efforts to modify climate,
specifically the civil engineering suggestions of Carroll Livingston Riker in
1912 to divert the Gulf Stream in order to warm eastern Canada and Greenland ,
making them more habitable. Riker worked on the Panama
Canal so knew the possibilities of large civil engineering
projects. Governments and their militaries also did climate modification
experiments such as cloud-seeding. This was also tested to break up hurricanes
and to increase rain for crops in dry areas. Results were marginal. In the
1960’s and 1970’s many scientists were concerned about the potential of global
cooling and some thought that increased greenhouse gases would be helpful. The
1975 National Academy of Sciences book Understanding
Climatic Change mentions both global warming and global cooling. The global
cooling effect of particulate pollution was considered but the warming effect
of CO2, etc. was thought to be more dangerous over time. It should be noted
that as we decrease particulate pollution as is necessary for improving human
health, global warming will be somewhat enhanced. The Soviets were particularly
worried about global cooling due to their northern latitudes. They developed
plans to melt ice by spreading black coal dust over it. There are efforts now
to study the effects of forest fires of the American west on enhancing melting
of the Greenland ice sheet as ash is deposited
by prevailing weather patterns. The concern about global cooling was based on
the general cooling trend from the years after WW II till the 1970’s. It was also
discovered in the mid-70’s that lichen had disappeared from Baffin Island from
about 1600 to about 1900 corresponding roughly to the coldest parts of the
Little Ice Age. What the author wants to convey is that fears of both global
cooling and global warming echoed from respected scientists and were reasonable
assumptions.
Next she conveys the history of global warming and the
effects of atmospheric gases on climate. Discoveries were made in the 1800’s
regarding the different effects of different gases. Even though the greenhouse
effect was understood in the early 1900’s no one predicted the massive
increases in world population and subsequent use of fossil fuels. Oceanographer Roger Revelle gave a lecture at Harvard in
1965. A graph of Charles Keeling’s curve of atmospheric CO2 increase was shown.
Al Gore was in the audience and often mentions how profoundly this affected him. The
graph shows quite obviously, and continues to show up to now, that the rate of
CO2 increase is increasing. The ice cores of the 80’s and 90’s showed
definitely the relationship between atmospheric CO2 and temperature. The data
also show multiple RCCE’s. Apparently, most scientists agree that it is
temperature rise that causes greater CO2 and methane in the atmosphere and not
the other way around:
“Most Americans who have seen Al Gore Jr.’s documentary An Inconvenient Truth or who have
followed public global warming arguments are sure of one thing: they believe
the ice core record shows that
carbon-dioxide and methane increases create warmer temperature on Earth. But
the significant news is that the facts actually run in the reverse direction.
On long time scales, increases in temperature, controlled by the Earth’s orbit
around the sun, create more methane and carbon dioxide. That’s right: from what
most scientists can tell, greenhouse gases are not the primary driver of
long-term climate change on Earth – Milankovitch’s orbital variations are.
Still, everything about climate is complex, and it’s quite possible that
greenhouse gases can help trigger changes at particular times, or they can help
exaggerate feedback processes already underway on Earth.”
She further reiterates that it is Milankovitch’s planetary
cycles that have initiated the major climate changes of the past seen in the
ice cores. Actually, the likelihood that temperature changed before CO2 is
probably not good news for mitigating global warming as it suggests that more
CO2 will be released from the oceans after it circulates through and out.
Hansen refers to this as global warming “in the pipeline” and it may take more
than 600 years to cycle through the oceans before it is released to the
atmosphere.
The author notes the growing influence of science-based
journalism, particularly in influencing public opinion and policy suggestions.
Groups like the Intergovernmental Panel on Climate Change (IPCC) have been very
influential. Climate modeling with supercomputers and statistics are now used
extensively to try and predict what will happen as more greenhouse gases enter
the atmosphere. The author thinks that statistical modelers need to work more
with traditional scientists. She examines the pros and cons of “group think” a
bit. She mentions the great details of climate change that came out of the
GISP2 ice core data as well as recent sea floor coring. Competition for
funding, policy formulation, and agreement on the degree of immediate danger of
global warming has been and continues to be confusing and difficult to balance.
Many favor the “precautionary principal” which means we should prepare for the
worst as best we can while others disagree. Al Gore and many others have
described climate change mitigation as a moral imperative. The IPCC is not
strictly scientific as it is a hybrid of scientists and government representatives.
The author suggests that what comes through as the nature of current climate
change is that it is a well-defined ordered change towards a runaway feedback
that needs to be stopped as soon as possible. She thinks that the policy
suggesters of IPCC fail to acknowledge the chaotic nature of climate change.
She then shows the famous “hockey stick” graph of Mann, etal. which depicts temperature
climbing abruptly in the early 1900’s and staying there till now. She also
describes McIntyre’s partial refutation of it using the same data, suggesting
that the temperature was not constant before 1900 as Mann depicted but up and
down as much as the increase in the early 1900’s. That is possible – but I
think it is a longshot as there seems to be much corroborating evidence for the
Industrial Age- linked temperature rise. The U.S. Congress hired a statistical
expert to investigate the matter and he came to the conclusion that McIntyre
was more correct – that the past temperature fluctuations were more chaotic. The
influence of bias and ideology in these matters can be complex as can be the
interface between science and policy. Obviously, it is difficult to make
decisions that might affect the lives of many people. Robert Muller, an
oceanographic researcher, recently changed his position and now agrees that
temperature has climbed strictly due to man-made global warming. It seems that
is the most reasonable position. I think the real question is, “How bad is it?”
She again invokes climate complexity but others lake James Hansen insist that
the evidence is more than compelling. Nowadays, we do have ideologically driven
“climate change deniers” as well as scientist “climate change skeptics”. As for
myself, as a scientist, I think that climate change as depicted in the global
warming models is likely, but the exact details and the immediacy of the danger
is not fully assessed. Yet, I think the “precautionary principle” should be a
guide and we should do everything we can to mitigate catastrophic climate
change as soon as possible.
In the last chapter the author actually makes her own plea
for a way to mitigate greenhouse gases. She advocates for worldwide efforts to
extinguish the many long-burning coal fires throughout the globe – many of
which are in places like China
and India
and are having negative health effects on local populations. Though she does
not give numbers, she notes that these unintentional coal fires “create a
meaningful fraction of total global greenhouse gas production.” These fires can
burn for decades, even centuries. The Centralia ,
PA fire has been burning for over
50 years, has caused the town to be abandoned, and even though eight attempts
have been made in the past to extinguish it – it still burns the equivalent of
400 acres of land space. Many coal fires were started by humans but some occur
naturally as wildfires encounter burnable coal seams. Open mines often allow a
supply of oxygen to keep the fires going. Some estimations say that coal fires
in China alone put out the
annual CO2 emissions of all cars in the US combined. Forest-clearing in Indonesia by
burning is estimated to have started around 3000 coal fires. This clearing
might be due to palm oil plantations used for food as well as bio-fuels –
though I am not sure how much for food and how much for biofuel. The author
thinks there should be way more effort and money spent on trying to extinguish
these fires and that it would ultimately be a cheaper way to mitigate a
significant amount of CO2 and particulates than other means – as well as improving
the health of poor local people living near the blazes.
The IPCC global warming predictions note greater warming for
arctic regions, less for the tropics, warmer winters, warmer nights, and
species ranges will change (which has already been happening). She suggests
that the media fail to report that there are some actual benefits of global
warming as noted by the IPCC reports – such as less deaths since there are more
deaths due to excessive cold than excessive heat, better crop yields in some areas,
and lower heating costs. Of course, the predicted downside dwarfs the predicted
upside, since many people living near coasts could be inundated and weather
patterns could become drastic as recent superstorms have indicated. The author
does generally express the opinion that global warming is not the only climate
change possibility and that it could be over-hyped and policy could lead to
over-preparation for it which could be detrimental to societies. I am not sure
if I agree but I think we do need to keep an open mind while sticking as much
as possible to the facts, timely data, and pre-caution.
Overall, this is a good book with some great background on
climate science but I think the view here about the dangers of man-made climate
change is overly muted somewhat.