ESS Notes 24/25 PDF

Quiero agradecer a la persona que ha hecho este documento (X2) ESS NOTES 24/25 Biome of choice (Tundra): · Alpine/ Arctic · Cold climate · Low biotic diversity · Simple vegetation · Permafrost: a thick subsurface layer of soil that remains below freezing point throughout the year, o...

Quiero agradecer a la persona que ha hecho este documento (X2) ESS NOTES 24/25 Biome of choice (Tundra): · Alpine/ Arctic · Cold climate · Low biotic diversity · Simple vegetation · Permafrost: a thick subsurface layer of soil that remains below freezing point throughout the year, occurring chiefly in polar regions. · Short growing season · Poor nutrients · Large population oscillations · Species; Snow leopards, moose, wolves. · Common in North America; Canada, Iceland. · Food Chain: Lichen, producers (a type of moss on trees) - Reindeer - Snow leopards (ultimate accumulators) top carnivores. Hard definitions: Zonation: changes in a community along an environmental gradient due to factors such as latitude, altitude, tidal level or distance from shore. (spatial change). Succession: the process of change over time in an ecosystem involving pioneer, intermediate and climax communities Ecological footprint: the area of land and water required to sustainably provide all resources at the rate at which they are being consumed by a given population Tipping point: minimum amount of change needed for a state to deviate into a new equilibrium when an ecosystem experiences a shift to a new state in which there are significant changes to its biodiversity and the services it provides. Fundamental niche: the full range of conditions and resources in which a species could survive and reproduce (ideal conditions) Realised niche: the actual conditions and resources in which a species exists due to biotic interactions. R-selected species: species that produce a large number of offspring and contribute few resources to each individual offspring, ex: frog K-selected species: characterised by long gestation periods lasting several months, slow maturity (and thus extended parental care), and long life spans. Respiration: the conversion of organic matter into carbon dioxide and water in all living organisms, releasing energy. Photosynthesis: the process by which green plants make their own food from water and carbon dioxide using energy from the sun. Bioaccumulation: the gradual accumulation of substances, such as pesticides or other chemicals, in an organism. Biomagnification: increasing concentration of toxic substances as they move up through different trophic levels in a food chain. Autotrophs: an organism that can produce its own food using light, water, carbon dioxide, or other chemicals. Ex; algae Heterotrophs: Opposite of autotrophs. Ex; humans Biomass: the living mass of an organism or organisms. Measured by obtaining the dry mass and usually calculated per unit area. Primary productivity: the rate at which plants produce biomass per unit area Gross primary productivity: the rate at which solar energy is captured in sugar molecules during photosynthesis Net primary productivity: the rate at which all the autotrophs in an ecosystem produce net useful chemical energy. GPP - R (respiratory losses) Gross secondary productivity: total energy or biomass assimilated (taken up) by consumers and is calculated by subtracting the mass of faecal loss from the mass of food eaten. Net secondary productivity: the total gain in energy or biomass per unit area per unit time by consumers after allowing for losses to respiration. NSP = GSP - R (respiratory losses) Maximum sustainable yield: the largest crop or catch that can be taken from the stock of a species without depleting the stock Optimum sustainable yield: The level of resource extraction that not only considers biological productivity but also includes ecological, economic, and social factors. Carrying capacity - “k”: the maximum number of a species or 'load' that can be sustainably supported by a given area Abiotic factors: non-living components; such as water, soil, atmosphere and temperature in an ecosystem. Biotic factors: living things within an ecosystem; such as plants, animals, and bacteria Overgrazing: a situation in which too many animals are feeding off of the crops in a specific area damaging the plants and the soil. Water degradation: the pollution of water Intertidal zone: the area where the ocean meets the land between high and low tides. Mangroves (Example for keystones species): tropical plants that are adapted to loose and wet soils, salt water and being periodically submerged by tides. Keystones species: species that have a disproportionately large effect on its environment. Estuaries: a partially enclosed, coastal water body where freshwater from rivers and streams mixes with salt water from the ocean. Lagoons: a shallow body of water protected from a larger body of water (usually the ocean) by sandbars, barrier islands, or coral reefs. Fisheries: places where fish are caught/harvested. Aquaculture: the farming and harvesting of aquatic plants and animals, fastest growing form of food production due to increase in demand. Governance of the Oceans: UN Convention of the Laws of the Sea (UNCLOS) – 1982 where their main point was that continental shelves belong to the country in which they arise. Turbot war 1995 Biochemical oxygen demand (BOD): a measure of the amount of dissolved oxygen required to break down the organic material in a given volume of water through aerobic biological activity by microorganisms Eutrophication: Is a drastic increase in algae growth and it occurs when there is an excess of nutrients in a body of water. Prevents sunlight from reaching plants for necessary photosynthesis. Red tides: a discoloration of seawater caused by a bloom of toxic red algae. Irrigation: extra water added to a soil/plant to encourage growth Water stress: the total annual extraction of water as a proportion of the renewable supply in a given area Water scarcity: a lack of water due to either physical or economic reasons Physical water scarcity: where water consumption exceeds 60% of the usable supply Economic water scarcity: where a country physically has sufficient water to meet its needs, but requires additional storage and transport facilities Water insecurity: a lack of access to sufficient amounts of safe drinking water Anoxia: lack of oxygen Leaching: a process where water passes through soil, rocks, or other materials and carries away dissolved substances, like minerals, nutrients, or chemicals, with it Humus: the dark, soft, and crumbly part of soil made from decomposed plants and animals. It’s full of nutrients that help plants grow, and it improves soil structure, making it better at holding water and air Agribusiness: All business associated with agriculture Commercial agriculture: large scale production of crops and livestock for a profit Subsistence agriculture: farming for self-sufficiency to grow enough for a family Soil fertility: the ability of a soil to enable plant growth Toxification: the decline in soil fertility due to the build up of toxic chemicals Salinization: increase in the amount of salt in the upper soil horizons Desertification: the spread of deserts into areas previously fertile Overgrazing: when animals eat too much grass or plants in one area without giving it enough time to regrow Waterlogging: when soil becomes too full of water, often because of heavy rain, poor drainage, or over-irrigation Albedo effect: the ability of certain surfaces to reflect sunlight, influencing the earth’s climate and temperature. Snow has a high albedo effect and dark forests have a low albedo effect. (higher albedo effect means colder temperatures) Greenhouse effect: A natural and necessary phenomenon maintaining suitable temperatures for living systems. Essentially it’s the role of greenhouse gases (CO2, methane and water vapour) to trap heat inside the atmosphere in order to keep all the organisms alive. CFCs: non-toxic, non-flammable chemicals containing atoms of chlorine, fluorine and carbon. They are used to manufacture aerosol sprays, foams and packing materials as refrigerants. These CFCs, if poorly stored or maintained, can destroy ozone molecules and the ozone layer. Primary pollutants: Pollutants that are formed and emitted directly from particular sources. Secondary pollutants: Pollutants that are formed in the lower atmosphere by chemical reactions. Carbon and Nitrogen cycles: Carbon cycle: Combustion: From fossil fuels to CO2 in the atmosphere Decomposition (two ways): From soil organic matter to CO2 in the atmosphere/ From O2 in the atmosphere to soil organic matter Respiration (two ways): From animals and plants to CO2 in the atmosphere/ From O2 in the atmosphere to animals and plants and then to soil organic matter. Photosynthesis (two ways): From plants to O2 in the atmosphere/ From CO2 in the atmosphere to plants. Diffusion: From CO2 in the atmosphere to Ocean marine deposits or other way around Nitrogen cycle Nitrification (two ways): From N2 in the atmosphere to NO3- in soil solution / From NH4+ to NO3- in soil solution Nitrogen fixation: From N2 in the atmosphere to NO3- in soil solution Denitrification: From NO3- in soil solution to N2 in the atmosphere Absorption: From NO3- in soil solution to Organic compounds in plants (proteins) Feeding: Animals eating plants Death and excretion: From either plants or animals to bacteria. Decomposition: From Bacteria and fungi to NH4+ Summary of each unit Unit 1.1 Environmental Value systems Brief unit consists of 3 main parts. Environmental value systems which are different worldviews or paradigms that depend on a person's perspective, values, culture among many other factors. The three EVS we focus on are Ecocentrics, Technocentrics and Anthropocentrics. Unit 1.2 Systems and Models Describes concept such as transfer (from place to place) and transformation (change of state) of Energy, Laws of Thermodynamics; 1st law - Principle of conservation of energy, which states that energy in an isolated system can be transformed but cannot be created or destroyed and 2nd law - Energy is transformed through energy transfers. An increase in entropy (amount of disorder in an ecosystem) arising from energy transformations reduces the energy available to do work. Positive feedback (lots of change) and Negative feedback (neutralises deviation from equilibrium). Unit 1.3 Energy and Equilibrium The progressive loss of energy in the Food chain. More clearly represented in this image: Also describes the different types of equilibrium: Steady state equilibrium, no change over long-term but small changes over short term (includes most open systems). Static equilibrium, no changes over time. Unstable equilibrium, system returns to a NEW equilibrium after disturbance from input/output. Stable Equilibrium: System returns to the same equilibrium after disturbance from input/output. Brief explanation on positive feedback loops (looks for new state) and negative feedback loops (discourages change). Unit 1.4 Sustainability Focuses on concepts of sustainability such as; renewable resources which are resources that can be used over and over again, replenishable resources which are non-living resources that are regenerated as fast as they are used up. Other ideas like intrinsic value - species have their own value irrespective of economic value. Unit 2.1 Species and Population Main concept, Species: a group of organisms that interbreed and produce fertile offspring. Stages of (S) population growth, LETS. Lag: Population grows slowly, Exponential: Population grows rapidly and exploiting resources, Transitional: population growth is slow as resources are starting to be limited, Stationary: Population reaches a plateau and uses ALL available resources. Also, on the J curve, the population grows exponentially at first and then, suddenly collapses. These collapses are called diebacks and they happen due to surpassing the carrying capacity. It’s important to note that the J curve doesn’t show a gradual slowdown of population growth with increasing population size. Both the S and the J curve are idealised curves, in real population measurements there are many unpredictable moments where the population can change dramatically. Unit 2.2 Communities and ecosystems Shows three types of ecological pyramids; Pyramids of numbers: number of organisms in each trophic level and usually the amount of species is larger at the bottom , Pyramids of Biomass: Illustrates the total biomass at each successive trophic level Biomass: measure of the total amt of living material (units g/m2) each level of the pyramid absorbs around 10% of the biomass from the level below. Finally, pyramids of productivity or energy: Illustrates how much energy is present at each trophic level and how much is transferred to the next level. Aerobic respiration can be summarised as: Glucose + Oxygen →Energy + water + carbon dioxide. Much of the energy produced in respiration is heat energy and is released into the environment. This increases the disorder or entropy of the system while the organism maintains a high level of organisation. Photosynthesis can be summarised as: carbon dioxide + water → glucose + oxygen. Unit 2.3 Flows of energy and matter Shows characteristics of Gross Productivity - Varies across the surface of the earth - Generally greatest productivity - In shallow waters near continents - Along coral reefs – abundant light, heat, nutrients - Where upwelling currents bring nitrogen & phosphorus to the surface - Generally lowest - In deserts & arid regions with lack of water but high temperatures - Open ocean lacking nutrients and sun only near the surface Net productivity - Some of GPP used to stay alive, grow and reproduce - NPP is what’s left - Most NPP – Estuaries, swamps, tropical rainforests - Least NPP – Open ocean, tundra, desert - Open ocean has low NPP but its large area gives it more NPP total than anywhere else Unit 2.4 Biomes, zonation and succession Presents various ecosystems such as the Tundra, Rainforest and many more. Climate determines the type of biome in a given area, although individual ecosystems may vary due to many local abiotic and biotic factors. Succession leads to climax communities that may vary due to random events and interactions over time. This leads to a pattern of alternative stable states for a given ecosystem. Ecosystem stability, succession and biodiversity are intrinsically linked. Unit 3.1 Introduction to Biodiversity Biodiversity is a combination of the species diversity, genetic diversity and habitat diversity of an ecosystem. There are various threats to biodiversity such as; Habitat Loss, Integration of non-native species, Pollution, Population Growth and Over-consumption among others. There are 3 types of Biodiversity; Species diversity which are the variation of species diversity within a habitat, Genetic diversity which is the range of genetic material present in a gene pool or population of a species and Habitat diversity which is the number of different habitats per unit area that a particular ecosystem contains *If habitat diversity increases so will species and genetic diversity. Another important term that is discussed in Biodiversity hotspots are regions with a high level of biodiversity that is under threat from human activities. Unit 3.2 Origins of Biodiversity Biodiversity comes from evolution and natural selection (survival of the fittest). Speciation is the formation of new and distinct species in the course of evolution. Speciation can happen for a number of reasons such as; Physical barriers, Land bridges and Continental drift among others. Unit 3.3 Threats to Biodiversity This unit mainly deals with the current decrease of biodiversity and how humans play a big role in it. It also focuses on the importance of conservation of species that are endangered. Some factors that help to maintain biodiversity are complexity of the food web - the more complex the more resilient it is to a loss of a species, stage of succession - communities in young ecosystems are more prone to change as older ecosystems are more resilient and reliable, limiting factors - abiotic and biotic factors and inertia - the ability of an ecosystem to resist change (maintain equilibrium) when subjected to a disruptive force. Moreover it explains the acronym “AND HIPPO”: practices of modern Agriculture, Natural disasters, Spread of Disease, Habitat destruction, Introducing alien species, Pollution, Population growth and finally Overexploitation. Some reasons as to why a species might be prone to extinction; narrow geographical range, small population, seasonal migrants and low reproductive potential among many others. Unit 3.4 Conservation of biodiversity Explains how biodiversity is very important and how it gives us direct values such as food sources and natural resources but also indirect values such as: Biorights, Genetic diversity, Human health and intrinsic value among others. Explains the role of organisations like WWF or Governments in the field of environmental matters such as species extinction. The CITES (The Convention on International Trade in Endangered Species of Wild Fauna and Flora) is an agreement between state actors to address the problem of wildlife trade, while it has been effective there is little to no incentive for governments to comply. Species are categorised in 3 levels called appendixes, 1 being the most endangered species. Keystone species are those who play a crucial role in maintaining the structure of the ecosystem which they live in, e.g. beavers. Unit 4.1 Intro to water systems Water plays an incredibly important role in our lives as without it we wouldn’t be alive. Water is considered either a renewable or non-renewable resource depending on where it’s stored. Fresh water is scarce and is becoming one of the leading issues in the world and many countries are experiencing droughts. The hydrological cycle is a system of water flows and storages that may be interrupted by human activity. Flows in the hydrological cycle include: evapotranspiration, sublimation, evaporation, condensation, advection, precipitation, melting, freezing, percolation and runoff. Ocean circulation systems are driven by differences in temperature and salinity. The resulting difference in water density drives the ocean conveyor belt, which distributes heat around the world and thus affects climate. Unit 4.2 Access to fresh water Due to all water on earth being 97% saline water (salt water) there is a reduced amount of the water species can use since most living organisms like humans cannot survive on salt water. While there are desalination plants in most developed countries it’s very expensive and it’s dependent on fossil fuels. Fresh water is used for many purposes but agriculture is the one that requires and uses most of the freshwater available. Water scarcity is a real problem due to several reasons such as: climate change and growing population. There are some methods of conservation of water like building dams, having a better domestic use and rain harvesting among many others. Water degradation or water pollution can also be stopped by using organic farming methods without toxic pesticides or a regulation of the amount of water being used. Unit 4.3 Aquatic FPS The continental shelf is a small area in the ocean that can be as small as 2 metres all the way to 200 metres. It generates more or less 50% of marine productivity in such a small area due to its upwelling increasing nutrients, shallow so light can penetrate for photosynthesis and near coast so countries claim rights to harvest and possibly exploit them. Phytoplankton are single celled producers and are responsible for more than 99% of primary productivity in oceans and their primary consumers are Zooplankton. More than 70% of the world’s fisheries are being exploited at an unsustainable rate and the demand is rising faster than the production rate. The farming of marine species also known as aquaculture which while it does have some benefits like the use of fish scraps, aquaculture has a lot of downsides; Loss of habitat, Pollution, Depletion of other species and more. Practices like Dredging, gillnets, trawling and blast fishing are also environmentally damaging. Overfishing is a serious issue that greatly affects the food web; by taking out one of the trophic levels it could cause harm to all other levels. There are ways to solve this problem by creating safe-catch limits, monitoring, enforcing and more. Sustainable yield is the amount of natural capital that can be extracted each year without depleting the stock to a point that doesn’t damage the ecosystem. On the other hand, MSY (maximum sustainable yield) is the largest yield catch that can theoretically be taken from a species’ stock without permanently depleting the stock (it’s still not sustainable). Typically the maximum sustainable yield is equivalent to half of k (carrying capacity) and it often leads to a decrease in the population due to difficulties in measuring the population, natural disasters, health of organisms and more. Unit 4.4 Water pollution Water pollution can come in many different ways; Anthropogenic (human pollution), natural pollution, Point-source from waste plants or factories, Non-point source from crops or rural homes, Organic (human and animal waste) e.g. petrol, inorganic e.g. heavy metals, direct and indirect. Water pollution can lead to negative effects such as eutrophication, loss of biodiversity and many more. There are two ways to measure pollution: direct using ph scale and more or indirect with the BOD (Biochemical oxygen demand). Another indirect method is by looking at indicator species; the species which has greater population will determine the level of pollution in the water. Indicator species chart: The biotic index is a scale from 1-10 where 10 is severe pollution which is obtained through the indicator species. It is often used with BOD and Simpson’s diversity index. Unit 5.1 Intro to soil systems Soil is a complex ecosystem consisting of various parts that make soil what it is; minerals, organic material (humus), gases and liquids. Soil systems are dynamic and they include transfers, storages, both inputs and outputs as well as transformations. Soil has layers or in this case horizons, each of them constituted by different parts. - O horizon: loose and decayed organic matter - A horizon: mineral matter with humus - E horizon: less humus and more inorganic minerals - B horizon: accumulation of clay from above - C horizon: partially altered parent material - R horizon: bedrock The lower the horizon the less organic matter in that level available. Soil texture triangle: Soil permeability refers to the rate at which water and air can flow through the soil and its different layers. Loam soils have the highest permeability then sand and finally clay. Unit 5.2 Terrestrial Food Production Systems Lots of malnourishment around the world even though there is more than enough food in the world to feed everyone. The problem lies upon food waste and lack of transportation to LEDCs. There are many inequalities when it comes to food production; excess of food production in MEDC, tariffs on food importation and exportation, MEDC looking to make money out of this situation, increased meat and dairy consumption and crop loss, LEDC not being able to compete with the technology available overseas. Farming systems: - Subsistence farming: low inputs of energy, production of food for family - Commercial farming: maximising yield, extensive and intensive use of land - Pastoral farming: land used for animals not crops - Arable farming: using good soil for crops in order to eat or feed to livestock - Mixed farming: crops and livestock feed each other. Food waste - LEDC: food waste tends to be wasted at the farm or market since these countries don’t have access to technology that preserves crops and animal products from going off. - MEDC: food waste in these countries mainly arises from people buying a surplus of food because of promotions, discounts. This also demonstrates the current era of consumerism present in these MEDC. Unit 5.3 Soil degradation and conservation Soil systems change through succession, a community of organisms that support healthy nutrient cycles and contribute to the soil's resistance to erosion can be found in fertile soil. Erosion or soil degradation can be caused by strong winds or water, leaching and pollution make soil less suitable for use. Human activity can also lead to soil degradation; overgrazing, overcropping, deforestation. To solve erosion, replanting with vegetation and covering with mulch are good solutions. Unit 6.1 Introduction to the atmosphere The atmosphere is composed mainly of nitrogen (78%) and oxygen (21%) with some argon and carbon dioxide present. Human activities impact the atmospheric composition by altering inputs and outputs of the system. Changes in the concentrations of atmospheric gases such as ozone, carbon dioxide and water vapour have significant effects on ecosystems. Unit 6.2 Stratospheric ozone The stratospheric ozone (10-50 km) can be classified as a “good” ozone since it blocks out ultraviolet radiation which is harmful to humans and some other organisms. However, the tropospheric ozone is considered to be “bad” since it triggers breathing problems and health issues like asthma. The Montreal protocol (1987) was an agreement between 30 countries in order to ban CFCs due to their immense threat on human kind. CFCs had made a hole in the stratosphere or ozone layer that had allowed a huge amount of ultraviolet rays into the atmosphere. Since then all states worldwide have signed this protocol and HFCs have replaced CFCs. ODS (ozone depleting substances) are those chemical compounds that deplete the ozone in the stratosphere, such as aerosols, refrigerants and air conditioners as well as HCFCs and halons from fire retardants and pesticides which release halogen atoms that react with ozone and break it into oxygen and molecular oxygen, as well as preventing oxygen from reacting to ozone in a catalytic process. UV radiation can promote vitamin D production as well as treating some diseases such as psoriasis and vitiligo but it gives skin cancer and cataracts in humans. UV also degrades the chlorophyll in plants resulting in a lack of photosynthesis and therefore reducing primary production. Three types of UV (A,B,C) C being the strongest and most toxic. HCFCs also destroy ozone but they have a shorter lifetime in the atmosphere making them less harmful to the ozone layer than CFCs. Unit 6.3 Photochemical Smog The combustion of fossil fuels produces primary pollutants which may generate secondary pollutants and lead to photochemical smog, whose levels can vary by topography, population density and climate. The tropospheric ozone is a main pollutant of photochemical smog and is formed as a result of primary pollutants such as; volatile organic compounds, carbon dioxide, carbon monoxide and nitrogen oxide. It’s found in road transportation, solvent release from drying paints, glues or inks, petrol handling and distribution. The tropospheric ozone is a secondary pollutant. Formation of the tropospheric ozone: This ozone layer causes the stomata in plants to close leading to plants not absorbing any CO2 and making air pollution more present. This also harms the plant since it decreases photosynthesis and plant growth (harming productivity). Photochemical smog is mainly caused by combustion of fossil fuels, but forest burning also contributes to creating this natural phenomenon. Ground-level ozone develops in the atmosphere from gases that come out of tailpipes, smokestacks, factories and many other pollution sources. When these gases come in contact with sunlight, they react and form ozone smog. Complex reactions create many chemicals in photochemical smog including VOCs (volatile organic compounds). Smog peaks in the afternoon due to the amount of sunlight present. Thermal inversion is a term which is used to describe how smog cannot escape from the sky due to high levels of warmth, keeping the air pollution at ground level and allowing for smog to remain. Unit 6.4 Acid deposition Acid deposition can impact living systems and the built environment, the pollution management of acid deposition often involves cross-border issues. Acid deposition is often seen as acid rain or as ash or dry particles. Normal unpolluted rain has a pH of 5-6, precipitation is called acidic when its pH is lower than 5-6. The pH scale is logarithmic, pH1 is x10 more acidic than pH 2, and x100 stronger than pH 3. Acid deposition can have direct or indirect effects on soil, plant and water: Direct - Weakening tree growth and killing plant life - Decreasing the pH of water and altering the realised niche of aquatic organisms - Limestone buildings react with this acid and dissolve Indirect  - Increased solubility of metal ions such as aluminium which is toxic to aquatic life and plant roots - Leaching of nutrients and reduction of soil fertility Unit 7.1 Climate change and energy production Discusses the term of energy security and how many countries like Spain depend on other states for their energy. In Spain alone around 74% of the energy used in Spain comes from other states such as Russia, Nigeria, Saudi Arabia and Mexico. This in hindsight can be a problem since falling out with the country or if fuel prices increase and Spain can’t afford all the energy needed to power the country. Take for example the Russia Ukraine war, most countries imposed trade sanctions on Russia but states like Spain that depended on Russia for oil and petrol production were at risk. Therefore many citizens complained about the huge rise in petrol prices due to this indo-european conflict. Energy sources are divided into non-renewable and renewable types, each with pros and cons. Fossil fuels are cheap and abundant but unsustainable and major contributors to global warming. Shale gas offers economic benefits but involves harmful fracking processes. Nuclear power generates large energy outputs with minimal emissions but poses risks of radioactive waste and rare catastrophic accidents (Italy voting against nuclear power because of chernobyl). Renewable sources like geothermal, hydroelectric, biomass, solar, and wind are sustainable but often expensive to implement and may have environmental or location-based limitations. Energy choices depend on availability, sustainability, technology, cultural attitudes, political factors, economic costs, and environmental impacts. Unit 7.2 Climate change, causes and impacts Weather refers to short term atmospheric conditions while climate is the weather of a specific region averaged over a long period of time. Climate change is a long term change and has always happened, factors that influence climate change; - Fluctuations in solar insolation affecting temperature - Changing proportions of gases in the atmosphere released by organisms Greenhouse gases reduce heat loss from the atmosphere, the more greenhouse gases the less heat is lost. The system changes in a dynamic equilibrium which may stabilise or reach a new equilibrium after a tipping point. It’s key to highlight that the global average temperature is increasing although there are fluctuations. Climate change is a complex issue with far-reaching and interconnected impacts on ecosystems and human societies. Uncertainty about feedback mechanisms, the extent of warming, and the distribution of effects complicates solutions. Changes in water availability, shifting biomes, and biodiversity loss threaten agriculture and habitats, while rising sea levels endanger coastal regions and ecosystems. Ocean acidification disrupts marine life, and warmer temperatures increase the spread of diseases like malaria. These challenges, compounded by conflicting environmental value systems, highlight the urgency of global cooperation and action. Positive feedback: Negative feedback: Unit 7.3 Climate change, mitigation and adaptation Mitigation involves reduction and or stabilisation of greenhouse gas emissions and their removal from the atmosphere. Adaptation is the adjustment in natural or human systems in response to actual or expected climatic stimuli or their effects, which moderates harm or exploits beneficial opportunities. There are different mitigation strategies: - Stabilising or reducing GHG (greenhouse gases): reduction of energy consumption, improving efficiency of energy production, alternative energy and reducing methane and nitrous oxide emissions from agriculture. - Removing carbon dioxide from the atmosphere (CDR): increasing the amount of photosynthesis, carbon capture and storage, using more biomass. - Geo-engineering: building with light coloured roofs to create albedo effect, deflecting solar radiation There are also various adaptation strategies: - Flood defences - Vaccination programmes against waterborne diseases - Desalination plants, reservoirs and dams - Planting crops and changing agricultural practices - Manage the weather with cloud seeding or planting trees for more evapotranspiration The Kyoto protocol (1997) was a UN conference with 160 countries after years of planning and informing countries on climate change. This protocol constituted the first ever legally binding documents to reduce global carbon dioxide and other GHG emissions. The headline results tell us that between 1990 and 2012 the original Kyoto Protocol parties reduced their CO2 emissions by 12.5%, which is well beyond the 2012 target of 4.7%. Moreover, countries instituted terms such as carbon emissions trading where countries that surpassed the limit of GHG emissions could buy credits from other countries in order to maintain this reduction of emissions. Doc nuevo de case studies: https://docs.google.com/document/d/1zW-XNNEXYLT-PStOWI0ZCa91cE1dxJTbZ2g WNG4Ymw8/edit?usp=sharing https://docs.google.com/document/d/1a5YHBzSsYMqRXZQF-jDqpNu0EblPtlhlu-lRl1 U78Qg/edit?tab=t.0 Methane comes from industrial applications, fossil fuels, livestock and farming, decomposition of food waste Paper 1 2020 november