7.2 Climate & Weather Flashcards
what are the extreme weather conditions and the country examples
- Drought: Brazil, Australia
- Heatwave: Iran, India
- Intense Rainfall: Ghana, Texas
- Cyclones: South Pacific (Cyclone Pam)
define climate and weather
Climate = average weather over a long term
Weather = average weather over a long period
factors affecting climate outside and within earth
Outside: solar rad from sun, tilting and orbit of the earth
Within: atmospheric & ocean circulation systems, GHG that trap heat and warm the planet, volcanic activity, feedback cycles
tilting & orbit of the earth causing seasons
- axis of the earth is tilted at 23.5° angle
- when northern hemisphere tilts towards the sun it absorbs more sunlight = summer and southern hemisphere is winter bc tilted away from sun
define the elliptical orbit and the Milankovitch cycle
= distance of earth from sun varies throughout the year (closest in jan)
= axical tilts, precession, and eccentricity –> it influences the amount of sunlight reaching earth so influences glacial & interglacial periods
atmospheric & ocean circulation systems
- more rad reaches the equator than the Polar Regions due to the earth’s curvature
- ocean circulation systems are caused by wind and difference in water temp & salinity
- movement of air from high (cold) to low pressure (warm) causes winds
what is the El Niño
Happens when warm ocean water piles up along the equatorial west coast of South America
- every two to seven years, and typically last nine to 12 months. It is a naturally occurring climate pattern associated with warming of the ocean surface in the central and eastern tropical Pacific Ocean
volcanic activity
- reactions in the atmosphere from volcanic gases form sulphate aerosol that reflects solar radiation into space = global cooling
e.g. eruption of Mt. Pinatubo in the Philippines in 1991 had cooling effect for ab 3 years
examples of negative feedback
Water vapour: a GHG so increase in temps resulting causing more ice to melt and water to evaporate
Ice albedo: temp increase = ice & snow melt = reducing solar reflected back = dark surfaces replacing them so increase absorption of sunlight = raised temps
Permafrost: increase in temps = melting of permafrost which releases methane (GHG) = increased temps
examples of negative feedback
Plant photosynthesis: if temps increase level of plant photosynthesis can rise & more CO2 absorbed = reduction in global temps
Cloud cover: low clouds reflect some incoming solar rad increasing cooling
temp increase
from 1880-2013 CO2 level went up by 40% so global temps increased by 0.85° =
- rise in temp = more water evap = more rainfall
sea level rise
- rose by 19cm between 1901-2013
- increase in temp leads to ocean thermal expansion and increased melting of snow and ice
- rise in sea levels may increase saline intrusion of groundwater near coastal areas (too salty for agricultural use)
- The Maldives, Netherlands, Bangladesh in trouble
impact of climate change on agriculture
- agriculture will improve in some areas w increase in temp and precipitation
- increased level of CO2 might increase photosynthesis but there’s limited water and nutrients
- increase in temps in other regions might make it easier for pests to spread (e.g. earworm from USA to Northern Europe)
impact of climate change on fisheries
- higher water temp can cause organism death, migration towards the poles, change in spawning period, and coral bleaching
- increase in ocean acidity caused by higher atmospheric CO2 (causes decline in reproduction and reduction in growth/development
range shifts
- shift of biomes w/ animals and plants towards the poles
- geographical range for some species will expand, threatening local species
- less adaptive species will decrease in numbers w risk of extinction
migration patterns
- change in mating time = earlier production might mean not enough resources available
climate septic and advocator views
Climate Septics: don’t believe in climate change or that it’s caused by humans –> argue that warming is natural caused by natural events and that climate change models are inaccurate
Climate Advocators: believe climate change is mainly human caused –> argue that rise in GHG since industrial revolution caused rise in temps
EVS
ecocentric: change in behaviour and lifestyle to reduce GHG or production
anthropocentric: regulations to reduce GHG
tehcnocentrics: invest in tech to reduce GHG in the atmosphere
