Transcript Climate Change

CLIMATE CHANGE
A current world debate
COLORADO STATE STANDARDS
Colorado Prepared Graduate
Competencies:
• Evaluate evidence that the Earth is a
complex system of interactions
between the geosphere, atmosphere,
hydrosphere and biosphere.
Concepts and Skills students know
include:
4. Climate is the result of energy
transfer among interactions of the
atmosphere, hydrosphere,
geosphere, and biosphere.
Inquiry:
• How have climate changes
impacted human society?
• Why are there different climates on
Earth?
• How can changes in the ocean
create climate change?
• How have climates changed over
Earth’s history?
• How are humans potentially
impacting Earth’s climates?
• How might global warming impact
all of Earth’s systems?
THE CLIMATE CHANGE DEBATE
Not debated: Climate has always changed
throughout Earth’s history.
Debated:
Current climate
change is due to man
made causes.
Versus
Current climate
change is a part of
Earth’s natural cycle.
In this lesson we will look at both sides of the debate
Review: Green House Effect

Without the greenhouse
effect are planet would be
cold and uninhabitable.
Interpreting CO2 Data Part 1



Graph CO2 data set.
This dataset from Mauna Loa is
the most complete and accurate
CO2 dataset in the world. CO2 is
measured in parts per million;
316 parts per million means that
for every 1 million particles in
the atmosphere, 316 of those are
carbon dioxide molecules.
Year should be on the x-axis and
CO2 emissions on the y-axis.
The scale should be appropriate
for the data.



Include all graph
requirements
(title, labeled axis, etc…)
Line Graph (2 lines & 2
different colors)
Answer questions on the back
of graph.
Analysis & Conclusions





What might account for differences in the CO2
concentrations measured in May and October of each
year?
Based on the data shown on your graph, what do you
think the carbon dioxide concentration will be in the
year 2020?
Why do you think carbon dioxide levels have
continued to rise during the past 45 years?
What types of activities might raise carbon dioxide
levels even faster?
How do you think this will affect Earth’s climate?
Is current climate change man made?
Analysis & Conclusions


What conclusions can you draw from this
graph?
Is the graph appropriate to make these
conclusions?
Arguments For Human Caused Climate Change
(Global Warming)
FACTS
 The burning of fossil fuels and the clearing of forests
release carbon dioxide (CO2) into the atmosphere.
 Carbon dioxide and other greenhouse gases in the
atmosphere trap heat through the greenhouse effect.
 Earth is warming because these gasses are being
released faster than they can be absorbed by natural
processes.
 It is very likely (greater than 90 percent probability)
that human activities are the main reason for the
world's temperature increase in the past 50 years.
 The rate of change in temperature is greater than and
change in geological history.
Arguments For Human Caused Climate Change
(Global Warming)
Scientists know with very high confidence, or even
greater certainty, that: (greater than 90 percent
probability)
 It is very likely that human activities are the main
reason for the world's temperature increase in the past
50 years.
 Human-induced warming influences physical and
biological systems throughout the world
 Sea levels are rising
 Glaciers and permafrost are shrinking
 Oceans are becoming more acidic
 Ranges of plants and animals are shifting
Arguments Against Human Caused Climate
Change (Global Warming)











Natural part of Earths cycle of climate changes.
The temperature increase is very small especially when it is spread over a
century.
The earth was warmer before. That did not have harmful consequences
on humans.
The increase in temperature will help plants grow in currently cold and
uninhabitable areas.
The increase in the level of carbon dioxide will stimulate plant growth.
Steps to limit global warming will decrease economic growth and hurt
the poor.
People in fossil fuel industries will lose their jobs.
Rise in carbon dioxide levels has always come after a temperature
change and not before.
The upsurge in solar activity in the sun has caused global warming.
Water vapor plays a major part in global warming. It is argued that man
made emissions like carbon dioxide has only minor effects.
The global warming is a natural phenomenon. Man has no role to play in
it. Only our environment is responsible.
U.S. survey based on the opinions of 3,146
scientists.
Two questions were key:
1.
Have mean global temperatures risen compared to pre-1800s levels.
2.
Has human activity been a significant factor in changing mean global
temperatures?



90 percent of the scientists agreed with the first question and 82
percent the second
The strongest consensus on the causes of global warming came from
climatologists who are active in climate research, with 97 percent
agreeing humans play a role.
Petroleum geologists and meteorologists were among the biggest
doubters, with only 47 percent and 64 percent, respectively, believing
in human involvement.
Study done by University of Illinois