The science of Earth’s global climate system and the responsibilities that all humans share as protective caretakers of our planet are important for every person to understand. We all have a vested interest in our planet because Earth is our only home. People have been observing, questioning, and analyzing collected information about the history of the Earth ever since the earliest humans first wondered about the world around them. Learning from the past is a smart and logical way to prepare for the future.
This unit will help 4th or 5th grade teachers prepare students to explore two big questions related to the Earth’s changing climate. The primary goal is to nurture an understanding of the element carbon, Earth’s carbon cycle, and how carbon dioxide and other gases contribute to the planet warming greenhouse effect of Earth’s atmosphere. The questions are:
1) What is carbon and why are all living things on Earth considered to be carbon-based lifeforms?
2) What is the greenhouse effect and why should we care about how much carbon is in our atmosphere?
These questions align with the Next Generation Science Standards (NGSS) for 4th grade that many states have adopted or adapted.1 An annotated list of the applicable NGSS and state science standards can be found in the appendix of this curriculum unit.
Under the NGSS, 4th grade students study concepts related to energy and learn that all fuels used to meet our continuously growing energy demand are derived from natural resources. Consequently, the production and usage of some energy resources adds more carbon dioxide to Earth’s atmosphere. Students are just beginning to develop an understanding of how human activities can impact the Earth and result in either positive or negative consequences.
There are several concepts from previous grades that serve as beneficial prior knowledge and may be worthy of review. Students should be familiar with the difference between weather and climate, have a general understanding of the Sun, and be aware that the Earth’s position and rotation on its axis as it orbits the Sun helps explain why we have changing seasons and different global climate zones. These concepts are taught and reinforced from kindergarten through third grade under the NGSS framework. Familiarity with them will help students develop a greater sense of the questions and content asked of them in this unit.
The ideal time to start this unit is after students have learned about Earth’s energy resources. Then they will be ready to learn about the stellar origin of the element carbon and why it is essential to organic life. They will be ready to learn about the Earth’s carbon cycle and why we need some carbon in our atmosphere. They will also be ready to learn about feedback loops in Earth’s systems, specifically the greenhouse effect and carbon dioxide’s role as a greenhouse gas. Finally, students will examine the potential effects of adding more carbon dioxide to Earth’s atmosphere and the actions we must collectively take to mitigate the adverse consequences.
The summative background information section was written with considerable attention to helping you, the teacher, gain some of the valuable understanding that I did while participating in the 2021 Yale New Haven Teachers Institute with Dr. Peter Raymond, Yale Professor of Ecosystem Ecology. Our five-month long seminar, “Physical Science of Climate Change,” explored the physical, chemical, and biological principles surrounding climate change science. Information about Dr. Raymond’s research and Yale coursework can be found on the Yale School of the Environment website (https://environment.yale.edu/profile/raymond). The scope of our seminars went beyond the content included here since there are many aspects of climate change science worthy of study. I was intentionally selective in order to focus on content essential to meeting the goals of this unit. After carefully reading the background information and following the included lesson ideas and resources, you will be in an informed position to guide students toward thinking carefully and critically about what it means to be a responsible caretaker of the Earth and its climate.
The background information is divided into two parts. It begins with an introduction to the element we call carbon and where on Earth it is found (the carbon cycle). The second part explores the concept of feedback loops, specifically the greenhouse effect, and how carbon dioxide and other greenhouse gases interact with the energy from the Sun to regulate Earth’s global temperature.
The teaching strategies section includes thoughtful and experienced approaches to help you deliver this content to your students. The lesson plans section contains a sequence of recommended lesson ideas and the suggested resources to accompany them.
NASA currently supports the statement that at least 97% of actively publishing climate scientists and hundreds of respected scientific organizations worldwide have reached the alarming consensus that the Earth is experiencing a warming trend.2 The changes this warming trend will bring are incredibly complicated to predict because of the multitude of contributing factors that can compound upon one other, sending ripple effects through many of Earth’s natural systems that disrupt our current planetary balance. Some regions may experience favorable outcomes while others experience disasters or become inhospitable.
Progress in climate science has been substantial in the past few decades and technologies utilizing ice cores, satellite monitoring, and sophisticated computer models have yielded new insights into the climate of the past, present, and future. We are certain that the warming trend is going to continue if the contributing factors do not change. We can expect to see a drastic reduction of sea ice. Sea levels will likely rise at least 12 inches and potentially up to 8 feet above current sea levels by the year 2100 according to some of the best and worst-case climate model scenarios. Sea levels have already risen about 8 inches since we developed a reliable means to measure the level in 1880.3 There will be changes in precipitation patterns and an increase in droughts and heat waves. Agricultural regions and food growing seasons will change. Hurricanes will become stronger and more frequent. The outlook isn’t pretty, but how bad it gets will largely depend on the actions we take.
Governments around the world need to collaborate effectively in order to mitigate the potential climate related harm on the horizon. Some of the issues they may need to prepare for include adapting to hotter temperatures; damage to infrastructure and property due to increased flooding, wildfires, or storms; loss or changes to food production that disrupt food supplies or cause famine; mass human displacement; loss of industries and economic collapse; plant and animal extinctions or migrations; and potential human conflicts over resources and territories.
Multiple lines of evidence suggest that human activity is a significant contributor. We have been releasing carbon into the air at exponential rates for 300 years, since the beginning of the Industrial Revolution. We dig up and burn fossil fuels to feed our growing populations’ appetite for energy while steadily releasing all that stored carbon into the atmosphere. Carbon also has the potential to remain in the atmosphere for hundreds of years and we are outpacing the Earth’s natural carbon sequestering abilities so the carbon build-up in our atmosphere continues to rise.
As a teacher, you appreciate the value of education. Knowledge is a powerful tool for shaping the future. The nature of science begins with making observations, asking questions, and testing ideas. Through repeated testing and discourse, eventually truths are separated from mere speculation, opinion, and downright falsity. Scientific skepticism is an intrinsic part of science methodology. Mitigating climate change is going to be economically daunting and require a coordinated global effort. It will force expensive changes to our established energy resources and infrastructure, as well as force governments to establish and enforce strict climate change related regulations. Unfortunately, some climate science critics have pushed to undermine public trust in the scientific community, cast unwarranted doubt, shift blame, downplay, or even outright deny that there is a climate problem. Some admit there is a concern but point to natural Earth cycles rather than accept human activity could be significant enough to make an impact. The attitude may be that if we need to change or adapt, we’ll do so at the time when it is necessary. Others have argued, despite contradictory evidence, that climate change is going to be globally beneficial.
Climate change has unfortunately become a divisive political issue around the world and there are powerful special interest groups that have influence over some politicians and political parties. In the United States, one tenet of the conservative Republican party is less government regulation. In 1981, Republican President Ronald Reagan’s administration reacted to growing public awareness of the greenhouse effect and global warming by immediately cutting federal spending on climate-related environmental research and atmospheric carbon dioxide monitoring. Reagan then appointed Secretary of Energy James B. Edwards, who said that there was no real global warming problem despite contradicting reports from the EPA.4 In 2015, only ten of the seventeen Republican presidential nominees acknowledged on record that climate change was real, and only one nominee offered specific proposals to reduce carbon emissions. More than half denied that climate change was caused by humans, including the winning candidate in 2016.5
One day, your students will be adults with the power to vote. They may even become political leaders, policy writers, or creators of carbon capturing technologies. They didn’t ask for it but adapting to a changing climate and mitigating damage is going to be a part of their future. The education you are providing now may counter the influence of misinformation and doubt so that future generations will be able to make educated and responsible decisions about the leaders they elect and the policies they support. That’s powerful. Regardless of what happens with Earth’s climate, the Earth will go on just as it has for billions of years. How long the Earth remains habitable for humans depends entirely on the actions we take now and carry into the future.