1.10: Lab 10 - Climate Change
- Page ID
- 25334
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- Explain the greenhouse effect.
- Differentiate among the major greenhouse gases based on their respective atmospheric concentrations and warming potential.
- Identify fluctuations of Earth’s average temperature over the past 800,000 years.
- Explain the scientific consensus on anthropogenic climate change.
- Analyze carbon dioxide emissions data by country and world region in terms of time, population size, and economic development.
- Interpret global patterns of carbon dioxide emissions from a climate justice framework.
Introduction
Weather is the current atmospheric conditions in a given place and time. Climate is the long-term patterns of weather. Atmospheric conditions are recorded each and every day—by observation, instrument, or, in the long term, by Earth itself. Aggregate records of temperature and precipitation become climate data, revealing averages and extremes over extended periods of time. The Earth’s climate system is a crucial life-sustaining system. It is complex and interdependent on the conditions of the oceans, ice sheets, atmosphere, and biosphere. In studying the Earth’s climate, scientists strive to attain and analyze the longest continuous datasets possible, often spanning hundreds of thousands of years, to learn about climate controls and patterns of climate variability. Their goal is to understand one of the greatest global issues of our time: anthropogenic climate change.
This lab consists of four parts. In the first two sections, you will explore the basic processes and methods scientists use to understand the Earth’s climate. This analysis will provide an understanding of the basis for the scientific consensus on anthropogenic climate change. In the last sections, a geographical analysis of four measures of global carbon footprints reveal patterns of global emissions and the disproportionate impacts of climate change.
Part A. Understanding Climate Science
The graphs below display the contemporary trends of global temperatures, based on the instrumental record, which is data directly recorded by instrumental measurement (Figures 10.1, 10.2, and 10.3). By comparing data sources, scientists can minimize measurement inconsistencies and create a generalized overview. Climate scientists often compute temperature anomalies—the deviation from a set average temperature—to detect temperature trends despite the variability of geographical conditions that impact temperature recordings. For example, a mountain and a valley will have quite different absolute temperature recordings. Looking at anomalies for both locations might reveal that despite different geographical conditions both places were warmer than average. Because temperature anomalies reveal trends, anomalies are often used to understand patterns of climate change.
- In one to two sentences, explain why computed temperature anomalies are often used in global climate studies instead of temperature averages.
Figure 10.1 depicts near identical long-term warming trends from four independent data sources: NOAA’s National Climatic Data Center (blue line), NASA’s Goddard Institute for Space Studies (black line), the Japanese Meteorological Agency (green line), and the United Kingdom’s Met Office Hadley Centre/Climatic Research Unit (orange line).
- Refer to Figure 10.1.
- For what period of time are the displayed instrumental records available?
- How do the four different instrumental records compare?
Figure 10.2 shows the five-year average variation of global surface temperatures between 1880 and 2015. Before 1970, global surface temperatures were generally cooler than the 1910 to 2000 average. Since 1970, the years have been increasingly warmer than the 1910 to 2000 average. Nine of the ten warmest years during this time frame have occurred since 2000.
- Refer to Figure 10.2.
- What does the 0 in the y-axis symbolize?
- How are temperature anomalies measured?
- What is the overall trend of global surface temperature anomalies?
- Refer to Figures 10.1 and 10.2. What is the overall pattern of temperature anomalies since 1880? Tip: identify the data thresholds, which are the points in time that new data patterns emerge.
Figure 10.3 maps the temperature anomaly relative to the 1951-1980 average.
- Describe the geographical distribution of temperature anomalies (Figure 10.3). What places have experienced the greatest temperature increases? Which have not?
An AccuWeather database of more than 3,800 global cities shows that 83% of cities experienced higher than normal temperatures in 2018.
How much warmer was your city in 2018 compared to normal? Search a database of your city (or a nearby city).
- Name your city (or nearby city):
- Was the temperature above or below normal?
- In °F, how much warmer or colder was the temperature?
- Click on °C; how much warmer or colder was the temperature?
- Apply What You Learned: Before searching the database, rank the following cities from 1 to 3 with 1 being the city that warmed the most and 3 with the city that warmed the least.
- Irkutsk, Russia (52°N):
- Nome, Alaska (64°N):
- San Luis Potosí, Mexico (22°N):
- Now, search the database to find out if your ranking was correct. In one to two sentences, explain why you think your ranking was accurate.
Climate Forcings
The interactions of solar energy with land, air, and water shape Earth’s climate system. Earth continuously receives energy from the Sun. A portion of the emitted solar energy that reaches the Earth is reflected back into space; some is absorbed directly by the atmosphere; but some moves through the atmosphere to the Earth’s surface, heating land and water. These processes contribute to Earth’s energy budget calculations that you analyzed in a previous lab. The atmosphere contains greenhouse gases; these gases act as a blanket and trap heat in the lower atmosphere. This process is called the greenhouse effect—it is natural and keeps Earth warm enough to support life (Figure 10.4).
- Do greenhouse gases absorb infrared radiation from the Earth?
- Do greenhouse gases re-emit infrared radiation to the Earth?
- Use Your Critical Thinking Skills: Do you think the greenhouse metaphor or the blanket metaphor best describe how greenhouse gases trap and re-emit longwave radiation? Explain your response in one to two sentences.
As the Earth absorbs energy from the Sun, it eventually re-emits it to space. The difference between incoming and outgoing radiation is known as a planet’s radiative forcing. A climate forcing is a factor impacting this energy budget with the potential to change the climate system. When these factors result in incoming energy being greater than outgoing energy, the planet will warm. Conversely, if outgoing energy is greater than incoming energy, the planet will cool.
Incoming Energy – Outgoing Energy = Radiative Forcing
Climate scientists have identified a number of main factors that influence Earth’s radiative forcing:
➢ Earth’s orbit: The Earth wobbles on its axis, and its tilt and orbit change over thousands of years. These cyclical changes result in significant variations in the amount of solar energy reaching the planet and pushing its climate into and out of ice ages.
➢ Solar output: The amount of solar energy received by the Earth varies, increasing or decreasing by about 0.1% during Sun’s natural 11-year sunspot cycle.
➢ Volcanic activity: Volcanic eruptions release greenhouse gases such as carbon dioxide into the atmosphere that result in warming. However, large volcanic eruptions can substantially increase atmospheric concentrations of sulfate aerosols and particles that shield the Earth from solar energy by reflecting sunlight and thereby cool the Earth’s climate.
➢ Greenhouse gases: Atmospheric gases—such as water vapor, carbon dioxide, and methane—trap heat. While these are naturally occurring gases, burning fossil fuels to fuel industrialization resulted in a large increase of emissions of greenhouse gases. Increased greenhouse gas concentrations result in greater trapping of heat in the lower atmosphere, which increases global average temperatures.
- Which of the main factors that influence Earth’s radiative forcing are from solely natural causes?
- Which of the main factors that influence Earth’s radiative forcing are from both natural and anthropogenic causes?
In order to better understand singular and combined factors’ impacts on climate, climatologists at NASA’s Goddard Institute for Space Studies (GISS) use climate models to test their assumptions and better understand controls of climate variability. As part of a contribution to an international climate research initiative called Coupled Model Intercomparison Project Phase Five (CMIP5), GISS sought to combine results from climate models to see how well they could reproduce what's known about the climate from 1850 to 2012 and to estimate how the various climate forcings contribute to those temperatures.
Figure 10.5 shows the observed global temperatures from 1880 to 2000 in the blue line. Modeled factors include greenhouse gases, volcanic eruption, ozone, solar output, Earth’s orbital changes, land use changes, and aerosols. The red line shows all of these forcings combined.
Figure 10.6 shows the same observed temperatures in blue and combined forcings in red as shown in Figure 10.5. It combines the anthropogenic contributions together in the black line and all of the natural contributions together in the green line.
- Refer to Figures 10.5 and 10.6.
- What is the overall observed pattern of temperature anomalies since 1880?
- Describe the impacts of the following climate forcings on observed temperature changes.
- volcanic eruptions:
- aerosols:
- orbital changes:
- solar output:
- greenhouse gases:
- Which of these forcings appear to have the greatest impact on current temperature patterns ?
- When looking at human factors and natural factors combined (Figure 10.6), how does the correlation to global temperature patterns change? Which factors display stronger correlation to the global temperature anomalies? Explain your response in three to four sentences.
Paleoclimatology
On a planet that is more than 4.5 billion years old, human existence is a short glimpse of time. Amidst such vast natural history, scientists attempt to understand the human context by seeking records and clues to a distant past. The field of study dedicated to understanding long-term patterns of the Earth’s climate beyond human records is called paleoclimatology. In order to reconstruct Earth’s climate history, paleoclimatologists rely on proxy data, or preserved physical attributes that can be measured and analyzed to understand the past. Coral reefs, lakebed and ocean sediments, pollen, tree trunks, and ice cores are some of the natural recorders of climate indicators that scientists use to understand the Earth’s climate beyond the instrumental record. Reading into the past allows us to better understand the present and the future.
Analyzing Ice-Core Data
Ice cores are cylinders of ice that paleoclimatologists drill from ice sheets and glaciers (Figure 10.7). Layers of ice can act as high time-resolution capsules by freezing samples of the atmosphere in tiny air bubbles, thus allowing scientists to access and analyze atmospheric temperatures and composition well beyond the instrumental record. The deeper scientists drill, the older the ice and atmospheric samples that can be extracted.
Under the European Project for Ice Coring in Antarctica (EPICA), scientists drilled and extracted an ice core that is about two miles long, the longest ice core sample as of 2020. The Dome C ice core enabled access to 800,000 years of continuous atmospheric data, revealing ancient atmospheric temperatures and greenhouse gas concentrations. Scientists can then test the data against other ice core data and other data proxies to create aggregate data sets such as the ones shown in Figure 10.8. These graphs represent proxy data from more than 63 locations interpolated by eight climate models with a 1,000-year resolution to reconstruct 800,000 years of Earth's climate.
The trends in the mean global temperature anomaly based on the average temperature of the last 1,000 years are shown in Figure 10.9.
- Refer to Figures 10.8 and 10.9.
- How many years of climate data have been reconstructed? How do scientists construct such extensive datasets?
- Describe the patterns of global temperature, radiative forcing, and greenhouse gases displayed in the graphs above.
- What are the maximum and minimum temperature anomalies recorded?
- How many interglacial periods (times when the temperature deviation reached 0°C) can be detected in this dataset?
- What is the correlation between temperature, radiative forcing, and greenhouse gas concentrations shown in this data record?
- How do concentrations of carbon dioxide and methane of today compare to the patterns of this data record?
- How do today’s recorded temperatures compare to temperature patterns of the past?
- What changes are projected for 2100? What factors do you think explain such a projection?
Part B. Anthropogenic Climate Change
“Human influence on the climate system is clear, and recent anthropogenic emissions of greenhouse gases are the highest in history. Recent climate changes have had widespread impacts on human and natural systems.”
IPCC 5th Assessment Report, 2014
The term climate change refers to the climatic changes that occur over long periods of time. As observed from the datasets in previous sections, Earth’s temperatures varied from epoch to epoch. The paleoclimate record also shows a strong correspondence between temperature and the concentration of greenhouse gases in the atmosphere observed during the glacial cycles of the past several hundred thousand years. Furthermore, studies gauging radiative forcings (Figures 10.5 and 10.6) suggest contemporary warming to be most attributed to increased greenhouse gases.
There is a strong scientific consensus that burning fossil fuels to power global industrialization has changed global atmospheric composition, increased greenhouse gas concentrations, and exacerbated the greenhouse effect. This is what scientists call anthropogenic climate change, or climatic change caused by humans. This change is defined by an increase in global average temperatures, or global warming. Global warming triggers a series of changes in the Earth’s climate system that disrupts life-supporting mechanisms, which will be discussed later in this lab.
Think About It…What is the Scientific Consensus on Climate Change?
Multiple studies in peer-reviewed scientific journals show that 97% of actively publishing climate scientists agree that warming trends of the past century are extremely likely to be anthropogenic (NASA). More than 200 scientific organizations worldwide, including the most prominent American scientific organizations, agree that the Earth is warming due to human causes (NASA).
The Intergovernmental Panel on Climate Change (IPCC) is a United Nations body of hundreds of international scientists that gathered to produce a six-year literature review of the latest climate science to guide policy makers. This panel continuously asserts that human influence on the climate is clear and it is disruptive of Earth’s natural systems (IPCC).
Does the news media that you follow convey the scientific consensus on climate change? What motives do news media have to present biased information on climate change and the scientific consensus about its human causes?
Why CO2 Matters
Carbon dioxide is an abundant greenhouse gas, a gas that absorbs and radiates heat. Different greenhouse gases have different global warming potential (GWP), which is the relative ability to trap heat. Carbon dioxide absorbs less heat per molecule than other greenhouse gases such as methane or nitrous oxide (Figure 10.10). One tonne of methane has 28 times the warming impact as one tonne of carbon dioxide. Nonetheless, carbon dioxide is more abundant and it stays in the atmosphere much longer. In 2018, carbon dioxide accounted for 81% of all greenhouse gasses emitted through human activities in the United States.
NOAA’s Annual Greenhouse Gas Index (AGGI) assesses the radiative forcing of long-lived greenhouse gases. The index compares the combined warming influence of these gases each year, starting in 1980 when NOAA’s global air sampling expanded significantly. Figure 10.11 shows the heating imbalance in watts per square meter relative to the year 1750 caused by all major human-produced greenhouse gases: carbon dioxide, methane, nitrous oxide, chlorofluorocarbons 11 and 12, and a group of 15 other minor contributors. While the radiative forcing of the long-lived greenhouse gases increased 43% from 1990 to 2018, CO2 has accounted for about 80% of this increase.
- Refer to Figures 10.10 and 10.11.
- In your own words, explain GWP.
- In relation to CO2, what is the relative GWP of methane and nitrous oxide?
- Based on NOAA’s Greenhouse Gas Index, how has the radiative forcing attributable to greenhouse gases changed over time? Which gases contribute most to this heating imbalance? Explain your response in two to three sentences.
400pm Threshold
Scientists have long warned about the dangers of unprecedented CO2 concentrations beyond 400 parts per million (ppm). The global average atmospheric carbon dioxide in 2019 was 409.8 ppm, with a range of uncertainty of plus or minus 0.1 ppm (Figure 10.12).
- Refer to Figure 10.12.
- Figure 10.12 displays CO2 atmospheric concentrations and CO2 emissions. Why are such comparisons valuable? What patterns emerge from this data? Explain your response in two to three sentences.
- What is the approximate concentration of CO2 in the atmosphere in 2020 (in ppm)?
- Compare and contrast early industrial atmospheric peak concentrations and emissions to contemporary data. List the similarities and/or differences.
Ice core proxy data provides evidence that carbon dioxide levels today are higher than at any point in at least the past 800,000 years (Figure 10.13).
- Refer to Figure 10.13. What is the approximate highest CO2 concentration recorded in the paleorecord? How does this compare to the 2020 value?
Direct observations and data collection at four observatories provide evidence of monthly average carbon dioxide concentrations since the 1970s (Figure 10.14). Note that in Figure 10.14, the annual oscillations at the two northern hemisphere sites (Barrow, Alaska and Mauna Loa, Hawai’i) are due to the seasonal imbalance between the photosynthesis and respiration of plants on land. The difference between Mauna Loa and the South Pole has increased over time as the global rate of fossil fuel burning, most of which takes place in the northern hemisphere, has accelerated.
Think About It…Why are the Baseline Observatories Located Where They Are?
Direct instrumental observations of carbon dioxide and methane occur at stations all around the world. Only four of these locations are called the baseline observatories. Figure 10.15 shows the locations: Barrow (Alaska); Mauna Loa (Hawai’i); American Samoa; and the South Pole (Antarctica). These observatories were established in order to provide sampling of the most remote air on the planet so that the true “background atmosphere” could be monitored.[171]
- Refer to Figure 10.14.
- Describe the overall trend shown.
- Approximately what year did all baseline observatories record 400 ppm concentrations?
- What CO2 (ppm) value was the maximum-recorded concentration? When and where did this occur?
- Use Your Critical Thinking Skills: Why do you think this location recorded the highest concentration of carbon dioxide? Explain your response in at least one sentence.
Future Scenarios
Based on present patterns of increasing greenhouse gas emissions, scientists warn of diverse negative impacts of increased average global temperatures on natural and human systems. A warmer world threatens oceans, coastlines, biodiversity, and agriculture, and exacerbates extreme weather events and tensions over resources. Commitments to reduce greenhouse gases have evolved over a series of global agreements, all of which have shown limited results. What does the future look like? Climate policy matters.
The visualization below shows a range of potential scenarios modeled based on contemporary patterns (Figure 10.16). The graph’s y-axis shows gigatonnes of carbon dioxide equivalents. Greenhouse gases are often normalized in measures of carbon dioxide equivalents, a standard unit based on the radiative forcing of a molecule of carbon dioxide over a time frame (often a 100-year period). Each scenario shows a range of shading due to the uncertainty of emissions—whether there are low or high emissions within each pathway is unknown. Here is a summary of each of the four scenarios:
➢ No climate policies: Represents expected emissions in a baseline scenario if countries had not implemented climate reduction policies. This would result in a warming of 4.1 to 4.8°C by 2100.
➢ Current policies: Represents emissions with current climate policies in place. This would result in a warming of 2.8 to 3.2°C by 2100.
➢ Pledges and targets: Represents emissions if all countries delivered on the reduction pledges they have made as of December 2019. This would result in a warming of 2.5 to 2.8°C by 2100.
➢ 1.5°C and 2°C pathways: Represents the goals outlined in the 2016 Paris Agreement by the United Nations Framework Convention on Climate Change. These pathways were developed based on more than 6,000 research papers to show that it is possible to limit warming and its ill-effects.
- Refer to Figure 10.16.
- Based on current policies, what is the projected temperature warming range for the year 2100?
- Use Your Critical Thinking Skills: Why do the three scenarios (no climate policies, current policies, and pledges and targets) have a wide range of emissions possible by 2100? Tip: list the variables that account for carbon dioxide emissions globally.
Part C. The Blame Game: Four Ways of Looking at Carbon Footprints
Globalized industrialization and fossil fuel based economic growth to fulfill the wants and needs of a growing population are largely responsible for increased greenhouse gas emissions, namely of CO2. But what countries are most responsible? Certainly, some countries emit more greenhouse gases than others, thus disproportionately contributing to a problem that is shared worldwide, also in a disproportionate manner.
Let’s analyze four datasets depicting global carbon footprints, mainly displayed in a series of maps:
- Current CO2 Emissions per Year (CO2/year)
- CO2 Emissions per Capita (CO2/person)
- Carbon Intensity (CO2/gross domestic product)
- Cumulative CO2 Emissions (from the Industrial Revolution to the present)
Depending on how emissions are measured, different countries stand out, thus exposing some nuances that relate to history, population, and economic development. As you go through each carbon footprint dataset, think about which countries and regions stand out as the largest contributors to carbon dioxide emissions (and thus anthropogenic climate change).
1. Current CO2 Emissions per Year (CO2/year)
Current emissions refer to the total CO2 emissions within a one-year time frame. See below some of the ways it can be displayed (Figures 10.17 through 10.19).
- Refer to Figure 10.17. Tip: use an atlas, Google maps, or go to the links provided in the captions to help you identify countries.
- What does Figure 10.17 convey about CO2 emissions?
- Use Your Critical Thinking Skills: Are you surprised by the information presented on this map? Why or why not?
- Refer to Figure 10.17.
- What does Figure 10.18 convey about CO2 emissions?
- Complete Table 10.1 below.
| Category | Country | World Region |
|---|---|---|
| Highest emitter of CO2 per year (tons) | ||
| Second highest emitter of CO2 per year (tons) | ||
| Third highest emitter of CO2 per year (tons) | ||
| World region that is the lowest emitter of CO2 per year (tons) | N/A | |
| World region that is the second lowest emitter of CO2 per year (tons) | N/A | |
| World region that is the third lowest emitter of CO2 per year (tons) | N/A |
- Refer to Figure 10.19. Tip: use an atlas, Google maps, or go to the links provided in the captions to help you identify countries.
- What does Figure 10.19 convey about CO2 emissions?
- Over time, which countries/regions have experienced the greatest increases?
- Refer to Figures 10.17 through 10.19. List the key differences between the three figures. Hint: compare and contrast the similarities and differences.
2. CO2 Emissions per Capita (CO2/person)
Another way to analyze carbon dioxide emissions is to divide the total emissions for a particular country or region by its population (Figure 10.20). This lets us know where in the world the average person emits the most CO2.
- Compare Figure 10.17 to Figure 10.20. What are three key differences that you notice between the two maps? Tip: use an atlas, Google maps, or go to the interactive versions online to help you identify countries.
Figure 10.21 highlights the fact that countries vary in their population sizes and levels of wealth, measured by gross domestic product (GDP), focusing on CO2 emissions per person. GDP represents all the goods and services that an economy produces in one year.
- Refer to Figure 10.21.
- What does the graph convey about CO2 emissions per capita and GDP per capita?
- Use Your Critical Thinking Skills: What does an analysis of per capita carbon dioxide emissions and GDP reveal in terms of reducing emissions globally? Explain your response in two to three sentences.
3. Carbon Intensity (CO2/gross domestic product)
Now you will investigate the relationship between CO2 emissions and economic output, as measured by the gross domestic product. Countries that generate a lot of economic output by emitting CO2 are known as carbon dependent economies, and they showcase high carbon intensity. Overall, as countries develop into information technology economies, the share of the GDP from carbon dependent energy and activities is likely to decrease.
Furthermore, wealthier countries are better able to invest in green technologies and enforce climate policies and commitments. Figure 10.22 presents carbon intensity as a graph while Figure 10.23 presents the same information as a map.
- Refer to Figures 10.22 and 10.23.
- As of 2016, which five countries had the highest carbon intensity?
- Use Your Critical Thinking Skills: List the underlying factors that explain why these five countries had the highest carbon intensity.
- What has happened to carbon intensity overall between 1870 and 2016?
- Use Your Critical Thinking Skills: List the underlying factors that explain the observed trend in carbon intensity.
4. Cumulative CO2 Emissions (Industrial Revolution–present)
While we tend to look at emissions yearly, it is important that a long-term perspective is also applied when analyzing carbon dioxide emissions. Figure 10.24 shows the cumulative CO2 emissions since the Industrial Revolution by country. Figure 10.25 shows the share of cumulative CO2 emissions as a percentage of total emissions.
- Refer to Figures 10.24 and 10.25.
- Which three countries had the highest cumulative CO2 emissions between the Industrial Revolution and the present day?
- Use Your Critical Thinking Skills: How does the cumulative analysis enhance your understanding of carbon dioxide emissions?
- Use Your Critical Thinking Skills: List the underlying factors that explain the observed trend in the share of cumulative CO2 emissions.
- Which three countries had the highest cumulative share of CO2 emissions in 1800?
- Which three countries had the highest cumulative share of CO2 emissions in 2017?
- Use Your Critical Thinking Skills: In one to two sentences, explain why your answers to questions a, d, and e above are not the same.
- You analyzed carbon dioxide emissions using four different measures: current CO2 emissions per year (CO2/year); CO2 emissions per capita (CO2/person); carbon intensity (CO2/gross domestic product); and cumulative CO2 emissions (Industrial Revolution–present). What are three overall conclusions you can make based on your analysis?
- Use Your Critical Thinking Skills:
- Which analysis would you use if you wanted to promote the narrative that the United States is to blame for carbon emissions? Explain your response in at least one sentence.
- Which analysis would you use if you wanted to promote the narrative that the United States is not to blame for carbon emissions? Explain your response in at least one sentence.
- Why is a nuanced perspective that incorporates all four methods of analysis preferred? Explain your response in at least one sentence.
Part D. Climate Justice
Given the realities of climate impacts, global movements have focused on climate justice, a concept that transcends discussing climate change from a purely physical or environmental issue to a political and ethical one. Because the effects of climate change are carried unevenly, discussing climate futures must consider how high-income countries will lead in resolving an issue they share greater responsibility in causing while at the same time supporting sustainable development for the world's poor. Furthermore, intersections of climate issues with racial, ethnic, gender, and national identities, for example, highlight the complexities of the issue. Climate justice contends that every person in the world has the right to enjoy the Earth's life-supporting environmental systems—a concept encompassed by the "rights to adequate standards of living" in the Universal Declaration of Human Rights.
Check It Out! Environmental Justice Atlas
Climate justice is one facet of the environmental justice movement. You can further explore case studies on environmental justice through the Environmental Justice Atlas.
Carbon Inequity
Data analysis from the previous section shows prominent global patterns of CO2 emissions. The disproportionate manner in which countries emit carbon dioxide is called carbon inequity. Historically, a handful of countries have emitted the most, causing an accumulation of CO2 in the atmosphere that scientists agree to have disrupted the Earth’s climate system. The breakdown of global carbon dioxide emissions in 2016 by World Bank income group (Figure 10.26) and by world region (Figure 10.27) reveals carbon inequity. Average per capita emissions are shown on the y-axes and population size is shown on the x-axes. The area of the boxes shown represent the total annual emissions in 2016. These graphs allow for an analysis of the disproportionality of per capita emissions.
Figure 10.28 shows a map of the World Bank’s income groups for reference.
- Refer to Figures 10.26 through 10.28.
- What are the five categories the World Bank uses to group countries by income?
- What is portrayed on the x-axes of Figures 10.26 and 10.27?
- What is portrayed on the y-axes of Figures 10.26 and 10.27?
- What income group are the United States and the United Kingdom classified as?
- What income group are China and Russia classified as?
- What income group is India classified as?
- Complete Table 10.2 below.
| Income Group/Region | % of Global Population | % of Global CO2 |
|---|---|---|
| High Income Group | ||
| Upper-middle Income Group | ||
| Lower-middle Income Group | ||
| Low Income Group | ||
| North America | ||
| Europe | ||
| Latin America and the Caribbean | ||
| Asia |
- What are three conclusions that you can make about per capita emissions by world region and income group? Your response should be at least three sentences in length and cite data provided in the figures and table.
Economic Impacts of Climate Change
For decades, the IPCC has reported that the impacts of a warming planet continue to trigger climatic changes at global, regional, and local scales. Sea level rise, glacier melting, flooding, drought, loss of terrestrial and marine biodiversity, increased frequency and intensity of megafires and storms, heat waves, and increased uninhabitable land are some of the examples of the present and future impacts of climate change. While the expressions of a disrupted global climate system vary geographically, its impacts are overall detrimental to and disruptive of livelihoods all over the world—in a disproportionate manner.
There are a myriad of ways that geographers and other scientists study the distribution of climate impacts. Often, researchers utilize climate projection datasets derived from the most reputable climate models to infer climate change impacts on various facets of our society. Some studies focus on impacts on food production, mortality, poverty, coastal infrastructure, storms, heat waves, climate-induced migrations and political conflicts, and so on. The dataset below utilizes climate impact projections of a global warming of 2°C and its impact on national GDP, a universal language for policy makers (Figure 10.29). The map is based on an analysis from the “Half a degree Additional warming, Prognosis and Projected Impacts” project (HAPPI) that assessed changes in economic growth using empirical estimates of climate impacts in a global panel dataset.
- Refer to Figure 10.29.
- In two to three sentences, describe the geographical distribution of the economic impacts of 2°C warming.
- Compare Figures 10.28 and 10.29. Which income group faces the most economic losses?
- Compare Figures 10.24 and 10.29. Are the countries projected to face the most economic losses the same countries as those with high cumulative emissions?
Another economic measure of the climate crisis is to look at its impacts on global poverty. Despite decades of global poverty reduction, the World Bank (2020, n.p.) estimates that without climate action 100 million more people will dip below poverty by 2030 (Figure 10.30). Poverty is an important measure, as it is a control factor on various measures of human well-being and quality of life. These measures include access to vital resources, education, health, safety, and so much more. Low income countries are less able to adapt to the challenges of climate change, and thus are more vulnerable to its impacts. Figure 10.30 shows the prediction of additional people at risk of extreme poverty in 2030. The map was created based on the differences in the projected number of people living in extreme poverty between the baseline (business-as-usual) scenario and the projected scenario. The international poverty line is measured as living on less than $1.90 per day, which adjusts for inflation and cross-country price differences. The data takes into consideration how, when combined, low economic growth, low educational attainment levels, and high population growth result in challenges to climate mitigation and adaptation.
NASA explains the difference between mitigation and adaptation:
➢ Mitigation—reducing climate change—involves reducing the flow of heat-trapping greenhouse gases into the atmosphere, either by reducing sources of these gases (for example, the burning of fossil fuels for electricity, heat, or transport) or enhancing the “sinks” that accumulate and store these gases (such as the oceans, forests, and soil). The goal of mitigation is to avoid significant human interference with the climate system, and “stabilize greenhouse gas levels in a time frame sufficient to allow ecosystems to adapt naturally to climate change, ensure that food production is not threatened and to enable economic development to proceed in a sustainable manner” (from the 2014 report on Mitigation of Climate Change from the United Nations Intergovernmental Panel on Climate Change, page 4).
➢ Adaptation—adapting to life in a changing climate—involves adjusting to actual or expected future climate. The goal is to reduce our vulnerability to the harmful effects of climate change (like sea-level encroachment, more intense extreme weather events, or food insecurity). It also encompasses making the most of any potential beneficial opportunities associated with climate change (for example, longer growing seasons or increased yields in some regions).[187]
- Refer to Figure 10.30.
- Which countries/world regions, shown in dark blue and light blue, are expected to reduce the number of people living in extreme poverty by 2030?
- Which countries/regions, shown in orange and red, are expected to have the highest increases of people at risk of extreme poverty by 2030?
- Do you think the map is a good indicator of climate vulnerability? Why or why not? Explain your response in two to three sentences.
- Use Your Critical Thinking Skills: In thinking about carbon inequities, list what tensions may arise in global climate policy decision-making.
Check It Out! Environmental Justice and Urban Heat
Learn about urban heat and the impact of racism in this article by National Geographic called “Racist housing policies have created some oppressively hot neighborhoods”. This article shows how the impacts of climate change, combined with institutional and interpersonal forms of racism, affect populations at the neighborhood level. In this lab, you have investigated climate change primarily at global and national scales. It is important to note that geographers also study climate change at regional and local scales; this article provides an introduction to this type of research.
Part E. Wrap-Up
Consult with your geography lab instructor to find out which of the following wrap-up questions you should complete. Attach additional pages to answer the questions as needed.
- What is the most important idea that you learned in this lab? In two to three sentences, explain the concept and why it is important to know.
- What was the most challenging part of this lab? In two to three sentences, explain why it was challenging. If nothing challenged you in the lab, write about what you think challenged your classmates.
- What is one question that you have about what you learned in this lab? Write your question along with one to two sentences explaining why you think your question is important to ask.
- Review the learning objectives on page 1 of this lab. How would you rate your understanding or ability for each learning objective? Write one sentence that addresses each learning objective.
- Sketch a concept map that includes the key ideas from this lab. Include at least five of the terms shown in bold-faced type.
- Create an advertisement to educate your peers on the important information that you learned in this lab. Include at least three key terms in your advertisement. The advertisement should be about half a page in size (about 4 inches by 6 inches).
- One way to think of physical geography is that it is the study of the relationships among variables that impact the Earth's surface. Select two variables discussed in this lab and describe how they are related.
- How does what you learned in this lab relate to your everyday life? In two to three sentences, explain a concept that you learned in this lab and how it relates to your day-to-day actions.
- How does what you learned in this lab relate to current events?
- Write the title, source, and date of a news item that relates to this lab.
- In two to three sentences, discuss how the news item relates to what you have learned in this lab.
- In one to two sentences, discuss whether or not the news item accurately represents the science that you learned. Tip: consider whether or not the news item includes the complexity of the topic.
- Search O*NET OnLine to find an occupation that is relevant to the topics presented in today's lab. Your lab instructor may provide you with possible keywords to type in the Occupation Quick Search field on the O*NET website.
- What is the name of the occupation that you found?
- Write two to three sentences that summarize the most important information that you learned about this occupation.
- What is one question that you would want to ask a person with this occupation?
[171] Text by NOAA is in the public domain
[187] Text by NASA is in the public domain