Evidence, Effects and Impacts of Climate Change Flashcards
What event indicated the beginning of the Little Ice Age?
Unseasonal cold weather around 1300, cold summers and storms at the time of the Spanish Armada.
When did the Little Ice Age occur?
1400 to 1850 AD
How much cooler were the temps in the Little Ice Age compared to today?
-2°C to -3°C on average less than the present.
Describe some of the effects of the Little Ice Age.
People froze to death Birds died on the wing Growth of glaciers closer to settlements Crop failures Freezing of rivers (Thames frost fair) and harbours (New York) Great famines Food prices rose Wages of farm workers increased Increase in crime Accusations of witchcraft (50,000 executions)
What is the importance of the Little Ice Age to climatologists?
Part of a recurring cycle.
How do ocean sediments assist in understanding past climate conditions?
Ratio of species of organisms (foraminifera).
Some are suited to warm conditions, some to cold conditions.
Direct relationship to temp.
Little Ice Age averaged 4°C colder than today.
Describe the period called the Little Climate Optimum (medieval warm period).
Allowed for greater prosperity. Temps suited for agriculture. Crops more reliable. Malaria on the decline. Population increased 40-60 million.
How did the Little Ice Age affect human development?
Population became more susceptible to disease and declined.
Describe the onset of the Little Ice Age.
Winter periods became longer and colder.
Glaciers did not retreat in summer.
Increase in the Arctic ice pack.
List the catastrophes that occurred in Europe in the 14th Century.
1315 (for 5 years) - heavy rain from the Urals to Ireland and destroyed marginal crops.
1371-1791 – 111 famines in France.
1601 - Russian famine killed 500,000.
Why was the choice of crops dangerous to the peasant’s food supply?
Cereal crops better for warmer periods and easily destroyed by cold.
Describe the effects of the famine on the population and its relation to climate.
High death rates (500,000 in Russia).
Families killed some children to preserve enough food for the rest.
Malnutrition and bubonic plague.
What were the results of the Black Death?
25 million or one-third of Europe’s population died.
How did the Little Ice Age affect the Viking Colonies in Greenland?
Colonists were not able to grow food and could not adjust to colder conditions - died out.
Identify the possible causes of the Little Ice Age?
Orbital forcing due to cycles of Earth’s orbit - long term cooling period.
Low sunspot activity reduced solar output.
Volcanic activity blocks insolation.
Slowing down of ocean conveyor belt (Gulf Stream).
Global temp cooling due to increase in reforestation (increasing the storage of CO2).
What is the Maunder Minimum and what was its effect on Europe?
1645-1715
Period of low sunspot activity
Coldest period of the Little Ice Age
How did the Europeans adapt to the conditions of the Little Ice Age?
Changed from the three-field farming system to modern farming using enclosures and the use of technology.
Global temperature cooling due to reforestation increases the storage of CO₂.
Define the Anthropocene.
Extent to which human activities are enhancing climate change
Increased rate of animal and plant extinctions since the spread of farming (8000 years ago).
Why is a hunter-gatherer existence not part of the Anthropocene.
Live as part of their ecosystems.
Devise tools to increase their effectiveness.
Restricted by the amount of plant and animal food sources available.
Why is farming part of the Anthropoene?
Clear natural landscapes.
Use techniques to intensify food production, sometimes using non-indigenous plant and animal species.
Potential for environmental destruction is greater.
Why did the Industrial Revolution rapidly increase the human footprint on the Ecosphere?
Commenced with a massive increase in burning of fossil fuels rapidly increasing CO₂ levels in the atmosphere.
Mechanised and intensified farming.
Why is CO₂ a more dangerous greenhouse gas when its ability to absorb heat is much lower than other greenhouse gases?
CO₂ is released in comparatively higher amounts compared to the other greenhouse gasses.
Define radiative forcing.
The warming (or cooling) effect produced by greenhouse gases in the atmosphere.
Give examples of greenhouse gasses.
CO₂
Methane
Halocarbons
Nitrous Oxide
Define negative radiative forcing.
The cooling trend of aerosols in the atmosphere
What factors produce negative radiative forcing and from what sources are they produced?
Occurs naturally from Sulphur in volcanic eruptions or from fossil fuel burning.
Produces Sulphuric acid in the stratosphere.
Consumer and industrial pollutants can also contribute aerosols.
List the human activities that impact on the enhanced greenhouse effect in order of their contribution.
Power stations Industrial processes Transportation Agriculture Fossil fuel retrieval processing and distribution Residential and commercial sources Land use and biomass Waste disposal and treatment
Explain how ruminant animals contribute to increased greenhouse emissions.
Accounts for 9% of CO₂, 65% of nitrous oxide and 37% of methane.
Use enteric fermentation as part of their digestion (emitting methane).
Cause soil erosion, water pollution, eutrophication and coral reef degradation.
List and briefly describe the ways in which agriculture (crop cultivation) contribute to the enhanced greenhouse effect.
Deforestation
Increases CO₂ (2% from 1999-2004)
Increases albedo (causes warming and cooling trends
Affects carbon absorption
Crops use less CO₂ than native plants
Reduces CO₂ sink of native plants
Burning biomass directly releases CO₂ into the atmosphere
Wet rice paddies release methane through the decomposition of plants
High use of fossil fuel in high yield mechanised agriculture
Define Urban Heat Island.
Caused by the increased temperatures of urban areas compared to their surroundings (up to 10ºC).
What aspects of urban areas contribute to the Urban Heat Island?
Concrete, bitumen and low levels of vegetation decrease a city’s albedo and increase the absorption of insolation.
Tends to be retained at night.
What is the possible rise in temp over the next century?
Between 1.1° and 6.4°C
What effect with the possible rise in temp have on Australia?
Temp rose between 0.2° and 1°C from 1970 to 2004
Temps could be expected to rise by more than 1°C
Define albedo.
The degree to which the Earth’s surface reflects solar radiation ranging from 0 (no reflection) to 1 (maximum reflection).
How do different surfaces vary in albedo?
Forests = 0.06-0.15 Deserts = 0.28 Icecaps = 0.85
How can changes to the Earth’s land cover affect its albedo?
Changes in land cover affect the heat budget and result in changes to global temperatures.
Deforestation and agriculture create bare soil, increasing albedo.
Loss of vegetation contributes to global warming.
List some of the potential impacts of climate change on water supplies.
Increased supplies in the tropics and high latitudes.
Decreased supplies in the mid-latitudes.
List some of the potential impacts of climate change on ecosystems.
At least 30% increase in extinctions, particularly those associated with coral reefs.
List some of the potential impacts of climate change on food supplies.
Localised negative impacts.
Cereal will decline at lower latitudes.
List some of the potential impacts of climate change on health.
Increased malnutrition and infectious diseases.
Deaths from heatwaves, floods and droughts.
Areal expansion of tropical diseases.
List the impacts of climate change on coastal areas.
Severe storms threatening 100 million people who live within one metre of sea level and 25% of people living within 30 metres.
Water and sanitation systems placed under threat.
Increased estuarine development along rivers.
Sea water invasion of groundwater.
Increased use of defensive barriers for storm surges.
Which areas of the world will suffer the biggest declines in freshwater supplies?
Central USA and California Amazonia Western Europe and European Russia Middle East Southern Africa Western Sahara
Define refugee species.
80% of plants and animals which have shifted their ranges closer to the poles.
Identify the temperature difference between the city centre and the surrounding rural area.
1° to 3°C
How does an urban landscape affect the carbon cycle?
Secondary industry, power production and transport.
Major producers of CO₂.
Outline the ways in which climate variability can affect agricultural production in terms of livestock.
Increases heat stress.
Creates conditions for more widespread disease (sleeping sickness).
Reduces pastoral and stocking ratios.
Reduce water supply through rainfall.
Outline the ways in which climate variability can affect agricultural production in terms of cropping.
Increases rainfall variability.
Causes changes to pests and fungal diseases.
Reduces soil moisture.
Increase extreme weather.
Improves growing seasons in cool temperate and sub-polar regions.
List the different ways in which agriculture may need to adapt to changes in local climatic conditions.
Selective breeding of livestock and crop varieties.
Use modified pastures or alternative crops.
Develop new pest management strategies.
Introduce dietary supplements and supplementary feeding.
Increase water storage and water saving.
Diversify farming practices.
Shift to better regions.
How will people living in cities have to adapt to climate change?
Construction of levees, sea walls and barriers.
Apply water-saving methods.
Use desalination plants.
Define ocean acidification.
The increase of CO₂ storage in ocean water increasing the carbonic acidity of the water.
Describe the problem of ocean acidification.
Acid reacts with carbonate ions to form bicarbonate. Reduces number of carbonate ions used by corals and shell fish- create carbonate shells.
Shells become thinner and more fragile.
More acid in the water dissolves calcium carbonate reducing the ocean’s ability to absorb more CO₂.
Changes the populations of microbial organisms, the basis of marine food chains.
What would be the Earth’s temperature without the atmosphere?
-18°C
What is the average temperature of the Earth due to the atmosphere?
15°C
Describe the relationship between insolation and the warming of the atmosphere.
Short-wave insolation is absorbed by the Earth’s surface (land and water) and is re-radiated as longwave terrestrial radiation which heats the atmosphere.
How does CO₂ absorb heat?
Dipole movements (vibrations of CO₂ molecules) capture infra-red radiation.
List and describe the methods of achieving stability.
Reduce our use of fossil fuels and change to alternate sources
Greater efficiency with present sources, e.g., gas instead of coal.
Stop clearing forests and plant more trees.
Reduction of labour-saving devices.
Financial incentives to make changes.
Establishing international protocols such a Kyoto
Carbon tax
Carbon trading
CO₂ sequestration
Carbon offsets
List examples of anthromes.
Urban (towns and cities) settlements Rural (village) settlement Grazing properties Cropland Mining Managed forests National parks
Examples of things that provide evidence for climate change.
Ice cores Tree rings Lake and ocean sediments Fossil pollen Corals Temperature records Ocean temperatures Sea levels Cryosphere
Describe how tree rings (dendrochronology) provide evidence for climate change.
Patterns in tree-ring widths, density, and composition directly reflect variations in climate.
In temperate regions where there is a distinct growing season, trees generally produce one ring a year, recording the climate conditions each year.
Describe how ice cores provide evidence for climate change.
Bubbles trapped within the ice capture the gas concentration of the atmosphere.
Describe how lake and ocean sediments provide evidence for climate change.
Consist of biological and other materials that washed in from nearby land or that were produced in the lake/ocean.
Preserved as tiny fossils in the sediments (foraminifera) - used to infer past climate.
Describe how fossil pollen (palynology) provides evidence for climate change.
Has unique shape depending on what plant it comes from.
Allows scientists to make inferences about past climates.
Describe how corals provide evidence for climate change.
Coral skeleton density varies with changes in water temperature, light, and nutrient conditions.
This produces growth rings.
