Ecology: Biology of Interaction. VI-05. Global Ecological Catastrophe of Our Time
{"translation": ""}
VI-5. Global Environmental Catastrophe of Our Time
If we did not wish to hear of worse,
It will come upon you unbidden...
William Shakespeare
Everyone has heard repeatedly that we are witnessing a global ecological crisis. The title of this section refers to an ecological catastrophe. What is the meaning of these terms?
First, it is necessary to distinguish between crisis, catastrophe, and collapse. A crisis is a reversible state of a system, during which it can either return to normal or transition to another state. A catastrophe is associated with the destruction of regulation mechanisms that maintained the former state of the system and transition to a different quality. Collapse is an irreversible change that leads to the destruction of the existing system as such. An ecological collapse is associated with the transition of the environment to a state that excludes the existence of organisms that previously inhabited it. Thus, crisis is a disruption of system functioning, catastrophe is its restructuring, and collapse is its destruction.
It is necessary to distinguish between local, regional, and global crises and catastrophes. Local ones are associated with problems of particular habitats and particular human populations. Regional ones encompass large areas. And global ones spread across the entire planet.
In what state is humanity at present—an ecological crisis (as is commonly said), or an ecological catastrophe (this is perceived as less familiar and more threatening)? Returning to the state we occupied previously is no longer possible. The task before us is not to "overcome" the crisis, but to avoid the transition of the ecological catastrophe into a collapse of the biosphere. Thus,we will discuss the global environmental catastrophe of our time.
Numerous crises were also experienced by our species. For example, population-genetic studies indicate that at some stage of our history (even before the dispersal of Homo sapiens beyond Africa), the numbers of our species declined to just a few dozen individuals. In population genetics, such declines in numbers are called passing through a "bottleneck"; its consequence is a significant reduction in genetic diversity. Strange as it may seem, despite racial and national differences, members of our species are genetically much more uniform than, for example, chimpanzees. It can be hypothesized that the chances of extinction for our species at that time were quite high.
During the era of fragmentation (before becoming global), humanity repeatedly passed through local ecological crises and catastrophes (and possibly through collapses of individual ecosystems). These catastrophes arose both independently of the actions of the human population and were consequences of its activity. The former include local ecological catastrophes caused by locust swarms, or the collapse of medieval Norwegian settlements in Greenland caused by climate cooling. However, the unfavorable consequences of human activity were much more extensive.
Our species was formed by the lifestyle of an unspecialized predator and gatherer of African savannas. As mechanisms for interaction among group members and planning their actions improved, representatives of our species became the most effective hunters that Earth history has known. As they spread across the planet, people began exploiting various populations of large ungulates. As the numbers of humanity grew, so did its ability to reduce the numbers of its victims. The catastrophe exploded approximately 10–12 thousand years ago when the possibilities for maintaining such a lifestyle were exhausted. The increased numbers of humanity, intensive hunting, and climatic changes independent of humans led to the complete extinction or sharp reduction of large mammal fauna. This change affected Eurasia to the greatest extent, but also touched Africa, Australia, and the Americas. The numbers of humanity decreased several-fold. Presumably,many populations of ancient humans perished. Nevertheless, humanity managed to pass through this catastrophe, fundamentally changing the nature of its relationship with the environment. The solution to the problem facing humanity was the transition to agriculture and animal husbandry, which led to a sharp reduction in hunting pressure on natural ecosystems. This turning point in human history received the name of the Neolithic Revolution.
This described transition occurred differently in different parts of the world. Depending on which region environmentally adapted human populations occupied, they used different crops and transitioned to raising different animals. The most sophisticated agricultural civilizations arose in the Near East, and the least transformed was the culture of the indigenous population of Australia. The further course of world history was largely determined by these circumstances.
It is interesting that the set of crops currently cultivated is a consequence of the choices of Neolithic people.
During our era "into culture (not counting essential oil, medicinal, and ornamental plants) only sugar beets, quinine, and the rubber tree (Hevea) were introduced" (M.M. Vorontsov, 1999).
Perhaps the list of plants provided by Vorontsov can be supplemented with several species (for example, rapeseed—a technical crop), but this does not cancel the exceptional dependence of modern agriculture on the consequences of the Neolithic Revolution. Thus,humanity has "experience" of transitioning through a global catastrophe accompanied by climatic changes. This transition was associated with the painful breaking of former foundations and a change in the nature of relations with the environment. Unfortunately,this caused the emergence of a series of local crises and accumulation of changes that led to the present catastrophic state.
"The greatest ecological result of Neolithic animal husbandry was the emergence of the Sahara Desert. Even 10 thousand years ago, the territory of the Sahara was savanna; hippos, giraffes, African elephants, and ostriches lived there. By overgrazing herds of cattle and sheep, humans transformed the savanna into a desert. Rivers and lakes dried up—hippos disappeared—savanna disappeared—giraffes, ostriches, and most antelope species disappeared. Following the disappearance of the North African savannas, the once numerous cattle here also disappeared" (M.M. Vorontsov, 1999).
Probably many Asian deserts, for example, the Karakum, have a similar origin. Also related to overgrazing is the formation of the largest deserted area in Ukraine—the Oleshky Sands in the Dnipro floodplain
Modern humanity is again in a state of fundamental changes, in a state of catastrophe. Due to the interconnection of different parts of humanity, it can be presumed that it will either pass through the present catastrophe as a whole (with greater or lesser losses), or undermine the possibilities for its existence during the collapse of the Earth's environment. The present nature of humanity's relationship with the environment, based on the rapid expenditure of fossil fuel reserves, cannot continue for long. Already during the 21st century, the lifestyle of humanity must change. How? We do not yet know. To some extent, it depends on our actions.
What is causing the present catastrophe?
The components of the modern ecological catastrophe are as follows. The growth in human numbers has caused food shortages, energy shortages, and fresh water shortages. Overcoming these problems is intensified by climate change, destruction of natural ecosystems, decline in biodiversity, environmental pollution, and military threat.
Each of the factors mentioned here is very complex. For example, pollution is an entire complex of environmental changes. Its partial components:
— change in gas composition and properties of the atmosphere (CO2 and O3problems);
— dispersion of combustion products and their consequences—smog, acid rain;
— poisoning of water, air, and soil with toxic substances;
— dispersion of alien elements and xenobiotics;
— contamination of air, water, and soil with radionuclides;
— pollution of natural environments with pathogenic microorganisms from waste;
— degradation of water bodies through excessive input of biogens, fish kills through excess organic matter, siltation from washed sediments;
— thermal, noise, electromagnetic pollution;
— local pollution of the human immediate environment: food, indoor air, household items, etc.
The main causes of the present catastrophe are related to human activity. At the same time, it can be intensified by external factors that do not depend on our activity. For example, one manifestation of irreversible global changes is global warming. International commissions of climatologists have concluded that humans most likely influence this process. All the more significant are the data of NASA (the space agency of the USA), which registered global warming on Mars. Probably, this phenomenon manifests both changes in solar activity and the consequences of industrial activity of humanity.