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All of these raise some very difficult questions. For example, ecosocialism is somewhat tarnished by the abysmal environmental record of Eastern European communist governments.
The obvious question for the manager blessed with the opportunity to manage among these minefields is which one of these mental models is "right"? The unfortunate truth is that we as a society are not ready to answer that question yet.
This is not just because most people – environmental professionals, environmentalists, regulators, industry leaders – are naive positivists, and therefore unwilling or unable for the most part to recognize their own mental models, much less to respect other parties’ mental models.
It also reflects a disturbing and almost complete ignorance about the implications of each model for the real world. What levels of human population, of biodiversity, of economic activity, would each mental model imply? What kind of governance structure? Who would win and who would lose (more precisely, what would the distributional effects of each model be)?
The important point, I think, is not the correctness of any particular model. Rather, it is the need to under- stand that differences among stakeholders in environmental disputes may arise not just from factual or economic disagreements, but from differences in fundamental worldviews – and that, at present, our current knowledge cannot anoint any particular one as "privileged."
A little sensitivity to how one’s position and practices are understood by others can go a long way towards facilitating collaborations, which are both necessary and plenty difficult as it is. Before one too readily criticizes others, one should recall the Socratic admonition and know thyself – and thy mental models.
PRE-CAMBRIAN PERIOD
The Earth formed under so much heat and pressure that it formed as a molten planet. For nearly the first billion years of its formation – called the Hadean Period (or "hellish" period) – Earth was bombarded continuously by the remnants of the dust and debris – like asteroids, meteors and comets – until it formed into a solid sphere, fell into an orbit around the sun, and began to cool down.
As Earth began to take solid form, it had no free oxygen in its atmosphere. It was so hot that the water droplets in its atmosphere could not settle to form surface water or ice. Its atmosphere was also so poisonous that nothing would have been able to survive.
Earth’s early atmosphere most likely resembled that of Jupiter’s atmosphere, which contains hydrogen, helium, methane and ammonia, and is poisonous to humans.
Earth’s atmosphere was formed mostly from the out gassing of such volatile compounds as water vapor, carbon monoxide, methane, ammonia, nitrogen, carbon dioxide, nitrogen, hydrochloric acid and sulfur produced by the constant volcanic eruptions that besieged the Earth. It had no free oxygen.
About 4.1 billion years ago, the Earth’s surface – or crust – began to cool and stabilize, creating the solid surface with its rocky terrain. Clouds formed as the Earth began to cool, producing enormous volumes of rain - water that formed the oceans. For the next 1.3 billion years (3.8 to 2.5 billion years ago), called the Archean Period, first life began to appear (at least as far as our fossil records tell us... there may have been life before this!) and the world’s landmasses began to form. Earth’s initial life forms were bacteria, which could survive in the highly toxic atmosphere that existed during this time. In fact, all life was bacteria during the Archean Period.
Toward the end of the Archean Period and at the beginning of the Proterozoic Period, about 2.5 billion years ago, oxygen-forming photosynthesis began to occur. The first fossils, in fact, were a type of blue-green algae that could photosynthesize.
Some of the most exciting events in Earth’s history and life occurred during this time, which spanned about two billion years until about 550 million years ago. The continents began to form and stabilize, creating the super continent Rodinia about 1.1 billion years ago. (Rodinia is widely accepted as the first super continent, but there were probably others before it.) Although Rodinia is composed of some of the same land fragments as the more popular super continent, Pangea, they are two different super continents. Pangea formed some 225 million years ago and would evolve into the seven continents we know today.
Earth’s atmosphere was first supplied by the gasses expelled from the massive volcanic eruptions of the Hadean Era. These gases were so poisonous, and the world was so hot, that nothing could survive. As the planet began to cool, its surface solidified as a rocky terrain, much like Mar’s surface and the oceans began to form as the water vapor condensed into rain. First life came from the oceans. Free oxygen began to build up around the middle of the Proterozoic Period around 1.8 billion years ago – and made way for the emergence of life, as we know it today. This event, of course, created conditions that would not allow most of the existing life to survive and thus made way for the more oxygen dependent life forms.
By the end of the Proterozoic Period, Earth was well along in its evolutionary processes leading to our current period, the Holocene Period, also known as the Age of Man. Thus, about 550 million years ago, the Cambrian Period began. During this period, life "exploded" developing almost all of the major groups of plants and animals in a relatively short time. It ended with the massive extinction of most of the existing species about 500 million years ago, making room for the future appearance and evolution of new plant and animal species.
And then, about 498 million years later – 2.2 million years ago – the first modern human species emerged.
EARTH’S TRUE VITAL SIGNS REVEALED FROM SPACE
Circling the Earth 16 times a day 438 miles above the surface, new satellite technology is revolutionizing earth science and now scientists are able to understand the health of the planet and distinguish between human impact and natural phenomenon. On February 4, scientists began collecting images of the earth’s vital signs from its bus-sized Terra satellite, the flagship of NASA’s 15-year Earth Observing System (EOS). EOS is an international collaboration designed to help scientists develop those answers about Earth’s climate and environmental changes that have not been available before.
Though the earth is approximately 4.5 billion years old, the earliest ancestors of the human race only appeared between three and four million years ago, according to most scientists. This is only one-tenth of one percent of Earth’s time span, a relatively insignificant period. Even the first known civilization did not appear until about 6,000 BC. But since the dawn of humankind, the earth supplied all of their wants and needs, which led to settled life in groups or villages. Yet during the entire lifespan of the earth, natural geologic forces have constantly been changing and rearranging the planet’s features, climate and environment. And now, there is "compelling evidence that human activities have attained the magnitude of geological force and are speeding up the rates of global change," according to Dr. Yoram Kaufman, Terra Project Scientist.
According to Dr. Kaufman, these changes have occurred without much knowledge at all about their impact on earth’s life systems. "Scientists don’t understand the cause-and-effect relationships among Earth’s lands, oceans, and atmosphere well enough to predict what, if any, impacts these rapid changes will have on future climate conditions," he said.
This image from Terra shows chlorophyll concentrations and phytoplankton health in the Arabian Sea via its MODIS instrument.
"There are some basic questions about the Earth system that need to be answered in order to understand our world’s climate system well enough to predict future changes, and how those changes may impact our quality of life," – said Dr. Kaufman during a recent NASA news briefing in Washington, DC. "Terra data, along with other measurements, will feed earth science models so we can predict climate variations and climate change, and prepare for the future. We anticipate that Terra data will revolutionize our understanding of the Earth’s climate system and help show the human impact," – he continued. "Terra is measuring a wide array of vital signs, many of them for the first time, to help us understand our planet, to distinguish between natural and man-made climate change, and to show us how the Earth’s climate affects the quality of our lives."
Dr. Kaufman describes that this revolution in earth science is necessary to help in the understanding of our world’s climate systems enough to accurately predict changes and how those changes will impact quality of life. Questions, which need to be answered, include "How are the soils and vegetation types changing around the world?"
"What are the changes in the extent of snow and ice, and why are 2 – 3 of the world’s glaciers disappearing each week?"
"What are the variations in the phytoplankton in the ocean and how are these plants affected by windblown Saharan dust?"
"What is the concentration of atmospheric airborne particles and gaseous pollutants, and how do they affect the ability of the atmosphere to cleanse itself?"
"What fraction originates from natural or man-made sources?"
"How do the availability of water vapor and the presence of pollutants affect cloud formation, properties and precipitation?"
"Is the Earth system taking in more radiant energy than it reflects and emits back into space, or is the radiation budget in balance (global warming)?"
"Is there a change in the frequency of wild fires, floods & volcanic eruptions?"
"Is the frequency related to climate change?"
The Terra observatory uses five instruments to thoroughly study and track Earth’s vital systems: Land,
Ocean, Atmosphere, and the life, exchange of nutrients, carbon, heat, moisture and pollution among them. The first instrument is called the Moderate-resolution Imaging SpectroRadiometer (MODIS). MODIS provides frequent global views of changes occurring within the Earth system, including the study of snow and ice cover, cloud cover and cloud type, vegetation cover and other land covers, the temperature of the oceans, and the study of plant life on land and in the oceans.
This thermal infrared image shows the urban heat island effect in the San Francisco Bay area through Terra’s ASTER instrument.
The second instrument is the Multi-angle Imaging SpectroRadiometer (MISR) that physically characterizes the Earth’s surface, atmosphere, and clouds, and how they interact with sunlight, the primary energy source for Earth’s climate system. The third instrument, the Advanced Space borne Thermal Emission and Reflection radiometer (ASTER) is a joint US-Japan project provided by Japan’s Ministry of International Trade and Industry. It is the zoom lens of the Terra satellite. The primary goals of ASTER are to characterize the Earth’s surface and to monitor dynamic events and processes that influence habitability at human scales. The Measurements of Pollution in the Troposphere (MOPITT) is a fourth instrument that helps scientists to determine the amount of carbon monoxide and methane at different altitudes in the atmosphere. MOPITT is a joint effort of the US and Canada.
The final instrument is called Clouds and the Earth’s Radiant Energy System (CERES), which measures reflective sunlight. Measuring the energy emitted by the surface and atmosphere of the Earth, CERES monitors the balance of the "radiation budget" which indicates whether the earth is warming or cooling. If the radiation budget if perfectly balanced, the earth should neither be warming nor cooling.
THE OZONE LAYER
Although ozone (O3) is present in small concentrations throughout the atmosphere, most ozone (about 90 %) exists in the stratosphere, in a layer between 10 and 50 km above the surface of the earth. This ozone layer performs the essential task of filtering out most of the sun’s biologically harmful ultraviolet (UV-B) radiation. Concentrations of ozone in the atmosphere vary naturally according to temperature, weather, latitude and altitude. Furthermore, aerosols and other particles ejected by natural events such as volcanic eruptions can have measurable impacts on ozone levels.
THE OZONE HOLE
In 1985, scientists identified a thinning of the ozone layer over the Antarctic during the spring months, which became known as the "ozone hole". The scientific evidence shows that human-made chemicals are responsible for the creation of the Antarctic ozone hole and are also likely to play a role in global ozone losses.
Ozone Depleting Substances (ODS) have been used in many products which take advantage of their physical properties (e.g. chlorofluorocarbons (CFCs) have been used as aerosol propellants and refrigerants).
CFCs are broken down by sunlight in the stratosphere, producing halogen (e.g. chlorine) atoms, which subsequently destroy ozone through a complex catalytic cycle. Ozone destruction is greatest at the South Pole where very low stratospheric temperatures in winter create polar stratospheric clouds (PSCs). Ice crystals formed in PSCs provide a large surface area for chemical reactions, accelerating catalytic cycles. The destruction of ozone also involves sunlight, so the process intensifies during springtime, when the levels of solar radiation at the pole are highest, and PSCs are continually present.
Although ozone levels vary seasonally, stratospheric ozone levels have been observed to be decreasing annually since the 1970s. Mid-latitudes have experienced greater losses than equatorial regions. In 1997, the Antarctic ozone hole covered 24 million km2 in October, with an average of 40 % ozone depletion and ozone levels in Scandinavia, Greenland and Siberia reached an unprecedented 45 % depletion in 1996.
ENVIRONMENTAL AND HEALTH EFFECTS
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