Climate change - causes and impacts Flashcards
What is weather?
Weather is the daily result of changes in temperature, pressure and precipitation in our atmosphere.
What is climate?
Climate is the average weather pattern over many years for a location of earth.
What is the difference between weather and climate?
The timescale on which they are measured
What is the similarity between weather and climate?
They are both affected by ocean and atmospheric circulatory systems.
What are weather and climate both affected by?
Clouds
Forest fires
Volcanic eruptions
Human activities
How can clouds effect weather and climate?
They can trap heat underneath them or reflect sunlight away from earth above them.
How can forest fires effect weather and climate?
They release carbon dioxide but regrowth traps it again in carbon stores.
How can volcanic eruptions effect weather and climate?
They release huge quantities of ash which circulate in the atmosphere, cooling the earth.
How can human activities effect weather and climate?
We burn fossil fuels and keep livestock, both of which release GHGs.
What is climate change?
Climate change is a change in the usual weather found in a place. This place could be the earth.
What factors effect climate change?
Fluctuations in solar insolation affecting temperature
Changing proportions of gases in the atmosphere released by organisms
How is it possible that climate changes on a global scale?
Inputs and outputs have the change
What do greenhouse gases do?
They reduce heat loss from the atmosphere.
When does a dynamic equilibrium reach a new equilibrium?
If a tipping point is passed
How much co2 is in the atmosphere?
0.04%q
What are some common GHGs?
Carbon dioxide Water vapour methane CFCs HCFCs nitrous oxide ozone
What is global warming potential?
A relative measure of how much heat a known mass of a GHG traps over a number of years compared to the same mass of carbon dioxide.
What is the GWP of carbon dioxide?
1
Where does ozone occur?
In two layers in the atmosphere, the troposphere and the stratosphere.
Which layer of the atmosphere is closest to the earth?
Troposphere
How does the ozone layer work?
Acts as a GHG in the troposphere but absorbs UV radiation in the stratosphere, it acts as a coolant.
What do CFCs do to the ozone layer?
They break it down when they reach the stratosphere but act as a GHG in frthe troposphere.
What are CFCs?
Human made chemicals so are not present in the atmosphere as a result of natural processes.
Why are CFCs dangerous?
They have a high GWP and a long lifetime in the atmosphere.
Why do scientists usually omit water vapour from their greenhouse effect calculations?
It is the most potent greenhouse gas but it varies so much in concentration.
Why is the greenhouse effect concerning if most GHGs are in the atmosphere naturally?
Because there is an increase in these due to anthropogenic
Anthropogenic sources of methane?
Cattle
Rice and paddy fields
Natural sources of methane?
Swamps and bogs
Termites
The tundra
What facts in global climate change are not up for debate?
There is a greenhouse effect
GHG emissions are increasing due to human activities and are probably increasing the greenhouse effect
There has been a recent pattern of an increased average global temperature
How can climate change over time due to a change in GHG levels?
Direct relationship Buffering action Acceleration Tipping point Stuck at new equilibrium
What is buffering action?
Solar radiation increases but climate change does not follow in a linear way, insensitive to change.
What does it mean if climate change reaches a tipping point?
The climate makes no response to changes but then reaches a threshold at which point it changes rapidly until a new, much higher equilibrium is reached.
What does it mean if climate change gets stuck at a new equilibrium?
In addition to the threshold change, even when the forcing decreases it can get stuck at the new equilibrium until a new tipping point is reached and it decreases rapidly.
Climate change has impacts on:
Oceans and sea levels Polar ice caps Glaciers Weather patterns Food production Biodiversity and ecosystems Water supply Human migration National economies
How does climate change have an impact on oceans and sea levels?
Temperatures rise leading to thermal expansion and land ice slips off the land and into the sea increasing the volume.
Oceans absorbing more CO2 increases the acidity which greatly damages coral as the zooxanthellae abandon them.
How does climate change have an impact on polar ice caps?
They melt
What are the social effects of melting polar ice caps?
Could open up trade route, make travel in the area easy and make it easier to exploit undersea minerals and fossil fuel reserves.
What are the social effects of melting glaciers?
Glacier summer melt proves a fresh water supply to those living below the glacier, which has provided water to many major asian rivers. In Tanzania glacier melt causes severe droughts as the Kilimanjaro glacier has lost over 80% of its volume.
How does climate change have an impact on weather patters?
more heat, more energy in the climate.
weather is sporadic as a result
global precipitation may increase
more soil erosion
How does climate change have an impact on food production
Photosynthesis increases BUT so does respiration so NPP is the same. In Europe crop growing season has expanded, but in other places its shorter.
Heatwaves and droughts kill livestock
How does climate change have an impact on biodiversity and ecosystems?
Animals can move to cooler regions but plants can’t.
Seeds can be dispersed but this occurs very slowly, they may become extinct. Alpine or tundra species have nowhere to go.
Plants break winter dormancy earlier.
Droughts increase, wildfires more likely.
Bugs don’t die when they’re supposed to and can completely wipe out trees, no equilibrium.
What are the social effect of melting permafrost?
Houses built on the land are shifting as it thaws.
How does climate change have an impact on water supplies?
Increased evaporation rates may cause rivers and lakes to dry up.
What is the social impact of decreased water supplies?
Humans need to live near water, they move away if there is no water. 2.4 billion people live in the river basins fed by the Himalayas and their water supply is decreasing.
What are the social impacts of global warming regarding health?
Heatwaves kill people.
Insects are able to spread more disease as less cold winters enable them to survive for longer.
Algal blooms may be more common, they can kill humans.
Wetter climates - fungal diseases.
Dryer climates - asthma and chest infections.
What diseases could thrive as a result of global warming?
Malaria
Dengue fever
Yellow fever
Could global warming benefit human health in any way?
Warmer temperature in higher latitudes would reduce the number of people dying from the cold each year and reduce heating bills for households.
Fewer snow storms and icy roads leads to lower death tolls on the roads.
How does climate change have an impact on human migration?
If people cannot grow food or find water they will move to regions where they can.
How does climate change have an impact on national economies?
Some suffer because decrease in water supplies or drought occurs.
Some gain because global warming makes it easier to extract minerals that would have been frozen in the permafrost or under ice sheets.
Hydroelectric power is more possible as rivers don’t freeze.
Agriculture may increase in higher latitude but decrease in the tropics.
Africa will probably lose food production and rainfall.
Positive feedback with oceans due to climate change?
CO2 increases average global temperature. Oceans get warmer as a result and as they do release more carbon dioxide into the atmosphere which amplifies the change.
Negative feedback with oceans due to climate change?
Oceans absorb more C02 when they are warmer as phytoplankton photosynthesise faster, producing more phytoplankton that absorb more C02 so dampening global warming.
Positive feedback with clouds due to climate change?
More evaporation leads to more clouds which trap more heat thus amplifying the change.
Negative feedback with clouds due to climate change?
More evaporation leads to more clouds which reflect more heat.
Positive feedback with pollution due to climate change?
Cloud formation is increased by use of aerosols which acts as insulation, trapping heat. More clouds, more heat trapped.
Black soot falling on ice decreases albedo, increasing heat absorption, increasing temperature and melting.
Negative feedback with pollution due to climate change?
Aerosols cause clouds to form from condensation which increases albedo, decreasing warming.
Positive feedback with polar ice due to climate change?
Temperature increases so ice melts becoming darker sea water, decreasing albedo and absorbing more heat thus amplifying the change.
Negative feedback with polar ice due to climate change?
Warmer air has more water vapour so more precipitation, some of which will be snow. Increased albedo and more reflection, thus leading to lower temperatures.
Positive feedback with forests due to climate change?
Forests cut down and burned. Less carbon absorbed, more C02 in the atmosphere so higher temperatures. Forests die due to high temperatures and may catch fire, further releasing C02.
Negative feedback with forests due to climate change?
C02 absorbed, removing C02 from the atmosphere.
Positive feedback with tundra due to climate change?
Permafrost melts, releases methane.
How do we know global warming is a result of humans?
From data we know the global average temperature is increasing.
CO2 and other GHG such as methane are increasing.
Humans produce CO2 on an immense scale by burning fossil fuels, at a rate it cannot be equalised.
We know from isotopes in the greenhouse gases that the majority was produced by humans - industry tag.
The troposphere temperatures are increasing faster than the stratosphere, indicating that it is the greenhouse gases that are causing the rise in temperature.
Impacts on coastline?
Flooding and erosion
