Directions for teachers: Ask students to read the online Science News article “It’s possible to reach net-zero carbon emissions. Here’s how,” which explores various solutions to decrease greenhouse gas emissions, and answer the following questions. Questions are broken up by article section. You may want to direct students to answer the first two sets of questions, then break them into groups to answer one of the remaining sets of questions. Groups can then share their answers with the class. A version of the article, “The road to net-zero,” appears in the January 28, 2023 issue of Science News.

Introduction

1. What does the phrase “net-zero emissions” mean?

Net-zero emissions refers to balancing the greenhouse gases emitted into the atmosphere with those taken out. The idea is that removing greenhouse gases from the atmosphere effectively cancels out the gases that are emitted. 

2. What problem do scientists hope net-zero emissions will help solve?

Scientists hope that this net-zero strategy will help keep Earth’s climate from warming 1.5 degrees Celsius above preindustrial levels, which would make rising sea levels, extreme weather and other impacts worse than they already are.

Section 1: The current state of CO₂

3. What are the greenhouse gases that researchers want to remove from Earth’s atmosphere? What are sources of these greenhouse gases, and how much did each greenhouse gas contribute to total U.S. emissions in 2020?

Carbon dioxide: Comes from sources such as vehicles and coal-burning power plants. Accounted for 79 percent of U.S. greenhouse gas emissions in 2020.

Methane: Comes from oil and gas operations as well as livestock, landfills and other land uses. Accounted for 11 percent of U.S. greenhouse gas emissions in 2020.

Nitrous oxides: Come from sources such as crop fertilization and burning fuels. Accounted for 7 percent of U.S. greenhouse gas emissions in 2020.

Fluorinated gases: Accounted for 3 percent of U.S. greenhouse gas emissions in 2020.

4. How has the United States contributed to climate change? What is the United States’ goal for reaching net-zero emissions?

The United States has historically been responsible for most of the greenhouse gas emissions. It currently emits around 5 billion metric tons of CO₂ annually. President Joe Biden said the country’s goal is to reach net-zero emissions by 2050.

Section 2: Make a lot more clean electricity

5. In your own words, summarize the article section’s main point.

Countries can work toward reaching net-zero emissions by scaling up the amount of clean energy they produce via existing renewable energy technologies, such as wind and solar power.

6. How could the United States use the solution to reach its goal of reaching net-zero emissions by 2050? What are some challenges to boosting the production of clean electricity?

The United States would have to quadruple its wind and solar power production by 2030 to reach net-zero emissions by 2050. Challenges include figuring out how and where to build new wind and solar farms, how to store and distribute the electricity, and overcoming public resistance to other types of low-carbon power such as hydropower and nuclear power.

Section 3: Get efficient and go electric

7. In your own words, summarize the article section’s main point.

Countries can work toward reaching net-zero emissions by boosting the energy efficiency of manufacturing and infrastructure such as heating and transportation, and electrifying these sectors as much as possible.

8. How could the United States use the solution to reach its goal of reaching net-zero emissions by 2050?

The United States could increase the amount homes heated via electric heat pumps from 10 percent in 2020 to about 80 percent by 2050, and have electric vehicles make up half of all new vehicle sales by 2030.

Section 4: Make clean fuels

9. In your own words, summarize the article section’s main point.

Countries can work toward reaching net-zero emissions by substituting fossil fuels with low- or zero-carbon fuels made from plants and other biomass.

10. How could the United States use the solution to reach its goal of reaching net-zero emissions by 2050?

The United States could build many biomass conversion plants, probably in the Midwest and Southeast where crops are grown, by 2050.

Section 5: Rein in other greenhouse gas emissions

11. In your own words, summarize the article section’s main point.

Countries can work toward reaching net-zero emissions by cutting methane, nitrous oxides and fluorinated carbon emissions via new regulations, improving soil management techniques and revamping production and recycling processes.

12. How could the United States use the solution to reach its goal of reaching net-zero emissions by 2050?

The United States could place new regulations on oil, gas and coal operations, which account for one-third of the country’s methane emissions. Recently, the United States joined an international pledge to reduce global methane emissions.

Section 6: Sop up as much CO₂ as possible

13. In your own words, summarize the article section’s main point.

To reach net-zero emissions, countries will need to remove and store an equivalent amount of carbon to what they still emit after cutting as much as possible. Ways to do this include carbon capture and storage, converting farmland into forests and preserving the forests Earth still has, such as the Amazon. 

14. How could the United States use the solution to reach its goal of reaching net-zero emissions by 2050?

The United States could add carbon capture technology to its industrial plants, turn the CO₂ into a liquid and pipe it deep underground where it can be stored long term.

Section 7: No time to waste

15. In your own words, summarize the article section’s main point.

Reaching net-zero by 2050 will require balancing major financial and technological investments over the next decade with ensuring that the lives of people in developing countries aren’t made worse by the transition.

16. Is the United States’ goal of reaching net-zero emissions by 2050 realistic? Explain based on evidence given in the article.

Student answers will vary. Encourage students to use data and information from the article to help support their answer. Students’ answers should suggest that the United States already has the primary technology for slashing and sopping up emissions. The country also has the innovation to create new technologies that could help.