weather gateway 2 Flashcards
Natural causes of recent climate change (2 factors)
- Variations in solar output (suns’s magnetic activity & sunspots)
- Volcanic eruptions (sulfur-based particles)
How does variations in solar output cause climate change?
The sun emits varying amount of solar radiation due to changes in its magnetic field, which affects the earth’s climate
periods of intense solar magnetic activity → there are more sunspots. → Areas surrounding the sunspots radiate more energy → compensate for the lower temperatures of the sunspot areas → increased solar output and higher global temperatures.
periods of low solar magnetic activity → there are fewer sunspots →Areas surrounding the sunspots do not need to radiate as much energy to compensate for the lower temperatures of sunspot areas, → decrease in total solar output and lower global temperatures.
How do volcanic eruptions cause climate change (dexa)
D: Volcano erupts → large carbon dioxide, water vapour, sulfur dioxide, dust and ash particles are released into the atmosphere
Ex: Mount pinatubo, philippines 1991 → 17 million tonnes of sulfur dioxide released → ↓ temp in the northern hemisphere by as much as 0.6°c lasting 2 years
A: particles reflect solar energy back into space → cooling influence on regional and global temperatures
Greenhouse effect
Incoming shortwave radiation from the sun passes through the atmosphere → some shortwave radiation is reflected by the earth into the atmosphere → most shortwave radiation is absorbed by the earth’s surface which then heats up the warmed surface of the earth emits longwave radiation to the atmosphere → greenhouse gasses absorb longwave radiation, warming the atmosphere
Enhanced greenhouse effect and how human activities lead to the enhanced greenhouse effect
Enhanced greenhouse effect → an increase in the concentration of greenhouse gasses in an atmosphere → global temperatures
The concentration has mainly increased due to Anthropogenic factors → factors caused by human activities such as deforestation and changing land use
General changes in climate change
Since 1800s → significant but irregular trend in temperature→ fluctuations of 0.3°c to 0.6°c → known as global warming → increase in global temp over a long period of time
Causes of enhanced green house effect: deforestation
D: Deforestation is the loss of forests due to the removal and clearance of trees in forested areas → wood to make products such as paper & building materials / clear the area for mining activities
Ex: 2000 to 2010 → 52000km2 of forest were cleared each year → 142.5km2 each day
A: Forests absorb billions of tonnes of carbon dioxide every year through photosynthesis → taking in a significant amount of global greenhouse gas emissions → fewer trees → ↑ in carbon dioxide
Causes of enhanced green house effect: Agriculture (changing land use)
D: Agriculture is the practice of cultivating land, producing crops and raising livestock
Ex: cattle farming contributes to greenhouse gas emissions because cattle releases methane as a waste gas → every cow produces 1,000 to 1,800 liters of emissions every day → study by scientists in argentina
A: ↑ in agriculture → ↑in emissions caused by livestock → ↑ in greenhouse gasses in the atmosphere
Causes of enhanced green house effect: urbanisation (changing land use)
D: Urbanisation refers to the process in which an increasing no. of people live in urban areas such as cities or towns →
Ex: singapore → 100% urbanisation rate
A: large amt of fossil fuels burnt to provide energy to provide electricity for household activities such as cooling → high amt of busses and cars → ↑ amt of greenhouse gasses emitted
Causes of enhanced green house effect: Industries (changing land use)
D: Industries refers to the production of goods and services within a country → manufacturing → burning of fossil fuels that result in greenhouse gas emissions
Ex: Greenhouse gasses are released as by-products when goods are produced → manufacturing of mobile phone → 60kg of CO2 → car traveling 7 times the length of pan island expressway in sg
A: ↑ in industries worldwide → ↑in greenhouse gasses produced → ↑in greenhouse gasses in the atmosphere
Impacts of climate change: rise in sea level
D: Sea level rise is the increase in the mean height of the sea’s surface between high tide and low tide relative to land
Ex: Intergovernmental panel on climate change (IPCC) → 33% of coastal and wetland habitats are likely to be lost in the next 100 years if the sea levels continue to rise at the current rates
A: high temp → melting of glaciers in greenland & antartica → resultant meltwater to cause an ↑ in sea levels → hihger temp in the atmosphere cause water in seas to expand → ↑ sea level → ↓ coastal habitats
Impacts of climate change: more frequent weather events
D: Extreme weather events → severe and rare weather phenomenon that results in significant economic losses and the loss of lives → heatwave
Ex: August 2003, europe heatwave → killed more than 70,000 ppl
A: ↑ in occurrence of extreme weather events → due to climate change → ↑ land and sea surface temp → ↑ in amt of latent heat & water vapour → serves as a powerful driving force for extreme weather events
Impacts of climate change: Spread of insect borne diseases
D: Climate change → ↑rainfall and temp → favourable conditions for insects → ↑ in spread of Insect borne diseases → malaria spread by mosquito parasite → high fever, flu like symptoms → dengue fever caused by birus transmitted into humans by the bite of an infectious mosquito → fever, headache and even severe bleeding
Ex: Dengue fever reported in the cool climate areas of nepal and bhutan for the first time in 2004
A:Heavy rainfall my allow mosquitos to grow in numbers in aquatic habitats leading to the spread of malaria and dengue fever → causing the distribution of insect borne diseases to change to regions with moderate temps
Impacts of climate change: Lengthen in growing season in certain regions
D: The growing season refers to a period during which crops can be grown → higher temps may lead to longer growing seasons in some regions
Ex: Canada → increase in soya beans and potatoes → decrease in average wheat grain yield
A: Climate change affects factors such as temperature, rainfall and humidity which may affect the growing seasons of some crops
Responses to climate change: Kyoto Protocal (international agreements)
D: International agreemetnt s are contracts signed by two or more countries
D: the Kyoto protocol refers to an agreement linked to the United Nations Framework Convention on Climate change → first drawn up in kyoto Japan on 11 dec 1997 and came into force on 16 feb 2005
Ex: From 2008 to 2012, countries were obligated to reduce their combined greenhouse gas emissions by at least 5% below their 1990 levels
A: Many countries have met or exceeded the targets set by the kyoto protocal such as finland, greece and ireland
L: there were still countries that did not achieve their targets such as denmark, Austria and spain
