The Grand Challenges

By Bennett Sherry
Every year, we humans release 51 billion tons of carbon. That’s a big problem. But by dividing the problem into five categories, we can make it easier to understand and solve.

Cookie Policy

Our website uses cookies to understand content and feature usage to drive site improvements over time. To learn more, review our Terms of Use and Privacy Policy.

Infographic showing the five grand categories of carbon humans release each year, totaling to 51 billion tons. 31% released making things, 27% released plugging in, 19% released growing things, 16% released getting around, and 7% released keeping warm and cool.
A picture of sharks floating with clouds in the sky.

If greenhouse gases were sharks, maybe we wouldn’t need this course! © Getty Images.

Climate change is threatening our world. It is caused by the buildup of greenhouse gases. These gases are mainly produced by the burning or heating of materials that contain carbon, including fossil fuels like coal, oil, and gas. When these materials are burned or heated, they emit, or release, gases that build up in the upper atmosphere. These gases trap heat. As a result, average global temperatures have risen over time. This global warming has created many new dangers.

Each year, 51 billion tons of greenhouse gases are emitted into Earth’s atmosphere. That’s a huge problem.

How do we begin to solve this problem? One way is to break it into smaller, more manageable pieces. In this course, we divide carbon emissions into five main categories. We call these categories the Grand Challenges. They are:

  1. How we plug in (27 percent of 51 billion tons)
  2. How we make things (31 percent of 51 billion tons)
  3. How we grow things (19 percent of 51 billion tons)
  4. How we get around (16 percent of 51 billion tons)
  5. How we keep cool and stay warm (7 percent of 51 billion tons)

Each of these Grand Challenges is a complex problem on its own. However, they are also very closely connected to each other. That makes things even more complicated. Let’s explore each of the Grand Challenges, their links to each other, and some of the things that make decarbonizing so challenging.

How we plug in (27 percent of 51 billion tons)

The first Grand Challenge is electricity generation. This Grand Challenge does not have the highest percentage of emissions. However, it is the most important. That’s because if we don’t decarbonize electricity generation, progress made in other Grand Challenges won’t really matter. For example, if we replace all gas-powered cars with electric vehicles but still use coal to generate our electricity, we haven’t really fixed the problem. We’ve just moved the carbon around.

This Grand Challenge is a good-news, bad-news situation. The good news is that we already have many solutions. Renewable energy sources like solar power and wind power are becoming cheaper and more widely available. The bad news is that we’re going to need much more electricity. First of all, populations are rising around the world. Secondly, as we electrify things such as cars and industrial processes that have relied on fossil fuels, we will be using more and more electricity.

Side by side images of a coal powered plant with smoke being released into the air and a solar and wind energy plant amongst a clear sky.

Coal power plant and solar and wind energy. © Getty Images.

By 2050, global electricity use could triple. That’s a big problem. In 2023, about 60 percent of global electricity production came from burning fossil fuels—especially coal and gas. Fossil fuels are the cheapest way to generate electricity. In some poorer countries and countries with very large populations, the use of coal-powered electricity is rising.

How we make things (31 percent of 51 billion tons)

The manufacturing processes we use to create concrete, steel, glass, and other materials are contributing greatly to climate change. Altogether, they produce almost a third of humanity’s yearly carbon emissions. These processes require a huge amount of energy. Right now, nearly all that energy comes from burning fossil fuels. But even if we were able to make all this stuff with zero-carbon electricity, we would still run into one major problem.

Side by side images of a massive rotary kiln depicting a cement plant, cement rotary kiln, and cement clinker paired with a diagram of the general layout of a rotary kiln used in cement manufacturing.

One of the massive rotary kilns in which limestone and other raw materials are treated with intense heat to produce the ingredients for cement (left). Cross-section diagram of a rotary kiln (right). By HandaKiln, CC BY-SA 4.0 and LinguisticDemographer, public domain.

That major problem is that for every ton of cement we make, we emit one ton of carbon dioxide (CO2). That’s because we make cement from limestone using extreme heat. This heat causes a chemical reaction which releases CO2. Cement is the key ingredient in concrete. And other than water, concrete is the most-used substance in the world. As populations grow and cities expand, we’re going to need much more of it.

How we grow things (19 percent of 51 billion tons)

A picture of cattle in a grassfield along with a bar graph comparing the gigatons of CO2 emissions per year. China is the highest at 10.2, followed by the United States at 5.3, the Republic of Cattle (if it were a country) is estimated at 5.0, and finally India at 2.5.

If cattle were a country, they would rank third in greenhouse gas emissions. Photo © Getty Images, graph courtesy Gates Notes.

How we produce our food emits huge amounts of greenhouse gases. As the world’s population grows, we’ll need to grow more food. We will need to reduce the emissions food production causes while also making sure everyone has the food they need.

Methane released in agriculture is a big problem. Methane is a powerful greenhouse gas. It is produced by fertilizer and cow burps, and it has about 28 times the warming power of CO2. That’s why cow burps are no laughing matter. In 2023, there were over a billion cattle in the world. They produced so much methane that if they were a country, they would rank third in greenhouse gas emissions.

How we get around (16 percent of 51 billion tons)

Fossil fuels have transformed the way humans live. The engines they power move us and our stuff around the world faster than ever. Gasoline and oil are incredibly powerful and extremely cheap. But that convenience has come at a great cost. Today in the United States, transportation is the largest source of greenhouse gas emissions.

Electric cars are one promising solution. But this Grand Challenge isn’t just about moving ourselves around. It is also about the large-scale movement of goods around the world. That’s bad news because ships, planes, and trucks are very difficult to electrify. They are just too heavy, and they travel too far to be battery-powered.

Photo of two cars, on the left an internal combustion engine is being fueled, and on the right an electric car is being charged.

Two cars, internal combustion engine (left) and electric (right). © Getty Images.

How we keep cool and stay warm (7 percent of 51 billion tons)

A photo of a technician wearing safety equipment and repairing an air conditioner unit.

A technician repairs an air conditioner unit. © Getty Images.

How we heat and cool our buildings is becoming increasingly important. In many regions, climate change is causing deadly heat waves. This makes air conditioning essential to survival. We’re going to need more and more air conditioners in the years to come. However, if we keep using the technology we have now, new units will create more emissions.

One solution is to design new buildings that need less energy and that are able to withstand extreme weather. In addition, buildings that already exist can be upgraded by improving their insulation and heating systems. We already have many of the innovations we need in this category, especially heat pumps. Heat pumps use less energy than gas furnaces. They’re also becoming more affordable. Still, they run on electricity. If we fail to decarbonize the electric grid, all the heat pumps in the world won’t solve this problem.

Conclusion

The five Grand Challenges seem like completely separate categories. But in fact, they are all connected. This can be challenging, but it also can be helpful. On the one hand, it’s hard to predict how changes in one Grand Challenge will influence another Grand Challenge. On the other hand, if we solve a big problem like electricity generation, we can make the other Grand Challenges easier to solve. This is what makes the five Grand Challenges such a helpful tool. By breaking the sources of emissions into separate categories, we can better understand how these sources affect each other. And that helps us decide which climate solutions would do the most good.

Bennett Sherry

Bennett Sherry holds a PhD in history from the University of Pittsburgh and has undergraduate teaching experience in world history, human rights, and the Middle East at the University of Pittsburgh and the University of Maine at Augusta. Additionally, he is a research associate at Pitt’s World History Center. Bennett writes about refugees and international organizations in the twentieth century.

Credit: “The Grand Challengers”, Bennett Sherry / OER Project, https://www.oerproject.com/

Image credits

Creative Commons This work is licensed under CC BY 4.0 except for the following:

Cover image: Climate Project 5 Grand Challenges infographic. By OER Project, CC-BY 4.0. https://www.oerproject.com/OER-Materials/OER-Media/Images/Climate/Unit-1/Course-Infographic

If greenhouse gases were sharks, maybe we wouldn’t need this course! © John M Lund / DigitalVision / Getty Images.

Coal power plant and solar and wind energy. © Martin Ruegner / Getty Images and Mint Images / Getty Images. One of the massive rotary kilns in which limestone and other raw materials are treated with intense heat to produce the ingredients for cement (left). Cross-section diagram of a rotary kiln (right). By HandaKiln, CC BY-SA 4.0 and LinguisticDemographer, public domain. https://commons.wikimedia.org/wiki/File:Cement-plant.jpg#/media/File:Cement-plant.jpg and https://commons.wikimedia.org/wiki/File:CemKilnKiln.jpg#/media/File:CemKilnKiln.jpg

If cattle were a country, they would rank third in greenhouse gas emissions. Photo Photo © Anthony Lee / OJO Images / Getty Images, graph courtesy Gates Notes. https://www.facebook.com/BillGates/photos/a.10150331291841961/10155779305771961/?type=3

Two cars, internal combustion engine (left) and electric (right). © 3alexd / E+ / Getty Images.

A technician repairs an air conditioner unit. © Visoot Uthairam / Moment / Getty Images.


Newsela

Articles leveled by Newsela have been adjusted along several dimensions of text complexity including sentence structure, vocabulary and organization. The number followed by L indicates the Lexile measure of the article. For more information on Lexile measures and how they correspond to grade levels: www.lexile.com/educators/understanding-lexile-measures/

To learn more about Newsela, visit www.newsela.com/about.

The Lexile Framework for Reading

The Lexile® Framework for Reading evaluates reading ability and text complexity on the same developmental scale. Unlike other measurement systems, the Lexile Framework determines reading ability based on actual assessments, rather than generalized age or grade levels. Recognized as the standard for matching readers with texts, tens of millions of students worldwide receive a Lexile measure that helps them find targeted readings from the more than 100 million articles, books and websites that have been measured. Lexile measures connect learners of all ages with resources at the right level of challenge and monitors their progress toward state and national proficiency standards. More information about the Lexile® Framework can be found at www.Lexile.com.