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Course: World History Project - Origins to the Present > Unit 6
Lesson 1: Era 6 Overview | 6.0READ: Data Exploration - Greenhouse Gas Emissions
It’s getting hot out there, folks. These charts provide an overview of historic changes in average temperature and greenhouse gas emissions— with an eye toward the future.
The data exploration article below uses “Three Close Reads”. If you want to learn more about this strategy, click here.
First read: preview – what do we have?
This will be your quickest read. It should help you get the general idea of what this chart is about and the information it contains. Pay attention to:
- Labels and titles. What is the title? How are the axes labeled? Is anything else on the chart labeled?
- Data representation. How many variables are there and what are they? What are the scales? What time period does the chart cover? Is the chart interactive?
- Data source. Where did the data for this chart come from? Do you trust it? Who created the chart?
Second read: key ideas – what do we know?
In this read, you will pay attention to the information that most helps you understand the chart and the information it is trying to convey. Pay attention to:
- Claim(s). What can you say about the data? What story does it tell? Can you make any claims about this data? Does it change when you zoom in compared to when you look at the data as a whole?
- Evidence. What data from the chart supports this story? Does this change if you change the scale or variables?
- Presentation. How does the way this chart is presented influence how you read it? Has the author selected certain variables or scales that change the conclusions that can be drawn? Is there anything missing from this chart?
By the end of the second read, you should be able to answer the following questions:
- According to Charts 1 and 2, when did the global average temperature start to rise most dramatically, and what caused it?
- Looking at Chart 2, who are the biggest producers of CO2 emissions?
- According to Chart 2, who produced most of the world’s CO2 emissions before 1900?
- According to Chart 3, what countries produced the most CO2 emissions during the First and Second World Wars? Are there any major countries that you think produced a lot of emissions but are not represented accurately on this map?
- Looking at the five possible future scenarios on Chart 4, which do you think is the most likely?
- Considering the information on Chart 1 and 4, if all countries act immediately and aggressively to decrease our greenhouse gas emissions, will the global average temperature decrease by 2100?
Third read: making connections – what does this tell us?
The third reading is really about why the chart is important and what it can tell us about the past and help us think about the future. Pay attention to:
- Significance. Why does this matter? Does this impact me, and if so, how? How does it connect what is going on in the world right now? How does it relate to what was happening at the time it was created?
- Back to the future. How does this data compare to today? Based on what you now know, what are your thoughts on this phenomenon 25 years, 50 years, and 100 years from now?
At the end of the third read, you should be able to respond to these questions:
- Why does this chart matter? What do these charts about average temperature and emissions tell us about the history of human production and distribution? Can data help us change the future?
- Using these charts, make one prediction about how global average temperature or greenhouse gas emissions will change in your lifetime. What evidence from the charts supports your prediction? What evidence challenges it?
Now that you know what to look for, it’s time to read! Remember to return to these questions once you’ve finished reading.
Greenhouse Gas Emissions Data Introduction
By Hannah Ritchie and Max Roser, adapted by Eman M. Elshaikh
It’s getting hot out there, folks. These charts provide an overview of historic changes in average temperature and greenhouse gas emissions— with an eye toward the future.
Introduction
Lately, there has been a lot of talk about carbon footprints. What people are referring to is carbon dioxide, a gas that contributes to the warming of the Earth's climate. Your carbon footprint measures the amount of carbon dioxide that is produced from your daily activities: the energy you consume, things you buy, and food you eat. But carbon dioxide is just one of many greenhouse gases. Greenhouse gases create the "greenhouse effect," which warms the Earth's climate. That's not necessarily a bad thing. In fact, we need these gases—like carbon dioxide (CO2), nitrous oxide, methane, and others—to keep the temperature of the planet livable for many organisms—including us. If there were absolutely no greenhouse gases (GHGs), the average surface temperature of the Earth would be about -18 degrees Celsius
Particularly since the Industrial Revolution, energy production has gone up dramatically. Energy production using fossil fuels has led to a rapid increase in GHGs, which has led to global warming. Climate change has a range of possible effects on the environment and on people's health. It can make extreme weather events, like floods, droughts, storms, and heatwaves more common and intense. It can cause the sea levels to rise, plants to grow differently, and water systems to change.
In light of this evidence, UN member parties have set a target in the Paris Agreement of limiting average warming to 2 degrees Celsius above pre-industrial temperatures. In this data exploration, you'll get a historical perspective on how CO2 emissions have evolved, how emissions are distributed, and the key factors that both drive these trends and hold the key to limiting climate change.
Looking at the data: Long-term global average temperature change
To set the scene, let's look at how the planet has warmed. In Chart 1 we see the global average temperature and how it's changed since 1850. The red line represents the average annual temperature trend through time. But we can't be 100 percent precise about these temperatures, so the two light-gray lines show the possible range.
In this chart, we see that over the last few decades, global temperatures have risen sharply. Overall, if we look at the total temperature increase since pre-industrial times, this amounts to approximately 1 degree Celsius. The chart also shows that the temperature increase in the Northern Hemisphere is higher (around 1.4 degrees Celsius since 1850) than in the Southern Hemisphere (around 0.8 degrees Celsius). This relates to the fact that the Northern Hemisphere has much more land than the Southern Hemisphere—and land heats and cools much more quickly than the ocean.
Chart 1:
CO2 emissions by region
So, we know that temperatures are rising, but what's causing it? The data shows a relationship between rising temperatures and increased emissions of greenhouse gases. Global emissions have increased from 2 billion tons of carbon dioxide in 1900 to over 36 billion tons 117 years later. Chart 2 breaks this data down by region. Chart 3 shows a map view of annual emissions in 2018.
Chart 2:
Chart 3:
Future emission scenarios
What does the future of our carbon dioxide and GHG emissions look like? In Chart 4, we show five possible future scenarios involving GHG emissions and temperature increases:
- No climate policies: Projected future emissions if no climate policies were implemented. This would result in an estimated 4.1 to 4.8°C warming by 2100 (relative to pre-industrial temperatures).
- Current climate policies: Projected warming of 2.8 to 3.2°C by 2100 based on current implemented climate policies.
- National pledges: If all countries achieve their current targets/pledges set within the Paris Agreement, it's estimated average warming by 2100 will be 2.5 to 2.8°C. This would exceed the overall target of the Paris Agreement to keep warming "well below 2°C."
- 2°C consistent: There are a range of emissions pathways that would be compatible with limiting average warming to 2°C by 2100. This would require a significant increase in ambition of the current pledges within the Paris Agreement.
- 1.5°C consistent: There are a range of emissions pathways that would be compatible with limiting average warming to 1.5°C by 2100. However, all would require a very urgent and rapid reduction in global greenhouse gas emissions.
Chart 4:
Author bios
Hannah is Senior Researcher and Head of Research at Our World In Data. She focuses on the long-term development of food supply, agriculture, energy, and environment, and their compatibility with global development. Hannah completed her PhD in GeoSciences at the University of Edinburgh.
Max is the founder and director of Our World in Data. He began the project in 2011 and for several years was the sole author, until receiving funding for the formation of a team. Max’s research focuses on poverty, global health, and the distribution of incomes. He is also Programme Director of the Oxford Martin Programme on Global Development at the University of Oxford, and Co-executive Director of Global Change Data Lab, the non-profit organization that publishes and maintains the website and the data tools that make OWID’s work possible.