climate change Flashcards

Question

significance of filing specialised niches in a habitat

Answer 1

1. avoids or minimises competition for resources 2. results in the coexistence of a great variety of species.

Answer 2

1. 29% is reflected back to space by clouds and earth’s surfaces 2. most of the radiation is absorbed by the atmosphere, clouds, oceans and land 3. land and oceans release energy back upward through evaporation, convection and reemits lower-energy, longer wavelengths, infrared energy

Answer 3

1. increasing open water at the poles worries climatologists, as water is extremely efficient at absorbing and storing energy, while ice is able to reflect most energy back into the atmosphere. 2. open water increasingly captures and stores that energy, further acelerating ice melting, exhibiting a positive feedback loop

Answer 4

1. as solar energy hits earth, most of it is absorbed 2. energy is re-released from the earth’s warmed surface as longwave radiation in the infrared part of the spectrum 3. greenhouse gases in the atmosphere absorb and redirect some of this energy downward, keeping heat near earth’s surface. 4. some of the energy absorbed by the earth’s surface is emitted back into space as terrestrial longwave radiation, keeping near surfaces warm. 5. if the amount of incoming shortwave radiation exceeds the amount of outgoing longwave radiation, surface temperature increases.

Answer 5

1. earth’s changing orbit: changes in the tilt of the earth can change the amount and seasonal distribution of solar radiation reaching the earth’s surface. more tilt means warmer summers and colder winters, while less tilt means cooler summers and milder winters. 2. ocean-atmosphere interactions: oscillations in the ocean currents and atmospheric circulation can result in fluctuation of ocean temperatures. el nino is the warming of the ocean surface, while la nina is the cooling of the ocean surface

Answer 6

1. increased emission of greenhouse gases caused by human activities 2. includes: burning of fossil fuels, deforestation and food choices

Answer 7

1. coal, oil and natural gas are fossil fuels which were formed from the remains of living organisms by exposure to heat and pressure in the earth’s crust. 2. they are the world’s primary energy source and provide most of the energy that supports human activities 3. burning of fossil fuels contribute most to carbon doxide emissions, which adds to the greenhouse effect and increases global warming

Answer 8

1. permanent clearing of forests in order to make the land available for other uses such as agricultural activites, by either burning trees and clear cutting 2. forests act as important ‘carbon sinks’ and deforestation decreases the absorption of carbon dioxide, as well as the carbon stores in the trees is released into the atmosphere as CO2

Answer 9

1. concentration or abundance in the atmosphere: 2. atmospheric lifetime: different GHGs can remain in the atmosphere for different amounts of time 3. global warming potential: the capacity of the various GHGs to cause climate change differs because each molecule interacts with heat differently. the GWP for a gas is a measure of the total energy that a gas absorbs over a particular period of time, compared to carbon dioxide.

Answer 10

1. respiration 2. soil respiration 3. forest fires 4. volcanic eruptions

Answer 11

1. uptake of carbon dioxide by photosynthetic organisms: carbon atoms are incorporated into sugar molecules during photosynthesis 2. release of carbon doxide during respiration 3. exchange of carbon dioxide between the ocean and atmosphere 4. dead plants and animals slowly decay under high TP to form fossil fuels, and this release of carbon is accelerated via the burning of fossil fuels 5. amounts of carbon are locked up as calcium carbonate to build shells and skeletons of marine organisms from tiny protozoans to corals, which are released via volcanic eruptions 5. carbon sinks absorb and store carbon dioxide 5. anthropogenic activities have tipped the balance and altered the carbon cycle by the removal of carbon from carbon sinks

Answer 12

1. there is an annual oscillation of 5-7 ppm in CO2 concentration which reflects seasonal changes of photosynthesis and respiration in terrestrial ecosystems in the northern hemisphere. 2. CO2 levels are rising at an accelerating rate, currently more than 2 ppm per year, and we are on track to double the preindustrial concentration of CO2 which was 280 ppm in about a century’s time

Answer 13

1. transportation: includes sources such as highway vehicles, air travel and rail, as almost all of the world’s transportation energy comes from petroleum-based fuels, largely gasoline and diesel 2. industry: industrial processes that produce CO2 without combustion include the production of cement, the production of metals and the production of chemicals. the burning of fossil fuels such as oil, coal and natural gas has also introduced carbon whicch was until then stored underground for millions of years into the carbon cycle 3. deforestation: the clearing of forests create space for the cultivation of crops as feeds for farmed animals, to supply grazing land for animals or for livestock farming to feed our increasing human populations. cutting down forests releases carbon stored in standing trees into the atmosphere. organic material in the exposed soil oxidises and decays too, producing more CO2 and CH4

Answer 14

1. methane is primarily produced in nature when plant matter or organic matter deomposes in oxygen-free conditions, as in the bottom of a wetland 2. ruminant animals also provide a nice source of CH4, as a cow’s stomach has little oxygen and digestion by microbes produces CH4 which cows then burp or fart into the atmosphere

Answer 15

1. approximately 40% of CH4 is emitted into the atmosphere by natural processes, and the remaining 60% comes from human activities. 2. alarmingly, there has been an increase in atmospheric CH4 levels by 150% since industrial revolution 3. CH4 is 25 times more effective a greenhouse gas than an equivalent mass of CO2, as it absorbs much more energy per gram as CO2 does and is accumulating at a faster rate than Co2

Answer 16

1. agriculture: domestic livestock such as cattle produce large amounts of CH4 as part of their normal digestive proces in low oxygen conditions. during enteric fermentation, carbohydrates are broken down by microorganisms into simple molecules for absorption into the bloodstream of the ruminant animals, increasing CH4 emissions. with a continuing expansion of meat consumption around the world, the demand for ruminant livestock and so the size of this CH4 has grown rapidly. when animals’ manure is stored or managed in lagoons or holding tanks, CH4 is produced. lastly, when the warm, waterlogged soil of rice paddles blocks oxygen from penetrating the soil and thus provides ideal conditions for bacteria to decompose organic material in order to produce CH4 by a process known as methanogenesis. 2. industry: CH4 is released into the atmosphere during the extraction, production, storage, transportion and combustion of fossil fuels. 3. landfill waste: CH4 is generated in landfills as waste decomposes and in the absence of oxygen. Similarly, CH4 can be created in oxygen-free systems involving manure or sewage treatment

Answer 17

1. defined as the total set of GHG emissions caused by an individual, organisation, or a single event. 2. the emissions are calculated over a set period of a year, to be used as a baseline against which reduction efforts can be measured. 3. carbon footprint is often expressed in terms of the amount of CO2 emitted, or the equivalent value of other GHGs

Answer 18

1. in the last decade, the largest amounts of deforestation occurred across the humid tropics, mostly in Africa, followed by South America. 2. it is estimated that around 420 milion hectares of forest were lost between 1990 and 2020, and the annual rate of deforestation has since slowed by was still 10 million hectares per year between 2015-2020 3. deforestation contributes almost 12-20% of global GHG emissions, and as a result of deforestation and degradation, some tropical forests now emit more carbon than they capture, turning them from a carbon ‘sink’ into a carbon source.

Answer 19

1. energy-related GHG emissions account for the majority of all anthropogenic emissions, and just the generation of electricity is responsible for over 40% of all energy-related emissions 2. measurement of life-cycle GHG emissions involves calculating the global warming potential of each energy source through life-cycle assessment, presented in units of gloal warming potential per unit of electrical energy generated by that enery source. it uses the carbon dioxide equivalent and the kilowatt hour to compare energy sources fairly on a common basis as well 3. coal and oil have the highest carbon footprint, followed by natural gas, generated from combustion 4. nuclear power and renewable energy sources primarily emit greenhouse gases upstream during construction, but have a significantly lower carbon footprint 5. biofuels may be considered carbon neutral because the plants used to make biofuels absorb CO2 as they grow, offsetting the CO2 emissions from producing or burning biofuels. however, they have significant life-cycle GHG emissions from harvesting, processing and transport, creating a ‘carbon-debt’

Answer 20

1. hydroelectric power 2. solar power 3. wind power 4. biomass 5. geothermal energy

Answer 21

1. fossil fuels such as coal, coil and natural gas 2. nuclear fuels

Answer 22

1. food production is responsible for one quarter of global GHG emissions, not only from emissions from food prodution itself, but also from the enormous use of resources. 80% of the world’s agricultural land is used for crop production, and the agricultural sector consumes 70% of global freshwater resources. 2. at current rates, meat production will double by 2050 to approximately 1.2 trillion pounds of meat per year, requiring more water, land, fuel, pesticides and fertilisers especially to meet the demand is developing countries with increased prospertiy. 3. ruminants require significantly more resources such as larger grazing land, fertiliser and energy-intensive fed and they generate more manure than other farmed animals 4. livestock production requires large quantities of harvested feed, and thus substantial areas of forests has to be cleared, leading to deforestation. in addition, significant quantities of nitrogen-based fertiliser are applied to maintain the cropland. N2O is a potent GHG which is a major component of fertilisers. 5. meat processing also includes freezing and packaging and electricity to run the plants and pump huge quantitives of wstewater is the main soource of GHG from slaughterhouses 6. transported-related emissions comes mainly from fossil fuel combustion and transporting animals, supplies and retail food products domestically to and from farms, slaughterhouses and stores produces about 10% of meat’s carbon footprint. as such, buying locally can significantly reduce the climate impact of vegetable production, but has a relatively smaller impact of meat. 7. discarded food accounts at least 20% on average of the emissions associated with producing, processing, transporting and consuming meat and dairy products. most of the emissions attributed to waste come from producing food that is ultiamtely discarded such as growing feed and fertiliser production. the source of these emissions is the methane produced during decomposition at landfill waste

Answer 23

1. explosive volcanic eruptions inject aerosols into the stratosphere, where they may be suspended for several years. 2 2. sulfate aerosols are formed when SO2 emitted by eruption volcanoes combines with water, in turn reflecting incoming solar radiation back to space, and reduce solar energy that would warm the earth’s surface 3. this contributes to a decrease in global temporature which cools the earth’s surface, but only lasts until the volcanic particles are cleansed from the atmosphere after several years 4. however, short term temperature effects that arise from natural factors cannot explain the long-term warming trend over the past few decades

Answer 24

1. ice sheets are known as continential glacier, 2. It is constantly moving under its own weight and covers the land surrounding it, spanning greater than 50,000km 3. they are formed in areas where snow that falls does not melt entirely over the summer 4. ice sheets contain more than 99% of the freshwater on earth

Answer 25

1. rise in sea level - polar ice caps start to shrink as they melt and break apart, and extra water enters the ocean 2. long term decline in freshwater resources - warming causes polar ice caps to melt into the sea which turn freshwater into seawater, decreasing water availability 3. accelerated warming from albedo - sea ice is white, so nearly all the sunlight that hits sea ice is reflected into space. when the climate has melted sea ice, it exposes dark, open waters, dramaticaly shifting the ocean surface from highly reflective to one that absorbs most of the sun’s energy. this leads to a positive feedback loop where ice loss can lead to further warming of the ocean surface, leading to more ice loss 4. severe threats to polar communities - the sea ice insulates the water beneath it, keeping it from becoming too cold, supporting algae, invertebrates and fish which live beneath it. sea ice also provides breeding and hunting grounds for marine mammals, and this forces them to remain on tundra, where they must fast and survive on reserves of fat due to insufficient food. the retreat of sea ice has also decreased the available platforms that seals and walruses use to rest on.

Answer 26

1. thermal expansion of seawater - as the land and lower atmosphere warm, heat is transferred into the oceans, and water becomes less dense 2. the melting of continential ice adds extra water into the ocean, and current ice models suggest that such a warming could lead to the eventual irreversible melting of the greenland ice sheet

Answer 27

1. threats to coastal communities - most of the world’s largest urban areas are on coastlines. due to destructive erosion and flooding, entire beaches can be washed away w the coastline, putting lives and money at stake. for people in low-lying islands, an additional 50cm rise in sea level could submerge these islands and make them more vulnerable to storm events. this can also have devastating effects on coastal habitats, such as coastal wetland flooding, agricultural soil contamination, and eventually lost habitat for fish, birds and plants 2. saltwater intrusion - saltwater intrudes into fresh groundwater drinking supplies, and many island nations will have their supplies of drinking water reduced. saltwater also contaminates irrigation supplies or overruns agricultural fields.

Answer 28

1. decrease in availability of freshwater - warming leads to the melting of glaciers and snowpacks, which increases water supply to rivers and lakes initially, and results in floods and long drought periods. eventually, warming causes polar ice caps to melt into the sea, turning scarce freshwater into seawater 2. increases rate of evaporation of water into the atmosphere - this may dry out some areas and fall as heavier rainfall on other areas. at higher temperature, more precicipation will occur as rain rather than snow, leading to more rapid movement of water from the atmosphere back to the oceans, reducing out ability to store and use it. heavy rainfall increases the amount of runoff into rivers and lakes, reducing the quality of water. freshwater regions along the coasts also face risks from sea level rise, known as saltwater intrusion which is the encroachment of saline water into fresh groundwater regions, decreasing freshwater supplies and increases the need for desalination 3.

Answer 29

1. a period of several days to weeks of very high temperatures (at least 5 degrees celcius above from average), resulting in abnormally hot weather 2. heat waves are likely to increase in frequency, intensity and duration over the next few decades as large parts of NA, europe, australia and africa continue to warm

Answer 30

1. combination of high humidity and high night-time temperature offers no relief and poses a particular threat for infants and the elderly who are unable to escape the persistent and oppressive heat 2. high temperatures at night can be damaging to agriculture, as some crops require cool night temperatures 3. heat stress for livestock rises when animals are unable to cool off at night, leading to decline in milk production, slower growth and reduced conception rates 4. low-humidity heat waves may result in droughts and wildfire

Answer 31

1. as temperature increases, the air becomes warmer and evaporation from oceans, lakes and soil increases, putting more water vapour into the atmosphere to produce more intense precipitation 2. however, this extraprecipitation is not evenly spread around the globe, and some places might have more intense precipitation

Answer 32

1. heavy rain increases the amount of runoff into rivers and lakes, washing sediments, nutrients, pollutants, trash, animal waste and other materials into water supplies making them unusable 2. increases in heavy rainfall have also led to a higher incidence of floods 3. heavy rainfall are likely to be especially harsh for regions like bangladesh which is already facing the pressures of rising sea level 4. further increases can lead to degraded water quality and the spread of water-borne diseases

Answer 33

1. invertebrates which live in compact colonises consisting of many identical soft-bodied organisms called polyps 2. corals use their tentacles to sting and capture microscopic organisms such as plankton 3. each colony excretes a calcium carbonate exoskeleton beneath it to build a structure of a coral reef 4. corals grow in warm, clear shallow waters that receive plenty of sunlight

Answer 34

1. zooxanthellae provide corals with food by using light energy to produce glucose, glycerol and amino acids to provide most of the coral’s food and nutrition requirement. the corals use these products to make proteins, fats, carbohydrates and calcium carbonate 2. coral provides nutrients for zooxanthellae such as inorganic nitrogen and phosphorus from the waste products of the coral polyps’ metabolic processes 3. coral produces compounds which offer the algae protection from UV radiation

Answer 35

1. corals are very sensitive to temperature changes, as photosynthesis in the zooxanthellae is disrupted at higher than usual temperature and they no longer produce food for the corals. this affect sthe metabolism of coral polyps, and the exoskeleton of corals are exposed. corals turn white as zooxanthellaes give corals their colour, and they are weak and less able to combat disease 2. rising concentration of CO2 has led to an increase in absorption of CO2 in the ocean, and it is transformed into carbonic acid, which makes the water acidic and less conducive for coral growth. corals cannot absorb calcium carbonate to maintain their exoskeletons and the stony skeletons that support corals will dissolve

Answer 36

1. protect shorelins from being damaged by winds, waves and floods 2. prevent erosion along coastlines stabilising sediments, which become trapped in the dense root system 3. act as nurseries for many marine species 4. provide habitate to endangered species 5. mangrove roots trap and filter sediments, enhancing the quality of coastal waters

Answer 37

1. mangroves are sensitive to changes in flooding duration and frequency as well as salinity levels that exceed a species-specfic physiological threshold of tolerance. leading to plant death at the seaward mangrove margins and shifts in species composition leading to a reduction in ecosystem services 2. extreme weather events such as cyclones can substantially intensity wave activity at the seaward margins uprooting trees and break branches and defoilate the canopy 3. extreme changes in precipitation alters the seasonal average salinity in some mangrove systems, while an increase in evaporation leads to increases in soil salinity and decreases in seedling survival 4. higher air temperatures stress mangroves at their warmer latitudinal limits

Answer 38

1. provides coastal protection by creating a natural barrier that stabilises the sediment 2. cover 0.1% of the ocean bu account for more than 10% of the oceans’s global carbon storage, known as blue carbon storage 3. serve as feeding and breeding grounds for many marine species, playing a role in supporting marine food webs 4. filter water by trapping suspended particles in the water, improving water clarity and quality

Answer 39

1. rising sea temperatures can stress or kill seagrass plants, as these species have limited tolerance for thermal variations 2. ocean acidification impairs their photosynthetic processes, reducing growth and resilience 3. as sea levels rise, the depth, light availability and substrate conditions in seagrass habitats are being altered, forcing these plants to adapt to rapidly changing environments

Answer 40

1. reduced carbon sequestration 2. reduced coastal protection 3. reduced fisheries support 4. increased shoreline erosion and landward retreat 5. habitat loss

Answer 41

1. fish move either north or south towarsd the poles, and puts these species into competition with other species over food and resources 2. commerical fishes may be affected if fishermen have difficulty catching the fish population, as it has an indirect effect on food security. global fisheries were increasingly dominanted by warm-water specis as a result of fish migrating towards the poles in response to rising ocean temperature 3. runoff from the melting mountain snowpack arrives earlier since winters are becoming warmer and shorter, and this disrupts the migatory behaviour and timing of species, impeding their ability to orient themselves for effective navigation

Answer 42

1. increasing temperatures contribute to a poleward migration of many insects so that they can remain within their temperature tolerance ranges to adapt 2. to escape the cold winters, millions of monarch butterflies from across the US begin a southward migration during autumn to central mexico where it is warm. 3. crop pests and diseases are moving toward poles at about the same speed as warmer temperatures, suggesting that climate change is driving their relocation, raising major concerns about food security 4. mosquitoes and other disease carrying bugs are thriving in parts of the world that are warmer due to climate change

Answer 43

1. microbes decomposes organic matter to release the stored carbon in the form of CO2 and CH4, which are powerful greenhoe gases 2. the active layer of permafrost has been found to be getting larger with time, and the extent of permafrost itslef has been seen to decline 3. a positive feedback loop between permafrost melting and cliamte change exist. as the atmosphere warms, permafrost melt which releases greenhouse gases

Answer 44

1. mangrove’s dense canopies and woody biomass capture large amounts of carbon above ground 2. mangrove’s roots slow tidal waters and trap carbon-rich sediments that would otherwise be carried away 3. when mangrove leaves fall into the water, they settle into these layers of sediment, along with decaying roots and other organic matter 4. mangrove’s grow in waterlogged soils, which are oxygen poor and slow decomposition, hence the carbon remains locked away for extensive periods of time

Answer 45

1. mangroves absorb the force of storm surges and waves, reducing wave height by more than 66%, and can even weaken tsunami waves. 2. the interlocking mangrove roots and branches interrupt rising water and large waves, protecting people, homes, and business infrastructure from powerful storm surges 3. mangrove’s intricate roots also stabilise shorelins, mitigating beach erosion, and helping shorelines rebuild and recover naturally after extreme weather events

Answer 46

1. mangroves serve as breeding grounds, nurseries and habitats for a variety of marine and terrestrial species. by supporting the juvenile stages of these species, mangroves help sustain fish populations and fisheries, ensuring food security for human communities 2. contributes to the stability and resilience of ecological communities which is crucial in adapting to and recovering from the effects of climate change. the ecosystem can better withstand and recover from disturbances, such as extreme weather.

climate change Flashcards

(72 cards)