7.2 Climate Change: Causes and Impacts Flashcards
climate definition
describes how the atmosphere behaves over relatively long period of time
weather definition
describes the conditions in the atmopshere over a short period of time
What are both weather and climate affected by?
- atmospheric circulation
- ocean circulation
- latitude
- altitude
- distance from sea
- prevailing winds
- human activities
Why does more radiation reach the equator than the Polar Regions?
Due to the curvature of the earth
What causes ocean circulation systems?
Winds and difference in water temperature and salinity
What occurs when air is warmed?
Low pressure is created as it expands and rises
What happens when air cools?
High pressure is created as it contracts and descends
What creates wind?
Movement of air from high to low pressure
What is the tricellular model used for?
To explain transfer of heat through the atmosphere
Name the three cells in the tricellular model.
- Hadley cell
- Ferrel cell
- Polar cell
What happens to air in the Hadley cell as it rises at the equator?
It cools with altitude and stops rising further
What causes the deflection of air in the Hadley cell?
Coriolis force caused by the rotation of the earth
Where does air from the Hadley cell typically descend?
At about 30°N or 30°S of the equator
What characterizes the subtropical high pressure region?
Sunny and dry conditions
What happens to air as it moves from the Hadley cell into the Ferrel cell?
It picks up moisture as it crosses the sea
What is formed when warm air from the Ferrel cell meets cold air from the pole?
A region of low pressure associated with high rainfall
What is the polar front?
The boundary where warm air meets cold air at about 60°N or 60°S
What happens to air in the Polar cell?
It descends and creates a high pressure region
How does climate in one part of the world influence another region?
Via atmospheric and ocean circulation systems
What is a key characteristic of El Niño events?
They influence weather and climate in North America and Europe
What occurs in the Western Pacific Ocean during normal conditions?
High surface water temperatures cause low pressure and heavy rainfall
What happens in the Eastern Pacific Ocean during normal conditions?
Upwellings bring cold waters to the surface, creating high pressure
What changes occur during an El Niño event?
Warm surface water extends eastwards, causing lower pressure above South America
What is the effect of El Niño on rainfall in East Asia and Australia?
Less rainfall and the possibility of drought
What happens to upwelling during El Niño?
It declines, leading to increased surface water temperatures
How often do El Niño events occur?
Every two to seven years
What is the greenhouse effect?
The role of greenhouse gases in warming the earth
What has happened to carbon dioxide levels since the industrial revolution?
Increased from 280 parts per million to over 400 ppm
What is the relationship between atmospheric carbon dioxide levels and global temperature?
Increase in carbon dioxide levels corresponds to an increase in average global temperature
What sources provide evidence for the increase in carbon dioxide levels?
- Direct measurements
- Deep sea sediments
- Ice cores from glaciers
What short term effect can volcanic activity have on climate?
It can cause global cooling
What gas from volcanic activity contributes to global cooling?
Sulphur dioxide
What main events do increasing levels of greenhouse gases in the atmosphere lead to?
- an increase in the mean global temperature
- increased frequency and intensity of extreme weather events
- the potential for long term change in climate and weather patterns
- rise in sea level
What gases have rising concentrations that contribute to higher average global temperatures?
Water vapour, carbon dioxide, methane, nitrous oxide
These greenhouse gases trap heat in the atmosphere, leading to global warming.
By how much did atmospheric carbon dioxide levels increase from 1880 to 2013?
Over 40%
This increase corresponds with a global temperature rise of 0.85°C.
What temperature increase is expected if GHG emissions are reduced and negative emissions occur?
0.3 to 1.7°C
What temperature increase could occur if high GHG emissions continue?
2.6 to 4.8°C
How will higher temperatures affect the hydrological cycle?
Increased evaporation leading to unequal rainfall distribution
Some regions may experience more rainfall while others, especially water-stressed areas, may receive less.
In which regions is the annual amount of precipitation expected to increase?
- High latitudes
- Equatorial Pacific
- Wet regions of the subtropics
In which regions is the annual amount of precipitation expected to decrease?
- Mid latitudes
- Dry regions of the subtropics
What is a likely consequence of warming oceans on ocean circulation?
Disruption of ocean circulation systems
How much did sea levels rise on average between 1901 and 2013?
19cm
What causes thermal expansion of the oceans?
Water absorbs heat and expands
What is the projected range of sea level rise by 2100 according to the IPCC?
26cm to 82cm
What factors could influence water availability due to climate change?
- Reduction in precipitation in arid regions
- Reduction in glacier or snow water storage
- Rise in sea level causing saline intrusion
What is one consequence of reduced water resources?
- Lakes and river beds drying out
- Increase in arid areas and desertification
- Loss of crops or reduction in yield
- Loss of livestock
- Migration of wildlife
- Increased risk of wildfires
- Conflict over limited water resources
- Migration of people for resources
What are some potential effects of flooding?
- Sewers overflowing
- Contamination of drinking water
- Landslides
- Injury or death by drowning
- Damage to homes
- Displacement of people
Which regions are expected to see an increase in agricultural yields due to climate change?
Mid to high latitudes
Which regions are expected to see a decrease in agricultural yields due to climate change?
Low latitude regions
What effect does increased atmospheric carbon dioxide have on plants?
May increase the rate of photosynthesis
This effect is limited by water and nutrient levels.
What impact does climate change have on pest populations?
May become more favorable for pests due to changing environmental conditions
What is one consequence of higher water temperatures on fish species?
- Death of species unable to cope
- Migration towards poles
- Change in spawning periods
What is coral bleaching?
Coral expels zooxanthellae, leading to increased susceptibility to disease
What effect does ocean acidification have on marine organisms?
Decline in reproduction and growth
Increased acidity affects biological processes and reduces available carbonate ions for shell formation.
What are the effects of climate change on ecosystems?
Ecosystems are threatened by:
* Increase in temperature
* Change in precipitation patterns
* Increased risk of flooding
* Drought conditions
* Increased risk of wildfires
* Increased spread of pests
* Ocean acidification
What is meant by range shifts in the context of climate change?
Range shifts refer to the movement of biomes with animals and plants moving towards the poles and upwards in elevation due to changes in climatic conditions.
Which species are threatened by Boreal forest expansion into tundra?
Species such as snowy owl and caribou are threatened by Boreal forest expansion into tundra.
What may happen to less adaptive species due to climate change?
Less adaptive species or those near their thermal tolerance may decrease in number and risk extinction.
True or False: Climate change can alter the timing of migration and mating in migratory species.
True
What are some ecosystems particularly vulnerable to climate change?
Ecosystems particularly vulnerable include:
* Coral reefs
* Mediterranean type ecosystems
* Sea ice ecosystems
What services do ecosystems provide that can be impacted by climate change?
Ecosystems provide:
* Provisional services (e.g. food, freshwater, timber)
* Regulation and supporting services
* Cultural services
What is the impact of storm intensity on coastal systems?
Storm intensity can cause:
* Coastal erosion
* Inundation
* Damage to settlements
* Loss of life
Fill in the blank: Over 40% of the world’s population lives in _______ areas.
coastal
What are the effects of rising sea levels on low lying coastal regions?
Rising sea levels can lead to:
* Salinization of agricultural land
* Degradation of coastal ecosystems
* Damage to inland ecosystems
* Contamination of freshwater resources
* Damage to infrastructure
How can climate change affect human health?
Climate change can affect health through:
* Insufficient water and food resources
* Degraded ecosystems
* Extreme weather events
What health problems can arise from heatwave episodes?
Heatwave episodes can cause:
* Cardiovascular problems
* Respiratory problems
* Heatstroke
What diseases may spread due to increases in temperature?
Diseases such as:
* Malaria
* Dengue fever
* Bluetongue virus
What are environmental refugees?
Environmental refugees are people who migrate due to environmental disasters leading to loss of livelihood.
What is the estimated number of environmental refugees by 2050 according to Norman Myers (Environmental Scientist)?
Approximately 150 million.
Fill in the blank: Damage to ecosystems can have a major impact on human _______.
livelihoods
What may be required to manage the issue of environmental refugees?
International cooperation and collaboration may be required.
What are some consequences of extreme weather events on health?
Consequences include:
* Injury or death by drowning
* Spread of diseases
* Malnutrition due to loss of harvest
Example Negative Feedback Mechanism within Global Warming “Increased co2 levels may increase rates of photosynthesis”
higher co2 levels -> higher temperatures -> more photosynthesis -> more NPP -> more growth of vegetation -> more co2 absorption -> lower co2 levels
Example Positive Feedback Mechanism within Global Warming “Increased snowmelt reduces Earth’s Albedo”
higher temperatures -> ice/snow melting -> more exposure of darker surfaces -> less albedo = less solar radiation is reflected back into space -> more absorption of sunlight -> higher temperatures
Examples of potential tipping points within Climate Change
- Increased temperatures in the high northern latitudes could lead to dieback of Boreal forest and their replacement with temperate forest or grasslands.
- Impact of climate change such as prolonged drought together with deforestation could lead to a stage where the amazon forest becomes savanna or desert; habitats more adapted to drought and wild fire events.
Outline how climate models work
- The Earth’s surface is divided into a three-dimensional grid of small cells
- Each cell represents a specific area of land, ocean, or atmosphere
- Climate variables like temperature, pressure, humidity, and wind speed are calculated for each cell.
- Cells interact with neighboring cells, allowing the model to simulate large-scale climate patterns.
- Equations for energy transfer, fluid movement, and chemical reactions are applied to each cell.
- Data is updated in time steps, simulating how conditions evolve over time.
- Supercomputers process these calculations to model climate changes over years or centuries.
What evidence is there to suggest that climate models are accurate?
Using **hindcasting ** -> using same models on past to see how accurate the models are
Some reasons why climate models arent 100% accurate
- Use of incomplete data sets.
- Use of data measured using different protocols and equipment.
- Yet unknown contribution of positive and negative feedback systems, such as effects of clouds on climate change.
- Yet unknown tipping points.
- Difficulty in predicting human behaviour and associated GHG emissions.
- Differences in interpretation of information from models leading to differing predictions.
What are the two broad viewpoints on climate change?
Climate sceptic and climate advocator views
These viewpoints represent opposing perspectives on the causes and implications of climate change.
Who is Martin Durkin and what is his stance on climate change?
Film producer known for the documentary ‘The Great Global Warming Swindle’ arguing that evidence for climate change is inaccurate
Durkin’s work suggests that climate change is fueled by scientists seeking funding.
What is a common argument made by climate sceptics regarding human activity and climate change?
Human-induced global warming is not proven; climate changes have always occurred
This argument suggests that warming precedes human alteration of greenhouse gas levels.
What natural phenomena do climate sceptics attribute climate change to?
Natural cycles, such as sunspot activity
These cycles are believed by sceptics to explain climate variations without human influence.
What do climate sceptics claim about the accuracy of climate change models?
They argue that climate change models are inaccurate and that impacts are exaggerated
This skepticism questions the reliability of predictions based on these models.
What is Sarah Palin known for in relation to climate change?
Her anti-climate change views
As a former Governor of Alaska, Palin’s views contribute to the climate sceptic perspective.
What do climate advocators believe about the causes of climate change?
They believe climate change is predominantly human-induced and requires major reforms to stop emissions
Advocators emphasize the necessity of action to mitigate climate change.
What type of scientific data do climate advocators cite as evidence of warming?
Data from sediments, ice cores, and direct measures
This data supports the argument that warming is occurring and is linked to human activities.
What is the current rate of global temperature increase described as by climate advocators?
Unprecedented
Advocators highlight that the current changes are unlike any in previous recorded history.
What do climate advocators say about scientific consensus on climate change?
There is a scientific consensus that climate change is occurring
This consensus includes agreement on the human role in climate change.
What do some climate advocators argue about climate change predictions?
Predictions are underestimates and do not consider tipping points
This suggests that abrupt changes may occur more rapidly than anticipated.
True or False: Climate sceptics believe that scientists manipulate results to attract future funds for research.
True
This belief underlines the sceptics’ distrust of scientific findings related to climate change.
Difference between climate skeptic and climate denier
Climate skeptic: accept climate change is happening but who dont believe it is caused by human activity
Climate denier: deny climate change is happening
