3.1.1.4 Climate change Flashcards
What is climate change?
Is any significant change in the Earth’s climate over a long period
What is the Quaternary period?
Is the most recent geological time period (spanning from 2.6 million years ago to today)
What was the Earth’s climate like in the period before the
Quaternary?
The Earth’s climate was warmer and quite stable
During the Quaternary, what happened to the global temperature?
Shifted between cold glacial periods (lasted around 100,000 years) and warmer interglacial period (lasted around 10,000 years)
What has been happening since the last glacial period ended (around 15,00 years ago)?
The climate has been warming
What is global warming used to describe?
Used to describe the sharp rise in global temperatures over the last century
Name 4 sources of evidence for climate change
- Ice and Sediment Cores
- Tree Rings
- Pollen Analysis
- Temperature Records
What are ice sheets made up of?
Layers of ice
When is a layer of ice formed?
Each year
How can we tell what temperature was each year using ice and sediment cores?
By analysing the gases trapped in layers of ice they can tell what the temperature was each year
e.g. ice core from Antarctica shows the temperature changes over the last 400,000 years
As trees grows, when do they form a new ring?
Each year
What conditions are the rings on trees thicker?
The tree rings are thicker in warm, wet conditions
How can we tell what the climate was like each year using tree rings?
Scientists take tree cores and count the rings to find the age of the tree → thickness of each ring shows what the climate was like
Explain how analysing pollen can provide evidence for climate change
- Pollen from plants gets preserved in sediment
- Scientist can identify and date the preserved pollen to show which species were living at the time
- Scientists know the conditions that plants live now, so preserved pollen from similar plants show that climate conditions were similar
Explain how temperature records can provide evidence for climate change
- Since the 1950s global temperatures have been measured accurately using thermometers (gives reliable but short-term record of temperature change)
- Historical records (e.g. Harvest dates, newspaper weather reports) can extend the record of climate change a bit further back
Name 3 natural possible causes of climate change?
- Orbital Changes
- Volcanic Activity
- Solar Output
Explain how orbital changes could have caused climate change
- The way the Earth moves around the Sun changes
- These changes affect amount of solar radiation (how much energy) earth receives - more energy, it gets warmer
- Orbital changes may have caused the glacial and interglacial cycles of the Quaternary period
Explain how volcanic activity could have caused climate change
- Major volcanic equations eject large quantities of material into the atmosphere
- Some of these particles reflect the Sun’s rays back to space so the earth’s surface cools
- Volcanic activity may cause short-term changes in climate E.g. Cooling that followed the eruption of Mount Pinatubo in 1991
Explain how solar output could have caused climate change
- The Sun’s output of energy isn’t constant
2. Periods when solar output is reduced may cause the Earth’s climate to become cooler in some areas
What do most scientists think about the solar output causing climate change?
Most scientists think that changes in solar output don’t have a major effect on global climate change
Why doesn’t CO2 that volcanoes release cause global warming?
They don’t release enough
What (generally) causes global warming and how?
Human activities are causing global warming by making
the greenhouse effect stronger
What is the greenhouse effect?
It is where greenhouse gases (e.g. CO2 and methane) absorb outgoing heat, so less is lost to space
What does too much greenhouse gas in the atmosphere mean?
It means too much energy is trapped and planet warms up
Name 4 ways humans are increasing the concentration of greenhouse gases
- Burning Fossil Fuels
- Cement Production
- Farming
- Deforestation
Explain how burning fossil fuels contributes to global warming?
CO2 is released into atmosphere when fossil fuels like coal, oil, natural gas and petrol are burnt
Explain how farming contributes to global warming?
- Farming of livestock produces a lot of methane
2. Rice paddies contribute to global warming, because flooded fields emit methane
Explain how cement production contributes to global warming?
Cement is made from limestone, which contains carbon. When cement is produced lots of CO2 is released into the atmosphere.
Explain how deforestation contributes to global warming?
- Plants remove CO2 from the atmosphere and convert it into organic mater using photosynthesis]
- When trees and plants are chopped down, they stop taking in CO2
- CO2 is also released into the atmosphere when trees are burnt (as fuel or to make way for agriculture)
Name 4 effects of climate change on the environment
- Causes sea level rise
- Species to decline
- Distribution and quantity of some species could change and biodiversity could decrease
- Precipitation patterns are changing - warming is affecting how much rain areas get
Explain how climate change can cause sea levels to rise?
Warmer temperatures are causing glaciers to shrink and ice sheets like Greenland to melt → melting of ice on land = water stored on land as ice returns to oceans
What is the effect of sea ice is shrinking?
Loss of polar habitats
What is the effects of sea levels rising? Name 2
- Low-lying and coastal area (like Maldives) will be flooded more regularly
- Coastal erosion will increase & some coastal areas will be submerged, so habitats lost
Give an example how species are declining due to warming
Some coral reeds are suffering from bleaching due to increasing sea water temperatures
Explain how the distribution and quantity of some species could change and biodiversity could decrease due to global warming
- Some species are now found in higher latitudes due to
warming temperatures - Some habitats are being damaged or destroyed due to climate change = species that are specially adapted to
these are may become extinct
Explain how global warming has changed number of deaths occurring
- In some places deaths due to heat have increased
- But deaths due to cold have decreased
Explain how global warming is causing places to be impossible to inhabit
- Some areas could become so hot and dry that they’re difficult or impossible to inhabit
- Low-lying costal areas could be lost to sea or flood so often that they become impossible to inhabit
What is effects of more places becoming impossible to inhabit?
Leads to migration or overcrowding in other areas
Explain how climate change is affecting farming in
different ways around the world
- Globally, some crops have suffered from climate change (e.g. Maize crops have got smaller due to warming in recent years)
- But some farmers in high-latitude countries are finding that crops benefit from warmer conditions
What does lower crop yields mean for people?
Means there could be an increase malnutrition, ill heath and death from starvation (particularly in lower latitudes)
How does climate change affect the weather?
It’s getting more extreme
What does extreme weather mean for people
Means more money has to be spent on predicting extreme weather events, reducing their impacts and rebuilding after them
What are two methods of tackling climate change?
- Mitigation Strategies
- Adaptation
What is the aim of mitigation strategies?
To reduce the causes of climate change, by reducing the concentration of greenhouse gases in atmosphere
Name 4 examples of migration strategies
- Planting Trees
- Carbon Capture
- Alternative Energy Production
- International Agreements
Explain how planting trees can reduce the causes of climate change?
Increases amount of carbon dioxide that is absorbed from atmosphere through photosynthesis
What is Carbon Capture and Storage (CCS)?
New technology designed to reduce climate change by reducing emissions from fossil fuels burning power stations
Explain how carbon capture can reduce the causes of climate change?
CCS involves capturing CO2 and transporting it to places where it can be stored safely (e.g. deep underground)
Explain how alternative energy production can reduce the causes of climate change?
Replacing fossil fuels with nuclear power and renewable energy can help reduce climate change by reducing greenhouse gas emissions from power station
What is the Kyoto Protocol?
An international agreement that most countries in the world signed, agreeing to monitor to cut greenhouse gas
emissions
Explain how international agreements can reduce the causes of climate change?
For the Kyoto Protocol: each country’s was set a target (e.g. The UK agreed to reduce emissions by 12.5% by 2012. The UK met the target, reducing emissions by an average of 22%)
What is adaptation?
Responding to changes caused by climate change
Name 3 ways of adapting to climate change
- Changing Agricultural Systems
- Managing Water Supply
- Coping with Rising Sea Levels
Why do agricultural systems need to be changed?
Changing rainfall patterns and higher temperatures will affect the productivity of existing systems
Explain how are/can agricultural systems be changed to reduce the effects of climate change
- May be necessary to plant new crop types that are more suitable to new climate conditions in an area
- Biotechnology is being used to create new crop varieties which are more resistant to extreme weather events
Why do water supplies need to managed?
Dry areas are predicted to get drier = more water shortages so people need to use water resources more efficiently
How can water supplies be managed?
- Water metres can be installed in people’s homes to discourage them from using a lot of water
- Rainwater can be collected and waste water can be recycled to make more water available
What is predicted to happened to sea levels and why os this a problem?
Sea levels are predicted to rise (by up to 82 cm by 2100), which could flood many islands and coastal areas
Explain how rising sea levels are being coped with
- Physical defences such as flood barriers are being built and better flood warning systems are being put in place
- In areas that can’t afford expensive flood defences,
(e.g. Bangladesh), people are building their houses on top
of Earth embankments and building raised flood shelters
to use in emergencies
