climate change Flashcards
what is the Quaternary period
the most recent geological time period spanning from 2.6 million years ago to present day
what was earth climate like in the period before the Quaternary
warm and quite stable
how has global temperature shifted during the Quaternary period
shifted between cold glacial periods and warmer inter glacial periods
how long do cold glacial periods usually last
100,000 years
how long do warmer glacial periods usually last
10,000 years
when did the last glacial period end
around 15000 years ago
what is global warming
the sharp rise in global temperatures over the last century
what are the four sources where evidence for climate change comes from
ice and sediment cores
temperature records
pollen analysis
tree rings
how does ice and sediment cores provide evidence for climate change
- ice sheets are made into layers - one layer formed per year
- scientists drill into sheets to get long cores
- by analysing gases trapped in the layers they can tell what the temp was each year
- remains of organisms found in cores taken from ocean sediments can also be analysed
how do temperature records provide evidence for climate change
historical records like harvest dates can extend the record of climate change back
how does pollen analysis provide evidence for climate change
- pollen from plants preserved in sediment e.g peat bogs
- scientists identify and date pollen to show what species were living at that time
- scientists know conditions that plants live in now so preserved pollen from similar plants shows climate conditions
how do tree rings provide evidence for climate change
- tree grows and forms a new ring each year
- tree rings are thicker in warm and wet conditions
what do orbital changes effect
how much solar radiation the earth receives
what are the variations in which the earth orbits the sun
stretch
Tilt
Wobble
what is the stretch when it comes to earths orbit
the shape of earths orbit around the sun
either circular or elliptical (oval)
what are the three natural factors that are possible factors for climate change
orbital changes
volcanic activity
solar output
what is the tilt when it comes to earths orbit
the earths axis is tilted at an angle when orbiting the sun
what is the wobble when it comes to earths orbit
the earths axis wobbles like a spinning top
what are orbital changes thought to have caused in climate change
the glacial and inter glacial cycles of the Quaternary period
how is volcanic activity a possible cause for climate change
major volcanic eruptions ejects large quantities of material into atmosphere
some of these particles reflect the suns rays back out to space and the earth cools
- short term climate change
is the suns solar output constant
no it changes in short cycles of about 11 years
what does it mean if there is reduced solar output
the earths climate might become cooler in some areas
how big is the effect of solar output on climate change
it is thought not to have a major effect
what are the ways that humans are increasing the amount of greenhouse gases in the atmosphere
deforestation
farming
cement production
burning fossil fuels
how does burning fossil fuels increase the amount of greenhouse gases in the atmosphere
Co2 is released when fossil fuels like coal,oil and natural gas are burnt
how does cement production increase the amount of greenhouse gases in the atmosphere
cement is made from limestone which contains carbon
when cement is produced lots of CO2 is released
how does farming increase the amount of greenhouse gases in the atmosphere
livestock produces methane - cows
rice paddies - flooded fields emit methane
how does deforestation increase the amount of greenhouse gases in the atmosphere
plants remove Co2 and convert to organic matter through photosynthesis
trees cut down - stop taking in co2
Co2 is released when trees are burnt as fuel or to make way for agriculture
What is the expected rise in temperatures between 2021 and 2100?
Temperatures are expected to rise by 1.0 to 5.7 °C.
What effect does warmer temperatures have on glaciers and ice sheets?
Warmer temperatures are causing glaciers to shrink and ice sheets to melt.
What is the consequence of melting land ice?
Melting land ice means that water stored on land is returning to the oceans, causing sea levels to rise.
What is happening to sea ice due to rising temperatures?
Sea ice is shrinking, leading to the loss of polar habitats.
What is the impact of rising sea levels on coastal areas?
Coastal erosion will increase with sea level rise and some coastal areas will be submerged, leading to habitat loss.
How are coral reefs affected by rising sea temperatures?
Coral reefs, like the Great Barrier Reef in Australia, are suffering from bleaching due to rising sea temperatures.
What changes are occurring in precipitation patterns due to global warming?
Global warming is affecting how much rain areas get.
How might species distribution change due to climate change?
Some species now live at higher latitudes due to warming temperatures.
What is a potential consequence for species that rely on specific habitats?
Some habitats are being damaged or destroyed, which may lead to extinction of species that adapted to these areas.
How might climate change affect giant pandas?
Climate change may limit bamboo growth, leading to a decline in numbers of giant pandas that rely on bamboo as a food source.
What has happened to deaths due to heat and cold in some places?
Deaths due to heat have increased, while deaths due to cold have decreased.
What could happen to low-lying coastal areas like the Maldives due to climate change?
They could be lost to the sea or flood so often that they become uninhabitable.
What issue are some areas facing regarding water supply?
They are struggling to supply enough water for residents due to changing rainfall patterns.
What could lower crop yields lead to in lower latitudes?
They could increase malnutrition, ill health, and death from starvation.
How is climate change affecting weather patterns?
The weather is getting more extreme, leading to increased spending on predicting events and rebuilding.
what are the different strategies that aim to reduce the causes of climate change
carbon capture
planting trees
alternative energy production
international agreements
what does carbon capture do
designed to reduce emissions from power stations
involves capturing CO2 and transporting it to safe places where it can be stored - underground
how does planting trees reduce the effects of climate change
increasing the amount of CO2 that is absorbed by photosynthesis
how does alternative energy production reduce the effects of climate change
replacing fossil fuels with nuclear or renewable energy - reduces emissions
e.g wind farms
what was the paris agreement
aims to reduce greenhouse gas emissions
encourages developed countries to help developing countries with mitigation strategies
what are some ways that people are adapting to the effects of climate change
changing agricultural systems
managing water supply
coping with rising sea levels
What does adaptation mean in the context of climate change?
Adaptation means responding to the effects of climate change.
How are agricultural systems changing due to climate change?
Changing rainfall patterns and higher temperatures will affect the productivity of existing systems.
What may be necessary for crops in new climate conditions?
It may be necessary to plant new crop types that are more suited to the new climate conditions in an area.
How is biotechnology being used in agriculture?
Biotechnology is being used to create new crop varieties which are more resistant to extreme weather events.
What is a predicted effect of climate change on water supply?
Dry areas are predicted to get drier, leading to more water shortages.
What are two methods for managing water supply?
1) Water meters can be installed in homes. 2) Rainwater and waste water can be collected and recycled.
What are some measures being taken to cope with rising sea levels?
Better flood warning systems are being put in place, and physical defences such as flood barriers are being built.
What are some adaptations in areas that can’t afford expensive flood defences?
People are building raised flood shelters and building houses on embankments.
