Changing Climates Flashcards
What is an ice age? Are we living in one now?
A period of time where there are permanent ice sheets.
We currently live in an ice age.
What is the Quantenary peirod?
The most recent period of geological time. It includes the pleistocene and holocene epochs.
What are the pleistocene and holocene epochs?
Pleistocene epoch - the period that began 2.6 million years ago and ended 11 700 years ago.
Holocene epoch - the period that began 11 700 years ago and continues today (interglacial period)
What is a glacial and interglacial period?
Glacial period - a colder period in Earth’s history
Interglacial period - a warmer period in Earth’s history
How had the temperature changed over the Quantenary period?
The temperature has fluctuated (cyclical changes) but the range of temperatures is increasing.
4oC difference 2.6m years ago, 8oC difference today
How has the temperature changed since 1880?
General trend of increase until 1970, then rapid increase until today
Ice cores can be used as evidence for climate change. What is the oldest ice thats scientists can study?
800 000 years ago
What do lighter layers of snow show? Dark Snow?
Lighter layers show snow laid in summer
Dark snow shows layers of snow laid in winter (more dust mixed in winter)
What are the two types of oxygen that scientists are looking for?
What do they each suggest?
16O - Earth was colder
18O - Earth was warmer
What does large amounts of carbon dioxide in the ice suggest about Earth’s temperature?
Lots of CO2 suggests warmer temperatures
How do we know if climate data is reliable?
By matching data to other sources
Sea ice can be used as evidence for climate change. How is sea ice measured?
By using satellites
What is meant by sea ice maximum/minimum?
Sea ice maximum - maximum area in the Arctic covered in ice in any year
Sea ice minimum - minimum area in the Arctic covered in ice in any year
How much smaller has the area covered by sea ice become since 1979?
13.3% smaller every decade on average
Why has global temperature data become more reliable as evidence for climate change?
New weather stations are being developed and added every year
What are the criticisms of global temperature data?
Recording instruments might be placed in positions that don’t give a fair record of an area’s real temperature (for example on top of a hill would give a lower result)
How can paintings and diaries be used as evidence for climate change? How can they not be fully reliable?
They may describe activities that are not possible today because of hotter temperatures (e.g. ice skating on Thames)
Elements can be emphasised and therefore not fully accurate, no fixed data to match it.
Describe the greenhouse effect and the enhanced greenhouse effect in in 8 steps
- Energy comes from the sun as short-wave radiation
- Most energy passes through a layer of naturally occuring greenhouse gases. Human activity has put more greenhouse gases into the atmosphere.
- Earth’s surface is warmed
- Some energy is reflected back into space as long-wave energy. Long-wave radiation does not pass through the greenhouse gases as easily as short-wave radiation.
- Some energy is absorbed by greenhouse gases and some is reflected back to Earth. The thicker layer of greenhouse gases absorbs more long-wave radiation and more is reflected to Earth.
- Earth is warm enough to exist or Earth becomes warmer, causing global warming
Underlined indicates the enhanced greenhouse effect
What is the greenhouse effect?
A natural process that warms the Earth’s surface.
What is the enhanced greenhouse effect?
The trapping of more of the Sun’s energy because of the cumulative effect of more greenhouse gases, causing Earth’s temperature to increase
What is the main greenhouse gas contributor to the greenhouse effect?
Carbon Dioxide
Name a source of each of these greenhouse gases: carbon dioxide, methane, halocarbons, nitrous oxide.
carbon dioxide: burning fossil fuels
methane: farm animals (like cows)
halocarbons: air conditioning
nitrous oxide: car exhausts
What are sun spots?
Dark spots on the sun’s surface - they are temporary on cycles
What are sun spots caused by?
Magnetic storms
What do sun spots do to the Earth’s surface?
They increase the amount of energy Earth receives from the sun, causing it to warm up
How long are sun spot cycles?
11 years
How do volcanic eruptions affect the Earth’s temperature?
When volcanoes erupt they release huge amounts of dust (containing ash, sulfur dioxide, carbon dioxide and water vapour) into the atmosphere. The dust blocks the sunlight, resulting in cooler temperatures.
What are two key periods of climate in the holocene epoch?
- little ice age (1300-1870)
- medieval warm period
Different climate change theories are linked to these such as sunspts or volcanic eruptions
What are the three Milankovic cycles?
- *Eccentricity:** orbit
- *Obliquity:** tilt
- *Precession:** (amount of) wobble
“What are the three Milankovitch cycles effects on the Earth’s climate?”
Eccentricity: more temperature variation due to Earth being further away from the sun at different times of the year
Obliquity: with less tilt, summers are cooler and winters are milder
Precession: can change severity of seasons
Does melting sea ice contribute to rising sea levels?
No
What is thermal expansion?
The tendency of matter (i.e. water in sea - increased water molecule size) to increase in volume or pressure when heated
In what ways are weather events becoming more extreme? (3 points)
Tropical storms (hurricanes) are becoming more intense in some areas
They are resulting in higher levels of precipitation
Droughts are becoming more severe and lasting longer
How do increased temperatures impact extreme weather? (2 points)
Warmer sea temperatures fuel more intense tropical storms (hurricane)
Warmer air can hold more water vapour, so leads to heavier rainfall
What are the impacts of increased extreme weather of tropical storms? (2 points)
Intense storms can have knock on effects and disrupt global weather patterns
While tropical storms are becoming more intense, there may be fewer of them globally
Why is climate change considered a global issue?
The ‘global’ nature of the issue
- the causes are global (emitting fossils fuels)
- the impacts are global
- we will all need to work together
- to minimise the impacts
Mention global environmental, social and economic factors in addition in a 6 marker in order to achieve full marks
Discuss how reliable data on atmospheric carbon dioxide collected from ice cores is as evidence for climate change. (4 marks)
Reliable as:
- Atmospheric carbon dioxide data from ice cores gives information over thousands of years ( )
- It is more reliable source than other shorter term sources ( )
Unreliable as:
- Doesn’t provide an exact date ( )
- Doesn’t provide an exact temperature/ the temperature has to be calculated ( )
List positive/negative economic impacts of climate change in the UK.
Positive:
Tourism
Opportunities - more staycations? - hotter weather
Agriculture
Wheat and sugar beet have higher yields
UK wine industry (vineyards growing grapes)
Negative:
Flooding
Flash floods more likely
Sea level rise to make flooding from rainfall worse
Damage could be £2-12 billion by 2080
Transport
Travel delays more likely
Increased temperatures could lead to railways buckling
Roads melting
Food prices
Volatility in global markets could affect supply chains
List positive/negative social impacts of climate change in the UK.
Positive:
- 4-24K cold-related deaths avoided each year (outweighed by deaths from heat)
Negatve:
- more strain on NHS due to more common heatwaves
- increased risk of drought
- 27-59 million people living in areas with water shortages by 2050
- more environmental refugees
List positive/negative environmental impacts of climate change in the UK.
- *Positive:**
- offspring born in colder months more likely to survive
- *Negatives:**
- flash flooding can lead to overflowing sewers - water contamination
- animals move northwards - increased competition for native species
You need 3 named places
List positive/negative economic impacts of climate change in the World
Western Europe (e.g. UK) - the WWA found that a heatwave was 10 times more likely than in a theoretical Earth without the enhanced greenhouse effect. Extreme heat linked with lower crop yields, so less can be sold
Bangladesh - soil salinisation makes it difficult to grow rice. So lower crop yields are produced that can be sold
Atlantic Hurricanes (e.g. Hurricane Harvey, Texas 2017) - caused $200bn in damage. Money needs to be spent on repair rather than funding public services
You need 3 named places
List positive/negative social impacts of climate change in the World.
Bangladesh - Climate refugees leave the coastal areas in large numbers. 200,000 arrive in the overpopulated Dhaka every year and this puts pressure on services in the city.
Western Europe (e.g. UK) - the WWA found that a heatwave was 10 times more likely than in a theoretical Earth without the enhanced greenhouse effect. Extreme heat linked with higher mortality
Atlantic Hurricanes (e.g. Hurricane Harvey, Texas 2017) - caused 107 fatalities
You need 2 named places
List positive/negative environmental impacts of climate change in the World.
Bangladesh - Soil salinisation makes it difficult to grow rice. People have switched to farming fish and shrimp which has a worse environmental impact.
Lake Chad - desertification (the degrading of semi-desert land areas to deserts). Loss of vegetation and animal habitats.
How do humans contribute to the atmosphere?
- Description of enhanced greenhouse effect
- Sources
- Deforestation - trees are natural carbon sink
- Burning fossil fuels (carbon dioxide) and how it affects enhanced greenhouse effect
- Effects (e.g. melting ice, flooding, droughts, rising temperatures)
- We have realised effects recently, attempts to reduce emissions (govt increasing petrol tax and funding sustainable development)
