Impact of Climate Change on Animals and Plants Flashcards
explain how burning of fossil fuels linked to increasing energy change have contributed to climate change through increased emission of greenhouse gases
- burning of fossil fuels largest contributor of carbon dioxide emissions from human sources
- 3 types of fossil fuels most widely used are coal, natural gas and oil
- coal largest source of CO2 emissions, followed by oil, and then natural gas bc coal is the most carbon-intensive fossil fuel of all the different types of fossil fuels and coal is also used at a high rate
- fossil fuels used in electricity/heat, transportation and industrial sectors
explain how clearing of forests have contributed to climate change through increased emission of greenhouse gases
- diminishing carbon sink: trees act as carbon sinks by removing carbon dioxide from atmosphere through photosynthesis. when forests are cleared for agriculture, crops that are grown in place of trees are less effective carbon sinks than trees, hence they remove less carbon dioxide from the atmosphere
- burning of trees (cheap and fast way to clear forest to make way for agricultural land) during deforestation releases a lot of carbon dioxide into the atmosphere since trees are mostly made of carbon compounds
- as carbon is also stored in soil, disturbances during deforestation will lead to further carbon emissions. disturbances also lead to soil erosion and nutrient leaching, which leads to loss of plants, further reducing area’s ability to act as a carbon sink
explain how food choices have contributed to climate change through increased emission of greenhouse gases
- ruminant aminals create large amounts of methane during their normal digestion process
- as humans include meat in their diets, methane emissions from livestock farming make it the second largest contributor of methane emissions frmo human sources
- large increase in livestock populations (meat consumption increased due to increase in human population and people are increasingly affluent, and are eating more meat)
- greenhouse gas emissions from livestock production is much higher than crop production
- forests cleared for livestock farming, indirectly increasing greenhouse gas emissions
- animal production requires 10 times more land than crop production
- increase in demand for soy and cereal crops for animal feed have grown exponentially, leading to clearance of vast land area for farming
explain effect of climate change in terms of heat waves and heavy rains
- increase in greenhouse gases leads to trapping of more longwave radiation, resulting in an increase in global temperature
- extreme weather conditions (hot weather) have been happening at a higher frequency and intensity
- higher temperature results in longer duration of heat waves, more intense and frequent heavy rain, increased rate of evaporation also leads to an increase in precipitation and hence increases risks of floods and more extreme weather conditions (more floods and droughts at different parts of the world)
explain effect of climate change in terms of melting of polar ice caps and rising sea levels
- increase in greenhouse gases leads to trapping of more longwave radiation, resulting in an increase in global temperature
- increased temperature leadsd to melting of polar ice caps, exacerbating the ice-albedo feedback, further increasing temperatures
- melting of land-based ice could lead to increased sea levels, putting coastal communities at low lying countries at risk
- increase in temperature results in thermal expansion of ocean water leading to increase in sea level
explain effect of climate change in terms of stress on freshwater supplies
- increase in greenhouse gases leads to trapping of more longwave radiation, resulting in an increase in global temperature
- higher temperature results in more precipitation in the form of rain, and not snow
- more snow will melt earlier in the spring
- since less snow is available at lower elevations, less water will be available to feed rivers
- there is too much water runoff (melted snow) through early spring, when it is not needed, and hence less water runoff in summer, when it is needed
- impacts hydropower output, fish migration and water availability in the dry summer season for crops, fish and people
explain the effect of climate change in terms of release of greenhouse gases in frozen organic matter
- climate change resulted in thawing of permafrost at polar regions
- organic matter that was previously frozen in permafrost would start to decompose when permafrost thaws, releasing carbon dioxide and methane
- large amounts of methane previously trapped is released in gaseous form or in solution by rivers
explain how human activities could damage coral reefs
- human activities such as burning of fossil fuels/deforestation/food choices increases amount of greenhouse gas emission into the atmosphere
- increased greenhouse gases lead to increased temperatures of the earth surface/heat waves which leads to coral bleaching and/or death
- increased CO2 in the atmosphere increases amount of CO2 dissolved in the ocean while leads to ocean acidification which results in inability to form the calcium carbonate skeleton of the corals
- thermal stratification resulting in reduced upwelling affects nutrient fluxes and hence affect coral reefs
- shipping/fishing activities leading to coral damage
suggest how the damage to the coral reefs could affect food security
- coral reefs are important habitats to many fish species/are often nurseries for fish fry
- damage to the coral reef habitats might result in a decrease in fish stock/marine organisms
- communities/countries dependent on marine organisms/fish stock for food supplies might be affected
explain the mutual relationship between corals and zooxanthellae
- coral polyps produce CO2 and water as by-products of cellular respiration which the zooxanthellae cells use to carry out photosynthesis
- zooxanthellae produce sugars, lipids and oxygen, some of which are used by the coral polyps in respiration. zooxanthellae also gives coral polyp its vibrant colour
- light recycling of products between the polyp cells and the zooxanthellae is the driving force behind the growth and productivity of coral reefs
describe coral bleaching
- increased temperature reduces photosynthetic ability of zooxanthellae, such that even normal amounts of light overwhelms the zooxanthellae, causing them to be released from corals
- removal of zooxanthellae results in loss of nutrition and colour for the corals. as zooxanthellae is usually coloured, its absence reveals the white coral skeleton. when there is a large scale loss of zooxanthellae from the corals, coral bleaching has occurred
- corals begin to starve and will die unless zooxanthellae are restored. bare skeleton of bleached corals makes them vulnerable to rapid colonisation by seaweeks, which block light from reaching the zooxanthellae that is left and accelerating their removal from the corals. over time, corals will die
- bare skeleton of bleached corals makes them vulnerable to slow degradation, especially during storm surges
explain effect of climate change in terms of migration of fish and fishes
- large fluctuations in temperature might reduce growth and fertility rates, cause endocrine imbalance, reduce foraging range and disrupt migration patterns
- rapid environmental fluctuations may result in fish breeding and migration periods not coinciding with an abundance of food (food sources for fish use day length as a cue for hatching)
- as sea surface temperature rises, plankton are moving progressively northward where the waters are cooler, affecting the distribution of fish and marine mammals that feed on phytoplankton and zooplankton. this migration of fish and marine mammals into new areas may put these species into competition with other species over food and other resources
- blocking of waterways by human structures (dams) prevent the migration of fish to suitable habitats
- rising sea levels impact estuaries by causing some areas to become permanently covered with water
- changes to volume and timing of water flowing into the estuaries from coastal rivers will have potentially catastrophic impacts on fish migration, habitat use, breeding and food availability
explain effect of climate change in terms of insects
- higher temperatures lead to more rapid development and higher survival rates in insects in mid to high latitudes, leading to a shift in the geographical range of inssect species
- due to their relatively short life cycles, high reproductive capacity and high degree of mobility, higher temperatures may cause insect populations to grow and spread quickly over a relatively short period of time
- as winter temperatures of regions near the poles are now higher, mortality of insect species may decrease, allowing poleward range expansions
- higher temperature also advances the onset of insect life cycles for many species, as they use thermal cues to match the timing of key events in their life cycles with the changing seasons
explain how climate change affects vertical plant distribution
- as temperature increases, higher altitudes now have environments of higher temperature, that are now favourable to lower-altitude plants
- this leads to low-altitude plant species shifting its vertical distribution upwards
- higher-altitude plants which are adapted to lower temperatures may not be able to survive temperature increases/competition from lower-altitude plants, extinction of these higher-altitude species might occur