hazardous earth - climate change Flashcards
natural causes, human causes, evidence of past climate change, greenhouse gases, greenhouse effect, human influence
what are the 4 types of natural causes of climate change
changes in solar output
variations in the earth’s orbit
volcanic eruptions/emissions
asteroid collisions
explain changes in solar output and its significance to climate change
solar output = sunspots
sunspots mean the sun throws out heat which warms the earth’s climate
this has not contributed to climate change in over 400 years - not significant
explain variations in earth’s orbit and its significance to climate change
aka milankovitch cycles
these happen approx every 100,000 years
when earth is close to sun - climate warms
when earth is further from sun - climate cools
it has altered solar energy in some areas by 25% and are main factors in interglacials and glacials - long term but significant
explain volcanic emission and its significance to climate change
volcanoes emit ash and gas
the effect of ash is more than GGH
ash blocks solar radiation (the sun) so climate cools
Mt St Helens eruption altered the world temperature for 1-2 years however eruptions are irregular - significant??
explain asteroid collision and its significance to climate change
impact creates dust and pulverised rocks
for it to be significant, the asteroid has to be over 1km across (RARE) however the effect could last 5-10 years
what are the 4 human causes of climate change
transport
deforestation
livestock farming
energy production
explain transport and its contribution to enhanced greenhouse effect
cars, planes, boats, trains use/produce greenhouse gases to run
more vehicles use oil (burning fossil fuels), gas and coal to run –> more CO2 –> contributes to enhanced greenhouse effect
long distance travel is getting cheaper so more flights are being booked making more emissions
explain deforestation and its contribution to enhanced greenhouse effect
cutting down trees over a large area or destruction of forests by people
it happens to make space for developments
- building towns
- making space for agriculture
trees absorb (sequester) CO2 and when we cut them down remove the ability to turn greenhouse gases into oxygen –> there are also less trees to sequester CO2
when we burn forests to rid trees for land, the burning releases CO2
explain livestock farming and its contribution to enhanced greenhouse effect
more trees need to be chopped down to make land for livestock
cows burp and fart methane
cows digestion creates methane which is a greenhouse gas that adds to the enhanced greenhouse effect
explain transport and its contribution to enhanced greenhouse effect
when we burn fuels to release the energy, we also release the greenhouse gases stored in them
- oil
- gas
- coal
are the big culprits
when fossil fuels are burnt for energy, they release CO2 - a greenhouse gas - which adds to the enhanced greenhouse effect
what are the 4 types of evidence of past climate change
ice cores
tree rings
temperature records
historical records (diary, painting etc)
what do ice cores show and what are the advantages and disadvantages
in the layers of ice, there are air bubbles that contain carbon dioxide and oxygen isotopes - this shows temperature and carbon dioxide emission
adv
- you can get it from places where people don’t live
- it can go back millions of years
what do tree rings show and what are the advantages and disadvantages
trees have rings in the trunk that are sensitive to temperature, sunlight and rain
the thicker and wider the rings - hot weather
the thinner and narrower the rings - cold weather
adv
- can go back up to 10000 years
- better than historical and temperature records
dis
- not as good as ice cores
what do historical records show and what are the advantages and disadvantages
suggests that climate changes regularly (every few 100yrs)
dis
- bias and subjective
what do temperature records show and what are the advantages and disadvantages
it shows temperature changes
dis
- doesn’t go too far back
- inaccurate
