Introduction

More than 11,000 scientists in late 2019, noting that they and their colleagues “have a moral obligation to clearly warn humanity of any catastrophic threat,” endorsed a report stating “clearly and unequivocally that planet Earth is facing a climate emergency.” In fact, virtually all climate scientists say overwhelming evidence shows that human-caused climate change is real. That consensus is evident in official statements from major scientific organizations, including the U.S. National Academy of Sciences, the American Association for the Advancement of Science, and the Intergovernmental Panel on Climate Change. “We are more sure that greenhouse gas is causing climate change than we are that smoking causes cancer,” explains one NASA atmospheric scientist.

We can already see the effects of climate change today, as the National Oceanic and Atmospheric Administration explains. These effects include more extreme weather events such as severe droughts and destructive storms. Such weather extremes are putting increasing pressure on water supplies and on the farmers and ranchers who supply our food. Rising temperatures also lead to more heat stress and other health challenges, including poor air quality and more infectious disease. Rising ocean levels threaten coastal populations, and more acidic ocean waters threaten marine life. And the negative impacts of climate change are severe for especially vulnerable communities — including low-income communities, rural communities, and people of color — that lack the resources to recover and adapt and already experience disparate challenges in health and health care.

Despite the overwhelming scientific evidence, political debate over the reality of climate change and human responsibility for it rages on. This debate is shaping public policies, good and bad, that determine our society’s response to the emergency scientists warn about. But to what extent are public schools helping students understand what is happening and preparing them to responsibly engage in civic deliberation on the problem and possible solutions? To help answer this question, the National Center for Science Education (NCSE) and the Texas Freedom Network Education Fund (TFNEF) engaged in a comparative study of how each state’s science standards for public schools address climate change.

State Science Standards

Every state has adopted and periodically revises its science standards, which identify the basic information and skills students are expected to master in their courses of study. These standards guide the content of statewide testing and assessment, textbooks and other instructional materials, and classroom instruction. Each state has its own process for writing and adopting standards.

Today 20 states and the District of Columbia use the Next Generation Science Standards, or NGSS. These NGSS states account for more than 36 percent of public school enrollment in the country. Released in 2013, the NGSS are the product of a consortium of states working together with the National Research Council, the National Science Teaching Association, the American Association for the Advancement of Science, and the nonprofit educational organization Achieve. The NGSS are based on the National Research Council’s A Framework for K–12 Science Education, released in 2011. Another 24 states, with about 35 percent of the country’s public school enrollment, have written their own standards guided by the Framework. The remaining six states, with close to 30 percent of public school enrollment, use science standards not based on the Framework.

Scope of the Study

Working independently, three expert reviewers, all Ph.D. scientists with differing specialties, evaluated how climate change is addressed in the NGSS and then the standards for each of the 30 states that have not adopted the NGSS. See Appendix A for information on the three reviewers. Note: The reviewers examined only the state standards, not model curricula or other guidelines created by some states.

The reviewers considered the treatment of climate change in each set of standards with respect to four key points that form a basic outline of the scientific consensus on the issue:

1. It’s real: Recent climate change is a genuine phenomenon.
2. It’s us: Human activity is responsible for the global change in climate.
3. It’s bad: Climate change is affecting and will continue to affect nature and society.
4. There’s hope: It is possible to mitigate and adapt to climate change.

In evaluating how the standards addressed those four points, the reviewers considered six focus questions for each:

1. To what extent is the treatment of the issue in the standards helpful in permitting students to reach these conclusions?
2. To what extent is the treatment of the issue in the standards appropriately explicit?
3. To what extent is the treatment of the issue in the standards integrated in a coherent learning progression?
4. To what extent do the standards make it clear to teachers what knowledge and skills students are expected to attain?
5. To what extent would a student who met the performance expectations in the standards relevant to the issue be prepared for further study in higher education?
6. To what extent would a student who met the performance expectations in the standards relevant to the issue be prepared for responsible participation in civic deliberation about climate change?

The reviewers assessed the standards by answering the six focus questions — as very good (i.e., helpful, explicit, integrated, clear, preparing for higher education, preparing for civic deliberation), somewhat good, somewhat bad, very bad, or not present — with regard to each of the four key points. These responses were assigned numerical scores.

Given the different areas of specialization and approaches of the reviewers, it’s not surprising that their views diverged somewhat as they evaluated each state’s standards. Such evaluations are by their nature subjective. In assigning overall grades to the standards, we sought to control for these factors by weighting areas of agreement among the three reviewers more heavily. Moreover, to help make state-by-state comparisons of quality clearer, we assigned letter grades on a curve. See Appendix B for a detailed explanation of how the scores were weighted and the grades curved. While the reviewers provided their knowledge and expertise in evaluating the standards for each state, the design of the study and the final grades assigned to all of the states are entirely the responsibility of NCSE and TFNEF.

The results of this study reveal that public education policymakers in many states are failing to ensure that science standards forthrightly and accurately address climate change. The scope and character of that failure are not uniform across the country, but they expose a serious deficit in the quality of science education in the United States.

By the Numbers

A bare majority — just 27 — of the 50 states and District of Columbia have standards that earned a B+ or better for how they address climate change. Those 27 include the 20 states and DC that have adopted the NGSS. Of the remaining 24 states, 20 earned no better than a C+. Ten of those received a D or worse, and they include some of the most populous states in the country, such as Texas (F), Florida (D), Pennsylvania (F), and Ohio (D). Six states received a failing grade overall.

The NGSS earned a B+ on addressing climate change. Only six non-NGSS states earned a B+ or better for their science standards, and all six are based on the National Research Council’s Framework. One earned an A, while four received an A- and one received a B+. It is important to note that the reviewers had varying degrees of concern with all of the sets of science standards they evaluated, including the NGSS. Therefore, even states receiving a final grade of A or A- for their standards should not necessarily be seen as having model standards that need no improvement. Even so, the top grades indicate that the standards in those states were superior compared to those in other states.

Interestingly, several of the states earning an A or A- for their standards have economies in which mining and fossil fuel extraction are particularly important: Wyoming, Alaska, and North Dakota. This fact suggests that even in states in which many jobs and tax dollars are substantially tied to the fossil fuel industry, education policymakers can do a reasonably good job of adopting science standards that reflect the scientific consensus about human-caused climate change and how society can mitigate and adapt to it.

Altogether, 24 states based their science curriculum standards on the Framework. In some cases, the reviewers found that such states largely replicated the NGSS. But the fidelity with which they followed the guidance from the Framework or replicated language from the NGSS varied significantly on the issue of climate change, with a number of states diluting or deleting the relevant standards. The result was that most of those standards rate poorly compared to the NGSS with respect to climate change. (The reviewers were not always in agreement, however. Arizona, a Framework state, was among two states for which reviewers had the widest divergence in their evaluations. The other was North Carolina, a non-Framework state.) In the end, 14 states that used the Framework as a basis ended up with a C+ or worse on addressing climate change. Three received an F.

Six states use science standards that are not based on the Framework. The standards of the majority of these states were adopted before the Framework or the NGSS were available: Pennsylvania’s standards were adopted in 2002, Florida’s in 2008, Texas’s in 2009, and North Carolina’s in 2010. The six non-Framework states cluster toward the bottom of the grading scale. Two states received a D and three an F.

The grades states received overall and for each category and focus question are available in the accompanying table. The table also identifies the NGSS, Framework, and non-Framework states. In addition, clicking on a state in the accompanying map will reveal a summary of the reviewers’ evaluations for that state.

Key Findings

A number of common problems with the state science standards’ treatment of climate change are evident in the reviewers’ evaluations. 

Promoting False Debate

A few state standards promote the false narrative that the existence, cause, and seriousness of climate change are a matter of debate among climate scientists. Particularly egregious are West Virginia’s standards (which received a D overall grade), which specifically require students to debate the issue in their science classrooms. “Debate is not a normal method of science,” one reviewer noted. “For what it's worth, there is not debate among climate scientists about the reality of human-caused climate change. Debating in K–12 science standards is a classic device employed by deniers (of evolution or climate change) to get their positions presented in public schools absent any (non-cherry-picked) data. Tellingly, this is the only place in the West Virginia standards that employs debate.” The same reviewer was disappointed that the NGSS (B+) did not “address how students can recognize willful attempts to misrepresent climate data.... Nor do they help teachers understand how they might do this effectively for their students.”

Failing to Address Climate Change Directly

The majority of state standards are clear that climate change is a real and serious global problem and that human activity is responsible for it. But the reviewers expressed concerns with a failure in many states to be explicit. In some cases, such as Pennsylvania and Virginia (each of which received an overall grade of F), the standards essentially ignore climate change altogether. In other cases, the standards address issues that are part of the problem without explicitly naming “climate change” or “global warming.” Teachers are left to assess whether a particular standard offers an appropriate opportunity to discuss the issue. “A skilled teacher who already knows and wants to address climate change can do so,” one reviewer noted (with regard to Georgia’s standards). “An inexperienced one or one confronting climate denial will have a hard time knowing how to.”

Muddling the Science

A related problem evident in many state standards is ambiguity about the scientific evidence itself. The reviewers’ comments are peppered with words like “tentative,” “vague,” “equivocation,” even “strange.” The net effect of such ambiguous wording in state science standards is to muddle the science, suggesting that the evidence on climate change isn’t as clear as it really is. For example, while the NGSS (which receive a B+ overall grade) expect students to study evidence that human activities and natural processes “have caused” a rise in global temperatures, the Alabama standards (which received an F) only suggest that such factors “may have caused” such a change. Similarly, one reviewer noted that “Utah’s standards [which received a C+] have been masterfully edited or otherwise changed to downplay if not ignore the reality, human cause, and seriousness of climate change.”

Missing Opportunities to Inspire Hope

In a number of cases, reviewers praised standards that helped students understand real-world impacts of climate change and ways to mitigate or adapt to them. The Minnesota standards (which received a B- grade overall), for example, urge students to reach out to Indigenous communities to learn about how climate change affects them and their regions. Other states usefully included standards expecting students to analyze and understand how engineering and technology solutions can help society deal with climate change. But the reviewers expressed considerable disappointment in the failure of many states to follow suit. One reviewer noted, for example, the failure of North Carolina’s standards (C-) to make sure students understand “that not only is there hope, but [also] some very meaningful and potentially rewarding career opportunities in mitigating climate change, e.g. smart grid technologies, design of more efficient transportation and housing options, installation, maintenance, and optimization of renewable energy infrastructure.” This failure was particularly discouraging to see in states — such those with extensive coastal regions — where the impact of climate change is, and will continue to be, particularly problematic.

Recommendations

The primary recommendation to education policymakers is obvious: revise state science standards as far as necessary to reflect the scientific consensus on climate change. The NGSS, which are in wide use, are a good model. But as the five states with science standards that received higher grades illustrate, it is possible to improve even on the NGSS.

Policymakers should also consider integrating climate change elsewhere in the state education standards. New Jersey provides one model for doing so, recently revising its standards to encourage practically every teacher in the state's public school system to discuss climate change in appropriate educational contexts with their students.

Importantly, it will be necessary for states to follow through on their commitment to climate change education by ensuring that in-service and pre-service teachers are equipped with the content knowledge and pedagogical training to effectively present climate change in accordance with the state science standards.

The purpose of public education is to prepare today’s students to flourish in the world that they will inhabit tomorrow. That includes equipping them with the knowledge they need to meet the challenges they will face in that world. Insofar as a set of state science standards fails to recognize that climate change is real, caused by human activity, serious, and soluble, it is not fit for this purpose. Students, and the rest of society, deserve better.

Appendix A

Reviewers

The National Center for Science Education and the Texas Freedom Network Education Fund recruited three specialists to review the science standards from NGSS and states across the country. The three brought different and complementary areas of specialization and experience to the project.

Sarah Myhre is a climate scientist, researcher, and environmental justice activist in Washington state. Dr. Myhre, who earned her doctorate in ecology from the University of California at Davis, was one of 151 young scientists selected as Kavli Fellows by the National Academy of Sciences in 2018. She has published numerous peer-reviewed articles largely on paleoecology and paleoceanography. She is also the founder and executive director of the Rowan Institute, a nonprofit focused on climate change leadership.

Steve Rissing is a professor emeritus in the Department of Evolution, Ecology and Organismal Biology at Ohio State University. A specialist in ant evolution and ecology, Dr. Rissing has also been actively involved in efforts to improve public understanding of science, including by conducting research on evolution education in higher education, through a regular column in the Columbus Dispatch, and by serving on state science standards-related projects in Arizona and Ohio.

Casey Williams is a former high school science teacher who earned a doctorate in educational psychology from Texas Tech University, where he studied under Katharine Hayhoe, director of the Climate Science Center at the university. His dissertation examined the barriers teachers face when considering how to address climate change in the classroom. Dr. Williams currently is an education researcher at the University of Kansas.

Appendix B

Methodology

For each state, reviewers were asked to examine the middle school science standards and then high school standards for biology, chemistry, physics, earth sciences, and environmental sciences. These are the standards for courses in which climate change is most likely to be discussed and which students are most likely to take. Elementary school standards and standards for more specialized areas of science — e.g., anatomy and physiology, aquatic sciences, zoology — were not considered. When there were multiple sets of standards within a grade band for the same subject — e.g., high school biology 1, high school biology 2, and AP high school biology — only the lowest set was considered.

Reviewers were first asked to perform a preliminary assessment on the NGSS (used in 20 states plus the District of Columbia) and submit their preliminary evaluations. The reviewers and staff from NCSE and TFN Education Fund then participated in a conference call to discuss their evaluations, with the goal of ensuring the comparability of their evaluations, both for the NGSS and for the remaining standards. Reviewers were free to revise their evaluations for the NGSS following the conference call. Reviewers then examined the remaining 30 sets of state science standards (in random order to avoid any order-dependent source of bias). 

In their evaluations, each reviewer provided 4 x 6 = 24 ratings on a Likert scale, very good (i.e., helpful, explicit, integrated, clear, prepared for higher education, prepared for civic deliberation), somewhat good, somewhat bad, very bad, or not present. Reviewers were also invited to provide free-form comments on the standards’ treatment of the four key points and in general.

The Likert-scale ratings were converted to a numerical scale: 4.0 for very good, 2.67 for somewhat good, 1.33 for somewhat bad, 0 for very bad or not present.

A weighted average was then taken, so that the closer that the reviewers came to maximal disagreement on an item, the less their scores for that item influenced the overall average, and the closer that the reviewers came to maximal agreement on an item, the more their scores for that item influenced the overall average. The effect of the weighting is thus to emphasize areas of agreement and de-emphasize areas of disagreement among the reviewers. The effect was slight: the correlation between the raw and weighted scores was 0.99.

The result was 24 numerical grades between 0 and 4 inclusive (ranging from 0.00 to 3.34, mean 1.49, standard deviation 1.06). Letter grades were then assigned on a curve: A to states at or over 1.67 standard deviations above the mean, A- to states at or over 1.33 standard deviations above the mean, etc.; states below one standard deviation below the mean received Fs.

Numerical grades between 0 and 4 inclusive were also calculated for the four topics (it’s real, it’s us, it’s bad, there’s hope) and the six aspects (helpfulness to students, explicitness, integration, clarity, preparation for higher education, preparation for civic engagement), using the same weighting scheme. The effect of the weighting was slight, with the correlation between the raw and weighted scores greater than 0.90 in all cases. Letter grades were then assigned on the same curve.

Details of the weighting scheme: where r_ij is the jth reviewer's numerical ranking for the ith item, the weighted overall average of n item rankings was calculated as follows:

Note that the constant 2.309401 is the maximum possible standard deviation for three items between 0 and 4 inclusive. Note also that the weighted overall average would be undefined if the denominator were 0. This would occur only in cases of maximal disagreement for every item under consideration; there were no such cases.