Humanity and Nature on Collision Course David Yarrow, April 5, 2006 2006: Facing Our Uncertain Future
This special report included six articles, dramatic photos and several sidebars describing climate change as a serious,
That same week, ABC News featured a week-long series of daily and nightly reports on
These media splashes followed a March 19 60 Minutes interview with NASA climate scientist James Hansen, who insisted the Bush administration is censoring and altering scientific data that reveals global warming is real, and preventing him from speaking freely to American people about this global ecological threat.
The White House made no response to these reports documenting climate change is the #1 challenge facing the human future worldwide. Clearly, U.S. global warming policy will change immediately after—but probably not until—George Bush and Dick Cheney leave office. But the serious question is whether we and the world can wait another two years for U.S. government to mobilize its immense resources to confront this challenge to the survival of industrial civilization. Meanwhile, insurance industry is sending out strong signals of the financial consequences of continued natural disasters, while the American public nervously listens to predictions for another unprecedented hurricane season driven by higher-than-normal water temperatures in the Gulf of Mexico and the Atlantic Ocean.
Experts—including James Hansen and former Vice President Al Gore—don't think we can sit on our hands for two years. Many leading climate scientists believe the Earth's thermal systems are near the "tipping point"—the point of no return, with runaway, out-of-control, irreversible greenhouse effects. Many of these experts fear we have only 10 years to reverse the alarming steady rise in global temperatures in oceans and atmosphere.
Based on my own 30-year observations of effects from carbon in Earth's atmosphere, I believe such acute concern, and the need for immmediate, drastic action is justified.
1975: Rising Carbon Curve In 1975, I read a self-published paper by John Hamaker, a retired civil engineer in Missouri, which described the steady rise in carbon dioxide in Earth's atmosphere, and potential consequences of this increase on global climate. Hamaker's graph of measured CO2 in the atmosphere revealed a rising curve. Not only was the level rising, by the rate of rise was increasing—an exponential curve. I didn't need a PhD in climate science to recognize that such a steeply rising curve will have serious consequences for humanity before the end of my own lifetime. I decided to keep close watch on this obvious pollution of Earth's atmosphere. Exactly what the consequences of rising CO2 levels are was still an open question with multiple answers. Some believed rising CO2 will bring a new Ice Age, with worldwide cooling and another massive continental ice sheet bulldozing down from the North Pole. Others expressed a view that accumulating CO2 and other carbon-containing gases will create a "greenhouse effect" that will trap solar heat in the atmosphere, producing worldwide warming and catastrophic climate change. Whichever climate scenario proved true, in the 1970's I saw ample evidence that humans are abusing the Earth and damaging Nature. This was only one of a cluster of conditions that were tipping the balance of life on Earth. I chose to confront what were obviously serious and dangerous challenges facing humanity. I decided to devote my life to efforts to address the challenges to human survival at the end of the millennium.
After fumbling about for a year, I elected to focus on agriculture and food supply as my area of special effort. Obtaining food is our most fundamental interaction with, and largest scale impact on, Nature. Agriculture and food distribution are the largest sector of any local economy—more money changes hands feeding people every day, three times a day, than any other ecnomic activity. And we are what we ate—food is the foundation for the health of each and every human being. But most critically, I questioned how we could continue to produce food to feed ourselves in an era when we can no longer predict weather or rely on climate. On February 1, 1990, data arrived that convinced me global warming-driven climate change was a reality in our time. I was on my way to the Syracuse train station, headed for Albany with 13 proposals for legislation to support ecological agriculture and organic food, when National Public Radio (NPR) News made three announcements that alerted my mind that climate change is really happening.
1990: Flood Stage for Sea Circulation The first was a second Lou Harris poll that had again found that 81% of Americans would buy organic food—if they could get it. And 51% of Americans would pay more for that food—if they could get it. And that 88% of Americans did not believe government was doing an effective job of keeping dangerous chemicals out of our food supply. This was a second poll confirming the results of an earlier survey. This was sweet and timely news to get on my way to lobby in the New York State Capital for ecological agriculture and a sustainable food system. Then, NPR News reported that Valdez, Alaska—made famous by the Exxon Valdez oil tanker disaster—had 22 feet of snow. This was more by mid-winter than Valdez usually gets in an entire winter. Then, NPR News reported northern Europe—Britain, Denmark and Scandanavia—had been hit by Weather Engine of the Climate System
Warm water out of the Gulf of Mexico and Caribbean Sea flows north in the Atlantic Ocean as the Gulf Stream on the sea surface along the North American coast and Greenland. Reaching the Arctic rim between Iceland and Scotland, this warm current turns and releases its heat into the atmospere. It cooler, denser waters then sink to begin their journey as a deep sea current back to tropical waters. Where the Gulf Stream makes its turn is the area of ocean that generates the weather systems that sweep across northern Europe.
Water as a much higher capacity to hold heat than air. Those ocean currents carry much more heat between the equator and the poles than the entire atmosphere—at least ten times more, and perhaps as much as 20 times more. Once these ocean currents reach their thresolds of maximum heat transport, the planet's thermal balance is under threat to go out of balance. And clearly to me, the Earth was at that threshold, and climate change seemed an inevitable consequence in the 1990s. For me, the question no longer was whether global warming was happening, but how bad would it get before humans woke up to this reality and decided to change their behavior to stop their contributions to this out-of-control pollution of air and oceans.
1991: Mount Pinatubo Buys Time On June 12, 1991, Mount Pinatubo—a volcano on the north island of Luzon in The Philippines in Southeast Asia—erupted in a ferocious and powerful exposion. Recognition of volcanic unrest at Pinatubo began with steam explosions on April 2, 1991. The unrest culminated ten weeks later in the world's largest eruption in over half a century. In the twentieth century, this 1991 eruption was second in size only to a 1912 eruption in Katmai, Alaska. Pinatubo's eruption was ten times larger than Mount St. Helens' eruption in 1980, and threatened the lives of a million people. The largest eruption in Pinatubo's history occurred over 35,000 years ago. The explosive eruption of June 1991 was one of Pinatubo's smallest. In early June, tiltmeter measurements showed the volcano was inflating as magma filled a reservoir under the summit. Seismic activity previously focused a few kilometers below a point five kilometers northwest of the summit, shifted to shallow depths below the summit. An evacuation radius was extended to 30 kilometers, and the number of evacuees increased to 58,000. On June 7, the first magma eruption took place, when a lava dome formed at the summit, and grew in five days, reaching a diameter of 600 feet and 120 feet high.
A major explosive eruption began at 8:51am on June 12, spewing ash and steam that rose 19 kilometers on weather-radar at Subic Bay Naval Station. A seismic tremor burst had occurred hours earlier, but no seismic event preceded this eruption. A high-level seismic signal and rise of an eruptive column began simultaneously. Seismic records show this event lasted 35 minutes. Ash was transported southwest past communities north of Subic Bay, and small pyroclastic flows traveled northwest and north. On June 15, the climactic eruption began. Large tremors started at 1:42pm, saturated seismographs at Clark Air Base, and by 2:30, all were inoperative from pyroclastic density currents. Intense atmospheric pressure variation was recorded. A giant ash cloud rose 35 kilometers into the sky, and hot blasts of gas and ash seared the countryside. The same day, Typhoon Yunya passed 50 miles north, making direct visual observation of the eruption impossible. Measurements showed ash was ejected to 34 kilometers high. The eruption's most violent phase lasted three hours. Pyroclastic flows poured from the summit. Typhoon rains mixed with the deposits caused massive lahars. Pyroclastic flows of super-heated ash and gas traveling over 100 miles per hour blasted all vegetation from the slopes, and distributed over 325 feet of pyroclastic material on all sides of the volcano, reaching as far as 16 kilometers away. Valleys carved into older volcanic terrain and partly filled by prehistoric eruptions were filled once again. Calculations indicate 5 cubic kilometers of dense magma supplied the Pinatubo eruption—approximately ten times the 1980 Mount St. Helens eruption.
This catastrophic event blanketed hundreds of square miles under hot volcanic ash deposits 5 centimeters or more thick, covering 4,000 square kilometers surrounding Pinatubo, causing the population to flee on massive scale. These deposits buried crops. The weight of ash ("tephra")—aided by repeated intense seismic shaking and wind buffeting—caused roofs to collapse in communities around the volcano and two U.S. military bases. Over 300 people died in the eruption, most from collapsing roofs. Typhoon Yunya's strong winds increased widespread dispersal of ash fall from the stratospheric eruption cloud, and heavy rain saturated the accumulating ash, causing more roof collapses and mudflows. Typhoon rain runoff eroded and redistributed pyroclastic deposits, resulting in lahars, floods and sedimentation, increasing the death toll and property damage. For many hours, Pinatubo blasted tons of rocks shattered into dust many miles into the atmosphere. This ash cloud covered some 50,000 square miles, bringing total darkness to much of central Luzon. Most of the island received some ashfall, which formed a heavy, rain-saturated, snow-like blanket. Tephra fell over most of the South China Sea, and was recorded as far away as Vietnam, Cambodia and Malaysia.
By 10:30pm, nine hours after the onset of the climactic phase, atmospheric pressure waves decreased to pre-eruption levels. Volcanologists believe this marked the end of the climactic eruption. Before June 1991, Pinatubo rose 5725 feet above sea level. Almost 500 feet of the volcano summit was blasted away by this eruption, so Pinatubo's height was substantially reduced. The eruption created a 2.5-kilometer-wide collapse caldera, centered northwest of the pre-eruption summit, and filled valleys around Pinatubo with 5.5 cubic kilometers of pyroclastic deposits. The elevation of the caldera lake is 820 to 840 meters above sea level, 650 meters below the height of the new caldera rim. The eruption left a wide-open vent system, and the caldera billowed ash continually for another month in a column that rose as high as 15 kilometers. East to southwest winds caused persistent fall of very fine powdery ash west to northeast of the new summit caldera. American military evacuated 18,000 personnel and dependents from nearby Clark Field, the US Air Force base where B-52 bombers had been staged for 40 years. The U.S. military never returned to Clark Air Base, turning the damaged base over to the Philippine government on November 26, 1991. Today, the region continues to rebuild and recover from the disaster. Pinatubo's Long-term Legacy: Global Cooling Pinatubo's1991 eruption is well-known for its near-global effects on atmosphere and climate due to dust and sulfur dioxide injected into the upper atmosphere. Over 90% of the material released by the volcano was ejected in the nine hour June 15 eruption. Pinatubo's gas and ash eruption plume reached high into the atmosphere within two hours, reaching an altitude of 21 miles. Satellite data Space Shuttle (Mission STS 43) photographed the Earth over South America on August 8, 1991 (on right), showing a double layer of Pinatubo aerosol cloud (dark streaks) above high cumulonimbus tops. Shuttle astronauts reported difficulty getting clear photos of equatorial Africa due to the high level dust in the atmosphere.
Overall, cooling effects of Pinatubo's eruption were greater than those of the El Niño taking place at the time, or the planet's greenhouse gas warming. In 1992, the U.S. experienced its third coldest and third wettest summer in 77 years. The eruption is believed to have influenced events such as 1993 Mississippi River floods, and drought in Africa's Sahel.
The eruption caused significant large increases in ozone destruction. Ozone levels at mid-latitudes reached their lowest recorded levels. In winter 1992, Antarctica's ozone hole reached its largest-ever size, with the fastest recorded ozone depletion rates. Ozone remained depressed in 1993. Mount Hudson's eruption in Chile in August 1991 also contributed to South Pole ozone destruction—measurements showed sharp decrease in ozone at the tropopause when Pinatubo and Hudson aerosols arrived. 1998: Ice Storm of the Century Pinatubo's eruption was personal for me. At ages 8 to 10, I lived in the Philippines on Mount Maquiling, an extinct volcano southwest of Manila. My family took a trip to northern Luzon to visit Clark Air Base and the Banaue rice terraces. When Pinatubo blew its summit into the stratosphere, I was beginning a project in upstate New York to train homeless men from New York City to homestead as organic farmers. I realized this equatorial zone eruption would spread dust around the Earth, reflecting sunlight and reducing solar heating. I warned our trainees this volcanic eruption at the Earth's other end would cool Earth's atmosphere enough to give a cool summer the next year, and reduce warm season crop yields. Equatorial dust from Pinatubo's eruption gave three years of global cooling. The eruption was a local catastrophe, but a global godsend by reversing the rise of equatorial air and water tempreratures. This lowered planetary heating from the greenhouse effect bought humanity a few extra years to prepare for this larger worldwide catastrophe. But this benefit was brief. By 1995, Earth temperatures again began to creep steadily and steeply upward. In January 1998, I witnessed a warning of one consequence of the planet's steady overheating. Frigid, dry arctic air slid south into southeast Canada and the northeast U.S. Simultaneously, warm, moist air from the Gulf of Mexico boiled north out of subtropical latitudes. These opposite air masses collided over the Northeast. Warm air rose up over denser arctic air, and began to release its moisture. Warm rain fell into frigid air below, and when striking the ground, trees, buildings, and structures that were below freezing, the water turned to ice. Freezing rain occurred from Lake Ontario to Maine, and from Albany to Ottawa. These air masses then stalled for six days, and freezing rain continued all over the St. Lawrence Valley and Adirondack Mountains all the way to Maine and Newfoundland. As much as six inches of ice coated roofs, trees, power lines, roads, bridges, and everything. The weight of this ice collapsed buildings, ripped limbs off trees, pulled down power and phone lines, and completely shut down transportation. This was the thickest and most widespread ice storm in history. This was catastrophic. Transportation was paralyzed. Steel towers carrying high voltage power were pulled down, and millions were without power and heat. Communication was shutdown. Trees and shrubs were ripped and splintered. Livestock and wild animals were killed. Many weeks were required to restore basic services in such a vast geographic area. For years after, forests were decimated, distorted and impassable from limbs littering the ground. 1999: Collapse of the Temperate Zone
These ice storms were early signs of a collapse of the temperate zone. Normally tropical and arctic air masses do not directly collide, but a buffered and blended in the middle latitudes by the temperate zone. The circulation of air between the equator and poles is normally broken into three distinct climate cells. The jet stream is a high velocity movement of air that form at high altitudes between these three climate zones. With the breakdown of the boundaries between these thre climate cells, the jet stream begins to swing further north and south, allowing warm, moist tropical air to penetrate further north, and also for cold, dry arctic air to flow deeper to the south.
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a third winter storm with winds over 100 mile per hour—greater than the century level mark. Thousands of ancient trees were blown over or snapped off by these fierce winds. The first such winter storm had aroused comments about evidence of possible climate change. The second such storm had provoked a more serious discussion about global warming, but was considered insufficient evidence of anything extra-ordinary about conditions in Earth's atmosphere. But with this third extreme storm by midwinter, even British Prime Minister Margaret Thatcher expressed grave concern that climate change was now a reality of history.
Similarly, in the eastern Pacific, a warm surface current transport heat out of the tropical ocean up along the west coast of North America. This warm water is responsible for the mild coastal climate of Oregon, Washington, British Columbia, and Alaska. But now, an excess of heat was dumping extra warm, moist air along the Alaskan coast. This moist air must rise up over the coast ranges of Alaskan mountains, and in the process, release its burden of heat and moisture. Hence, the extraordinary winter snowfall along the Alaskan panhandle.
showed the climactic eruption cloud rose high into the stratosphere, and spread umbrella-like over 200 kilometers in all directions—the largest disturbance of the stratosphere since Krakatau's 1883 eruption. With a total mass of SO2 of 17 million tons injected, this was the largest volume ever recorded by modern instruments—ten times larger than Mount St. Helens in 1980. The aerosol cloud spread around the Earth in two weeks, covered the planet in a year, and persisted for three years.
This huge stratospheric injection of ash and aerosols over the Earth reduced sunlight reaching Earth's surface by up to 5%, and reduced global temperatures. In 1992 and 93, the Northern Hemisphere's average temperature was reduced 0.5 to 1.1°C, and the entire planet cooled 0.4 to 0.7°C. Maximum reduction in global temperature was in August 1992, with a 0.73°C reduction (see chart at right). At the same time, temperatures in the stratosphere rose several degrees higher than normal due to radiation absorbed by aerosols.
Pinatubo also ejected 15 to 30 million tons of sulfur dioxide gas, which mixes with water and oxygen to become sulfuric acid, which triggers ozone depletion. Sulfur dioxide oxidised in the atmosphere into a haze of sulfuric acid droplets (see map at right), which gradually spread throughout the stratosphere the year after the eruption.
This unprecedented weather was a prelude to an increasing series of such extreme events. Such ice storms continued to strike large areas from North Carolina all the way into Canada. Some were small scale, affecting mountaintops or a few square miles. But moer and more these freaks weather calamities distrupted wide geographic areas, creating weather emergencies and disasters. In February 1999, I drove from New York to Florida; never in my life had I seen such extensive deformities of trees from these recurring ice storms. Shenandoah National Park on the Blue Ridge in western Virginia looked like a disaster scene. Forests in North Carolina were grotesque from disfigured trees with shattered crowns and broken limbs.