Earth's Life Support Systems

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Carbon And Water cycles. Start: more co₂ from human activity acts as greenhouse gas more greenhouse gasses. releases gas into the atmosphere more co₂, water vapour, water goes Clouds and back in to methane in the atmosphere co₂ back into Global temps rise. warms tondra warming tundra releases more CO₂ + methane atmosphere water evaporates from ocean's surface atmosphere Dissolved CO₂ warms oceans. released by warmer oceans. increased oceanic more energy for evaporation warm water less able to dissolve CO₂. IMPUES, DEPUTES & STORES of Water 3 main stores are: 0 Atmosphere (water vapour) • Oceans • land (cryosphere + terrestrial) oceanic water there are 5 oceanic bodies of water and several smaller seas that cover around 71% of the Earth's surface. The Pacific Ocean is the largest ocean. Cryospheric water composed of sea ice, ice caps, ice sheets, alpine glaciers and permafrost. Mainly in high-altitude and high-latitude areas. Terrestrial water Rivers, lakes, wetlands, groundwater, soil water and biological water. Sedimentary rocks (60-100 million Gt) Atmospheric water the most common form wing-1- water within Rivers 17. is water vapour. It is important as it absorbs and reflects incoming solar radiation. warm air holds more. water vapour than cold air - a small increase in water rapour will lead to an increase in atmospheric temps (positive feedback). ocean deep layer (38.000 Gt). terrestrial biomass (560 Gt) water is held in these stores for varying amounts of time. Eg. a water molecule is held in the atmosphere for around 9 days. The sizes of the words land and ocean stores are here. Carbon stores/sinks. All water fossil fuels (4130Gt) Ground water 20% lakes 52% oceans -97% freshwater 3%. fresh water: ///// Carbon Stores !!!! The majority of carbon (99.9%) is stored in sedimentary rocks. (at = Giga tonnes, 1 at = 1 billion tonnes). ice caps + glacier's -79% Surface fresh water - 17. Surface fresh water: Soil moisture 38% Atmospheric water vapour -8% atmosphere (600Gt) Soil (2300 Gt) Ocean surface (700 Gt) Lithosphere - sedimentary rock. deposits (limestone, dolomite, chalk) and fossil fuel deposits. Hydrosphere. (oceans) Surface layer-photosynthesis by. plankton. Intermediate + deep layer-carbon passes through marine food chains + sink to floor, where it's decomposed into sediment. Living +dissolved organic matter. Calcium carbonate shells in marine life. Atmosphere - co₂ gasses in the air is a 'trace' gas counting for 0.04%. of atmosphere, but this doesn't reflect it's importance to life on Earth. CO₂ is a potent greenhouse gas that helps regulate Earths surface temperature. Terrestrial/Biosphere - organic matter in soils, plant litter, soil hummus and peat. As organic molecules in living and dead organisms. Characteristics WATER CYCLE 2 Moisture Leaves the atmosphere as precipitation and condensation. water is released from ice cover by ablation and sublimation. of the ↳ Inputs and outputs of water form the ↳ Runoff transfers water from land surface. water cycle budget. Evaporation from oceans, souls, lahes + rivers and transpiration from plants are inputs of water into the atmosphere (together = evapotranspiration) to rivers which flow into the sea. some precipitation infiltrates the soil and becomes groundwater flow. Some water may perlocate deeper into rock stores (aquifers). -terrestrial /fast carbon cycle. This relates to the uptake of CO₂ from the atmosphere by plants during photosynthesis.co is released back to the atmosphere during plant and animal respiration and CO₂ + methane are released back during the decomposition of dead organic matter. The cycling of carbon between the soil, vegetation and atmosphere is relatively rapid and is sometimes referred to as the 'fast' carbon cycle. oceanic carbon cycle Carbon is held in a dissolved form in the ocean. water and in the tissues in oceanic organisms. inputs and outputs occur through gas exchange. with the atmosphere and through an input of organic carbon + carbonate ions from continental run-off. Due to the large size of the oceanic cycle, small changes have a large, global impact. ocean sediments are an important long-term carbon store. C02 CO₂ Respiration Characteristics OF THE CARBON CYCLE The carbon cycle has four sub-systems: Death Decaying organisms Decaying organisms •Slow carbon cycle. This refers to the cycling of carbon between. rock stores and the atmosphere and oceans through the process of weathering over millions of years. Weathering of rocks on land creates a net carbon sink in the oceans. Here, organisms use it to create shells. When these organisms die the carbonate sediment forms limestone. This long-term carbon cycle is released to the atmosphere by volcanic activity. ·atmospheric carbon cycle. Atmospheric carbon occurs as co₂ and methane. Methane is a more powerful greenhouse gas but is short lived in the atmosphere. Co₂ is removed from the atmosphere through interactions with the terrestrial and oceanic carbon cycles (e-g. photosynthesis or water absorption. Store of co₂ in the atmosphere Respiration Death. carbonification, Slow production of fossil fuels Peat oil ceal + gas Photosynthesis Combustion PROCESSES of the WATER CYCLE evaporation + transpiration These are physical processes where Liquid becomes. gas. Heat energy is required, provided either by the movement of water or by solar energy, as well as air which is not saturated and therefore can therefore absorbo evaporated water molecules. Transpiration is a biological process where water is lost from plants through stomata. Together the two processes are referred to as evapotranspiration factors effecting this include: temp, humidity, wind and climatic factors such as hours of sunshine. cloud formation Clouds are visible masses of water droplets or ice crystals held in the atmosphere. They form by: conduction causes a mass of air to warm faster than the air around it, causing it to rise by convection because it is less dense than the air around it. The atmosphere is called unstable here. 2. As air rises it cools, due to it expanding as it rises (cools 10°c for every km risen). This is due to the air being drier (aka. dry adiabatic lapse rate ~ DALR). 3. Air continues to cool until reaching dew point where water vapour condenses into clouds. 4. Condensation releases latent heat and the air becomes saturated with water. Air is still rising. but this slows the rate that the air cools (now 7°c per km) aka saturated adiabatic lapse rate. 5. The air mass continues to rise until it's the same temperature as the surrounding air. Atmosphere is now described as stable and is at the top of the cloud. condensation A physical process where gas becomes a liquid. It happens when air cools and is less able to hold water vapour. In the cooling process, water molecules condense on to nuclei (dust or smoke) or Surfaces (grass) to form water droplets or frost... Precipitation occurs when the air can no longer hold the condensed water. Causes of precipitation Condensation and cloud formation can be the result of conduction and convection. Precipitation produced in this way is called convectional rainfall. Air may also be forced to rise, cooling to form clouds and precipitation: over hills and mountains, producing orographic rainfall. ↳when air masses of different temps + densities meet- the warm air rises over the cool air and causes frontal rainfall. Cryospheric processes. These affect a mass of ice at any scale. including: accumilation-inputs to glacial system. from snowfall. ablation-output from glacial system due to melting. →Sublimation - ice changing directly into gas. catchment hydrology. A drainage basin is an area of land drained by a river and it's tributaries. The drainage basin water cycle... ..forms a sub-system of water cycle. is an open system. ... is composed of inputs, flows and transfers and outputs to the sea or atmosphere. Doorsers or Tur ^^ carbon cycle precipitation Atmospheric CO₂ dissolves in rainwater to form weak carbonic acid. Rising concentrations of co₂ in the atmosphere resulting from anthropogenic emissions have increased the acidity of rainfall which leads to an increased acidity of ocean surface waters. photo synthesis Plants use energy from sunlight and combine. with CO₂ from the atmosphere with water from the soil to form carbohydrates. Virtually all organic matter is formed the this. Carbon is stored (sequestered) for long periods of time because trees can live for thousands of years and resistant structures such as wood take a long. time to decompose. respiration All plants and animals release co₂ back into the atmosphere through respiration. Soil respiration involves microscopic organisms that live in the soil releasing co₂ as they respire. decomposition A process of decomposition by fungi and bacteria returns co₂ to the atmosphere. Decomposition also produces soluble organic compounds dissolved in nun-off from the land surface. Greenhouse gasses are released as a bi-product. Sequestration by plants Vegetation an Land also sequesters carbon by the process of photosynthesis. Sequestration in the ocean- · CO₂ moves from the atmosphere to the ocean by diffusion. At low latitudes, warm water absorbs co₂. At high latitudes, cold water sinks and the carbon is transferred deep into the ocean (downwelling). where cold water returns to the surface and warms up again (upwelling), it loses CO₂ to the atmosphere. In this way, CO₂ is in constant exchange between the oceans and the atmosphere. This vertical circulation is a processes called the physical/inorganic pump. •Phytoplankton also fix CO₂ through photosynthesis, and the carbon passes through the ocean food web. Carbonate is removed from the sea by shell- building organisms. When organisms die the Shells sink into deep water. The decay of manne organisms releases some carbon dioxide into the deep water. This is called the biological/organic pump. • Some material forms layers of carbon rich sediments which, over millions of years turn. into sedimentary rocks. weathering • weather breaks down rocks on surface. Small particles carried to ocean along with plant + Soil particles. Large particles left on shore. The sediment accumulates in layers and eventually shale rock is formed due to surface pressure. - In the ocean, dissolved sediment mix with sea water and are used by marine organisms to make skeletons/shells containing calcium carbonate when these organisms die, carbonate collects on ocean floor and sedimentary rock is formed