Global Climate Change Flashcards
What is weather
the short-term condition of the atmosphere at a given place and time. This is done by measuring changes in daily temperature, precipitation, wind speed, atmospheric pressure and cloud cover
What is climate
the long term average weather conditions for a location, calculated over long term periods of time
What is climate variability
refers to the year to year variation in monthly or seasonal conditions
What is climate change
the long term shift in area’s climatic conditions
What are three ways heat is distributed
Transmission: this is when heat energy passes through transparent materials,
Reflection: This heat energy bounces off and is reflected off a surface
Absorption: this is the heat energy that is retained by various substances
What is abledo
the reflectivity of a surface
What are three ways heat is returned to space
Terrestrial Radiation: After heat energy has been absorbed, it is transferred back to space it is transferred as longwave terrestrial radiation.
Conduction and convection: this is when the cool air warms up due to the warm land, this heats ups and expands causing it to rise causing convection currents
Evaporation and condensation: this is the heat required to turn water from a liquid to a gas, and heat remains in the air
How do the seasons effect the equator
- During the summer solstice for the southern hemisphere the heat equator exists of the Tropic of Capricorn.
- During the winter solstice the heat equator is located over the Tropic of cancer.
- There are also the spring and autumn equinox, this is when the sun’s rays pass exactly across the equator.
What is a heat equator
The heat equator refers to the point on the earth that is closest to the sun, which receives the most insolation.
What is anthropogenic climate change
human induced climate change
How does the heat equator affect climate
As the heat equator moves between the two tropics, that is why this area is generally the hottest part of the earth’s surface.
What is the angle of incidence and how does it affect climate
the angle at which insolation hits the sun, angle the angle of incidence changes it will affect how much the heat is dispersed and how much atmosphere it will have to pass through.
Where are the 4 main areas where high rainfall occurs and briefly explain why
low latitudes - because the strong heat from the sun creates evaporation
mid-latitudes - when cold air moves across which pushes the warm air up and clouds
coastal areas - more water is evaporated
windward slopes - moisture filled air forced to move up over landforms where the increasing altitude results in decreasing temperatures, the moisture condenses and rain is produced
What are 4 areas that have low levels of rainfall and briefly explain why?
- high pressure: because the warm air sinks down so there is no evaporation
- high latitude: doe to lack of evaporation because of the angle of incidence
- inland areas: due to lack of evaporation
- Leeward slopes: due to orographic rainfall there is now dry air
What are 3 areas of high temperature and briefly explain why
low latitudes: due to the angle of incidence so they receive the most sunlight (temp is slightly reduced by the clouds and rainfall)
subtropical zone: high amount of insolation and high pressure area
low albedo areas: more heat is absorbed and less is reflected increasing the temperature
What are three areas of low temperature and briefly explain why
- areas of high latitude: due to the angle of incidence there is reduced evaporation
- areas of high albedo: as increased insolation is reflected/not absorbed
- high altitude: because the atmosphere is thinner and cannot retain heat
What is the heat budget
The balance between the amount of incoming solar radiation and outgoing longwave terrestrial radiation
What is the heat budget
The balance between the amount of incoming solar radiation and outgoing longwave terrestrial radiation
How is insolation distributed
30% is reflected, 19% is absorbed by the atmosphere, 51% absorbed by the land and ocean
How does insolation differ from long wave radiation
the incoming solar radiation is much higher in energy and can therefore easily pass into the atmosphere however the terrestrial long-wave radiation cannot easily pass through or exit the atmosphere as there is less energy
How is long wave radiation distributed
70% is absorbed by the surface and atmosphere which is transferred backt o space through water vapour, conduction/convection, absorbed by greenhouse gases, some leaves through the atmospheric window.
What is the difference between insolation and long wave terrestrial radiation
it enters as short-wave radiation which has a lot of energy so it is easily able to pass through the atmosphere, terrestrial long wave radiation which has a lot less energy which makes it hard for it to pass through the atmosphere so it gets trapped.
What is the natural greenhouse effect
when gases in our atmosphere (known as greenhouse gases) retain heat and keep the planet warm, due to the terrestrial longwave radiation which is much slower to exit the atmosphere
What are the factors that affect variability in earths climate (LAPDOG)
Latitude - the distance from the equator
Altitude - height above sea level
Prevailing Winds - wind that constantly blows in a direction
Distance from the ocean - affects clouds, rainfall and wind
ocean -the movement of seawater
great barriers - the orographic rainfall effect which effects rainfall and moisture.
What is the hydrological cycle and what is it driven by
The hydrological cycle is the continuous movement of water as a liquid, gas and solid through the lands, ocean and atmosphere it is driven by solar energy.
List the 10 different processes in the hydrological cycle?
evaporation, condensation, virga, precipitation, sublimation, deposition, run-off and snow-melt run off, ground water, transpiration
What are different processes of evapotranspiration?
evaporation - this is when water changes from liquid to a gas
transpiration - this is when water is evaporated from the pores of the plant
sublimation - this is when snow is directly evaporated
virga - this is when precipitation is evaporated befor eit reaches the ground
What are the different processes when water is returned to earth?
precipitation - when enough liquid has condensed due to gravity the water will fall from the clouds, back to earth
deposition - When snow falls
What is condensation and describe how clouds are formed?
as water vapour rises and cools, causing it to turn back into a liquid state, during this process the latent heat is released into the atmosphere. Clouds are formed when water vapour combine with particles of dust, salt and smoke to form water droplets. As the water droplets coalesce they form clouds
What are the different processes water moves on the earth’s surface?
ground water - it soaks or infiltrates into the ground, it can be collected in aquifers, layers of permeable rock that hold water
run-off - when water flows across the earths surface
snow-melt run-off - when snow melts and flows across the earth’s surface
What is an example of how alterations to the hydrological cycles can effect climate?
changes in temperature have altered the spatial distribution of weather patterns which can be seen in lake cargengie which usually only gets 235mm per year, however recently they received 270mm in one day
What is the carbon cycle?
The carbon cycle is the continuous movement of carbon compounds between the lands oceans, atmosphere and living organisms
Describe the ocean processes involved in the short term carbon cycle.
carbon dissolve into the water, it then sinks to the bottom of the ocean to form a sedimentary layer, some is taken back ot the surface via ocean current which can can then be evaporated back into the atmosphere
Describe the land processes involved in the carbon cycle
green plants remove CO2 from the atmosphere through photosynthesis
As well there is the production of CO2 as it is a byproduct of cellular respiration.
As well the decaying or burning of plants releases CO2.
How does carbon dioxide affect climate?
CO2 is an important greenhouse gas as it helps the earths atmosphere retain heat which increases earth average surface temperature
Provide 2 examples of how carbon affects the climate
since the Industrial revolution the amount of CO2 in the atmosphere has increased by 48% and the global surface temperatures have risen by 1.1 degrees Celsius, as well the pH has gone from 8.2 to 8.1
What are natural causes of climate change?
The amount of solar energy and volcanic energy
Explain how sunspots form and how they affect climate
the solar output changes over an 11 year cycle, a sunspot is a sudden burst of energy formed by a magnetic storm causing the magnetic field to break, more sunspots increases the amount of insolation earth receives.
Provide an example of sunspots
during the 1950s where over 150 suns spots were observed which can partially explain the increased warming and heat waves that occurred during this time
How do volcanoes affect the climate?
eruptions send gases and ash into the air where they are dispersed around the globe, the SO2 reacts with the water to produce H2SO4 which reflects the sun’s energy back into the atmosphere, this can last for a long time - while the CO2 can provide a inor short term warninf
provide an example of how volcanoes affect climate
Tambora is a large volcano in Indonesia. Its eruption in 1815 was almost the most explosive ever recorded. . Its released 150km cubed of ash and gases into the atmosphere. As a result of the eruption, global temperatures fell 0.5 degrees in average. In Europe 1816 was ‘the year without a summer’:
What are two anthropogenic causes for climate change?
agriculture (rice cultivation and livestock) and deforestation
Explain how rice cultivation causes climate change
rice require the paddock to be flooded which cuts off the supply of oxygen causing anaerobic respiration. The soil starts to break down and with the help of methanogen archaea methane is produced as a by product
Give an example of how rice cultivation affects climate
Globally the cultivation of rice contributes 10 percent of global methane emissions as between 50 to 100 million tonnes are produced by rice cultivation per year.
How has livestock affected climate?
during digestion methanogen archaea breaks down the grass and methane is produced as a by-product, this is released through belching or through flatulence.
Provide an example of how livestock contributes to climate change?
livestock contributes to almost 13% of total national greenhouse gas emissions, and 25% or methane emissions.
WHat is deforestation?
Deforestation is the clearing of forests and natural vegetation on a large scale for agriculture and urban settlements.
Explain the 3 ways deforestation contributes to climate change
- trees are major carbon sequesters, by removing trees we are increasing amount of carbon in the atmosphere as it can no longer be stored
- decaying and burning of the biomass causes the release of the carbon into the atmosphere
- increased albedo of the forest floor decreases evapotranspiration which reduces rainfall
Give an example of how deforestation affects the climate
The global loss of forests contribute an extra 4.8 billion tonnes of CO2 to the atmosphere and In WA there has been a 20% decrease in rainfall due to large scale farming
Describe deforestation in the amazon rainforest
due to clearing of the rainforest through burning techniques. It is estimated that the amazon has emitted 13% more CO2 than it has stored in the past 20 years, this has resulted in more severe droughts and heat waves
What is evidence for the increased rate of climate change?
the annual rate of concentration of CO2 increase in the past 70 years has been 100 times faster than ever seen before
What is evidence of climate change over geological time and how do they work?
Ice cores - We can use the bubble that are trapped in the ice, as well as the location and thickness, oxygen isotopes, and dust particles in the ice which allow you to determine the atmospheric composition and weather conditions.
What are two examples of ice core?
- Vostok ice core, this was taken at the Russian Vostok Station in Antarctica in 1987, they drilled an ice core that was over 3000 m deep
- another ice core drilled in Antarctica which found that 69 gigantic volcanic eruptions occurred during the last ice age
What is evidence for climate change in recent human history and how does it work?
atmospheric concentration - these can be used by taking samples or remote sensing techniques
Give an example of atmospheric concentrations that suggest climate change.
during the 1750s the concentration was record at 278ppm whereas during March 2022 the concentration reached 417ppm
since 1880 Earth’s average global temperature has risen by 1.1 degrees.
What is the difference between land use and land cover?
The functional purpose for which land is used is land use and land cover is The physical surface of the earth, both natural and anthropogenic
What is a feedback loop, and what kind of feedback loops exist in the environment?
A feedback loop is a self-perpetuating cycle, whereby a change in one component, is a stimulus that results in an further change in the same direction of the initial stimulus.
- bi directional –> goes both directions
Describe the ice albedo feedback loop with an example
The increase in global temperatures has caused a decrease in snow and ice cover, this results in less energy being reflected by the snow and ice and more being absorbed by the ground and water, this leads to further warming and ice melting. We are losing artic sea ice at a rate of 13% per year. And studies suggest that a quarter of global warming is due to a loss in sea ice.
Describe the deforestation feedback loop
When vegetation is cleared through deforestation and agricultural practices the surface reflectivity increases meaning less heat energy is absorbed by the earth, this results in a short term cooling effect, however there is a long term warming effect as the carbon dioxide is released into the atmosphere, there is also a decrease in rainfall as there is less evapotranspiration which results in further decline in canopies.
Give an example of the deforestation feedback loop
The amazon is now emitting 13% more CO2 than it is storing which means by 2050 the temperature will have increase by 2-3 degrees and a large decline in rainfall
Explain 4 reasons urban heat island occur and give an example
Urban heat islands are caused by lower reflectivity and albedo due to the dark surfaces,
- reduced atmospheric circulation as it is block by building
- waste heat from urban processes
- reduced vegetation which reduces clouds, shade and rainfall
some urban areas of perth can be 6 degrees hotter than the surrounding areas.
Explain the urban heat island feedback loop with an example
as temperature increases and rainfall declines (due to decreased albedo from causes trees to become stressed and more vulnerable to pest attacks and diseases such as in the Jarrah forests in the southwest Australia, which has the disease Dieback present, which reduces the tree cover and canopies
Explain using an example the carbon sequestration feedback loop.
The removal of trees reducing carbon sequestration and burning of biomass increases the level of greenhouse gases in the atmosphere, results in warming which causes trees to become stressed. In brazil modification to the agricultural practices has allowed the continuation of carbon sequestration in soil which has offset emission by 20%.
How does climate change impact the natural environment (give 4)
- Warming temperature may shift the ecological boundaries of some trees
- increase vulnerability of trees
- longer growing periods and carbon dioxide fertilization
- increase natural hazards
Explain with an example the shifting ecological boundaries.
Climate controls the spatial distribution of the vegetation, trees may shift their boundary to the poles or a higher altitude where it is cooler. This can be seen with the paper birch tree which has begun to migrate towards canada.
Explain how climate has put increase stress on trees with an example
Increase temperature puts stress on trees making them more vulnerable to pest attacks in the north America forest belt, where because of the increased temperatures, there has been increase beetle activity, they are now active for a six month period instead of the 2 week period they are usually active for
How has climate benefitted trees? Use an example.
On the other hand, the increase in temperatures has resulted in longer growing periods which has lead to additional plant growth. There has been a 14% increase in productivity of ecosystems
increase in vegetation can also be attributed to the increase in CO2 levels as CO2 is required for plants to grow NASA suggest that 70% of earths greening can be explained by increased CO2 levels.
How has climate impacted the environment in relation to hazards, use an example.
events such as droughts and fires are becoming more common An example of this was in the 2019-2020 bushfires season in Australia which burned through 20% of the country’s forests
How has climate impacted the environment in the northern hemisphere? Use an example.
Areas in the northern hemisphere will experience warmer and moister climates, meaning the agricultural growing season will increase, but they will also experience more weeds and pest attacks.
For example, Northern Russia which is expected to have 150% increase in arable land
How is climate predicted to affect the southern hemisphere? Use an example.
Areas in southern hemisphere are predicted to see a decrease in arable land due to the increase in temperature but the decrease in rainfall. The Australian Wheatbelt is expected to see a decrease in yield by 9%, this has led to farmers to move more towards the coast
