be reabsorbed by trees and other vegetation. The rate of emitting carbon dioxide was equal to the rate of absorption. Consequently, the carbon cycle was in balance and there was no violation of System Condition 1. The concentration of carbon dioxide was consistently about 280 ppm. However, we are now emitting carbon dioxide at a faster rate than it is being absorbed, thus causing an increase in the carbon dioxide concentration in the atmosphere—exceeding 400 ppm. This cover of carbon dioxide is preventing the release of reflected sun rays back into the atmosphere, thus causing an increase in the temperature of the Earth—global warming, which is also known as climate change.
If this condition is not met, the concentrations of substances in the ecosphere will increase and eventually reach some limits beyond which it will be almost impossible to reverse. In the case of carbon dioxide, many scientists believe that it will be impossible to reverse, even if we stopped emitting carbon dioxide. In a report by the National Oceanic and Atmospheric Administration, it stated that “changes in surface temperature, rainfall, and sea level are largely irreversible for more than a thousand years after carbon dioxide emissions are completely stopped.” In an interview with the lead author, Susan Solomon, she said, “People have imagined that if we stopped emitting carbon dioxide that the climate would be back to normal in 100 or 200 years. What we're showing here is that that's not right” [4].
System Condition 2—Substances Produced by Society Must Not Systematically Increase in the Ecosphere
This means that substances must not be produced at a faster rate than the rate at which they can be broken down and integrated back into nature or redeposited into the earth's crust. If this condition is not met, the concentration of substances in the ecosphere will continue to increase and eventually reach undesirable limits beyond which it will be difficult reverse. In most cases, this upper limit is not known.
It is critical that we eliminate our contribution to the progressive buildup of chemicals and compounds produced by society such as dioxins, polychlorinated biphenyls (PCBs), and dichlorodiphenyltrichloroethane (DDT). In addition to these very toxic chemicals, there are many other substances produced by society that are accumulating in nature and are detrimental to the environment.
A very interesting example of the violation of System Condition 2 is that of ozone. The chemical name for ozone is tri-oxygen as it consists of three oxygen atoms as opposed to two atoms for the oxygen molecule. Electromagnetic radiation or the sparking from high voltage applications will cause the oxygen molecule in the air to disassociate into two oxygen atoms, and then each atom will combine with another oxygen molecule to form ozone. Devices that require high voltages and as a result produce ozone are arc welders, ionic air purifiers, laser printers, and photocopiers. Ozone is also created by precursors such as nitrogen oxides, carbon monoxide, and various volatile organic compounds (VOCs).
Ozone in the lower atmosphere is a pollutant and may cause respiratory problems. In the upper atmosphere, however, ozone is beneficial as it prevents potentially damaging electromagnetic radiation from reaching the earth's surface. Other man-made substances like chlorinated fluorocarbons (CFCs) break up in the atmosphere and the free chlorine or fluorine atoms become catalysts to break up the ozone molecule. This has caused the formation of an “ozone hole” in the atmosphere that allows electromagnetic radiation to reach the earth. So this is an example of the formation and destruction of ozone being the result of violating System Condition 2.
As a result of the damage created by the CFCs, the Montreal Protocol of 1987 called for the reduction and the eventual ban of CFCs chemicals for use as refrigerants and other applications. The major chemical companies then started producing hydrogenated chlorinated fluorocarbons (HCFCs), which are considerably less destructive to the ozone layer [5]. Electrolux, the refrigerator and appliance company, decided not to replace their CFC chemicals with a less toxic HCFC because this still went against System Condition 2. Instead, they opted to research for a totally biologically harmless substitute.
System Condition 3—The Physical Basis for Productivity and Diversity of Nature Must Not Be Systematically Diminished
This means that we cannot harvest or manipulate ecosystems in such a way that productive capacity, ecosystem services, and diversity systematically diminish. While the first two system conditions refer to generation of substances into the ecosphere, this condition pertains to the destruction of the natural resources in such a way or to an extent that they cannot regenerate and be useful. An example is the over harvesting of forests to meet the current demand for wood, or for its conversion to paper. This also has a detrimental effect in reducing the sequestration of carbon dioxide. Human activities need to work in harmony with the cyclic principle of nature. Carbon dioxide emitted as a result of the combustion of fossil fuels is absorbed by vegetation and returned to the earth's ecosphere. Overharvesting to meet the current demand may make it impossible for future generations to meet their requirements.
Other examples include the destruction of forests to convert the land for agricultural use. The increase in demand for food has forced some nations to trade off forests for agricultural land. This condition can also be considered in violation for the production of ethanol from corn. The land needed for this industrial crop could also be used for food crops. Overharvesting of fish may eventually deplete the fish population to a level below which regeneration to its original level may be impossible.
System Condition 4—There Must Be Fair and Efficient Use of Resources with Respect to Meeting Human Needs
Basic human needs must be met with the most resource-efficient methods possible. Unless basic human needs are met worldwide through fair and efficient use of resources, it will be difficult to meet conditions 1, 2, and 3 on a global scale. As the human population continues to grow, it becomes more and more critical for the efficient use of the natural resources.
In 2019, the human population reached 7.7 billion and this will require even more consumption of the earth's natural recourses. This increase in population will lead to an increase in energy consumption, and with a finite quantity of available fossil fuels more efficient use of coal, oil, and natural gas will be necessary. More efficient use also means an increase in renewable energy development and consumption. More efficient use of these energy resources will satisfy System Condition 4. At the same time, by adopting as much renewable energy as possible, less carbon dioxide will be emitted into the ecosphere and this will satisfy System Condition 1.
The use of plastic beverage containers is continuing to increase as the population grows and as more people drink bottled water. Unfortunately, in 2016 over 480 billion beverage [6] containers were sold and about 79% accumulated in landfills [7]. It is critical that more efficient use of plastic beverage containers is adopted in order to use less of the natural resources in their manufacturing and satisfy System Condition 4. In addition, there will be less plastic containers in the ecosphere and thus satisfy System Condition 2.
As the population continues to grow, another negative impact is the continued increase in fish consumption. Fishing is central to the livelihood and food security of 200 million people, especially in the developing world, while one of five people on this planet depends on fish as the primary source of protein. According to the UN Food and Agricultural Organization [8] in 2015, two-thirds of the world's fish species are either fully exploited or depleted. The dramatic increase of destructive fishing techniques worldwide destroys marine mammals and entire ecosystems. More efficient harvesting of the fish population is critical in order to meet the needs of future generations and thus satisfy System Condition 4. By decreasing the fish population, the ability to increase the population will also diminish thus violating System Condition 3. This is another example of showing that meeting System Condition 4 is critical to meeting the other three conditions.
SCIENTIFIC RATIONALE FOR THE NATURAL STEP
There
