feedback loop
something that speeds up or slows down a warming trend
positive feedback loop
accelerates temperature raise
negative feedback loop
slows down temperature raise
the natural greenhouse effect is caused by:
radiation
convection
conduction
radiation
the emission of electromagnetic waves such as x-rays, short waves, and long waves
convection
the transfer of heat by he movement of a gas or a liquid
conduction
the transfer of heat by contact
albedo
the fraction of the sun’s radiation reflected from a surface
troposphere
lowest and warmest layer of the atmosphere
includes nearly all water vapour, clouds, and pollutants
most of the weather occurs in this layer
the greenhouse effect occurs here
stratosphere
second layer of the atmosphere
ozone in this layer absorbs higher level UV radiation
mesosphere
third layer of the atmosphere
without ozone or other particles, the temperature decreases dramatically
thermosphere
top layer of the atmosphere
UV and X-radiation from the sun is absorbed, which breaks molecules apart into atoms (oxygen, nitrogen, helium, etc)
temperature increases with height and can reach 2000 degrees celsius
the natural greenhouse effect
the process where shortwave solar radiation passes through the gas molecules in our system (CO2, methane, and water vapour) because they are transparent to solar radiation, in absorbed by the Earth, and then reemitted (by entities in our system: the oceanic land surfaces, vegetation) as infrared radiation. the gas molecules are opaque to the IR radiation, so they absorb the IR and re-irradiate it in all directions, including back to Earth. the heat they send downwards is energy that the Earth has to keep it much warmers then it would be without the presence of GHG.
milankovitch cycles
the pattern that explained why the Ice Ages happened based on two key ideas
the Earth’s climate is strongly affected by how much sunlight the northern latitudes receive during the summer
the amount of sunlight varies based on changes in the Earth’s orbit and rotations
eccentricity, obliquity, and precession affect the amount of sunlight (and energy) that is absorbed by the sun
climate forcing
a factor that drives climate change
global dimming
the amount of sunlight reached has seen a slight decline throughout the years; this is called global dimming. dimming is caused by an increase in particles and surface aerosols which reflect sunlight back into space. water (from clouds) coalesces around the particles and form larger droplets with higher albedo.
the enhanced green house effect
human activity has increased the proportion of GHG in the atmosphere and there is no longer a balance between the incoming and outgoing energy because of additional GHG that trap extreme heat in the atmosphere
reasons for water vapour increase
industry and transportations and as a byproduct of the combustion of fossil fuels
electricity generation (fossil fuels, geothermal and nuclear power release large amounts of steam)
irrigation from agriculture
reasons for carbon dioxide increase
combustion of fossil fuels for heating, electricity, transportation
removal of vegetation
industry production: cement and petrochemicals
reasons for nitrous oxide increase
agriculture: microbial process that breaks down nitrogen in inorganic fertilizers, manure, and urine
combustion of fossil fuels
industrial processes such as the production of adipic acid which releases nitrous oxide
vulnerability
the sensitivity and susceptibility to the adverse affects of climate change and the ability (or otherwise) to cope with them
risk
the potential that the variables associated with climate change will reach such extreme levels that they will have an adverse impact on human life
risk perception
a subjective judgement that people make about a particle risk (it’s severity, possible impacts, etc.)
factors that affect risk
level of education
gender
culture
Bangladesh risks
rising sea levels could reduce land
extreme weather: increase rainfall and more cyclones
soil degradation and erosion
food and water insecurity
Guinea Bissau risks
rainfall is becoming irregular and unpredictable
thermal expansion is increasing flooding
flooding is destroying infrastructure
loss of fishing grounds is reducing food availability
northern Canada risks
decreased ice could allow increased shipping through Arctic waters (risk of oil and chemical spills)
unpredictable weather could cause more accidents
changes in permafrost, sea ice thickness, and extreme weather could present more safety risks
atmosphere
the mixture of gases that surrounds the Earth
the majority of the air we breath is nitrogen
biosphere
contains all living organisms (plants, animals, microorganisms)
hydrosphere
all water in all three phases
the oceans contain 97% of all Earths water
two thirds of fresh water is currently locked up in ice sheets
cryosphere
the part of the Earth where surface is frozen
ex. ice sheets, glaciers, permafrost, and frozen sea ice
overlaps with hydrosphere and lithosphere and influences biosphere and atmosphere
lithosphere
the solid part of Earth - the rocky crust
sea level rise
example: Tuvalu, Oceania
sea levels have been slowly rising because of thermal expansion and ice sheets melting
small pacific islands are slowly starting to disappear
ocean acidification
example: Great Barrier Reef, Oceania
when carbon dioxide is absorbed by water, chemical reactions occur that reduce seawater pH (increases the acidity)
excess hydrogen ions reach with carbonate to make bicarbonate which is bad because marine life uses carbonate to build their calcium carbonate exoskeletons
drought
example: Texas, USA, North America
as average temperatures have risen because of climate change, the Earths water cycle has sped up through an increase in the rate of evaporation which dries out the Earth
droughts cause a significant reduction in crops such as cotton in Texas
74% loss of crops in Texas due to drought
wildfires
example: Greece, Europe
Greece experienced the largest forest fire ever recorded in Europe
fast changing winds made the path of the fire hard to predict and extinguish
animal migration
animals will move to more colder places, but the ones that are already living the coldest places (ie. polar bears) have nowhere to go
species that are already at the top of there thermal tolerance range will decrease band may become extinct
long summers will spread insects and pests
animals will shift poleward
soil erosion
example: South America (Bolivia, Ecuador, Chile, Peru)
a problem in various parts of SA due to poor land management practices deforestation, and extreme weather events
more than 68% of SA is affected by soil erosion because of deforestation and overgrazing
hurricanes
example: US, North America
forms when warm over a warm ocean rises
cool air fills in below and creates cyclonic action
powerful hurricanes in recent years because of unusually warm waters
hurricanes are moving north
deforestation
example: Brazil, South America
deforestation will cause a reduction in carbon sinks
more carbon to be released when fallen trees release them
what usually replaces a forest, livestock and crops, generate massive amounts of GHG
health consequences
heatwaves and other heat related illnesses will increase
vector-born diseases (malaria and dengue) will increase because the geographic range of vectors will expand
ocean transport routes
reduced sea ice in the Arctic will open up new, faster shipping routes
increase in severity and frequency of storms and disrupt shipping schedules
mitigation
actions to reduce emissions that cause climate change
ex. sustainable transport, clean energy, energy efficiency
adaptation
actions to manage the risks of climate change impacts
ex. disaster management and business continuity, flood protection, infrastructure upgrades
examples of things that are mitigation and adaptation
water conservation, local food, education, urban forests
kyoto protocol
1997/2005 - operationalizes the United Nations Framework Convention on Climate Change by committing industrialized countries and economies in transition to limit and reduce greenhouse gases (GHG)
didn’t work because some developing countries that were major GHG emitters (China and India) were exempt.
paris agreement
2015 - the aim is to strengthen the global response to the threat of climate change by keeping a global temperature rise in this century to well below 2 degrees about pre-industrial levels
additionally, the agreement aims to strengthen the ability of countries to deal with the impacts of climate change
carbon price
a carbon “tax” is a free that the government imposed on companies that burn fossil fuels. the money goes towards green technologies. additionally, taxes are lowered on non-fossil fuel products and most is refunded back to individuals.
carbon trading (cap and trade)
government issue permits that are given or auditioned out ti companies. if the company curbs its own carbon, it can trade the excess permits for cash.
geoengineering
large scale manipulations of the environment to counteract climate change
carbon sequestration
planting trees and using soil conservation practices establishing new forests and restoring degraded land
afforestation
planting trees in land that had not been previously forested
reforestation
replacing trees in areas that have been deforested
revelation
restoring vegetation cover in areas where it has been lost
civil society
an organization or movement that works to negotiate matters of public concern
they include non governmental organizations, non profit organizations, labor unions, churches, and other service agencies