How to cease the ‘succession’ of anthropogenic environmental problems using the knowledge on their interconnected nature?

Some man-made environmental problems are in a succession. Usually this happens due to the establishment of unsustainable solutions to the identied man-made environmental crisis. When the human driven solutions to the environmental problem also become a threat, the chain continues as a succession of man-made environmental crises until a permanent sustainable or regenerative solution is achieved. For instance, in early 1950s, Dayak people suffered from malaria. World Health Organization (WHO) had permitted to spray huge amount of DDT to kill mosquitoes. The attempt was a success and vector borne disease malaria was mitigated, however, their houses began to fall down on their heads. This is because application of DDT also killed the parasitic wasp that had previously controlled thatch eating caterpillars. In this scenario the worst event is DDT poisoned insects were eaten by geckos, which were eaten by cats, the cats died (biomagnication of DDT) and the rat population increased. The people were affected by sylvatic plague and typhus. To nd solution to this WHO was obliged to parachute 14,000 live cats into Borneo. Thus, to prevent this succession of man-made environmental crises a need for clear understanding on all man-made environmental issues and their causes and effects is required. This article reviews the previously published research paper “Keystone Links of Anthropogenic Environmental Problems and Emergence of Interconnected Man-made Environmental crises” on this journal. In that study 40 identied man-made environmental crises were mapped by their interconnections as causes and effects. And established concept map could be used in problem mitigation, or identifying most promising solution to the man-made environmental crises. Qualitative content analysis method was applied in that study, and 252 links between man-made environmental crises were identied and supported by real-world examples in the elaborated thesis.


Introduction
Most of the anthropogenic environmental problems depict the succession of problems, or expressly, when we try to solve one man-made environmental issue, the result would be a different man-made environmental problem, and this ow of varying man-made environmental crises continues inevitably. E.g., to solve pest outbreak agrochemicals are used. Agrochemicals cause water, soil, and air pollution. Here, one man-made environmental problem is replaced by another. And in some cases, this chain of problems continues as a succession. This is due to most of the anthropogenic solutions to the man-made environmental problem accompanied with another man-made environmental problem, which prevents nding a permanent or sustainable solution to the crises. Thus, it is clear there is a need for mapping of man-made environmental crises based on cause-and-effect relationship. When a complete map or concept diagram of all man-made environmental problems and their effects is revealed, that map can be used to prevent the occurrence of continuous succession of anthropogenic environmental crises. This is because, choosing the safe alternative solution by checking with the concept map the emergence of another man-made environmental problem could be prevented.
Records reveal that attempting to correct one environmental problem unknowingly created or exacerbated other environmental problems. For instance, after EPA has reduced the emission of particles larger than 2 mm by 78% (1) as cited in (2), the air became clearer but it caused another problem of acid deposition in the region of north-eastern United States. This is because the larger particles in the emission were alkaline and it neutralizes the acidity caused by smaller sulphur oxide particles. And in the absence of alkaline large particles, smaller acid sulphur oxide accumulated in the air and leads to acid deposition. Mitigation to SOx also reduced the concentration of acid aerosol. This created another unexpected problem that the sulphuric acid aerosol also served as nuclei for the formation of clouds. More nuclei, smaller droplets were present. These droplets scatter incoming solar radiation before reaching the earth's surface resulting in dimming or global cooling effect. Absence of aerosol in the air intensi ed the impact of global warming (3) as cited in (2). In addition, aerosol particles are normally found in combustion emission along with manmade CO 2 , however, unlike CO 2 , aerosol particles have harmful effects on the human health. Due to this global mitigation of aerosol emission, China in particular has reduced the aerosol pollution by 2006, as it peaked in the same year and caused severe respiratory health issues, and the global warming was accelerated (4).
Similarly, in early 1950s, Dayak people suffered from malaria. WHO had permitted to spray huge amount of DDT to kill mosquitoes. The attempt was a success and vector borne disease malaria was mitigated, however, their houses began to fall down on their heads. This is because application of DDT also killed the parasitic wasp that had previously controlled thatch eating caterpillars. In this scenario the worst event is DDT poisoned insects were eaten by geckos, which were eaten by cats, the cats died and the rat population increased. The people were affected by sylvatic plague and typhus. To nd solution to this WHO was obliged to parachute 14,000 live cats into Borneo (5).
Similarly, invasive species of zebra mussel colonization was observed in the Lake Erie, which caused fouling and occupied all the pipelines, water intakes and outfalls. Control of these invasive species later became a success. However, it has been found that mussels increased the concentration of chemical contaminants through the entire aquatic food web in the lake and the associated waterways. It has been proved during the past industrial age many chemical e uents were disposed at Erie Lake, and the muscles consumes those sediments and recirculated the contaminants through the biological food chain. However, solutions to the rst environmental problem are not mitigating the second. Similarly, in early 1980s selenium (heavy metal) toxicity caused biodiversity loss (death of cattails, algal blooms and decline in water fowl use) in Kesterson National wildlife refuge (6) as cited in (2).
Today water scarcity is an increasing global threat. To solve this there are more than 1600 desalination plants function all-over the world, and they produce more briny toxic sludge. A study revealed that for every litre of fresh water extracted, a litre and a half of salty chemical laden sludge (brine) is dumped into the ocean. When we consider the total brine emission of all present-day desalinisation plants that is enough to cover the state of Florida in a one food (30 cm) layer of slime (7). Thus, solution to one anthropogenic crisis leads to another crisis. Today energy crisis is an increasing problem worldwide. Thus, energy e cient technologies are being implemented, such as substitution of LED bulbs instead of high energy consuming incandescent light bulb. Because LED bulb is 90% more energy e cient than the low-cost incandescent bulb. But LED bulbs has created another environmental problem while solving energy crisis. E-waste from LED bulbs contain toxic hazardous heavy metals such as arsenic, lead, mercury, and other metallic salts that contaminate the soil and water environment when it is not recycled safely.
According to Gerard Wynn (2014) (8), after the banning of Chloro uorocarbon in 1987 Montreal Protocol, hydro uorocarbons (HFC) are being used. Now the ozone depletion issue is getting solved, but the HFC has created another problem. HFC is 1000 times more potent greenhouse gas than the equivalent CO 2 . UN data on atmospheric HFC levels shown that annual HFC levels has grown rapidly by 10-15% annually from 2006-2010. Study further revealed that early phase-out of super climate gases such as HFC could stop release of 146 billion tonnes of CO 2 -equivalent by 2050.
According to Hood (2019) (9) energy crisis leads to rise in oil prices in 1970s, this has boosted the production of biofuels from corn, sugar cane, and palm oil. Earlier use of biofuels believed as a solution to climate change because CO 2 generated during the burning of biofuels would be partially offset by the CO 2 absorbed by photosynthesis when the plants were growing. However, intensive farming of palm trees for biofuel causes severe deforestation in Indonesia and threatens the wildlife, such as deforestation encroached the habitats of orangutan. Scientists now estimated that twice the size of India would be needed to cultivate the biofuel plants to meet the global biofuel needs. This form of deforestation may severely intensify climate change and may occupies the remaining land allocated for food crops.
According to Hood (2019) (9), green solution for global energy crisis is wind farms. Globally more than 350,000 wind turbines generate more than 500kW of emission free electricity. However, windfarms kill birds. Annually, 328, 000 birds (mostly nocturnal) killed or injured by fast spinning blades. It has been revealed in a study that wind farms in Western Ghats, India (UNESCO listed mountain range and forest) caused severe decline in predatory raptor bird population. In that region the predatory raptor birds found four times rarer than the adjacent areas. This has affected the food chain, where the population of prey fan throated lizard has been increased in the region, thus, this has become a crisis causing loss of biodiversity.
According to "www.scdhec.gov" (n.d.) (10), it has been estimated that globally 500,000 solar panels are installed every day. Report further stated that although solar panels provide a solution for global warming and providing a clean energy source, it has created hazardous heavy metal waste. Following data is given in the website, "Cadmium telluride (CdTe) solar panels may be a hazardous due to cadmium, gallium arsenide (GaAs) panels may be hazardous due to arsenic, some older silicon solar panels may be hazardous waste for hexavalent chromium coatings, newer, thin-lm solar panels contain copper indium selenium (CIS) and copper indium gallium selenium (CIGS) and may be hazardous due to the presence of copper and selenium." Thus, solar panels have created heavy metal toxicity issue due to its hazardous waste while it is solving global energy crisis and global warming due to its clean energy. Author Guillaume Pitron in his book "Rare metals war" (published in 2018) has mentioned that toxic lakes in Mongolia is due to toxic leachate from these heavy metals of solar panels (9). A study on thin lm solar panels (TFSPs) (11) revealed that corroded and degraded thin-lm solar panels released toxic heavy metals pollutants such as zinc (Zn), copper (Cu), nickel (Ni), gallium (Ga), lead (Pb), indium (In) and chromium (Cr) in to the soil and water. Besides, study also stated that release of metallic pollutants in soil can be increased in the acidic conditions.

Literature Review
Environmental systems are complex and interconnected (2). Present humans are experiencing the environmental problems that have not been experienced before in this century and they are manmade (2). In 1986 United States Environmental Protection Agency (USEPA) embarked on analyzing the risk caused by more than 30 environmental issues (12,13) and subsequently United States National Research Council (USNRC) addressed these on the same basis as risk characterization (14,15,13).
A "casual model" derived from (16) gives key characteristics of environmental problems such as persistence of the pollutant in the environment, the population exposed and health impacts. Vicky and coauthors (13) have also de ned a sum of 18 speci c descriptors to measure these characters.
In the UNEP (2012) report 21 issues were categorized based on the following criteria: i. Issues that are critical to the global environment. Issues can be either positive or negative. But must be environmental in nature or environmentally related.
ii. Given priority over the next 1-3 years in the work programme of UNEP and/or other UN institutions and/or other international institutions concerned with the global environment.
iii. Issues have a large spatial scale, and they should be global, continental, or 'universal' in nature (issues that occur in many parts of the world).
iv. Issues that were recognized as 'emerging' based on newness, which can be the result of new scienti c knowledge, new scales or accelerated rates of impacts, increased level of awareness and/or new ways to respond to the issues. , protecting the life on land or secure the biodiversity (E05), democratic governance and peace building and establishing global partnerships to achieve these goals (17). Similarly, in the recent 2012 GEO 5 report, issues such as heavy metal toxicity (E20), invasive or alien species (E42), and water scarcity (E12) such as groundwater depletion (E15) were classi ed along with other modern issues. Two dozen of reports were reviewed by (18), included reports of National Research Council, EPA's Science Advisory Board, technical societies and research institutions.
In addition, according to the paper published by the Ministry of the Environment of Japan (2001), interconnected nature of several environmental problems such as overexploitation of natural resources, intensive farming, deforestation, energy crisis, urban sprawl, pollution (air/ fresh water, groundwater and marine), hazardous wastes, ozone depletion, soil degradation and acid rain were depicted (see gure 1).

Materials And Methods
Qualitative content analysis methodology was used. Major environmental problems were screened from published documents. And precisely 252 links were found. To validate the hypothesis, existence of all 252 links should be a rmed with the support of real-world examples collected from the reliable scienti c literature. A concept diagram was created with the principles of the visualization tools of the Stockholm Environment Institute (SEI) of the United Nations Environment Manage-ment Group (EMG), which depicts a complete "mental map" of relationships among the man-made environmental problems. Data collection was done until the data saturation was achieved or when major categories showed depth and variation.
As archival work, books, peer-reviewed journals, and papers from various sources including the internet was searched for relevant codes (links). The following diagram describes the functional ow of the qualitative content analysis methodology, see Fig. 2. Finally, keystone environmental problems were identi ed from the concept map based on the criteria given by the following approach. When mitigating a man-made environmental problem, if it results in the permanent disappearance of one or more man-made environmental problems, then that mitigated problem can be considered as a possible keystone man-made environmental problem, in a hypothetical situation where human adaptability factors such as economic, social, political, health, genetics, evolution and behavioural factors are absent (20).

Results
Man-made environmental problems are interconnected as cause and effect to one another. For instance, water pollution and water scarcity (E12) is caused by several other man-made environmental problems such as agrochemicals (E40), solid waste (E19), plastic pollution (E21), e-waste (E24), heavy metal contamination (E20), pollution through mining activities (E08), establishment of dams (E09), Similarly, causes of land degradation, deserti cation, and soil erosion (E07) are deforestation and destruction of mangroves (E28), agrochemicals (E40), pollution through mining activities (E08), overexploitation of natural resources (E01) (excess land usage), intensive farming (E43), heavy metal contamination (E20), water pollution and water scarcity (E12), establishment of dams (E09), invasive species or exotic species (E42) (e.g. Eucalyptus sp. causes land degradation through its oily litter). Similarly, impacts of land degradation, deserti cation and soil erosion (E07) are poverty, disease, disability and food insecurity (E38), in this group of problems, land degradation (E07) causes impacts such as food insecurity (E38) (while the disease and disability caused by famine or malnutrition are less pronounced) and biodiversity loss (E05) (poor soil no longer harbor organism and biodiversity). In the aforesaid scenario twelve environmental issues are directly linked to the land degradation, deserti cation and soil erosion (E07) (ten causes and two impacts).

Discussion
Based on the concept map in Fig. 3 now it is possible for us to check for possible resulting environmental problems when a solution is established. For instance, when we are mitigating energy crisis by using heavy metal containing photovoltaic cells, we can check the concept diagram (Fig. 3) for link between heavy metal contaminants and soil pollution or land degradation, water pollution, and biodiversity loss.
Thus, use of the above concept map Fig. 3) in a computerized software system can simply indicate the list of possible environmental threats before implementing the proposed solution. Thus, it is possible for us to choose a sustainable to regenerative solution that are really safe to the nature and humankind, such as establishing a safe recycling mechanism for heavy metal components of photo voltaic cells when implementing the solar panels, or establishing class 3 land lls as in South Carolina, where the safer municipal solid wastes with non-hazardous solar panels are being disposed (10).

Conclusion
The concept map developed in the study could be used to analyze the man-made environmental problems that could emerge when establishing a proposed project. It has been evidenced that certain man-made environmental problems result in succession of anthropogenic environmental issues. Thus, use of concept map produced by this study may help the project designer to choose the best possible option where the emergence of resulted environmental problems, or succession of environmental crises is avoided, or minimized. Figure 1 Global Environmental Issues as an Interconnected System Source: (19) Figure 2 Qualitative content analysis methodology Source: (21) Figure 3 Concept map of interconnected man-made environmental problems based on cause-and-effect relationships