For comparison, here is a look back at other warm periods:⁹⁶

• The Medieval Warm Period (900-1400 A.D.) brought more warmth to northern Europe and some other regions of the Northern Hemisphere, but did not much raise average world-wide temperature. The highest average Northern Hemisphere temperatures during this period were about those of the mid-20th century.

• The Mid-Holocene Epcoh (6000 years ago) marked the peak warmth of the current natural inter-glacial period. Since then, the Earth should be gradually and naturally cooling towards the next ice age in 50,000 years or so. But today’s warming climate change has halted that trend for a while, and may even — with continued fossil fuel burning — cancel the next ice age.⁹⁷⁹⁸

• The Eemian Stage (120,000 years ago) was the prior inter-glacial period. Regular wobbles in the Earth’s orbit cause the coming and going of the Earth’s ice ages on about a 100,000 year cycle. The orbital wobbles affect the amount of solar radiation hitting the planet. When the solar radiation on the continents strengthens, it triggers the inter-glacial warming. After hundreds of years of warming, CO2, having maybe been flushed from the deep ocean, rises in the atmosphere, which amplifies the warming, driving the glaciers back towards the poles.⁹⁹

• The Pliocene Epoch (5.3 – 2.6 million years ago) was the last warm period before the glacial cycles started. Northern Hemisphere ice sheets had not yet formed, as high atmospheric CO2, the Earth’s orbital state, and constant El Nino winds and ocean currents likely kept them at bay.¹⁰⁰

• The Paleocene-Eocene Thermal Maximum (55 million years ago) was a big warming climate change (5 – 8°C over a few thousand years) from an already-warm climate. Somehow, a huge amount of greenhouse gas got up into the atmosphere, as clathrates in the ocean may have melted to free trapped methane, or a massive volcano may have heated up vast swaths of coal.¹⁰¹

• During the Mid-Cretaceous Age (120 to 90 million years ago) the Earth was very different. Rolling back 100 million years of continental drift, we find the continents clumped together, giving very different ocean currents and climatic rhythms. CO2 levels were at least twice today’s, and it was so warm that the tropical breadfruit tree likely grew in Greenland (55°N).

Each warm period has its own story, but today’s is not yet finished. The effects of today’s climate change could put heavy stress on human and other life that has gotten used to the more-or-less regular climate since the last ice age.¹⁰² As more CO2 is added to the atmosphere, the outlook for future life becomes more dire. Now, it is up to the human species to muster its social sense and clever wit, and stop the rise of CO2 in the atmosphere that it started.

Sources

⁹⁰ IPCC FAQ 6.2: Is the Current Climate Change Unusual Compared to Earlier Changes in Earth’s History?

⁹¹ IPCC FAQ 6.1: What Caused the Ice Ages and Other Important Climate Changes Before the Industrial Era?

… There are three fundamental ways the Earth’s radiation balance can change, thereby causing a climate change: (1) changing the incoming solar radiation (e.g., by changes in the Earth’s orbit or in the Sun itself), (2) changing the fraction of solar radiation that is reflected (this fraction is called the albedo – it can be changed, for example, by changes in cloud cover, small particles called aerosols or land cover), and (3) altering the longwave energy radiated back to space (e.g., by changes in greenhouse gas concentrations). In addition, local climate also depends on how heat is distributed by winds and ocean currents. All of these factors have played a role in past climate changes.

⁹² IPCC FAQ 2.1: How do Human Activities Contribute to Climate Change and How do They Compare with Natural Influences?

FAQ 2.1, Figure 2. Summary of the principal components of the radiative forcing of climate change. All these radiative forcings result from one or more factors that affect climate and are associated with human activities or natural processes as discussed in the text. The values represent the forcings in 2005 relative to the start of the industrial era (about 1750). Human activities cause significant changes in long-lived gases, ozone, water vapour, surface albedo, aerosols and contrails. The only increase in natural forcing of any significance between 1750 and 2005 occurred in solar irradiance. Positive forcings lead to warming of climate and negative forcings lead to a cooling. The thin black line attached to each coloured bar represents the range of uncertainty for the respective value. (Figure adapted from Figure 2.20 of this report.)

⁹³ IPCC FAQ 8.1: How Reliable Are the Models Used to Make Projections of Future Climate Change?

There is considerable confidence that climate models provide credible quantitative estimates of future climate change, particularly at continental scales and above. This confidence comes from the foundation of the models in accepted physical principles and from their ability to reproduce observed features of current climate and past climate changes. Confidence in model estimates is higher for some climate variables (e.g., temperature) than for others (e.g., precipitation). Over several decades of development, models have consistently provided a robust and unambiguous picture of significant climate warming in response to increasing greenhouse gases.

⁹⁴ ‘Bush on “The Fundamental Debate”’ – RealClimate.org, 2006-03-31

Data show that carbon dioxide levels are rising, they are now 30% higher than at any time during at least the past 650,000 years, and likely even the past several million years. This rise is caused entirely by human activities. This is also demonstrated beyond any reasonable doubt by data – for a start, we know how much CO2 we have emitted, and the observed rise is equal to 57% of this (the rest has been taken up by ocean and biosphere). That carbon dioxide acts as a greenhouse gas, trapping longwave radiation, is also a measured fact and well-established physics since the 19th Century. …

What about a “natural” explanation for the observed global warming? There is none. Indicators and measurements of solar activity show no increasing trend over the past 60 years. The orbital cycles, which cause the ice ages, would currently tend towards cooling, if anything. There is no remotely feasible alternative explanation for the observed warming published in the scientific literature.

⁹⁵ IPCC FAQ 9.2: Can the Warming of the 20th Century be Explained by Natural Variability?

… Human activities over the last 100 years, particularly the burning of fossil fuels, have caused a rapid increase in carbon dioxide and other greenhouse gases in the atmosphere. Before the industrial age, these gases had remained at near stable concentrations for thousands of years.

⁹⁶ ‘Paleoclimatic Data Before 2000 Years Ago’ – National Climate Data Center

⁹⁷ ‘The global cooling myth’ – RealClimate.org, 2005-01-14

Interpretations of future changes in the Earth’s orbit have changed somewhat. It now seems likely (Loutre and Berger, Climatic Change, 46: (1-2) 61-90 2000) that the current interglacial, based purely on natural forcing, would last for an exceptionally long time: perhaps 50,000 years.

⁹⁸ ‘The Long Thaw: How Humans are Changing the Next 100,000 Years of Earth’s Climate, David Archer Publisher’s description:

In The Long Thaw, David Archer, one of the world’s leading climatologists, predicts that if we continue to emit carbon dioxide we may eventually cancel the next ice age and raise the oceans by 50 meters.

Archer shows how just a few centuries of fossil-fuel use will cause not only a climate storm that will last a few hundred years, but dramatic climate changes that will last thousands. Carbon dioxide emitted today will be a problem for millennia. For the first time, humans have become major players in shaping the long-term climate. In fact, a planetwide thaw driven by humans has already begun. But despite the seriousness of the situation, Archer argues that it is still not too late to avert dangerous climate change–if humans can find a way to cooperate as never before.

⁹⁹ ‘What does the lag of CO2 behind temperature in ice cores tell us about global warming?’ – RealClimate.org, 2004-12-03

From studying all the available data (not just ice cores), the probable sequence of events at a termination goes something like this. Some (currently unknown) process causes Antarctica and the surrounding ocean to warm. This process also causes CO2 to start rising, about 800 years later. Then CO2 further warms the whole planet, because of its heat-trapping properties. This leads to even further CO2 release. So CO2 during ice ages should be thought of as a “feedback”, much like the feedback that results from putting a microphone too near to a loudspeaker.

In other words, CO2 does not initiate the warmings, but acts as an amplifier once they are underway. From model estimates, CO2 (along with other greenhouse gases CH4 and N2O) causes about half of the full glacial-to-interglacial warming.

¹⁰⁰ ‘Rolling up the circus tent: Dispatch #7’ – RealClimate, 2007-12-19

The Pliocene was the latest warm time in the Northern Hemisphere before the great glaciations of the Pleistocene closed in. To some extent, as we increase the atmosphere’s CO2 content, we are traveling backward in time so far as climate is concerned. Hence the Pliocene, which ended about two million years ago, has attracted a lot of attention as an analog climate for what may lie ahead. It’s not a perfect analogy, but the challenge of understanding Pliocene climate provides another test of the operation of model physics in a warm climate. …

… There was also a modelling talk by M. Vizcaino, evaluating several factors proposed to have accounted for Pliocene warmth. The ones that seem to contribute the most to conditions unfavorable for Northern Hemisphere glaciation are elevated CO2, the orbital configuration, and a permanent El Nino.

¹⁰¹ ‘Climate myths: It’s been far warmer in the past, what’s the big deal?’ – by David L Chandler, New Scientist, 16 May 2007

The warmest [“hothouse Earth” period] was probably the Paleocene-Eocene Thermal Maximum (PETM), which peaked about 55 million years ago. Global temperatures during this event may have warmed by 5°C to 8°C within a few thousand years, with the Arctic Ocean reaching a subtropical 23°C. Mass extinctions resulted.

The warming … was caused by the release of massive amounts of methane or CO2. It was thought to have come from the thawing of methane clathrates in deep ocean sediments, but the latest theory is that it was caused by a massive volcanic eruption that heated up coal deposits. In other words, the PETM is an example of catastrophic global warming triggered by the build-up of greenhouse gases in the atmosphere.

¹⁰² ‘Climate myths: It’s too cold where I live – warming will be great’ by Michael Le Page, New Scientist, 16 May 2007

As global temperature climbs to 3°C above present levels – which is likely to happen before the end of this century if greenhouse emissions continue unabated – the consequences will become increasingly severe. More than a third of species face extinction. Agricultural yields will start to fall in many parts of the world. Millions of people will be at risk from coastal flooding. Heatwaves, droughts, floods and wildfires will take an ever greater toll.

There are two factors should borne in mind when thinking about the impacts. Firstly, even countries that escape the worst of the direct effects will feel the economic effects of what happens elsewhere. There may be social and political problems too, as migration increases and water becomes increasingly scarce in some regions.

By Quinn Hungeski – Posted at TheParagraph.com

155 million years ago, algae bloomed in a shallow sea, poisoning thousands of creatures.⁷¹ The belemnite came to feed on the dead creatures, and met the same fate. It sank into a sea floor rich in phosphorus, which within days — before the body could rot — mineralized in and around the body parts and saved the belemnite’s image.⁷² Somehow along the way, the ink sac came loose from the body, and the somewhat acidic water reacted with the melanin in the ink to make it solidify, and hold its full spatial shape inside the forming rock.⁷³⁷⁴ As the earth churned through the ages, the area of sea floor became the Oxford Clay in the south of Great Britain. In the 1840’s, railroad builders cut into the clay and came across the rich fossil bed. Many fine fossils were taken to London, where they were shattered by bombing in World War II.⁷² Through the years, with overgrowth and flooding, the location of the fossil bed became lost to scientists and the public — until Dr. Wilby’s crew went looking for it. They drilled here and there around Christian Malford, until they pulled up a core sample with a fossil.⁷⁰ Over ten days, they gathered many fossils, and cracked open one rock to find the belemnite’s ink sac.⁷⁵ The scientists took a piece of the solidified ink and mixed it with an ammonia solution to liquefy it for the “ultimate self-portrait”.

Nearly all animal fossils are rock impressions of the slower-to-rot hard body parts, like bone and shell, and there are only a few fossil beds in the world with impressions of soft body parts. And it is rarer still to find fossil original material — like cephalapod ink — from an organism. “It’s absolutely incredible to find something like this,” said Dr. Wilby — and the story made quite a stir. But such a story also made a stir in the nineteenth century, as was noted in 1884 in The standard natural history:⁷³

The ink is not readily decomposed; on the contrary it is occasionally found fossil in the rocks along with the remains of the animal which produced it. So well has it been preserved that in one celebrated instance a naturalist drew the portrait of a fossil squid with the sepia derived from its fossil, but not fossilized ink-bag.

the fossil ink sac — BNPS

Fossil belemnite with fish in grasp. — Palaeo News Files

Artist’s conception of belemnites on the prowl — BNPS

Wilby’s crew strikes paydirt in an ammonite fossil. — British Geological Survey

Sources

⁷⁰ ‘After 150m years as a fossil, Belemnotheutis antiquus takes up its pen’ — The Times, 2009-08-19

⁷¹ ‘The Fossil Treasure Hunt’ – British Geological Survey

⁷² ‘Calamari killing field – fossils found in sea that covered middle England’ By Paul Eccleston, Paleonews, 2008-08-21

⁷³ ‘Fossil squid ink story has whiskers’ by Ray Girvan, JSBlog, 2009-08-25

⁷⁴ ‘155million years old and still inky: The perfectly preserved squid fossil amazing scientists’ – by David Derbyshire, Daily Mail, 2009-08-19

⁷⁵ ‘Scientists draw squid using its 150 million-year-old fossilised ink’ By Murray Wardrop, The Telegraph, 19 Aug 2009

By Quinn Hungeski – Posted at G.N.N. & TheParagraph.com

A microbial fuel cell taps into the energy that soil microbes generate when they break down organic matter. Literally, this is energy from dirt: no special microbes or conditions are needed other than enough moisture for the bugs to do their work.

Essentially all you do is dig a hole, layer an anode, some soil, sand and a cathode — and connect the anode and cathode to a circuit board to charge a battery that can power an LED (light emitting diode) light, run a radio or charge a mobile phone.

In Africa, 74% of the population is off the electric grid. Lebônê‘s website describes the problem:x³

… Imagine a village at night in which students are walking to distant highways to study under streetlights, where small merchants are investing half of their resources to pay for kerosene lighting to run their operations, and where emergency health workers, if operating at all, are trying to stitch up wounds and perform surgeries by candlelight. …

A Lebônê MFC electric unit can replace a kerosene lamp for $10 and a cubic meter of dirt. Units can be easily linked to multiply energy output. The underground system works through day and night, in wind and calm, is rugged, simple, lasts for years, and can be made in the region where it is used. This month, Lebônê won a $200,000 World Bank grant in the Lighting Africa competition held in Accra, Ghana. Lebônê will use that money as it begins field studies in the foothills of Kilimanjaro in July. It plans a large-scale product rollout in Tanzania for 2009.

Video from floor of Accra conference; Interview with Hugo Van Vuuren starts at 1:00

Sources

¹ Harvard School of Engineering and Applied Sciences press release – May 14, 2008

² ‘Literally, This Is Energy From Dirt’ – Interview with Lebônê founder Hugo Van Vuuren, IPS News Agency

³ Lebônê – The Problem

By Quinn Hungeski – Posted at G.N.N. & TheParagraph.com

On Saturday the 8th the ore boat Charles S. Price shoved off at Ashtabula, Ohio, into Lake Erie with a load of coal and without its first assistant engineer. Milton Smith had chosen to skip the last voyage of the 1913 season — and any early November gale that might arise — and had taken the train home to his wife and children in Port Huron, Michigan. After midnight on Sunday morning, as the Price steamed up the St. Clair River and past Smith’s house into Lake Huron, a gale was blowing in from the northwest. That afternoon sailors on the downbound (south-going) H.A. Hawgood saw the Price fighting its way upbound as it passed. The Hawgood had been heading into the storm north of Saginaw Bay, when it turned around to seek safety at the St. Clair River and let the gale blow itself out. But, instead of blowing out, the gale became the White Hurricane. By dark the snow “got so thick we couldn’t see the smokestack”, reported the Hawgood‘s captain. “The seas went right over the pilothouse.” Later, the Hawgood ran up on a beach at the southern end of the lake, and its crew survived. Likely the Price also turned and headed back toward the foot of Lake Huron, where it would have had to turn again to avoid running aground. On that final turn, the Price may have gotten caught sideways in a deep trough between the waves, and rolled. Its upturned hull floated for several days, and the papers speculated on the identity of “the mystery ship”, until a diver went down to read its name. On Tuesday the 11th, after the storm had quieted, seven bodies of sailors from the Price washed ashore in Ontario near Port Franks. On Thursday, a week and a day after leaving the Price, Milton Smith boarded the train in Sarnia, and headed for the makeshift morgue to identify the bodies of his shipmates.

Another ore boat upbound on Lake Huron that Sunday, when the White Hurricane raged, was the George C. Crawford. The boat fought the waves to north of Point Aux Barques with winds “blowing great guns”, according to Captain Walter C Iler. Waves rushed over the deck and boilerhouse through a broken skylight into the engine room, smashed the ship’s galley and drenched the crew’s sleeping rooms. So, like the captains of the Hawgood and the Price, Captain Iler decided to turn his boat around to seek calmer waters. While heading back down, Iler could make out the passing upbound ore boat Argus through the snow and waves. He later recalled what he saw just after the boat passed by. “The Argus seemed to crumple like an eggshell,” he said. “Then, she was gone.” Bearing that horrible image, the crew of the Crawford had to tend their boat as it ran fast with the wind and the mountainous waves towards the foot of Lake Huron. “It snowed for a solid twenty-six hours,” Iler later recalled. “We hadn’t seen a thing, but were guided by the sounding machine. It gave us excellent service.” Not being able to see to find the St. Clair River, Iler decided to turn around before running out of lake and ripping into the shoals. But the boat got stuck in a trough and could not climb out, so the captain ordered the anchors thrown. The anchors grabbed and the ship came around, but soon the anchor chains snapped, and once again the storm pushed the Crawford towards the shore. Around 2 A.M. Monday a lull in the wind allowed the boat to turn, and it once again battled upbound on its original course towards the Soo Locks. On Tuesday the battered boat reached the St. Marys River that leads to the Soo. In the calm, the crew wielded steam hoses to melt the thick ice off the deck, and found something stunning. Hundreds of rivets were missing, and cracks ran across several of the inch-thick steel deck plates. The crew might have pictured then how their own boat could have crumpled like the Argus. Records show that the Crawford did not finish its last voyage of 1913, but turned back to Toledo for repair. And in the spring of 1914 it set out again.

The Detroit News, November 13, 1913

the upturned bow of the 504 ft (154 m) Charles S. Price

Source: ‘White Hurricane: A Great Lakes November Gale and America’s Deadliest Maritime Disaster’ by David G. Brown, 2002, International Marine / McGraw-Hill

After the press of westward settlement, and the U.S. Army, drove out the Indians, the government fashioned a road through the Great Black Swamp to the land of milk and honey beyond. “A bank of muck and mud twenty feet wide and about three feet high was build mostly by Ox Power,” wrote a dweller, C. H. Opperman, of the Maumee and Western Reserve Road (now US 20)x⁵⁷. “Nearly all … who took the swamp route regretted their unwise decision, for many of them had ox teams to draw their high-wheeled covered wagons. Often the Oxen would sink to their bellys and the wheels to the hubbs and in many cases made only a mile or two of progress in a day.” So 31 inns rose to stand along the 31 miles of road and aid the slow moving pioneers⁵⁸. Some men would claim a mud hole and charge money to pull wagons out of it. One traveling pioneer spent his life savings of $100 on getting pulled out of mud holes. So he stopped and staked out his own mud hole, and made his money back before he carried on.

After settlers claimed the land around the Great Black Swamp, later settlers turned their sights inside it. “No night was too dark or precinct too sacred for [the mosquitoes] to get in their work,” wrote J. R. Tracy of living on the 80 acres his father bought on a sand ridge in the heart of the Great Black Swamp (where Bowling Green now stands)x⁵⁹. “Many a meal was eaten with a smudge under the table and many a would be sleeper owed what rest he secured to the smoke that overspread his bed and compelled his bloodthirsty assailants to retire.” The mosquitoes also brought malaria to swamp dwellers. Tracy described his bout with it: “If there is anything in this world that will stay by a fellow when it has found him it is the ague. My! How it will snuggle up to him, and hug him, and squeeze him, and shake him, and freeze him, and then bake him and fry him, until it would seem every drop of moisture is out of him …” After receding, the fever would sometimes return with double strength in a day or two: “And so the round went on, week by week, month by month, sometimes year by year (Brother Isaac was held two years, didn’t go to school or do a day’s work in that time).” Another swamp settler, Robert Fenton, also lived the hardship of malaria, as well as slow travel, dangerous animals, and the lack of a local mill to grind the grain⁶⁰. But he looked back on it like this: “We were happy, since we all were on about a common level and the exigencies of the situation made us alert, active and energetic. We had to be up and doing and we rather seemed to enjoy it.”

In 1840 the Great Black Swamp stood at its last years of full glory. From then on more settlers came in and cut down trees, and some dug ditches to drain water off their land – often on to their neighbor’s⁶¹. After a big outbreak of the waterborne disease cholera, the Ohio government in 1859 gave counties the power to seize land for more effective ditching. When farmers found that surface ditching left their land still too soggy, some tried underground drains of loose stone, or of pairs of planks nailed into a “V” and laid open end down. These underground drains did not work nearly as well as clay tile, but it was too costly to bring clay tile in. Then in the 1860’s, after someone discovered the bed of clay under the topsoil, many drainage tile factories arose. The factories’ kilns were fed by the swamp’s clay and fired by the swamp’s trees. And by 1900 the kilns’ product had drained and dried the Great Black Swamp. In its place lay fine farmland, with crops growing on a 10,000 year-old compost heap.

The Great Black Swamp (Maumee Valley Historical Society)

The Everglades (USGS)
The Everglades historic boundary is marked here by the yellow line. It includes the area of sheet water flow from Lake Okeechobee to the sea, and excludes some adjacent wetlands.

Black Swamp Conservation and Restoration Area
A 110 acre tract in Wood County, Ohio

Sources

⁵⁰ ‘Lost Ohio’ by Randy McNutt, 2006, Kent State University Press, P.114

⁵¹ ‘Wetlands – Did you know?’ – Ohio EPA

The Great Black Swamp was Ohio’s largest wetland. The swamp was once 120 miles long and about 40 miles wide. In 1859, the “ditch law” was passed to allow the installation of pipes to drain the swamp for agriculture and development. Today, only five percent remains in scattered areas throughout northwestern Ohio.

⁵² ‘Background of the Entire Everglades/Florida Bay Ecosystem’ – South Florida Water Management District

The present Everglades has been subdivided by the construction of canals, levees, roads and other facilities and has resulted in the loss of connections between the central Everglades and adjacent transitional wetlands. …

… the historical Everglades that once extended over an area approximately 40 miles wide by 100 miles long, from the south shore of Lake Okeechobee to the mangrove estuaries of Florida Bay.

⁵³ ‘The Great Black Swamp’ by Jim Mollenkopf

For thousands of years much of northwest Ohio lay covered by a vast, luxuriant swamp. According to early observers parts of it were watery meadows, veritable seas of living, moving green that would undulate beautifully in a summer breeze. Other parts of it were majestic and untouched forests, cathedralesque stands of oak, sycamore and hickory trees that soared skyward and blocked out the sun. Still other parts of it were thick, impenetrable brush and wild growth. Its thousands of square miles spread over all or parts of 12 counties stretching east to west from Sandusky, Ohio to near Fort Wayne, Indiana and north to south from the Maumee River valley to near Findlay, Ohio.

⁵⁴ ‘THE HISTORY OF LAKE ERIE’ by Michael C. Hansen

Fertile clays deposited on the lake bottom during high-water stages and the wetland areas that remained when lake levels dropped form one of the richest agricultural regions of the state. The beaches which formed along the shorelines of these higher lake stages are preserved as ridges elevated above the nearly flat former lake beds. …

…

The sandy beach deposits rising above the nearly flat lake plains, especially in the region called the Black Swamp, in northwestern Ohio, captured the attention of Native Americans and European explorers and settlers because the ridges provided dry passage through the swamps formed on the former lake beds.

⁵⁵ ‘Frontier Fauna – Ohio’s Wild Heritage’ – OHIO STATE PARKS MAGAZINE, FALL/WINTER 2005/2006

As Ohio’s frontier days came to a close, the impenetrable woods of the Great Black Swamp of northwest Ohio became a last refuge for elk, wolves and lynx. …

⁵⁶ ‘The Great Black Swamp II’ by Jim Mollenkopf, © 2000 Lake of the Cat Publishing, Toledo, Ohio, P.37

… For the Indian, “the Maumee River was a delightful homne and a secure retreat,” one unknown early writer recorded. “Its banks were studded with their villages, its rich bottomlands covered with their corn, while their light canoes glided over a beautiful current which was at once a convenient highway and an exhaustless reservoir of food. Forest, stream and prarie produced, spontaneously, and in superabundance, game fish, fruits, nuts, – all things necessary to supply their simple wants.”

⁵⁷ Ibid, P.114

⁵⁸ ‘The Great Black Swamp’ by Jim Mollenkopf, © 1999 Lake of the Cat Publishing, Toledo, Ohio, P.41

⁵⁹ ‘The Great Black Swamp II’ by Jim Mollenkopf, © 2000 Lake of the Cat Publishing, Toledo, Ohio, pp.49-52

⁶⁰ ‘The Great Black Swamp’ by Jim Mollenkopf, © 1999 Lake of the Cat Publishing, Toledo, Ohio, pp.24-25

⁶¹ ‘The Great Black Swamp II’ by Jim Mollenkopf, © 2000 Lake of the Cat Publishing, Toledo, Ohio, pp.59-62

“The Great Desert is frequented by roving bands of Indians who have no fixed places of residence but roam from place to place in quest of game.” – Geographical, Statistical and Historical Map of Arkansas Territory by Major Stephen H. Long, Topographical Engineers from the Carey and Lea’s Atlas of 1822 / full map 3184×2703 pixels

The Ogallala Aquifer holds as much water, but spreads over an area seven times the size of Lake Huron. – BLUE: Unconsolidated sand and gravel aquifers at or near the land surface. – YELLOW: Semiconsolidated sand and gravel aquifers. – GRAY: Sand and gravel aquifers of alluvial and glacial origin are north of the line of continental glaciation. Source: USGS

Circles formed by center pivot irrigation in Kearny County, KS. Source: Kansas Geological Survey

Sunflower crop in North Dakota. Source: USDA

Sunflowers ready to harvest in eastern Colorado. Source: Denver Post / Andy Cross

Sources

³⁰ ‘Report of the Great Plains Drought Area Committee, August 27, 1936’ [newdeal.feri.org/hopkins/hop27.htm] See maps of ground cover, rainfall and wind speed.

³¹ ‘Ogallala Aquifer’ – Wikipedia [en.wikipedia.org/wiki/Ogallala_Aquifer] “Much of the plains region is semi-arid with steady winds that hasten evaporation of surface water and precipitation.”

³² ‘American buffalo, (Bison bison)’ – U.S. Fish and Wildlife Service “Because the great herds were nearly gone before any organized attempts were made to survey populations, we may never know just how many buffalo once roamed North America, although estimates range from 30 to 75 million. “The moving multitude…darkened the whole plains,” wrote Lewis and Clark, who encountered a herd at South Dakota’s White River in 1806.”

³³ ‘Geographical, Statistical and Historical Map of Arkansas Territory by Major Stephen H. Long, Topographical Engineers from the Carey and Lea’s Atlas of 1822’ – The University of Tulsa

“… It is essentially the map documenting Major Stephen H. Long’s 1819-1820 expedition. …”

The Long map became a “master map,” to be built upon and added to by a generation of cartographers …

…

The delineation of the area as a desert, unsuitable for sustainable agriculture such as was known to Long, a man from New Hampshire, illustrates how the expectations Americans had for the West were turned upside-down when confronted with its realities. The western Plains were not the farmer’s garden or paradise as imagined by Thomas Jefferson; the area was exceedingly arid with unbroken grasslands compared to the wet, green and timbered east.

³⁴ ‘High noon at the Ogallala aquifer’ by Jacques Leslie, Salon.com
“One of the largest underground repositories of water in the world, the Ogallala stretches from Texas to South Dakota and once held more water than Lake Huron. That was a century ago, before the advent of cheap electric pumps gave farmers the power to lift water hundreds of feet”

³⁵ ‘The Good Earth’ by David McConnell [www.mhhe.com/earthsci/geology/mcconnell/demo/hpaq.htm]

… Approximately 170,000 wells draw water from the aquifer that has brought prosperity to an area described by Major Stephen Long in 1819 as “almost wholly unfit for cultivation and . . . uninhabited by people depending upon agriculture for their subsistence.” The aquifer covers an area of 480,000 square kilometers, making it the largest area of irrigation-sustained cropland in the world.

…

… the aquifer contains “fossil” water, the product of a wetter ancient climate associated with the end of the last ice age. There is no sufficient contemporary source for water to recharge the whole aquifer although substantial recharge does occur in some areas from streams (e.g. Platte River, Nebraska) and from irrigation projects supplied with surface waters.

³⁶ ‘Aquifer’ – Wikipedia [en.wikipedia.org/wiki/Aquifer#Misconception]

A common misconception is that groundwater exists in underground rivers (e.g. caves where water flows freely underground). This is only sometimes true in eroded limestone areas known as karst topography which make up only a small percentage of Earth’s area. More usual is that the pore spaces of rocks in the subsurface are simply saturated with water — like a kitchen sponge — which can be pumped out …

The beach provides a model to help visualize an actual aquifer. If a hole is dug into the sand, very wet or saturated sand will be located at a shallow depth. This hole is a crude well, the wet sand represents an aquifer, and the level to which the water rises in this hole represents the water table.

³⁷ ‘GROUND WATER ATLAS of the UNITED STATES’ – United States Geological Survey [capp.water.usgs.gov/gwa/ch_d/D-text2.html]

… the velocity of water that moves through the aquifer is estimated to average about 1 foot per day.” [At that rate, to go 400 miles, as does the Arkansas River through Kansas, would take 5786 years.]

…

The potential yield of wells is greater than 750 gallons per minute in most of Nebraska and large parts of Kansas. A well capable of producing 750 gallons per minute can irrigate 125 acres and effectively supply one center-pivot irrigation system.

³⁸ ‘GROUND WATER FOR HOUSEHOLD WATER SUPPLY IN RURAL AMERICA: PRIVATE WELLS OR PUBLIC SYSTEMS?’ – Andrew W. Stone, American Ground Water Trust, Concord, NH 03301, USA [www.agwt.org/Education_Papers/RuralWaterInUSA.pdf] “The evolution of drilling technology in the late 1870s was important for opening up much of the Midwest and High Plains, especially in those areas where few rivers were perennial. … Once drilling machines, and wind powered pumps became economically available, settlement patterns were changed by the almost ubiquitous availability of ground water for domestic water use.”

³⁹ ‘Mining Water’ by Richard Cowen, University of California, Davis [www-geology.ucdavis.edu/~cowen/~GEL115/115CH18miningwater.html]

Cheap deep drilling for water wells became available only in the 1930s, and powerful submerged electric pumps were invented just as the government provided Federally subsidized installation of electric power on farms all across the Plains. As the United States came out of the Depression years into a highly stimulated wartime economy, farmers were encouraged by cheap loans and strong crop prices to maximize production. Deep drilling and irrigation with Ogallala water became economic options for the first time, but the generally wet years of the 1940s did not require much additional water for irrigation. Some innovative farmers were rewarded for their enterprise by bumper crops, but for many others the natural rainfall gave a good return.

Ogallala water allowed the agricultural transformation of the High Plains in the 1950s. Renewed drought led to major well drilling, especially on the Texas High Plains. With the technology now well established, the water pumped and the acreage irrigated increased dramatically. …

⁴⁰ ‘Hugh Hammond Bennett Stopped Further Dust Bowls’ – TheParagraph.com [theparagraph.com/2007/01/hugh-hammond-bennett-stopped-further-dust-bowls]

⁴¹ ‘The High Plains’ – Bureau of Land Management Environmental Education

… Approximately 90 percent of the water pumped from the Ogallala Aquifer is used for irrigation. Precipitation and surface streams replenish the aquifer, but surface streams in the arid High Plains are sparse and many are ephemeral, wet only at certain times of the year. Because of the heavy demand for water and the slow replenishment rate, the average water level of the aquifer declined nearly 3 m between 1940 and 1980, then another 30 cm in the 1980s. Better water management and new technologies have helped to slow this depletion. However, greater efforts will be needed to ensure that the water levels in the aquifer stabilize.

⁴² ‘Kansas Ground Water’ – Kansas Geological Survey

In terms of measured declines in the water table, a 10-foot (3-m) decline has been common across much of western Kansas. The much greater declines – in some cases the water table is now 200 feet (60 m) below its level prior to irrigation – are mostly centered in southwestern and west-central Kansas, where irrigation development has been greatest and the amount of water in the aquifer [in Kansas] has been greatest.

⁴³ ‘Farmers’ tower of power’ By Jeremy P. Meyer, Denver Post, 10/02/2006

For three decades, farmer Dennis Coryell has seen the amount of water that can be pumped from his field’s well drop from 1,200 gallons a minute to 600 gallons a minute.

…

“Sunflowers just take less water, less overall input,” he said. “They are a real hardy crop. They produce well under arid conditions.”

A native to Colorado’s Eastern Plains, sunflowers need about 30 percent less water than corn and 50 percent less than hay, said Ron Meyer, a CSU Cooperative Extension agronomist.

“It’s probably the fastest-growing crop in Colorado,” Meyer said. “A couple of years ago, we had 80,000 acres. Last year, we had 215,000 acres.”

⁴⁴ ‘High Plains Sunflower Production Handbook’ – Colorado State University – Kansas State University – University of Nebraska – University / USDA–ARS—Central Great Plains Research Station, Akron, Colorado – pdf

Sunflower has an extensive root system that is capable of using large amounts of available soil water from deep in the soil profile. In a detailed study of sunflower root development and soil water use in Kansas, researchers found 87 to 96 percent of observed roots in the sampled soil profile were above 65 inches, although some roots were found as deep as 106 inches.

For ages before, tough grasses had held the soil and fed the buffalo that, in turn, fed the Indians⁶⁹. But Americans whacked down that food chain: the Army vanquished the Comanches, Texans killed the last millions of the southern plains buffalo, and farmers plowed up the grass. The farmers were urged to move to the region by cattle ranch investors and the federal government. Unlike buffalo, cattle did not fare well on the southern High Plains, with its wind-whipped winters and harsh summer heat⁷⁰. So around 1900, when the market price of cattle dropped, owners divided the huge ranches into small sections to sell to farmers. Marketeers lured farmers with claims such as “rain follows the plow”, saying that the very act of farming would bring rain in that arid land⁷¹. The federal government wanted to populate the region. It gave farmers free train rides to No Man’s Land, and stated that the soil “is the one resource that cannot be … used up⁷²x⁷³.” Cowboys also had something to tell the sodbusters: “the best side is up, don’t plow it under⁷⁴.” Farmers used tractors and the disc plow to turn under the grass of 33 million acres, and many did well selling wheat, until the grain market crashed, not long after the stock market crash of 1929⁷⁵. About the same time a dry phase started in the Great Plains, and in 1930 the first dust storm of the period kicked up in western Kansas. The storm – black and rolling and crackling – was a curiosity. The weather bureau wrote it up and filed it away⁷⁶.

“I didn’t know so much costly misinformation could be put into a single brief sentence,” said Hugh Hammond Bennett of the government’s claim that the soil cannot be used up. Bennett knew the country’s soil. He grew up farming in the foothills of the Blue Ridge Mountains using contour plowing and terracing, studied land use in college, went to work as a scientist for the Department of Agriculture (USDA), and took soil surveys in every state in the country⁷⁷. In his field work he discovered sheet erosion, where each heavy rain takes a thin layer of uncovered soil. Few policy makers cared about soil erosion, but more took notice in 1928 when Bennett published a USDA report, “Soil Erosion: A National Menace”, which helped him get funding for a national soil erosion study⁷⁸. In 1933, the energetic, problem-tackling New Deal administration of President Franklin Delano Roosevelt (FDR) came in, and Bennett became head of the new Soil Erosion Service. With over 150 Civilian Conservation Corps camps at his command, Bennett set up many large demonstration projects for erosion control, planting trees and cover crops, and building control structures. But Bennett wanted a permanent soil conservation agency, and, a few days after Black Sunday, he went to Capitol Hill to try to sell a Senate committee on creating one. Bennett knew that a dust storm was coming up the Ohio River Valley bound for D.C., so he stretched out his testimony. “Chapter by chapter, he annotated each dismal page with facts and figures from a reconnaissance he had just completed,” wrote a Bennett biographer, William Brink. “Out of one corner of his eye, he noted the polite stifling of a yawn, but Hugh Bennett continued deliberatively. … Presently one of the senators remarked—off the record—‘It is getting dark. Perhaps a rainstorm is brewing.’ Another ventured, ‘Maybe it’s dust.’ ‘I think you are correct,’ Bennett agreed. ‘Senator, it does look like dust.’ The group gathered at a window. The dust storm for which Hugh Bennett had been waiting rolled in like a vast steel-town pall, thick and repulsive. The skies took on a copper color. The sun went into hiding. The air became heavy with grit.” Before the month ended, FDR signed the Soil Conservation Act, creating the Soil Conservation Service. Bennett, as head of the new agency, created Soil Conservation Districts where the farmers in an area contract to use soil holding methods, and get federal guidance, equipment, seeds, supplies and labor for doing so⁷⁹. These Soil Conservation Districts kept another dust bowl from forming during similar droughts in later decades⁸⁰. The government also helped by turning parts of the Dust Bowl area back to its natural state, and today the Forest Service plans to bring buffalo back to the southern plains in these national grasslands⁸¹x⁸².

Black Sunday

Above 3 maps from Report of the Great Plains Drought Area Committee, August 27, 1936

Reseeded prairie, Baca County, Colorado (from series compiled by R.E. Rosiere, Tarleton State University, Texas)

Sources

⁶¹ ‘Ford County Dust Bowl Oral History Project – Interview: Clayton Hall’ July 29, 1998

⁶² ‘Ford County Dust Bowl Oral History Project – Interview: Arthur W. Leonard’ June 23, 1998

⁶³ ‘The Worst Hard Time’ by Timothy Egan © 2006 P.8

⁶⁴ Ibid pp.198-199

⁶⁵ Ibid drifts P.158; mud drops P.264; death pp.5-6,173

… Dr. John H. Blue of Guymon, Oklahoma, said he treated fifty-six patients for dust pneumonia … He was blunt. The doctor had looked inside an otherwise healthy young farm hand, a man in his early twenties, and told him what he saw. “You are filled with dirt,” the doctor said. The young man died within a day. – P.173

⁶⁶ Ibid pp.180,195,236

⁶⁷ Ibid P.223

One hundred million acres had lost most of its topsoil and nearly half had been “essentially destroyed” and could not be farmed again, Bennet said. Think about the size, Bennet said: an area stretching five hundred miles north to south and three hundred miles east to west was drifting and dusted; two thirds of the total area of the Great Plains had been damaged by severe wind erosion – an environmental disaster bigger than anything in American history.

⁶⁸ Ibid pp.150-2

⁶⁹ Ibid pp.16-17

⁷⁰ Ibid P.22

⁷¹ Ibid pp.24-5

⁷² Ibid P.37

⁷³ ‘Hugh Hammond Bennett: the Father of Soil Conservation’ by Maurice G. Cook, Emeritus Professor of Soil Science, North Carolina State University

Also in 1909, as a measure of the Bureau’s view of the perishability of soils, whether by erosion, by chemical or physical degradation, or by these factors in combination, the Bureau of Soils published its Bulletin 55. In this Bulletin, Professor Milton Whitney, Chief of the Bureau of Soils, argued that the soil was of inexhaustible and permanent fertility: “The soil is the one indestructible, immutable asset that the Nation possesses. It is the one resource that cannot be exhausted; that cannot be used up.” At a later time, Bennett reacted to Whitneys statement: “I didn’t know so much costly misinformation could be put into a single brief sentence.” While Whitney no longer censored discussions of erosion out of Bennett’s reports, he apparently intended to “cool” Bennett down by sending him on surveys and projects in Alaska and Cuba, and in South and Central America.

⁷⁴ ‘The Worst Hard Time’ by Timothy Egan © 2006 P.25

⁷⁵ Ibid 33 million acres P.101; tractor & plow P.47; did well selling wheat pp.42-43; market crash pp.101-102

⁷⁶ Ibid P.88

⁷⁷ ‘Hugh Hammond Bennett: the Father of Soil Conservation’ by Maurice G. Cook, Emeritus Professor of Soil Science, North Carolina State University

⁷⁸ Ibid

Soon after the publication of this circular, Bennett finally saw some federal funding approved for erosion research. This came about through his connection to A. B. Conner, Director of the Texas Experiment Station. According to a prearranged plan, Conner was to discuss erosion with Congressman Buchanan of Texas. When the congressman maintained, as they expected he would, that federal money was to be spent for defense, Conner would bring up the large expenditure for battleships, and then argue that protecting the soil that supports the citizenship protects the nation. This devious arrangement worked and, as a result, Bennett was soon asked to testify before Buchanan’s subcommittee. An amendment was attached to the 1929 appropriation for the Department of Agriculture authorizing $160,000 over four years for soil erosion research. This money was to be used by the USDA “to investigate the causes of soil erosion and the possibility of increasing the absorption of rainfall by the soil in the United States.”

⁷⁹ ‘Small Farms, Externalities, and the Dust Bowl of the 1930s Gary D. Libecap University of Arizona National Bureau of Economic Research and Zeynep K. Hansen Washington University, St. Louis July 26, 2002 – PDF file

The government response was the organization of Soil Conservation Districts to coordinate erosion control efforts and to subsidize investments. Since the federal government did not have authority to regulate private land use via local government units, state legislation was required. 18 states enacted some variant of the law by June 1937 and all had by 1947. Once state legislation was enacted, farmers in a region could form a Soil Conservation District upon petition and favorable vote. In the Great Plains states of Colorado, Kansas, Montana, Nebraska, Oklahoma, and North and South Dakota there were 39 districts by 1938 covering 18,248,000 acres and 568 covering 318,316,000 acres by 1950.39 Within the districts, individual farmers entered into contracts with the SCS to cooperate in reducing soil erosion for five years. The SCS would provide equipment, seeds, fencing, and personnel for erosion control. Erosion control ordinances imposing land use regulations on all farmers could be adopted upon a favorable vote of a majority of the farmers in a district. Under the statute, the district supervisors could occupy parts of farms and begin erosion control with the costs plus 5 percent levied by court order against the farmer. Further, farmers who did not comply were ineligible for SCS assistance.

⁸⁰ Ibid – PDF file

The Dust Bowl was one of the most severe environmental crises in North America in the 20th Century. Severe drought and damaging wind erosion hit in the Great Plains in 1930 and lasted through 1940. Sustained strong winds blew away an average of 480 tons per acre of topsoil. Although there were similarly severe droughts in the Great Plains earlier in the 19th century and later in the 1950s and 1970s, there were no comparable levels of wind erosion.7 Excessive cultivation in the 1930s is the standard explanation for the Dust Bowl. The issue to be explained is why cultivation was more extensive and use of erosion control techniques more limited in the 1930s than later in the twentieth century.

…

Beginning in 1937, the federal government promoted local soil conservation statutes and districts within each state to subsidize and often force adoption of erosion controls. These included use of strip cropping, certain types of
fallow, terracing, and the planting of trees for windbreaks or shelterbelts. Soil Conservation Districts were established throughout the Great Plains so that by December 1956, there were 827 Soil Conservation Districts in the Great Plains states. The Soil Conservation Districts generally encompassed entire counties or more, and hence, were much larger than individual farms and better able to internalize the externalities associated with soil erosion control and to coordinate anti-erosion efforts among the farmers in their districts. Further, by the 1950s, gradual consolidation increased farm size. As a result, by the 1950s use of wind erosion control techniques was much more prevalent in the Great Plains than in the 1930s.

⁸¹ ‘The Worst Hard Time’ by Timothy Egan © 2006 P.309

⁸² ‘The National Grasslands Story’ – USDA Forest Service

… we saw a set of polar bear tracks ambling off to the west. They were older tracks judging by how drifted they were; however, with all this open water around us one must be near. We have placed our camp on orange alert as a result of the sighting. …

… The day started nice enough, the wind had shifted, cooling things a bit and firming up the snow. But like so many of the other ‘good’ conditions we experienced, it didn’t last.

The light soon went flat and we were once again stumbling blindly forward. It started to snow too, and hard. We wondered if another blizzard was on its way, but it just kept falling at the same steady rate all day. The new snow stuck thickly to the bottom of our skis, made them heavy with no glide. Stopping to scrape the snow and ice off only helped for a few minutes. We switched to snowshoes.

When we put on our MSR snowshoes, it’s like putting a truck into four-wheel drive. We are able to pull the sled-canoes up and around ice that would be impossible with skis. On the down side, our travel slows and we expend extra energy lifting (instead of sliding with skis) each step. Still, without snowshoes, we would still be on the ice post-holing our way to madness or worse.

The only really good part of today was that we were able to laugh about it once it was over. For over six hours, we snowshoed. The sled-canoes seemed like a pallet of bricks and stopped dead at even the slightest pause in forward momentum. The ice was worse – small pans, pressured together in random ways, lots of open water leads filled with compressed snow and some brash ice. We had to veer so much east and west that at times, we thought we might be going in circles.

It’s hard to convey the feelings we have during a day like today. Several times we were near temper tantrum level when a sled-canoe got stuck or a piece of ice disintegrated underneath us. There’s intense fear when facing a tenuous brash ice crossing or relief like when three car-sized chunks of ice heeled over just after (not while) we had hopped across them. Frustration and despair as we scout the route and see more bad ice. Physical exhaustion as we try to pace our efforts. Hunger. Desire to stop and quit. Drive to keep moving forward.

When we finally reached a big flat piece of ice with 15 minutes left in the travel day, we didn’t know whether to laugh or cry.

It is equally hard to describe our emotions now that today is nearly complete. Before today we had hoped for good ice to the Pole, now we expect bad.

Sources

¹ ‘Project Thin Ice’ – Greenpeace

² ‘Last Day in Grand Marais’ – Explorers’ Blog, April 27, 2006

³ ‘Not Easy’ – Explorers’ Blog, June 15, 2006

‘ Working Group I: The Scientific Basis; Figure 1’ – IPCC

Sources

¹ ‘The Discovery of Global Warming’ by Spencer Weart “In 1896 a Swedish scientist published a new idea. As humanity burned fossil fuels such as coal, which added carbon dioxide gas to the Earth’s atmosphere, we would raise the planet’s average temperature. This “greenhouse effect” was only one of many speculations about climate, and not the most plausible. Scientists found good reason to believe that our emissions could not change the climate. Anyway major change seemed impossible except over tens of thousands of years.”

² ‘A.2 The First and Second Assessment Reports of Working Group I’ – Intergovernmental Panel on Climate Change [IPCC] “… the balance of evidence suggests a discernible human influence on global climate.” – Second Assessment Report, 1996 [¶]

³ ‘Some Like It Hot’ by Chris Mooney “Victory will be achieved when recognition of uncertainty becomes part of the ‘conventional wisdom’.” – American Petroleum Institute [¶]

⁴ ‘Some Like It Hot’ by Chris Mooney “… these [free-market, antiregulatory] groups are funded by ExxonMobil, the world’s largest oil company.” [¶]

⁵ ‘Contrarians’ by Stephen H. Schneider “… these contrarians are given disproportionate representation in the media (see Mediarology) and by certain governments, especially the Bush Administration, so far …”

⁶ ‘A.1 The IPCC and its Working Groups; Box 1: What drives changes in climate?’ – IPCC “The Earth absorbs radiation from the Sun, mainly at the surface. This energy is then redistributed by the atmospheric and oceanic circulations and radiated back to space at longer (infrared) wavelengths. For the annual mean and for the Earth as a whole, the incoming solar radiation energy is balanced approximately by the outgoing terrestrial radiation. Any factor that alters the radiation received from the Sun or lost to space, or that alters the redistribution of energy within the atmosphere and between the atmosphere, land, and ocean, can affect climate.” [¶]

⁷ ‘C.1 Observed Changes in Globally Well-Mixed Greenhouse Gas Concentrations and Radiative Forcing’ – IPCC “the observed increase in CO2 is predominately due to the oxidation of organic carbon by fossil-fuel combustion and deforestation” … “Most of the emissions during the past 20 years are due to fossil fuel burning, the rest (10 to 30%) is predominantly due to land-use change, especially deforestation.” [¶]

⁹ ‘What is the Evidence for Global Warming?’ by Robert R. Stewart “b. Stable isotopic composition, especially the ratio (18O/16O) where 18O is the concentration of the oxygen 18 isotope, and 16O is the concentration of oxygen 16 isotope. The ratio gives temperature at which H2O condensed as water or snow. c. Air bubbles trapped in the ice gives atmospheric gas content, especially the concentration of carbon dioxide.”

¹⁰ ‘Deciphering Mysteries of Past Climate From Antarctic Ice Core’ by Vostok Project Members “These [ice core] studies … tie carbon dioxide and methane concentrations to temperature” [¶]

¹¹ ‘Paleoclimatic Data Before 1000 Years Ago’ – NOAA “The latest peer-reviewed paleoclimatic studies appear to confirm that the global warmth of the 20th century may not necessarily be the warmest time in Earth’s history, what is unique is that the warmth is global and cannot be explained by natural forcing mechanisms”

¹² ‘The truth about global warming’ By Sandi Doughton, Seattle Times staff “With each passing year the evidence [that greenhouse gases are altering the world’s climate] has gotten stronger — and is getting stronger still.” [¶]

¹³ ‘ Working Group I: The Scientific Basis; Figure 1’ – IPCC

¹⁴ ‘Deciphering Mysteries of Past Climate From Antarctic Ice Core’ by Vostok Project Members “The chronology of the ice at Vostok has been established down to 2546 m, which is dated at 220,000 years before present.” [¶]

¹⁵ ‘C.1 Observed Changes in Globally Well-Mixed Greenhouse Gas Concentrations and Radiative Forcing’ – IPCC “There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities.” – Third Assessment Report, 2001 [¶]

¹⁶ ‘Hot and Bothered: An Interview with Ross Gelbspan’ Interviewed By Dave Gilson, April 18, 2005 “… the purpose of this publicity campaign using greenhouse skeptics was to reposition global warming as theory rather than fact.” [¶]

¹⁷ ‘The truth about global warming’ By Sandi Doughton, Seattle Times staff “… climate researchers say skeptics are recycling discredited arguments or selectively using data to make points. And as Oreskes showed, few skeptics publish in peer-reviewed journals, which check for accuracy and omissions.” [¶]