Learning Objectives for Chapter 1: What is Climate Change?
1. Explain the scientific basis for the consensus that climate change is real, that
it is primarily caused by human activity, and that it poses significant risks:
o Scientific Consensus:
▪ IPCC (Intergovernmental Panel on Climate Change) reports
state that human activities, particularly the burning of fossil
fuels, are responsible for warming the climate system. This
consensus is based on multiple lines of evidence, including
rising temperatures, shrinking ice sheets, and higher sea levels.
▪ The Sixth Assessment Report by the IPCC declares it is
"unequivocal" that human influence has warmed the
atmosphere, oceans, and land.
o Human Causes:
▪ Emissions of greenhouse gases (GHGs) such as carbon dioxide
(CO2), methane (CH4), and nitrous oxide (N2O), mainly from
burning fossil fuels (coal, oil, and gas), deforestation, and
industrial processes.
▪ Land use changes (deforestation, urbanization) reduce the
Earth's capacity to absorb carbon dioxide, further amplifying
global warming.
o Risks:
▪ Climate change threatens economic stability, health,
ecosystems, and biodiversity. Extreme weather events like
floods, droughts, and heatwaves are becoming more frequent,
and sea-level rise threatens coastal cities.
▪ Key Risk: Future climate impacts will worsen if GHG emissions
are not rapidly reduced.
2. Explain how the global climate system functions and the physical processes
that determine the Earth's temperature:
o The global climate system includes interactions between the
atmosphere, oceans, ice, land, and biosphere.
o Greenhouse Effect:
▪ The Earth absorbs sunlight and emits heat (infrared radiation).
Greenhouse gases trap some of this heat in the atmosphere,
warming the Earth. Without this natural greenhouse effect,
Earth would be too cold to support life.
, ▪ Enhanced Greenhouse Effect: Human activities are increasing
the concentration of GHGs, leading to excessive warming.
o Ocean and Ice Feedbacks: The ocean absorbs heat and CO2, and ice
sheets reflect sunlight (high albedo). As oceans warm and ice melts,
less sunlight is reflected, contributing to more warming (positive
feedback).
o Key Concept for Exam: Earth's temperature depends on the balance
of incoming solar radiation and outgoing infrared radiation, which is
affected by greenhouse gases, ocean absorption, and ice cover.
3. Define and distinguish between weather, climate, and climate change:
o Weather: Short-term changes in atmospheric conditions (e.g., rain,
wind, temperature) occurring over days or weeks.
o Climate: Long-term averages of weather patterns in a particular
region, typically measured over decades or more.
o Climate Change: A significant long-term shift in climate patterns due
to natural processes or human activities (mainly the burning of fossil
fuels).
o Key Distinction: Weather is what happens day-to-day, while climate is
the average of weather over time. Climate change refers to changes in
long-term climate patterns, typically driven by human activities.
4. Summarize the evidence for modern warming:
o Temperature Records:
▪ Global surface temperatures have risen by around 1.07°C since
the late 19th century, with most of the warming occurring since
the 1970s.
▪ The last decade (2010-2019) was the hottest decade on record.
o Melting Ice and Sea-Level Rise:
▪ The Arctic sea ice is shrinking, glaciers are retreating, and
Greenland and Antarctica are losing ice mass at increasing
rates.
▪ Global sea levels have risen by approximately 20 cm since 1900.
o Extreme Weather:
▪ There has been an increase in the frequency and severity of
extreme weather events, such as heatwaves, heavy rainfall, and
droughts.
o Ocean Warming:
1. Explain the scientific basis for the consensus that climate change is real, that
it is primarily caused by human activity, and that it poses significant risks:
o Scientific Consensus:
▪ IPCC (Intergovernmental Panel on Climate Change) reports
state that human activities, particularly the burning of fossil
fuels, are responsible for warming the climate system. This
consensus is based on multiple lines of evidence, including
rising temperatures, shrinking ice sheets, and higher sea levels.
▪ The Sixth Assessment Report by the IPCC declares it is
"unequivocal" that human influence has warmed the
atmosphere, oceans, and land.
o Human Causes:
▪ Emissions of greenhouse gases (GHGs) such as carbon dioxide
(CO2), methane (CH4), and nitrous oxide (N2O), mainly from
burning fossil fuels (coal, oil, and gas), deforestation, and
industrial processes.
▪ Land use changes (deforestation, urbanization) reduce the
Earth's capacity to absorb carbon dioxide, further amplifying
global warming.
o Risks:
▪ Climate change threatens economic stability, health,
ecosystems, and biodiversity. Extreme weather events like
floods, droughts, and heatwaves are becoming more frequent,
and sea-level rise threatens coastal cities.
▪ Key Risk: Future climate impacts will worsen if GHG emissions
are not rapidly reduced.
2. Explain how the global climate system functions and the physical processes
that determine the Earth's temperature:
o The global climate system includes interactions between the
atmosphere, oceans, ice, land, and biosphere.
o Greenhouse Effect:
▪ The Earth absorbs sunlight and emits heat (infrared radiation).
Greenhouse gases trap some of this heat in the atmosphere,
warming the Earth. Without this natural greenhouse effect,
Earth would be too cold to support life.
, ▪ Enhanced Greenhouse Effect: Human activities are increasing
the concentration of GHGs, leading to excessive warming.
o Ocean and Ice Feedbacks: The ocean absorbs heat and CO2, and ice
sheets reflect sunlight (high albedo). As oceans warm and ice melts,
less sunlight is reflected, contributing to more warming (positive
feedback).
o Key Concept for Exam: Earth's temperature depends on the balance
of incoming solar radiation and outgoing infrared radiation, which is
affected by greenhouse gases, ocean absorption, and ice cover.
3. Define and distinguish between weather, climate, and climate change:
o Weather: Short-term changes in atmospheric conditions (e.g., rain,
wind, temperature) occurring over days or weeks.
o Climate: Long-term averages of weather patterns in a particular
region, typically measured over decades or more.
o Climate Change: A significant long-term shift in climate patterns due
to natural processes or human activities (mainly the burning of fossil
fuels).
o Key Distinction: Weather is what happens day-to-day, while climate is
the average of weather over time. Climate change refers to changes in
long-term climate patterns, typically driven by human activities.
4. Summarize the evidence for modern warming:
o Temperature Records:
▪ Global surface temperatures have risen by around 1.07°C since
the late 19th century, with most of the warming occurring since
the 1970s.
▪ The last decade (2010-2019) was the hottest decade on record.
o Melting Ice and Sea-Level Rise:
▪ The Arctic sea ice is shrinking, glaciers are retreating, and
Greenland and Antarctica are losing ice mass at increasing
rates.
▪ Global sea levels have risen by approximately 20 cm since 1900.
o Extreme Weather:
▪ There has been an increase in the frequency and severity of
extreme weather events, such as heatwaves, heavy rainfall, and
droughts.
o Ocean Warming:
