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
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?
climate patterns in the Pacific Ocean
What is the effect of El Niño on rainfall in East Asia and Australia?
Less rainfall and the possibility of drought
What is the greenhouse effect?
The role of greenhouse gases in warming the earth
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 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.
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.
What is a likely consequence of warming oceans on ocean circulation?
Disruption of ocean circulation systems
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 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
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 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 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
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 Myres (Environmental Scientist)?
Approximately 150 million.
What may be required to manage the issue of environmental refugees?
International cooperation and collaboration may be required.
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
Outline how climate models work
Climate models work by dividing the Earth into a 3D grid made up of many small cells, which cover the land, ocean, and atmosphere. Each cell contains data on climate variables like temperature, humidity, wind, and pressure. The cells interact with each other, allowing the model to simulate how weather and climate patterns move and change over time. Scientists use mathematical equations to represent processes like energy transfer and fluid movement within each cell. These models update in steps to show how conditions might change in the future, and powerful supercomputers are used to run all the calculations needed to predict climate changes over years or even centuries.
