GlobalClimateChange Alexi Lindsay
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Dec 6, 2023
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GEOL 121 Name Alexi Lindsay
Lab Section 16
GLOBAL CLIMATE CHANGE LAB
Student Handout
Learning objectives:
To analyze global temperature data to see if Earth’s average global temperatures are really increasing
To analyze CO
2
data to see if atmospheric levels are really increasing
To correlate CO
2
data with global temperature to see if there is a relationship
To compare current trends with rates of change during pre-historic periods using ice core data
To interpret what these results mean for understanding current climate change Why this matters:
Current climate change is affecting many aspects of the environment, with socio-
economic consequences. For example, a warmer climate can allow new diseases to be introduced and persist (e.g. West Nile became established in the United States after an unusually warm winter allowed the mosquitos that carry the virus to survive and spread). We are concerned not only with the actual temperature, but also with the rate that the temperature changes. Very rapid changes make it more difficult for humans to adapt and more likely that other species cannot adapt and will go extinct. Activity A: How much are temperature and atmospheric CO
2
changing? Changes in air temperature -
Scientists from the Goddard Institute for Space Studies, NASA, compiled temperature datasets from weather stations all over the world to create the dataset you are going to be working with today to answer the question: Is earth “warming”? The data you will use are from years 1880-2022. 1.
Before you conduct your analysis, you should first make your predictions. What slope would indicate a warming Earth? What slope would indicate Earth’s average global temperature was not
changing? What slope would indicate a cooling Earth? Sketch lines in the axes below to show what the expected slopes would be in these different scenarios.
cooling
warming
no change
This module was initially developed by O’Reilly, C.M., D.C. Richardson, and R.D. Gougis. 15 March 2017. Project EDDIE: Climate Change. Project EDDIE Module 8, Version 1. http://cemast.illinoisstate.edu/data-for-students/modules/climate-
change.shtml
. Module development was supported by NSF DEB 1245707.
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GEOL 121
Global Climate Change Lab
Getting the air temperature data: These data are compiled by the Goddard Institute for Space Studies, NASA, and are made available at https://data.giss.nasa.gov/gistemp/
. For this lab, the data has been organized into an Excel spreadsheet for you, which you can find on the lab Canvas page. Open up the Global Temperature dataset by selecting the correct tab at the bottom of the spreadsheet.
2.
Examine Graph A.
Describe in words how global temperature has changed between 1880 and 2022.
3.
We will now determine the rate of temperature change. Determining rates of change graphically is straightforward. The average rate of change is just the change in temperature divided by the change in time, or change in y divided by the change in x, or the slope of a line that fits through the data. Excel can calculate the slope of a line very easily. In Graph B
, a linear trendline has been added to the global temperature data (
black dashed line
). The equation for the trendline is also shown (outlined in black). The equation is written in the form y = mx + b
, where m
is the slope and b
is the intercept. Another name for the slope (
m
) is the rate of change. Y=0.0077x-15.03 Y=MX+B ------ Rate of Change (M) = 0.0077 – degree Celsius per year
M = Slope
B= Y intercept
The R-squared (R
2
) is a statistic resulting from a linear regression analysis, which is the statistical name for what we just did by adding a trendline. It describes the proportion of variation in the dependent variable explained by the independent variable. When R
2
~1, the data form a perfectly straight line. As the data become more scattered from the line, R
2
decreases toward 0. Higher R-squared values indicate a stronger relationship between the two variables. Record the R
2
value down with your slope.
a.
Equation for the line: Y=0.0077x-15.03 b.
R
2
= 0.763
c.
Rate of air temperature change (include units): 0.0077 Ft per second.
d.
Given your analysis, is Earth warming? How do you know?
Given my analytical perspective while plugging in the number and looking at the graphs/numbers. The earth is in fact warming every single year solely by looking at the numbers.
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GEOL 121
Global Climate Change Lab
4.
Many scientists suggest that drastic changes in global temperature began in the mid-1900s when fossil-fuel-powered transportation became a mainstay for most families. We can test this hypothesis by adjusting the trendline so that it only looks at the most recent decades, after personal transportation became common. The red solid line
on Graph B
only includes data from
1965-2022. Record the values for the red solid trendline below.
a.
Equation for the line: y=0.0183x – 36.109
b.
R
2
= 0.9194
c.
Rate of air temperature change (include units): 0.00183 Ft per second.
d.
Compare the slopes of these two lines (1880 through 2022 (black) versus 1965 through 2022 (red)). Do your analyses support the hypothesis that the rate of global average temperature is greater in recent decades? By comparing the black line and the red line for the different lengths of time in years, my analysis supports my hypotheses of the rate of global average temperatures increasing much greater in recent decades as we take a good look at the lines. We can see the black line increasing over time at a consistent pace but the red line has skyrocketed in the last couple of decades.
Changes in atmospheric CO
2
- In 1958, Dr. Charles David Keeling (1928-2005), who was a scientist at
Scripps Institute of Oceanography, began collecting data on atmospheric CO
2
concentration at the Mauna Loa Observatory located in Hawaii. This dataset is what allowed us to understand the degree to which climate change is human-caused through our burning of fossil fuels and release of CO
2
into the atmosphere. Due to his scientific achievements, Dr. Keeling was awarded the National Medal of Science
by President George W. Bush in 2002. This is the highest award for lifetime scientific achievement that can be granted in the U.S. Today, you get to analyze this same dataset, except that you have more data than was available to Dr. Keeling and his colleagues, because your dataset extends up to current time.
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GEOL 121
Global Climate Change Lab
Getting the atmospheric CO
2
data: The longest measurements of atmospheric CO
2
concentrations have been done in Mauna Loa, Hawaii. The simplest way to access the data is directly from the Mauna Loa page. http://www.esrl.noaa.gov/gmd/ccgg/trends/
For this lab, the data has been organized into an Excel
spreadsheet for you, which you can find on the lab Canvas page. Open up the dataset by selecting the Mauna Loa CO
2
tab at the bottom of the spreadsheet. 1.
Examine Graph C. Describe in words how atmospheric CO
2 has changed between 1959 and 2022.
CO
2 has changed steadily but it has increased in the recent years as from1959 to 2022 the atmospheric CO
2 jumped 100 units causing the earth to warm up in Mauna Loa, Hawaii
2.
The black dashed line on Graph C
is a linear trendline applied to the CO
2
data. Record the equation and R
2
for this trendline below. Determine the current rate of change for atmospheric CO
2
data, as you did for air temperatures. a.
Equation for the line: 1.6244x-2875.2
b.
R
2
= 0.9818
c.
Rate of air CO
2
change (include units): 0.006244 ft per second
d.
Based on your analysis, has atmospheric CO
2
concentration increased? How confident are
you in these results? I’m beyond confident that the atmospheric CO2 concentration concertation has increased over time especially on in island miles away from a huge continent where the carbon dioxide concentration will still be at high levels.
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GEOL 121
Global Climate Change Lab
Activity B:
How related are the changes in temperature and CO
2
?
1.
To determine whether a change in CO
2
corresponds well with a change in air temperature, you can plot temperature against CO
2
.This is done for you in Graph D
. Describe in words the relationship between atmospheric CO
2
and global temperature.
Determining the change in CO
2 along side the change in temperature we can easily the relationship between the two is very similar as they’re both been increasing over the years rapidly at a consistent pace and both will be friends alongside one another for many more years to come until a proper solution is put in to affect.
2.
The blue solid line is a linear trend line through the CO
2
and temperature data. Record the equation and R
2
below.
a.
Equation for the line: y= 0.0104x – 3.3726
b.
R
2
= 0.9259
c.
Based on your analysis, could atmospheric CO
2
concentration explain the increase in
average global temperature? How strong is the relationship between CO
2
and
temperature? How can you tell?
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GEOL 121
Global Climate Change Lab
Atmospheric CO
2
concentration can most certainly explain the increase in average global temperature as
they almost like cousins to one another, they both line up in the graphs one another side by side. They both benefit from one another only ultimately causing the earth to get warmer each year to great lengths.
Activity C: How do current trends compare to pre-historic rates of change?
An exploration of the Vostok Ice Core - When analyzing Earth’s climate, it is important to remember that Earth is 4.54 billion years old. Our analyses so far have only looked at recent history. How can we compare the recent data to pre-historic time? Are the current rates of change similar or different than those the earth has experienced in the past? To explore this, we can use data taken from ice cores that were drilled at the poles. Hundreds of ice cores have been extracted from polar ice because they contain valuable data on atmospheric chemistry over pre-historic time. These valuable data exist in tiny air bubbles that are trapped in the ice. These air bubbles contain the same gases in the same ratios as the atmosphere at the time when the ice formed. The data you will be analyzing today are from ice cores extracted from the Vostok research station in Antarctica. As you have probably assumed, the depth of the ice core is related to how old the ice is; deep ice is older. There are two other variables that you will be analyzing from the ice cores. The first is temperature, which is reflected by isotopic ratios in the ice of the core so that these isotopic ratios can be converted into air temperatures. The second variable you will analyze is CO
2
concentration, which has been measured from air bubbles trapped in the ice. We can use these data to see
what rates of change were like during this pre-historic period, during which human activity has been minimal. The Vostok ice core data is available through the Carbon Dioxide Information Analysis Center (CDIAC)
http://cdiac.esd.ornl.gov/
. For this lab, the data has been organized into the Excel spreadsheet for you in the Vostok CO
2
and Vostok Temp tabs.
In these data, temperature is calculated from the ‘delta D’ content. Deuterium, or delta D, stands for the relative proportion of two types of hydrogen (
2
H: 1
H). Changes in the proportion of these two types of hydrogen in ice-water correlate to the amount of evaporation and the temperature of the atmosphere. In the next column, paleo-temperatures at Vostok are calculated based on the formula describing the empirical relationship between temperature and deuterium concentration: Temperature (in degrees C) = -55.5 + (delta D + 440) / 6
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GEOL 121
Global Climate Change Lab
1.
Begin with the temperature data, and examine Graph E
. Keep in mind that the x axis refers to how many years ago; so the years go up as you go back in time. This is the custom for research that investigates patterns over long time periods. Describe in words how Antarctic temperature has changed over the last 420,000 years.
Antarctic temperatures have bounced around in change over the last 420,000 years as from the more beginning of time itself in the year 50000 was sitting almost near to -66 degrees Celsius but over time it has bounced around a lot but of recent times from the official marking of -63 to -53 degrees Celsius, that
a 10 degree drop.
2.
On this graph, the colder times correspond to glacial periods (ice ages) and the warmer times correspond to interglacial periods.
a.
Are we currently in a glacial or interglacial period? As of now we’re in an interglacial period of time.
b.
Approximately, how long does a glacial and interglacial period last?
i.
Glacial: 70,000 to 90,000 years
ii.
Interglacial: 10,000 to 30,000 years
3.
On Graph F
a trend line has been added to the ice core temperature data (black dashed line). Take a look at the R
2
value. Do you think this line is a good representation of long-term rates of temperature change? The R
2
value stays at 0.0006, I believe this line is an okay representation of temperature chance on long-
term rates I just don’t see any specific value to the trend line, it feels like I’m not getting enough info or I’m just reading it wrong.
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GEOL 121
Global Climate Change Lab
4.
The next step is to calculate what the fastest rate of change might be. To do this, you want to identify a section of your data where the temperature is changing very rapidly. If you hover your mouse over a data point, it will tell you the data values for that particular point. What is the data point values at the beginning and end of the time period segments that you think
have the steepest slopes:
Graph A for Global Temperature anamoly starts at -0.17 in the year 1880 and now to presents time is 0.89.
5.
The time periods with the greatest rate of temperature change tend to be at the end of the glacial periods. These are call deglaciations. The red solid line and the blue solid line on Graph F are trend lines fit to the data during the two most recent deglaciations. (Note that the slopes of these lines are negative because the time on this graph increases as we go back in time.)
What are the rates of pre-historic temperature change (with units) during each of these deglaciations? Blue Line: Y= -0.0012x + 103.19
Red Line: Y=-0.0001x – 43.683
6.
How do these rates of temperature change compare to what you found for the recent global temperature in Activity A?
They change in opposites as Graph A is global temperatures rising and Graph F is the temperature going back in time as It’s getting colder.
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GEOL 121
Global Climate Change Lab
Now move to the Vostok ice core CO
2
data
7.
Examine Graph G
. This is a plot of CO
2
concentration as a function of (gas) age. Describe in words how CO
2
has changed over the last 420,000 years.
CO
2
has changed over the last 420,000 years by it’s consistent trend over the years but most importantly it’s skyrocketing spike in the most recent years has taken it’s toll on the environment.
8.
According to the CO
2
data from ice cores, during which time frame(s) was there the greatest rate of change in atmospheric CO
2
concentration? How does this change in atmospheric CO
2
concentration correspond to what you see in the ice-core temperature record? The time frame where the greatest rate of change of change in atmospheric CO
2 would be in the most previous years such as 45000, this change in atmospheric CO2 concentration correlates with the ice-core temperature records has the later years was when the levels we’re level and the temperature were colder.
9.
How do the CO
2
concentrations recorded over time in the ice core compare to the current values for today, which you can see in the Mauna Loa data? The co2 concentration record over time in the ice core compared to the current values as a lot had changed in so little time, the differential in temp is so drastic it’s a hard sight to see
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GEOL 121
Global Climate Change Lab
10. Linear trendlines have been added to the Vostok CO
2
data in Graph H
. The black dashed line includes all of the data. The red and blue solid lines just include the two most recent deglaciations (same time periods that we included for the Antarctic temperature). What are the rates of pre-historic atmospheric CO
2
change (with units) for the two deglaciations:
Y=5E-05x +221.02 Is the black dashed line
Blue line = y=-0.0101 +1579.3
Red Line= Y=-0.104x +368.45
11. How do these natural rates of change compare with the modern rate of change? How do current (i.e., in the past ~200 years) changes in atmospheric CO
2
concentration and average global temperature compare to pre-historic (i.e., in the past hundreds of thousands of years) changes in these variables? What does this suggest about whether recent changes in temperature are due to natural or anthropogenic (human) factors? It is plausible that recent increase in atmospheric carbon dioxide is a result of natural fluctuations and not human-induced?
A lot of the changed of temperature may still have to due with naturalist fluctuated factors playing over time but we all know the real reason is due to human factors. 12. If atmospheric CO
2
concentrations continue to rise in the future, how would you expect global temperatures to change?
If atmospheric CO
2
concentrations continue to rise in the future, I would expect global temperatures to change at all time highs, winter will begin to get warmer and summer’s will be drastically hot and the world have failed to prevent this from happening as we enter a new era in our world.
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GEOL 121
Global Climate Change Lab
13. What is still unclear about changing global temperatures and the relationship between atmospheric CO
2
and global temperature? What questions do you have?
N/A
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