Lecture Notes - Systems thinking Flashcards

Question

Do the laws of thermodynamics apply to all things in the universe?

Answer 1

Yes. Thermodynamic laws dictate that to sustain any activity without stopping, all systems (living or not) have to disperse energy.

Answer 2

- conservation of energy - energy can neither be created nor destroyed - it only changes it form (e.g. chemical to mechanical, mechanical to heat) In ecosystems, this law implies that the total amount of energy remains constant as it flows through the system. Energy enters an ecosystem primarily as sunlight, which is captured by plants through photosynthesis and converted into chemical energy (in the form of glucose). This energy is then transferred through the food web from producers to consumers and decomposers. At each stage, the energy is merely transformed, not lost, though the form it takes changes (e.g., from light to chemical to heat).

Answer 3

- When energy changes in form, it always goes from a more useful to a less useful form (more disorganised). - The efficiency of the energy conversion is never 100%; heat that is released in the conversion is less useful (disorganised) energy. - This means that the amount of useful energy available to do work decreases over time, as the disorder increases. - Entropy is a scientific concept that is most commonly associated with a state of disorder, randomness, or uncertainty. It is irreversible. As energy moves through an ecosystem, it becomes less available for work. At each trophic level, energy is lost as heat due to metabolic processes (e.g., respiration, movement, digestion). This explains why energy pyramids are typically narrow at the top—there is less available energy at higher trophic levels because much is lost as heat at each transfer, resulting in reduced biomass and fewer organisms at these levels.

Answer 4

Photosynthesis produced via primary producers, which are organisms such as plants or algae that perform photosynthesis. Cellular respiration is reversed photosynthesis - using stored energy to do work.

Answer 5

The total amount of energy that primary producers in a given area capture in a given time

Answer 6

The amount of carbon retained in an ecosystem (increase in biomass); it is equal to the difference between the amount of carbon produced through photosynthesis (GPP) and the amount of energy that is used for respiration (R) It is measured as grams of dry matter / metre squared / year.

Answer 7

Abiotic factors such as access to nutrients, shelter, etc. Biotic factors, such as primary production (i.e. storing of energy), presence of predators, population density, competition, etc.

Answer 8

The nutrient which is present in the least quantity in an ecosystem is termed a limiting nutrient in an ecosystem E.g. phosphorus, nitrogen, iron, boron. Limiting nutrients are essential for plant growth, can accelerate and check growth.

Answer 9

- Release of enriched sewage and inorganic nutrients, which causes eutrophication – Accelerated sediment pollution – Thermal pollution from industries (release of heated water) – Release of harmful substances (e.g. disease-causing agents) – Release of organic compounds (e.g. pharmaceuticals, pesticides, plastics) and inorganic compounds (e.g. heavy metals)

Answer 10

Organic wastes increase the BOD, which is the Biological Oxygen Demand. Decomposition of organic wastes requires oxygen, which means that excess levels of organic compounds exhaust the dissolved oxygen in the water. BOD measures the need for oxygen to support organisms in a body of water (mg dissolved O2 / litre of water). Fish die when oxygen levels are lower than 4mg. Implications include anaerobic decomposition (odors and deteriorated water quality), as well as dead zones e.g. hypoxia in water.

Answer 11

Excess runoff of sediment into the water is harmful, e.g. erosion from agriculture, logging, mining, etc. Implications include reduced visibility due to increased turbidity, decreased light penetration leading to decreased primary production, burying of sea floor and organisms, sediments can carry toxic substances, clogging of waterways.

Answer 12

- Comes from industries and nuclear power plants – Warmer water has lower capacity to hold oxygen Implications: – Biological stress: – Less oxygen in water – Affects reproductive cycles, digestion rates and respiration – Warmer temperatures increases decomposition rates → lower oxygen levels – Fish need more food to maintain body weight in higher temperatures – Less oxygen requires fish to ventilate gills more frequently

Answer 13

N2, O2, argon, CO2, Water vapor. Services include: UV block, moderating climate, redistributing water

Answer 14

Troposphere, stratosphere, mesosphere, thermosphere

Answer 15

Primary air pollutants (immediately released through the air e.g. through combustion) Secondary air pollutants (formed when released substances react with substances in the air e.g. forming of ozone)

Answer 16

Nitric oxide, nitrogen dioxide, nitrous oxide (a GHG). Released and formed with high temperatures e.g. via combustion, transport, industry. NOx are poisonous. Nitrous oxide can deplete stratospheric ozone. Acid deposition (NOx reacts with water forming nitric or nitrous acid).

Answer 17

A lowering of pH of soil and water bodies. Ecosystems can be naturally acidic but acidification can be accelerated by acid deposition from Nitrogen Oxide and Sulfur Oxide. pH is an important factor because it determines the availability of nutrient minerals, due to their solubility. Some soil nutrients may become insoluble and thus inaccessible to plants. Low pH increases leaching of e.g. aluminium ( Increased levels of soluble metals (e.g. Al): toxic levels-> fewer algal species-> low productivity (eventually) very clear water ) Phosphorus concentrations are reduced due to chemical binding with aluminium. In lakes, species composition is altered at pH levels below 6. Fewer species can tolerate the lower pH levels; reproduction among especially fish is disturbed-> populations eventually collapse.

Answer 18

Liming (adding of calcium carbonate) Inefficiencies of this include mining of lime, only treats the symptoms, is done repeatedly.

Answer 19

-Great in the stratosphere, harmful in the troposphere. -Ground-level ozone is a secondary air pollutant. - Formed by NOx and hydrocarbons, catalysed by sunlight. - Found in urban smog-> leads to adverse health effects, stresses plants, lowers crop yields. - Tropospheric ozone does not replenish stratospheric ozone: stratospheric ozone is broken down by CFCs (e.g. refrigerants– banned through the Montreal Protocol 1987). Very persistent, effects are still seen.

Answer 20

Released naturally or by human activities: Soot, soil particles, lead, sea salt, sulfuric acids, etc. from combustion, industrial processes, and wear out of roads (studded tires).

Answer 21

Particulate matter size is measured in micrometres (µm): PM10 =adiameter of 10 µm or less. These are inhalable;-- PM2.5 = fine particulate matter. A portion of PM10. Can transfer deep into the lungs, where compounds can transfer to the bloodstream. PM2,5 mobile– large transportation distances-> System boundaries are international-> UN Convention on long-range transboundary air pollution (1979)

Answer 22

Concentrations of PM10 and PM2.5 are used as air quality indicators (µm/m3 )

Answer 23

Chemical reactions carried out in organisms (can be a response to instake of pollutants)

Answer 24

Insoluble in water Fears water

Answer 25

Likes water and is soluble in water

Answer 26

Likes fat - dissolves in fats, oils, etc.

Answer 27

Does not like fat

Answer 28

- Agriculture - Cleaning / detergents - Electronics - Batteries - PFAS - Per- and polyfluoroalkyl substances

Answer 29

- Many of these chemicals are central for addressing other sustainability challenges, both environmental and social (electrification, famine, fighting decease, etc.) – Release of chemical compounds come with many unknowns and potentially detrimental effects to ecosystems and humans – Novel entities: the presence in nature of some compounds has been relatively short, and responses in terms of evolution of protective responses are still rather scarce

Answer 30

Man-made chemical compounds: did not exist in nature before mankind → any detectable level is abnormal – E.g. pesticides – PFAS Naturally occurring compounds: background levels vary with time and location – E.g. metals, SO2, NOx , PAH – Levels are increased by human activities

Answer 31

“the study of harmful effects of chemicals upon ecosystems and includes effects upon individuals as well as consequent effects at the levels of population and above”. Deals with movement of pollutants in: * air, water, soils, sediments * food chains * chemical transformation and biotransformation.

Answer 32

- Pollutant - Biochemical changes - Physiological changes - Whole organism responses - Population changes - Community composition - Ecosystems Linear would be : - Response time - Difficulty of linking to specific pollutant - Importance

Answer 33

Via air, organisms, water or soil. Range depends on:– molecular size and properties;– Hydrophilicity, lipophilicity (e.g. gaseous pollutants may transport longer than particles or droplets in the air);– abiotic factors;– Water currents, wind, temperature, etc.

Answer 34

Ingestion, Inhalation, absorption

Answer 35

Original ground surface is covered by foreign material such as construction waste. Has been used for filling in port areas of larger cities e.g. Malmo.

Answer 36

PBT - Persistent Bioaccumulative Toxic. vPvBvT - otherwise.

Answer 37

Persistence; The resistance to being degraded by organisms or in the environment. - Favoured by low temperatures (slower volatilization/biotransformation/chemical breakdown);-- - Allows substances to remain in the environment for extensive times; - Allows an extended spreading of substances via air and water, beyond point of emission; - Biological/degradation half-life: time it takes for concentration of substance to decrease by 50%

Answer 38

Degradation half-life, with temperature thresholds and day thresholds.

Answer 39

The process through which substances are stored within organisms, leading to higher concentration than what is found in the environment. The relationship between intake and excretion/metabolization. - Lipophilic substances are more bio-accumulated as they are stored in fatty tissues of organisms; - Hydrophilic substances are water soluble and more readily excreted. Metabolization in terrestrial vertebrates often involves increasing the polarity of substances to make them more hydrophilic. If the substance is resistant to metabolization/detoxification it is more likely to be stored; - Substances may be transferred to offspring via placenta or milk. Bioaccumulation leads to biomagnification.

Answer 40

where concentrations of a substance increase further up in the trophic levels– organisms at higher trophic levels may experience more toxic effects.

Answer 41

The large variation on reactions to chemicals between species and individuals, and between different strains of the same species due to evolving resistance. - Effect of toxins depends on the route of uptake (e.g. ingestion faster than application on skin); - “The dose makes the poison”– some compounds are essential for life, but become toxic at too high concentrations (e.g. selenium); - The metabolism of a compound may lead to formation of metabolites that are more toxic or harmful than the parent compound (e.g methanol oxidised to formaldehyde, which oxidises to formic acid. These cause blindness, respiratory failure, and death)

Answer 42

Further complications ★ Potentiation/synergism = when the toxicity of two or more chemicals are larger than the parts; ★ Antagonism = the sum is lesser than the parts; ★ Cocktails of chemicals may lead to activation or deactivation of other harmful substances, when organisms are exposed to them simultaneously; Thus the relationship between the dose and toxic effect of each chemical in the cocktail

Answer 43

Example of potentiation What happens if chemical A changes the metabolism of chemical B? 1. A inhibits the enzyme system that detoxifies B. → B is not detoxified as quickly, and toxic effects may be seen on the organism 2. A induces an enzyme system that activates B. → B gets activated more quickly, e.g. by generating highly reactive metabolites that damage the cells. BUT! activation may also activate other enzymes that have a detoxifying function that compensate for increased activation – very complex!

Answer 44

Toxic effects on organisms may be delayed-> Case study: Netherlands, 1960s female eider ducks died from dieldrin (a pesticide) poisoning during the breeding season whereas males did not. Toxic substances may be stored in fat depots: if the food supply is good then fat depots are built up; when food is scarce/during illness/egg laying/migration, fat depots are used for energy. Toxic substances are released into the bloodstream and potentially become activated. This is seen among all ecosystems-> species (top predators) top of the food web most at risk.

Answer 45

Death, Biochemical - beneficial or detrimental responses in organisms Physiological - effects may be seen on cellular or organ levels e.g. cardiovascular effects Reproductive - egg shell thinning, sterility, etc. Behavioural - disturbances in foraging or vigilance.

Answer 46

Persistent Organic Pollutants. POPs are created by mankind both intentionally and unintentionally in industrial processes. They are long lived and may be toxic. Organic compunds: * Contain carbon * Have a high variety of molecular structures * Chemical properties and behavior depend on size, shape, and structure

Answer 47

Some examples (the dirty dozen): Pesticides: aldrin, chlordane, DDT, dieldrin, endrin, heptachlor, hexachlorobenzene, mirex, toxaphene;-- Industrial chemicals: hexachlorobenzene, polychlorinated biphenyls (PCBs); By-products: hexachlorobenzene; polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans (PCDD/PCDF), and PCBs.

Answer 48

Persistence– Resistance to degradation in the environment. Bioaccumulative– Organisms storing substances as intake-> excretion/metabolization, Toxic– detrimental effects on organisms from a substance differs between individuals and species. Mobile– transportation potential. Often seen as readiness to move in aquatic environments. Mobile substances are often polar (having an electrical charge)-> water soluble

Answer 49

Chemical substances do not affect ecosystems in the same way. Effects depend on:– Chemical properties (PBT);– The quantities produced and released.

Answer 50

Plastics, increasing problem for living organisms: Entanglement; Ingestion; Microplastics; Radioactive isotopes: Radon gas; Nuclear catastrophes; Altered albedo from black carbon particles. Risk of erosion of social resilience and loss of knowledge and traditions (e.g. traditional pest control vs. use of pesticides).

Answer 51

DDT, along with a lot of other of these organic contaminants, actually travel through the atmosphere, toward the polar regions by a process of evaporation and then condensation in cooler climates. Settles within penguin fat and eggs.

Answer 52

Earth consists of many physical and biological systems. Its abundant resource have allowed many forms of life to thrive and evolve. Humans through our growing population and technology, have exploited these resources to the point that we are putting the environment at risk.

Answer 53

- Human development is typically characterized by factors associated with wealtH - such highly developed countries have represented less than 20% of the global population but account for more than 50% of resource use - Historically, Less developed countries (LDCs) are developing countries with high poverty rates, low levels of industrialization, high fertility rates, high infant mortality rates, and very low per capita incomes (relative to highly developed countries). - Increasingly, many of the world's countries, such as China and India, have mixed development, with some urban residents owning considerable wealth but other urban and most rural residents living in poverty.

Answer 54

Renewable resources are those that nature replaces fairly rapidly (on a scale of days to centuries), and can be used forever as long as they are not overexploited in the short term. E.g. sun, wind, water. Nonrenewable resources are present in limited supplies and are depleted by use. E.g. coal, oil, natural gas.

Answer 55

As population increases, people can exceed the capacity of a region to support basic needs for food, shelter, and clean water. When consumption by individuals substantially exceeds these basic needs, the resources in a region will be exceeded even more quickly. In either case, consumption that exhausts both non-renewable and renewable resources is unsustainable.

Answer 56

An individual's ecological footprint is the amount of productive land, fresh water, and ocean required on a continuous basis to supply that person with food, energy, water, housing, material goods, transportation, and waste disposal.

Answer 57

- Number of people (P) - Affluence per person (A) - measure of the consumption or amount of resources used per person - Environmental effect of the technology used to obtain and consume those resources (T) Equation is Impact = P x A x T

Answer 58

Sustainability is the ability to meet current human natural resource needs without compromising the ability of future generations to meet their needs; in other words, it is the ability of humans to manage natural resources indefinitely without the environment going into a decline from the stresses imposed by human society on the natural systems that maintain life.

Answer 59

Garrett Hardin contended that our inability to solve many environmental problems is the result of a struggle between short‐term individual welfare and long‐term environmental sustainability and societal welfare.

Answer 60

Common‐pool resources are those parts of our environment that are available to everyone but for which no single individual has responsibility—shared resources such as the atmosphere, fresh water, forests, wildlife, and ocean fisheries.

Answer 61

Sustainable development is economic development that meets the needs of the present generation without compromising the ability of future generations to meet their own needs. Three factors—environmentally sound decisions, economically viable decisions, and socially equitable decisions—interact to promote sustainable development.

Answer 62

the interdisciplinary study of humanity's relationship with other organisms and the nonliving physical environment.

Answer 63

each system is a set of components that interact and function as a whole At a global level are Earth systems, which include Earth's climate, atmosphere, land, coastal zones, and the ocean.

Answer 64

The scientific method is the way a scientist approaches a problem by formulating a hypothesis and then testing it by means of an experiment.

Answer 65

State the problem or unanswered question; develop a hypothesis; design and perform an experiment to test the hypothesis; analyze and interpret the data; and share the conclusion with others.

Answer 66

1. Scientific assessment involves gathering information about a potential environmental problem. 2. Risk analysis evaluates the potential effects of intervention. 3. Public education and involvement occur when the results of scientific assessment and risk analysis are placed in the public arena. 4. Political action is the implementation of a particular course of action by elected or appointed officials. 5. Long‐term evaluation monitors the effects of the action taken.

Answer 67

Lake Washington exemplifies a successful approach to addressing a relatively simple environmental problem. The pouring of treated sewage into Lake Washington had raised its level of nutrients to the point where the lake supported excessive growth of cyanobacteria. Disposal of the sewage in another way solved the lake's pollution problem.

Answer 68

Ecology is the study of interactions among organisms and between organisms and their biotic environment

Answer 69

A population is a group of organisms of the same species that live in the same area at the same time. A community is a natural association that consists of all the populations of different species that live and interact within an area at the same time. An ecosystem is a community and its physical environment. A landscape is a region that includes several interacting ecosystems. The biosphere is the parts of Earth's atmosphere, ocean, land surface, and soil that contain all living organisms.

Answer 70

Energy is the capacity to do work. Energy can be transformed from one form to another but is often measured as heat; the unit of heat is the kilocalorie (kcal).

Answer 71

Potential energy is stored energy; kinetic energy is energy of motion. Using a bow and arrow as an example, potential energy is stored in the drawn bow and is converted to kinetic energy as the string is released and the arrow speeds toward its target.

Answer 72

system refers to a group of atoms, molecules, or objects being studied; the rest of the universe other than the system is known as the surroundings.

Answer 73

A closed system is self‐contained; that is, it does not exchange energy with its surroundings. In contrast, an open system exchanges energy with its surroundings.

Answer 74

According to the first law of thermodynamics, energy cannot be created or destroyed, although it can change from one form to another. According to the second law of thermodynamics, when energy is converted from one form to another, some of it is degraded into heat, a less usable form that disperses into the environment. The first law explains why organisms cannot produce energy but must continuously capture it from the surroundings. The second law explains why no process requiring energy is ever 100% efficient.

Answer 75

Plants, algae, and some bacteria capture radiant energy during phototsyntehsis and incorporate some of it into chemical energy contained within carbohydrate molecules. All organisms obtain the energy in carbohydrates and other molecules by cellular respiration , in which molecules such as glucose are broken down, releasing energy.

Answer 76

A trophic level is an organism's position in a food chain, which is determined by its feeding relationships. A food web is a representation of the interlocking food chains that connect all organisms in an ecosystem.

Answer 77

Photosynthesis is essential to all life on earth; both plants and animals depend on it. It is the only biological process that can capture energy that originates in outer space (sunlight) and convert it into chemical compounds (carbohydrates) that every organism uses to power its metabolism.

Answer 78

Producers are the photosynthetic organisms (plants, algae, and some bacteria) that are potential food resources for other organisms. Consumers, which feed on other organisms, are almost exclusively animals. Decomposers feed on the components of dead organisms and organic wastes, degrading them into simple inorganic materials that producers can then use to manufacture more organic material.

Answer 79

Energy flow is the passage of energy in a one‐way direction through an ecosystem. Energy flow through an ecosystem is linear, from the sun to producer to consumer to decomposer.

Answer 80

A pyramid of numbers shows the number of organisms at each successive trophic level. A pyramid of biomass illustrates the total biomass at each successive trophic level. A pyramid of energy illustrates the energy content of the biomass of each trophic level.

Answer 81

Biomass is a quantitative estimate of the total mass, or amount, of living material; it indicates the amount of fixed energy at a particular time.

Answer 82

Gross primary productivity (GPP) is the total amount of photosynthetic energy that plants capture and assimilate in a given period. Net primary productivity (NPP) is productivity after respiration losses are subtracted. Scientists have estimated that as much as 32% of the global NPP is appropriated for the human economy. Human use of global productivity is competing with other species' energy needs.

Answer 83

In the carbon cycle, carbon enters plants, algae, and cyanobacteria as carbon dioxide (CO2), which is incorporated into organic molecules by photosynthesis. Cellular respiration by plants, by animals that eat plants, and by decomposers returns CO2 to the atmosphere, making it available for producers again. Combustion and weathering also return CO2 to the atmosphere.

Answer 84

In the nitrogen cycle, nitrogen fixation is the conversion of nitrogen gas to ammonia. Nitrification is the conversion of ammonia or ammonium to nitrate. Assimilation is the biological conversion of nitrates, ammonia, or ammonium into nitrogen‐containing compounds by plants; the conversion of plant proteins into animal proteins is also part of assimilation. Ammonification is the conversion of organic nitrogen to ammonia and ammonium ions. Denitrification converts nitrate to nitrogen gas.

Answer 85

The phosphorus cycle has no biologically important gaseous compounds. Phosphorus erodes from rock as inorganic phosphates, and plants absorb it from the soil. Animals obtain phosphorus from their diets, and decomposers release inorganic phosphate into the environment.

Answer 86

In the sulfur cycle, most sulfur occurs as rocks or as sulfur dissolved in the ocean. Sulfur‐containing gases, which include hydrogen sulfide, sulfur oxides, and dimethyl sulfide (DMS), comprise a minor part of the atmosphere and are not long‐ lived. A tiny fraction of sulfur is present in the proteins of living organisms. Bacteria drive the sulfur cycle.

Answer 87

The hydrologic cycle, which continuously renews the supply of water essential to life, involves an exchange of water among the land, the atmosphere, and organisms. Water enters the atmosphere by evaporation and transpiration and leaves the atmosphere as precipitation. On land, water runs off to lakes, rivers, and the ocean or filters through the ground. Groundwater is stored in underground caverns and porous layers of rock.

Answer 88

Of the solar energy that reaches Earth, 30% is immediately reflected away and the remaining 70% is absorbed. Albedo is the proportional reflectance of solar energy from Earth's surface, commonly expressed as a percentage. Glaciers and ice sheets have high albedos, and the ocean and forests have low albedos. Ultimately, all absorbed solar energy is radiated into space as infrared (heat) radiation. A combination of Earth's roughly spherical shape and the tilt of its axis concentrates solar energy at the equator and dilutes solar energy at higher latitudes.

Answer 89

The troposphere is the layer of the atmosphere closest to Earth's surface; weather occurs in the troposphere. The stratosphere, found directly above the troposphere, contains a layer of ozone that absorbs much of the sun's damaging ultraviolet radiation. The mesosphere, found directly above the stratosphere, has the lowest temperatures in the atmosphere. The thermosphere has steadily rising temperatures because the air molecules there absorb high‐energy X‐rays and short‐wave ultraviolet radiation.

Answer 90

Variations in the amount of solar energy reaching different places on Earth largely drive atmospheric circulation. Atmospheric heat transfer from the equator to the poles produces a movement of warm air toward the poles and a movement of cool air toward the equator, moderating the climate. The atmosphere also exhibits winds, complex horizontal movements that result in part from differences in atmospheric pressure and from the Coriolis effect.

Answer 91

The Coriolis effect is the influence of Earth's rotation, which tends to deflect fluids (air and water) toward the right in the Northern Hemisphere and toward the left in the Southern Hemisphere.

Answer 92

Surface‐ocean currents result largely from prevailing winds, which, in turn, are generated from solar energy. Other factors that contribute to ocean currents include the Coriolis effect, the position of landmasses, and the varying density of water. Gyres are large, circular ocean current systems that often encompass an entire ocean basin. Deep‐ocean currents often travel in different directions and at different speeds than do surface currents. The present circulation of shallow and deep currents, known informally as the ocean conveyor belt, affects regional and possibly global climate.

Answer 93

El Niño–Southern Oscillation (ENSO) is a periodic, large‐scale warming of surface water of the tropical eastern Pacific Ocean that affects both ocean and atmospheric circulation patterns. ENSO results in unusual weather in areas far from the tropical Pacific. During a La Niña event, surface water in the eastern Pacific becomes unusually cool.

Answer 94

Weather refers to the conditions in the atmosphere at a given place and time, whereas climate refers to the typical patterns of weather conditions that occur in a place over a period of years. Temperature and precipitation largely determine an area's climate. Precipitation is greatest where warm air passes over the ocean, absorbing moisture, and is then cooled, such as when mountains force humid air upward.

Answer 95

A tornado is a powerful, rotating funnel of air associated with severe thunderstorms. A tropical cyclone is a giant, rotating tropical storm with high winds. Tropical cyclones are called hurricanes in the Atlantic, typhoons in the Pacific, and cyclones in the Indian Ocean.

Answer 96

Plate tectonics is the study of the processes by which the lithospheric plates move over the asthenosphere. Earth's lithosphere (outermost rock layer) consists of seven large plates and a few smaller ones. As the plates move horizontally, the continents change their relative positions. Plate boundaries are sites of intense geologic activity, such as mountain building, volcanoes, and earthquakes.

Answer 97

Evolution = cumulative genetic changes that occur over time in a population of organisms; evolution explains many patterns observed in the natural world

Answer 98

Natural selection = process in which better‐adapted individuals—those with a combination of genetic traits better suited to environmental conditions—are more likely to survive and reproduce, increasing their proportion in the population.

Answer 99

1. Each species produces more offspring than will survive to maturity. 2. The individuals in a population exhibit heritable variation in their traits. 3. Organisms compete with one another for the resources needed to survive. 4. Those individuals with the most favorable combination of traits are most likely to survive and reproduce, passing their genetic characters on to the next generation.

Answer 100

Organisms are classified into six major groups: bacteria, archaea, protists (algae, protozoa, slime molds, water molds), plants, fungi (yeasts and mushrooms and some molds), and animals.

Answer 101

A population is a group of individuals of the same species that live in the same geographic area at the same time. Growth rate (r) is the rate of change of a population's size, expressed in percent per year. On a global scale (when dispersal is not a factor), growth rate (r) is due to birth rate (v) and death rate (d): r = b − d. Emigration (e), the number of individuals leaving an area, and immigration (i), the number of individuals entering an area, affect a local population's size and growth rate. For a local population (where dispersal is a factor), r = (b − d) + (i − e).

Answer 102

Intrinsic rate of increase is the exponential growth of a population that occurs under ideal conditions. Exponential population growth is the accelerating population growth that occurs when optimal conditions allow a constant reproductive rate over a period of time. The carrying capacity (K) is the maximum number of individuals of a given species that a particular environment can support for an indefinite period, assuming there are no changes in the environment. Although populations with a constant reproductive rate exhibit exponential population growth for limited periods (the J curve), eventually the growth rate decreases to around zero or becomes negative. The S curve shows an initial lag phase (when the population is small), followed by an exponential phase, followed by a leveling phase as the carrying capacity of the environment is reached.

Answer 103

A density‐dependent factor is an environmental factor whose effects on a population change as population density changes. A density‐independent factor is an environmental factor that affects the size of a population but is not influenced by changes in population density. Hurricanes and fires are examples.

Answer 104

Survivorship is the probability that a given individual in a population will survive to a particular age. There are three general types of survivorship curves. In type I survivorship, death is greatest in old age. In type III survivorship, death is greatest among the young. In type II survivorship, death is spread evenly across all age groups.

Answer 105

Many species exist as a metapopulation, a set of local populations among which individuals are distributed in distinct habitat patches across a landscape. Source habitats are preferred sites where local reproductive success is greater than local mortality. Sink habitats are lower‐quality habitats where individuals may suffer death or, if they survive, poor reproductive success.

Answer 106

The ecological niche is the organism's place and role in a complex biotic and abiotic system. An organism's ecological niche is the totality of its adaptations, its use of resources, and the lifestyle to which it is fitted

Answer 107

Competition is the interaction among organisms that vie for the same resources (such as food or living space) in an ecosystem. Many ecologists think two species cannot occupy the same niche in the same community for an indefinite period. In competitive exclusion, one species excludes another as a result of competition for limited resources. Some species reduce competition by resource partitioning, in which they use resources differently.

Answer 108

Symbiosis is any intimate relationship or association between members of two or more species. Mutualism is a symbiotic relationship in which both partners benefit. Commensalism is a type of symbiosis in which one organism benefits and the other one is neither harmed nor helped. Parasitism is a symbiotic relationship in which one organism benefits and the other is adversely affected.

Answer 109

Predation is the consumption of one species (the prey) by another (the predator). During coevolution between predator and prey, the predator evolves more efficient ways to catch prey, and the prey evolves better ways to escape the predator.

Answer 110

A keystone species is a species, often a predator, that exerts a profound influence on a community in excess of that expected by its relative abundance. One example of a keystone species is the gray wolf. Where wolves were hunted to extinction, the populations of deer, elk, and other herbivores increased. As these herbivores overgrazed the vegetation, many plant species disappeared. Many smaller animals such as insects and trout decreased because the plants they depended on for food were now less abundant. Thus, the disappearance of the wolf resulted in an ecosystem with considerably less biological diversity.

Answer 111

Species richness, the number of species in a community, is often great when there are many potential ecological niches, when the area is at the margins of adjacent communities, when the community is not isolated or severely stressed, when one species does not dominate others, and when communities have a long geologic history.

Answer 112

Ecological succession is the orderly replacement of one community by another. Primary succession is the change in species composition over time in a previously uninhabited environment. Secondary succession is the change in species composition that takes place after some disturbance destroys the existing vegetation; soil is already present.

Answer 113

The planetary boundaries framework defines a "safe operating space" for humanity based on Earth’s biophysical processes. It aims to avoid abrupt, potentially catastrophic environmental change at a global scale by not crossing key thresholds

Answer 114

The authors identify nine planetary boundaries, seven of which have quantifiable thresholds: climate change, ocean acidification, stratospheric ozone depletion, biogeochemical flows of nitrogen and phosphorus, global freshwater use, land system change, and biodiversity loss. Two remain unquantified: chemical pollution and atmospheric aerosol loading.

Answer 115

Except for stratospheric ozone depletion, atmospheric aerosol loading and ocean acidification, seven out of eight globally quantified ESBs have already been transgressed. Many regional boundaries, especially in more than half of the global land area, have also been exceeded

Answer 116

The threshold for CO₂ concentrations is set at 350 ppm, and radiative forcing should not exceed +1 W/m² above pre-industrial levels. Current levels are already beyond this, pushing the planet toward dangerous climate shifts. The ESB for climate change suggests that global warming beyond 1.0°C (already exceeded) risks triggering dangerous tipping points, such as the collapse of the Greenland ice sheet. Limiting warming to 1.5°C is necessary to avoid severe impacts

Answer 117

The boundary for biodiversity is set at an extinction rate of fewer than 10 species per million per year. Current rates are much higher, indicating a significant breach.

Answer 118

Human activities now convert more nitrogen (N) from the atmosphere into reactive forms than the Earth’s natural processes. The limit is set to 35 Tg N/year to avoid ecosystem disruptions like waterway eutrophication and atmospheric pollution.

Answer 119

Global freshwater use is limited to 4,000 km³ per year. Exceeding this could disrupt the water cycle and harm ecosystems, particularly through impacts on monsoon patterns and freshwater ecosystems.

Answer 120

Transgressing one boundary may shift others or create feedback loops, amplifying risks. For instance, changes in biodiversity can affect the resilience of ecosystems, influencing climate change and water cycles.

Answer 121

The concept of planetary boundaries suggests a shift from minimizing negative externalities to managing human development within safe planetary limits, promoting sustainability and resilience.

Answer 122

In complex systems, thresholds are a major reason for nonlinear behaviour. A tipping point has a similar meaning but is more related to systems: signifying a critical point after which the system shifts radically and potentially irreversibly into a different equilibrium state.

Answer 123

In geological history, the Earth has undergone significant changes, labelling as epochs. One where Earth later stabilises and this allows civilization and the life as we know it today is called Holocene epoch. This epoch is the only time in geological history that has evidence of sustaining humans on earth. The human impact on modern-era Earth and its ecosystems may be considered of global significance for the future evolution of living species. The PB are set as a safe zone for human operation that will keep the planet on a Holocene like state, It is the reference used to set most of the boundaries as the uncertainties are more controllable based on the evidence we have from the Holocene state.

Answer 124

Climate change and biosphere integrity (formerly biodiversity loss) are identified as the two "core" planetary boundaries due to their fundamental role in regulating Earth's system. Crossing these boundaries has the potential to drive the Earth into a new, less hospitable state.

Answer 125

For some boundaries, such as biosphere integrity and land-system change, a two-tiered approach is adopted. It recognizes regional-level thresholds that aggregate into global impacts, allowing for a more nuanced understanding of how local changes affect the planet as a whole.

Answer 126

The paper emphasizes the importance of setting boundaries upstream of potential tipping points, allowing a buffer for uncertainty and early warning signals. This precautionary approach helps ensure that humanity avoids pushing Earth's systems too far.

Answer 127

ey ESBs are proposed for different Earth system processes, including: Climate: Global warming should be limited to 1.0°C to 1.5°C to avoid triggering climate tipping points. Biosphere: At least 50-60% of the Earth's land surface should remain as natural ecosystems to maintain life-support functions. Water: Surface water flows should not be altered by more than 20% from natural flows to protect freshwater ecosystems. Nitrogen and Phosphorus Cycles: Nitrogen and phosphorus inputs into ecosystems should remain below levels that cause eutrophication and ecosystem collapse.

Answer 128

- Blue water, which is freshwater that is available on the land surface i.e. in rivers, streams, lakes, including ice caps and glaciers. - Green water, water available on the soil (soil moisture) and groundwater. The PB for blue water include the activities of altering water streams i.e. building of dams and excessive use of freshwater from river posing threat to the reduction of available freshwater. For green water, excessive pumping of groundwater is one example of the case that may lead to ground sinking and reduced soil moisture, with effect on agriculture activities.

Answer 129

1. **Nitrogen (N) Cycle**: - Human activities, particularly industrial and agricultural practices, have dramatically increased the conversion of nitrogen from its inert form in the atmosphere into reactive forms, primarily through the use of synthetic fertilizers. Excess nitrogen enters ecosystems through runoff, causing problems like eutrophication (excessive nutrient loading in water bodies), which leads to algal blooms, dead zones, and biodiversity loss. The planetary boundary for nitrogen aims to limit the amount of nitrogen that humans add to ecosystems to avoid these disruptions. 2. **Phosphorus (P) Cycle**: - Like nitrogen, phosphorus is a crucial nutrient for plant growth, and it is heavily used in fertilizers. However, phosphorus is mined from finite geological deposits and, once applied to land, much of it runs off into freshwater systems. Excess phosphorus causes similar problems to nitrogen, such as eutrophication in lakes and coastal waters. The phosphorus boundary focuses on controlling the amount of phosphorus that enters water systems to prevent ecological damage and protect water quality. Both nitrogen and phosphorus are essential for life but, when used excessively, they destabilize ecosystems, leading to long-term environmental harm. Managing these biogeochemical flows within safe limits is key to sustaining ecosystem health.

Answer 130

Genetic Diversity: Genetic diversity refers to the variety of genes within species, which is essential for populations to adapt to environmental changes and maintain long-term resilience. Loss of genetic diversity can result from habitat destruction, over-exploitation, and pollution, leading to a higher risk of species extinction and reduced ecosystem health. The planetary boundary for genetic diversity is often measured by the rate of species extinctions. A safe threshold is set to maintain ecosystem services, and transgressing this boundary can destabilize ecosystems and reduce their ability to support life, including human well-being. Functional Diversity: Functional diversity refers to the range of different biological functions and processes performed by species within an ecosystem. It reflects the roles species play in ecosystem functioning, such as nutrient cycling, pollination, and carbon storage. When functional diversity is reduced—either through species loss or the degradation of ecosystems—key ecosystem services are compromised. This can lead to reduced ecosystem resilience, making them less capable of withstanding environmental shocks and stresses (e.g., climate change, deforestation). Maintaining functional diversity ensures ecosystems can continue providing essential services that support all forms of life. Both genetic and functional diversity are essential for the stability and resilience of ecosystems, making them critical to maintaining the overall health of the biosphere. The planetary boundary framework emphasizes the importance of protecting both to prevent irreversible damage to Earth's ecosystems.

Answer 131

Loss of Biodiversity (Biosphere Integrity): Climate change exacerbates habitat destruction and alters ecosystems, driving species extinction and reducing genetic diversity, which are key aspects of biosphere integrity. Rising temperatures, shifting weather patterns, and extreme events disrupt ecosystems, pushing species beyond their adaptive limits. This impacts biodiversity by reducing both genetic and functional diversity, leading to ecosystem degradation and loss of resilience. Ocean Acidification: Climate change increases the concentration of carbon dioxide (CO₂) in the atmosphere, which is absorbed by oceans, causing ocean acidification. This reduces the pH levels of seawater, harming marine ecosystems, especially organisms that rely on calcium carbonate (e.g., coral reefs, shellfish). Ocean acidification is a direct consequence of climate change but is also recognized as a separate PB due to its significant and distinct impacts on marine biodiversity and ecosystem services. Disruption of the Water Cycle (Freshwater Use): Climate change intensifies the global water cycle, causing more extreme weather events, including floods, droughts, and changes in precipitation patterns. This alters the availability and distribution of freshwater, putting stress on freshwater ecosystems. As climate change accelerates, it exacerbates overuse of water resources, leading to the transgression of the freshwater use boundary, which is critical for maintaining both ecosystem services and human needs.

Answer 132

Land-system change, particularly through deforestation, agricultural expansion, and urbanization, leads to habitat destruction, contributing directly to the loss of genetic diversity and functional diversity within ecosystems. This degradation of habitats reduces the ability of species to survive, contributing to biodiversity loss and undermining ecosystem services. The fragmentation of ecosystems due to land-use change also limits species’ ability to migrate in response to climate change, further exacerbating the loss of biodiversity.

Answer 133

Excess nitrogen and phosphorus from fertilizers run off into rivers, lakes, and oceans, causing eutrophication, where excessive nutrient levels lead to algal blooms. These blooms deplete oxygen levels in water bodies, creating “dead zones” where aquatic life cannot survive, undermining freshwater use and ecosystem health. The contamination of freshwater systems through nutrient runoff also directly impacts the availability of clean water for human use, affecting drinking water supplies and agriculture.

Answer 134

Aerosols, both reflective and absorbing, have complex effects on climate change. Reflective aerosols can cool the Earth's surface by reflecting sunlight, while absorbing aerosols, such as black carbon, contribute to warming. These aerosols impact regional climate patterns, such as monsoon systems, and can exacerbate or mitigate warming depending on their type and concentration. Aerosols also influence cloud formation and precipitation patterns, which have knock-on effects on the freshwater use boundary by altering rainfall distribution and water availability.

Answer 135

The conversion of forests and grasslands to agriculture significantly alters biogeochemical flows. Intensive farming increases the need for nitrogen and phosphorus fertilizers, leading to nutrient runoff into surrounding ecosystems. This runoff contributes to eutrophication, affecting both biosphere integrity and freshwater systems. Changes in land use reduce the ability of ecosystems, particularly forests, to act as carbon sinks, exacerbating climate change and increasing the reliance on fertilizers, creating a feedback loop between these boundaries.

Answer 136

Ocean acidification, driven by increased CO₂ emissions from climate change, affects marine ecosystems, particularly coral reefs and species that depend on calcium carbonate for their shells and skeletons. This reduction in pH levels causes a loss of genetic and functional diversity in marine ecosystems, threatening the resilience of ocean ecosystems and their ability to provide services such as fisheries and coastal protection. The loss of coral reefs and marine biodiversity due to ocean acidification also weakens biosphere integrity, as these ecosystems play a critical role in supporting marine life and regulating carbon and nutrient cycles.

Answer 137

Ocean acidification is a change in the properties of ocean water that can be harmful for plants and animals. Scientists have observed that the ocean is becoming more acidic as its water absorbs carbon dioxide from the atmosphere.

Answer 138

Aragonite is a carbonate mineral formed by biological and physical processes. A naturally occurring form of calcium carbonate in the waters, it is used in the formation of shells and skeletons by marine organisms.

Answer 139

Ocean acidification, driven by increased CO₂ emissions from climate change, affects marine ecosystems, particularly coral reefs and species that depend on calcium carbonate for their shells and skeletons. This reduction in pH levels causes a loss of genetic and functional diversity in marine ecosystems, threatening the resilience of ocean ecosystems and their ability to provide services such as fisheries and coastal protection. The loss of coral reefs and marine biodiversity due to ocean acidification also weakens biosphere integrity, as these ecosystems play a critical role in supporting marine life and regulating carbon and nutrient cycles.

Answer 140

Stratospheric ozone depletion allows increased levels of harmful UV radiation to reach Earth’s surface, which has direct effects on biosphere integrity. Increased UV exposure damages plant life, affects genetic diversity, and impairs ecosystems' ability to function, especially in polar and marine environments. The ozone layer’s depletion can also impact human health and agriculture, which links to biosphere integrity through its effects on food security and species’ survival.

Answer 141

In essence, adaptation can be understood as the process of adjusting to the current and future effects of climate change. Mitigation means preventing or reducing the emission of greenhouse gases (GHG) into the atmosphere to make the impacts of climate change less severe. Examples of adaptation measures include large-scale infrastructure changes, such as building defences to protect against sea-level rise. Mitigation is achieved either by reducing the sources of these gases — e.g. by increasing the share of renewable energies, or establishing a cleaner mobility system.

Answer 142

Man-made sediments (sediment of nuclear waste) in lakes.

Answer 143

Gasoline is the source of energy that is converted to turn on the engine of the car. The used energy is not gone, but converted to movement and also part of it becomes waste/pollution. In the conversion process, the energy goes from a more useful to less useful form of energy. Meaning that if for e.g. the gasoline initially had 10000 kj of energy, there will only be 8,000 kj of energy converted in the engine. The rest of the energy is scattered and not useful, which we call as entropy.

Answer 144

For e.g. with the effect of climate change, the temperature on earth surface has become higher, causing ice to melt in the arctic. With ice melting, less of the sun energy is reflected. Instead, it is absorbed by the ocean making the temperature even warmer.

Answer 145

The greenhouse effect traps the Sun's energy at the Earth's surface. It is essential for life on Earth. The enhanced greenhouse effect is where extra greenhouse gases in our atmosphere trap too much of the Sun's energy. This causes a warming effect, which some people call global warming.

Answer 146

A) Having an extremely small (localized) range B) Requiring a large territory D) Living on islands, E) Having low reporductive success, F) Needing specialized breeding areas, G) Having specialized feeding habits.

Answer 147

Reinforcing

Answer 148

ecosystem negative/balancing closed

Answer 149

A balancing feedback loop works to maintain (1) system’s dynamic equilibrium. A reinforcing feedback loop on the other hand, moves the system further and further away from the target (1) of equilibrium.

Answer 150

Are everywhere Dynamic Has a purpose

Answer 151

The natural greenhouse effect describes the natural process of the Earth absorbing incoming solar radiation and emitting this as long- wave infrared radiation (heat) (1) to the lower atmosphere. This radiation is then absorbed and released by greenhouse gases in the atmosphere, retaining some of this energy in the atmosphere instead of travelling back to space. This natural process is essential to providing a hospitable planet with regular temperatures (1). However, this natural process can be impacted by the increasing concentration of greenhouse gases in the atmosphere as a result of human activity (1). This increases the amount of radiation ‘trapped’ (1) in the atmosphere instead of passing through the atmosphere and back to space. Four common greenhouse gases, which are naturally occurring as well as increasing due to human activities, are water vapor, carbon dioxide, methane, and nitrous oxide.

Answer 152

Chemical compositions of ecosystems and nutrient cycles Depletion of natural resources Planetary boundaries are exceeded Biodiversity loss Amount of green house gas emissions Traces in sediments / ”stuff”, plastics

Answer 153

The Great Acceleration is the dramatic, continous and rougly simultaneous surge in growth rate across a large range of measures of human activity, first recorded in mid-20th century and continuing to this day (1). Within the concept of the proposed epoch of anthropocene, these measures are those specifically of humanity's impact on Earth's geology and its ecosystems (1)

Answer 154

A: The main cause for problematic aerosols are emissions rising from industries and urban areas.

Answer 155

A: This is false. Despite rising pressure, the boundary has not been transgressed.

Answer 156

A: It is believed that anthropogenic aerosols such as Sulphur have made the planet 0.7°C cooler than it would have been without these particles in the atmosphere. This is because many aerosols have a cooling effect on earth, and they reflect the sun’s energy back into space. If we remove these aerosols from the atmosphere, this will likely result in warmer temperatures and even faster warming of the planet and more drastic climate change.

Answer 157

“Biogeochemical flows” is one out of nine essential processes for sustaining the stability and resilience of the Earth system. It refers to the flow of important chemical elements like nitrogen (N) and phosphorus (P), but also carbon and Sulphur. This is identified as a planetary boundary, as these flows are vital for maintaining Earth systems and environmental functions. Human influence on these flows is causing a disruption in the nutrient balance, and can lead to loss of biodiversity and alteration of ecosystem services.

Answer 158

Model Answer: Using too much synthetic fertilizer to compensate for soil degradation due to intensive agricultural systems à runoff into waters when it rains à nutrients cause algae bloom and eutrophication in waters, killing marine life. Possible solutions: regenerative farming to restore soil quality and reduce fertilizer use, poly cropping, planting nitrogen fixating crops and/or cover crops. Planting catchment crops to reduce runoff from fertilizers.

Answer 159

Dead zones are areas in oceans or lakes with low oxygen, making them uninhabitable for most marine life. They occur due to nutrient pollution, mainly nitrogen and phosphorus from agricultural runoff, which causes algae blooms. When the algae die, bacteria decompose them, using up oxygen and creating hypoxic conditions.

Answer 160

Here’s a breakdown of the four justice concepts in relation to the Earth system and sustainability: A. **Interspecies Justice and Earth System Stability** - **Interspecies justice** refers to the moral obligation to protect not only humans but also other species and ecosystems. This concept rejects the idea of human exceptionalism, recognizing that other species also have a right to exist and thrive. - In the context of **Earth system stability**, interspecies justice is about maintaining the integrity and stability of ecosystems, ensuring that human activities do not disproportionately harm other species. Preserving biodiversity and ecosystem services is key to ensuring that the planet remains habitable and resilient for all forms of life, not just humans. C. **Intergenerational Justice** - **Intergenerational justice** refers to the ethical responsibility to consider the rights and well-being of future generations when making decisions about resource use and environmental impacts. It is about ensuring that today’s actions do not compromise the ability of future generations to meet their own needs. - This concept is particularly relevant to **climate change** and other planetary boundaries. Actions taken now, such as reducing greenhouse gas emissions or protecting biodiversity, help prevent irreversible damage to the Earth system that would disproportionately harm future generations. D. **Intragenerational Justice between Countries, Communities, and Individuals** - **Intragenerational justice** focuses on fairness within the current generation, specifically regarding disparities between different countries, communities, and individuals. This includes addressing inequalities in the distribution of environmental harm and benefits. - For example, poorer countries and communities often suffer the most from environmental degradation and climate change, despite contributing the least to the problem. Intragenerational justice seeks to ensure that vulnerable populations are protected, and that environmental policies distribute risks and benefits more equitably across society. These justice principles are crucial for designing sustainability policies that balance the needs of humans and the environment, both now and in the future. They are central to discussions on planetary boundaries and environmental ethics.

Answer 161

Mass biodiversity loss would destabilize ecosystems, reducing their ability to sequester carbon, regulate nutrient cycles, and support essential services like water purification and soil fertility. This would exacerbate climate change, disrupt biogeochemical flows, and increase land degradation. It would also weaken the resilience of ecosystems to recover from shocks, pushing some systems toward tipping points of collapse. The interdependence of biodiversity with other Planetary Boundaries means that its loss would amplify problems like freshwater scarcity, ocean acidification, and pollution, ultimately threatening Earth’s stability and human well-being.

Answer 162

The planetary boundary for climate change is primarily defined by the concentration of atmospheric carbon dioxide (CO₂). The boundary is set at 350 parts per million (ppm) of CO₂, a level which corresponds to a global mean surface temperature increase of around 1°C above pre-industrial levels. This threshold was chosen based on strong evidence that beyond this level, the risk of crossing dangerous tipping points rises significantly. The 350-ppm boundary reflects the precautionary principle, which aims to prevent irreversible damage to the Earth’s system. For context, the pre-industrial concentration of CO₂ was about 280 ppm, a level that persisted throughout the Holocene. However, since the Industrial Revolution, human activities, particularly the burning of fossil fuels, have pushed CO₂ levels well beyond this boundary, currently exceeding 415 ppm.

Answer 163

Natural ecosystems, particularly forests, play an important role in absorbing atmospheric CO₂. Indeed, forests are essential for both carbon sequestration and local climate regulation. Recent studies suggest that limiting deforestation and increasing reforestation efforts can transform terrestrial ecosystems from carbon sources to carbon sinks, thereby stabilizing the Earth’s carbon cycle and limiting the concentration of CO₂ in the atmosphere.

Answer 164

The concept of "safe and just" planetary boundaries applies to climate change by recognizing that the global rise in temperatures must be limited not only to avoid catastrophic environmental tipping points but also to protect vulnerable human populations. A "safe" boundary for climate change focuses on preventing extreme events such as more intense storms, prolonged droughts, and rising sea levels, which could disrupt ecosystems, agriculture, and water supplies. The "just" aspect, however, stresses that while climate change is a global issue, its impacts are disproportionately felt by those least responsible for causing it. This highlights the importance of balancing efforts to stabilize the Earth's climate system while also promoting justice for populations who are most vulnerable to adverse effects.

Answer 165

Polar stratospheric clouds accelerate the impact of chlorine, such as human-made CFCs, by providing chlorine surface in the form of ice crystals and preventing chlorine deactivation.

Answer 166

Stratospheric ozone helps to shield dangerous UV rays from earth, while tropospheric ozone is a human-made pollutant.

Answer 167

The Montreal Protocol is successful due to the fact that it is universally ratified, it was put into action rapidly after the problem of ozone depletion was discovered and it has changed the trajectory of the ozone hole.

Answer 168

. Biodiversity Loss (Biosphere Integrity): Land-system changes, such as deforestation, urbanization, and agricultural expansion, drastically reduce natural habitats. This destruction leads to the loss of species and ecosystems. Deforestation, for example, fragments habitats and forces species into smaller areas, making them more vulnerable to extinction. The degradation of ecosystems disrupts the balance of biodiversity, affecting ecosystem services like pollination and soil fertility, which are vital for human and ecological well-being. 2. Biogeochemical Flows (Nitrogen and Phosphorus Cycles): Conversion of natural landscapes into agricultural land intensifies the use of fertilizers, which alters the nitrogen and phosphorus cycles. Excessive use of these nutrients can lead to eutrophication of freshwater and marine ecosystems, causing harmful algal blooms, oxygen depletion, and loss of aquatic biodiversity. Land-system changes increase the pressure on these cycles by disrupting the natural flow of these elements in ecosystems. 3. Climate Change: Land-system changes, such as deforestation and land degradation, release stored carbon into the atmosphere, contributing to climate change. Forests and natural landscapes act as carbon sinks, absorbing CO2 from the atmosphere. When these areas are converted into agricultural or urban land, not only is this carbon storage capacity lost, but the carbon stored in vegetation and soil is released, exacerbating global warming.

Answer 169

Multiple answers possible. Circular economy, screening, green chemistry etc. Explanations for why the solution helps should either be related to how it helps define and screen the boundary, or how it is a precautionary measure that helps release less chemicals all together.

Answer 170

e.g., Stratospheric ozone depletion, Atmospheric aerosol loading

Answer 171

In short: emissions of carbon dioxide, mostly from human activities, that are absorbed in seawater is the main cause of ocean acidification.

Answer 172

Plankton need carbonate ions to build their shells and without sufficient access to it plankton populations are at risk of decline. Since they are the basis of the marine food chain, a disruption of the plankton population could be devastating to all marine ecosystems.

Answer 173

Ecosystem disruption, marine life impact, quick lime necessarily has large energy and fossil fuel CO₂ footprints, cost of the materials and infrastructure, large scale application is difficult and implementing it locally can create imbalance in the ecosystem.

Answer 174

Carbon cycle; Shifting of carbon from underground deposits through combustion of fossil fuels and deforestation. Implications? Increased CO2 in the atmosphere (from preindustrial 0,029% to 0,04%); Climate change. Nitrogen cycle; Increased amount of fixed nitrogen through fertilisers. Combustion of fossil fuels, releasing NOx. Implications?---- Decreased biodiversity in enriched land; Contamination of groundwater; Runoff-> eutrophication; Acid deposition; Poor air quality. Phosphorus cycle; Use of phosphorus in fertilisers and detergents. Implications? Depletion of resource; Limiting nutrient; Eutrophication. Sulphur cycle; Combustion of coal and oil. Extraction of (some) metals through smelting. Implications? Creation of SO2-> acid deposition-> Damage to ecosystems. Hydrologic cycle; Release of aerosols through combustion. Release of GHG. Land use (for e.g. dams, irrigation). Implications?-- Formation of aerosols-> alters cloud formation/precipitation patterns; Climate change-> ice-cap melting etc.; (Locally) altered patterns for water infiltration/retention/evapotranspiration

Answer 175

a Renewable resources are those that nature replenishes/replaces fairly rapidly and can be used forever as long as they are not overexploited in the short term. Non-renewable resources are present in limited supply and are diminished by use.

Answer 176

a As population increases, people can exceed the capacity of a region to support basic needs. When consumption by individuals substantially exceeds these basic needs, the resources in a region will be exceeded even more quickly.

Answer 177

n individual’s ecological footprint is the amount of productive land, fresh water, and ocean required on a continuous basis to supply that person with food, energy, water, housing, material goods, transportation, and waste disposa

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