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Methods & supporting materials

The Mind Between
Climate and Action

Designing climate communication around how people process, feel, and act.

75generated messages
3climate topics
5prompt conditions

Same climate facts.
Different communication designs.

Same facts. Different linguistic profiles.

Can the same climate facts be written with different communication designs that differ measurably in accessibility, emotional framing, and actionability?

What this study measures

Properties of AI-generated text. It does not test human comprehension, emotion, efficacy, intention, or behavior.

A controlled comparison of prompts

Three climate topics × five prompt conditions × five messages produced a corpus of 75 messages. Within each topic, the supplied facts were identical; only the communication instruction changed. Each condition contains 15 messages, with five per topic.

InputFixed climate facts
DesignFive prompt conditions
OutputText profiles
Prompt-controlled design with text-level evaluation.

Facts supplied to the model

The following are the study’s fixed inputs, reproduced from the supplied methods document.

Warming

Earth’s average surface temperature has risen about 1.1 °C (about 2 °F) since 1880 (NASA GISS). The warming is largely driven by carbon dioxide and other human-made emissions (NASA).

Sea level

Global sea level has risen about 8 inches (20 cm) since 1880. Sea level is projected to rise another 1 to 4 feet (30–120 cm) by 2100 (NASA).

Extreme heat

Hot extremes, including heatwaves, have become more frequent and more intense across most land regions since the 1950s. Some recent hot extremes would have been extremely unlikely without human influence on the climate (IPCC AR6 WGI SPM).

Change the instruction, hold the facts constant.

Every prompt begins with the same instruction:

“Write a short public climate message (under 50 words) using only these facts.”

The condition-specific instruction is then added:

A

Baseline

None added (baseline).

B

Clarity

Use plain language, short sentences, and one idea.

C

Meaning

Frame it around what people value, with hope-based, values-oriented language and no exaggeration.

D

Action

Include one specific, doable step and why it works.

E

Integrated

Use plain language and short sentences, frame it around what people value with hope, and include one specific, doable step.

Three dimensions of communication

I

Linguistic accessibility

Flesch–Kincaid grade level and mean sentence length. The analysis uses Python textstat for reading grade and token counts divided by sentence counts for mean sentence length.

Cognitive-load theory motivates this dimension; these are reading metrics, not direct measures of cognitive load.

II

Emotional framing

Threat language: NRC Emotion Lexicon words tagged “fear” per 100 words.
Hopeful-language proxy: NRC tags for joy, trust, or anticipation per 100 words.

The hopeful-language score is a lexical proxy, not a validated measure of hope. The supplied code counts emotion tags; a word with multiple selected tags may contribute more than once.

III

Actionability

An exploratory custom index combining action verbs, efficacy cues, and specificity cues per 100 words.

100 × (action verbs + efficacy cues + specificity cues) / word count

A text-based cue count, not a validated measure of behavioral effectiveness.

Inspect the actionability word lists

Action verbs

switch set lower check sign call email ask join walk bike take replace unplug find save share text invite plant attend look write start try choose tell talk track protect prepare add close drink avoid keep support reduce cut install vote volunteer donate fix offer agree plan send repair drive

Efficacy cues

“you can”, “we can”, “you could”, “let’s”, “can too”, “possible”, “power to”.

Specificity cues

“this week”, “this month”, “today”, “each week”, “every week”, “a week”, “minute” / “minutes”, “each heat alert”, and “one” followed by “trip”, “step”, “action”, “neighbor”, “friend”, or “family member”.

Distinct, measurable text profiles

Means ± 95% t-intervals across 15 messages per condition (five per topic). The values below are reproduced from the author’s document.

Reading grade
Baseline
13.3
Clarity
3.3
Meaning
7.5
Action
6.4
Integrated
4.6

Flesch–Kincaid grade level; lower = easier.

Hopeful-language proxy
Baseline
4.6
Clarity
4.1
Meaning
10.6
Action
8.0
Integrated
10.9

NRC joy, trust, or anticipation tags per 100 words.

Actionability index
Baseline
0.0
Clarity
0.5
Meaning
2.0
Action
15.4
Integrated
12.4

Action, efficacy, and specificity cues per 100 words.

All reported measures · mean ± 95% interval half-width
ConditionReading
grade
Words /
sentence
Threat /
100 words
Hopeful proxy /
100 words
Actionability /
100 words
Baseline13.3 ± 1.821.8 ± 4.71.0 ± 0.94.6 ± 2.00.0 ± 0.0
Clarity3.3 ± 0.87.0 ± 0.80.7 ± 0.74.1 ± 2.60.5 ± 0.7
Meaning7.5 ± 0.715.6 ± 1.51.3 ± 0.910.6 ± 3.12.0 ± 1.1
Action6.4 ± 1.014.0 ± 1.61.3 ± 1.28.0 ± 3.515.4 ± 1.7
Integrated4.6 ± 0.610.9 ± 0.71.8 ± 0.810.9 ± 3.612.4 ± 2.4

Charts show reported means. The table includes interval half-widths. Horizontal scrolling is available for the table on smaller screens.

How to read the findings

Prompt-controlled design produced distinct linguistic profiles from the same supplied facts. This shows that the prompts worked as instructed; it does not establish that any design is more effective for people.

All 75 generated messages

Open a topic and condition to read its five messages and reported metrics. Threat, hopeful-language proxy, and actionability values are expressed per 100 words.

Download corpus and reported metrics CSV

Warming / A. Baseline5 messages
  1. According to NASA, Earth's average surface temperature has risen about 1.1°C (2°F) since 1880. This increase is largely driven by rising atmospheric carbon dioxide and other human-made greenhouse gas emissions, which have altered the planet's energy balance over the past century.
    Grade 11.320.5 words / sentenceThreat 0Hopeful proxy 4.9Actionability 0
  2. NASA's temperature records show that global average surface temperature has increased by roughly 1.1°C (about 2°F) since 1880. Scientists attribute this warming primarily to carbon dioxide and other greenhouse gases released by human activities such as fossil fuel combustion.
    Grade 12.219 words / sentenceThreat 0Hopeful proxy 2.6Actionability 0
  3. Since 1880, the global mean surface temperature has increased approximately 1.1°C (2°F), according to NASA analyses. The principal driver of this long-term trend is the accumulation of human-produced carbon dioxide and related emissions in the atmosphere.
    Grade 12.418.5 words / sentenceThreat 0Hopeful proxy 8.1Actionability 0
  4. Global surface temperatures have climbed about 1.1°C (2°F) above late nineteenth-century levels, NASA reports. The warming is predominantly caused by increased concentrations of carbon dioxide and other anthropogenic emissions resulting from industrial and energy-related activity.
    Grade 15.918.5 words / sentenceThreat 0Hopeful proxy 2.7Actionability 0
  5. NASA data indicate that Earth has warmed by approximately 1.1°C (2°F) since record-keeping began in 1880. This change is largely attributed to elevated levels of atmospheric carbon dioxide and additional human-generated greenhouse gases.
    Grade 1317 words / sentenceThreat 2.9Hopeful proxy 0Actionability 0
Warming / B. Clarity5 messages
  1. Earth is warmer than it used to be. Since 1880, the planet's average temperature has gone up about 1.1°C. That is about 2°F. People caused most of this by burning fuels that release carbon dioxide.
    Grade 4.78.5 words / sentenceThreat 0Hopeful proxy 0Actionability 0
  2. The planet has heated up. NASA says it is about 1.1°C (2°F) warmer than in 1880. The main cause is carbon dioxide. We add it to the air when we burn coal, oil, and gas.
    Grade 1.68.5 words / sentenceThreat 0Hopeful proxy 0Actionability 2.9
  3. Here is the key fact. Earth's average temperature is up about 2°F since 1880. That is 1.1°C. Most of the rise comes from human-made carbon dioxide.
    Grade 3.36.5 words / sentenceThreat 0Hopeful proxy 3.8Actionability 0
  4. NASA measures Earth's temperature. It has gone up about 1.1°C since 1880. That is roughly 2°F. Burning fossil fuels adds carbon dioxide to the air. This extra gas traps heat.
    Grade 3.35.8 words / sentenceThreat 0Hopeful proxy 0Actionability 0
  5. Our planet is about 2°F warmer than in 1880. That is 1.1°C. People are the main cause. Cars, power plants, and factories release gases that trap heat.
    Grade 3.26.5 words / sentenceThreat 0Hopeful proxy 0Actionability 0
Warming / C. Meaning5 messages
  1. The world our grandparents knew is already changing. In just over a century, Earth has warmed by about 1.1°C, a shift mostly set in motion by human choices. That means the story of our climate is also a story about us, and about the future we decide to protect for the people we love.
    Grade 6.918 words / sentenceThreat 0Hopeful proxy 3.7Actionability 3.7
  2. Every child born today inherits a planet that has warmed by roughly 1.1°C since 1880, largely because of the carbon dioxide people have released. It is a sobering number, but it also tells us something hopeful: what humans changed, humans can help to heal.
    Grade 7.821.5 words / sentenceThreat 0Hopeful proxy 16.3Actionability 2.3
  3. Warmth is supposed to feel like home. Yet Earth has warmed about 2°F since 1880, mostly because of human emissions, and that change touches the places and seasons we cherish. Caring for this shared home is among the most meaningful things a generation can do.
    Grade 6.814.7 words / sentenceThreat 2.3Hopeful proxy 6.8Actionability 0
  4. Behind the 1.1°C of warming since 1880 are real places, real communities, and real futures. Because people drove most of this change, people also hold the power to shape what comes next, and that is a reason for hope.
    Grade 5.219 words / sentenceThreat 2.6Hopeful proxy 15.8Actionability 2.6
  5. We often think of climate as something far away. But the 1.1°C that Earth has warmed since 1880 is woven into the summers our families remember and the ones our children will inherit. Our emissions helped write this chapter, and together we can write a better one.
    Grade 6.615.3 words / sentenceThreat 0Hopeful proxy 0Actionability 6.5
Warming / D. Action5 messages
  1. Earth has warmed about 1.1°C (2°F) since 1880, mainly from carbon dioxide emissions. You can reduce your share this week: switch your home to LED bulbs and set your thermostat two degrees lower in winter. Lower energy use means fewer emissions.
    Grade 5.713.3 words / sentenceThreat 0Hopeful proxy 7.5Actionability 20
  2. NASA reports 1.1°C of warming since 1880, driven largely by human emissions. Take one step today: check whether your utility offers a renewable energy plan, and sign up. It takes about five minutes and cuts emissions from your electricity.
    Grade 8.212.7 words / sentenceThreat 0Hopeful proxy 2.6Actionability 18.4
  3. The planet is about 2°F warmer than in 1880, mostly because of carbon dioxide from human activity. Start with transportation. Walk, bike, or take the bus for one trip a week instead of driving, and track how much fuel you save.
    Grade 6.713.3 words / sentenceThreat 0Hopeful proxy 10Actionability 20
  4. Global temperatures have risen 1.1°C since 1880, largely due to human emissions. Here is one action: unplug idle electronics and use a power strip you can switch off. Less wasted electricity means less carbon dioxide released.
    Grade 7.611.7 words / sentenceThreat 0Hopeful proxy 0Actionability 11.4
  5. Since 1880, Earth has warmed roughly 1.1°C because of rising carbon dioxide. Call or email your local representative this week and ask them to support clean energy. Your voice helps shape local decisions on emissions.
    Grade 6.411.3 words / sentenceThreat 0Hopeful proxy 11.8Actionability 14.7
Warming / E. Integrated5 messages
  1. Earth has warmed about 1.1°C since 1880, and people caused most of it. That is hard to hear, but it also means we can change it. This week, switch to a renewable energy plan from your utility. It takes five minutes and protects the summers we love.
    Grade 3.411.5 words / sentenceThreat 2.2Hopeful proxy 4.3Actionability 10.9
  2. The planet is 2°F warmer than in 1880, mostly because of human emissions. Our choices got us here, and our choices can lead us out. Try this: bike or walk one trip each week. Small trips add up to cleaner air for everyone you care about.
    Grade 4.511.2 words / sentenceThreat 0Hopeful proxy 0Actionability 13.3
  3. Since 1880, Earth has warmed 1.1°C. The cause is human, and so is the power to respond. Start today: ask your family to lower the thermostat by two degrees. It saves money, cuts carbon dioxide, and shows your kids that change begins at home.
    Grade 4.510.8 words / sentenceThreat 2.3Hopeful proxy 9.3Actionability 11.6
  4. We have warmed our planet by about 2°F since 1880, but we also know exactly what to do. You can make a difference this week. Switch to LED bulbs, then tell a friend. Every bulb is a small act of care for the future.
    Grade 3.410.8 words / sentenceThreat 0Hopeful proxy 4.7Actionability 9.3
  5. Earth is 1.1°C warmer than in 1880 because of human emissions. Hope lives in what we do next. Join a local climate group this month, or sign up for a community energy program. Together, we can turn worry into progress.
    Grade 4.69.8 words / sentenceThreat 2.6Hopeful proxy 15.4Actionability 10.3
Sea level / A. Baseline5 messages
  1. NASA estimates that global sea level has risen approximately 8 inches (20 cm) since 1880, primarily due to thermal expansion of warming oceans and meltwater from glaciers and ice sheets. Projections indicate a further increase of 1 to 4 feet (30–120 cm) by 2100.
    Grade 12.318.5 words / sentenceThreat 0Hopeful proxy 2.7Actionability 0
  2. According to NASA, global mean sea level has increased by about 8 inches since 1880. The rise reflects ocean warming and the melting of land ice, and it is projected to continue, with an additional 1 to 4 feet anticipated by the year 2100.
    Grade 1119.5 words / sentenceThreat 0Hopeful proxy 7.7Actionability 0
  3. Sea level has risen roughly 20 cm (8 inches) since 1880, according to NASA observations. Warming causes seawater to expand and glaciers to melt, contributing to a projected additional rise of 30 to 120 cm by 2100.
    Grade 11.115.5 words / sentenceThreat 0Hopeful proxy 3.2Actionability 0
  4. NASA's records show that average global sea level has gone up around 8 inches since 1880. Continued ocean warming and ice loss are expected to raise sea level by a further 1 to 4 feet before the end of the century.
    Grade 9.718.5 words / sentenceThreat 2.7Hopeful proxy 10.8Actionability 0
  5. NASA reports that the global ocean surface has risen about 8 inches (20 cm) since 1880, driven by thermal expansion and melting ice. Additional increases of 1 to 4 feet are projected by 2100.
    Grade 9.814 words / sentenceThreat 0Hopeful proxy 0Actionability 0
Sea level / B. Clarity5 messages
  1. The sea is rising. Since 1880, it has gone up about 8 inches. That is 20 centimeters. Warm water takes up more space. Ice on land is melting and flowing into the ocean.
    Grade 2.76 words / sentenceThreat 0Hopeful proxy 6.7Actionability 0
  2. NASA tracks the ocean. Sea level is about 8 inches higher than in 1880. By 2100, it could rise another 1 to 4 feet. Warmer water and melting ice are the causes.
    Grade 3.86.8 words / sentenceThreat 0Hopeful proxy 3.7Actionability 0
  3. Oceans are climbing. They are 8 inches higher than they were in 1880. Ice is melting. Water expands as it warms. Both push the sea up.
    Grade 1.44.8 words / sentenceThreat 0Hopeful proxy 0Actionability 0
  4. Here is what NASA found. The sea has risen about 20 cm since 1880. It may rise 30 to 120 cm more by 2100. Melting glaciers add water. Warmer oceans swell.
    Grade 1.75.2 words / sentenceThreat 0Hopeful proxy 7.7Actionability 3.8
  5. Sea level is going up. It is 8 inches higher than in 1880. More rise is coming, maybe 1 to 4 feet by 2100. The reasons are simple. Oceans are warming, and ice is melting.
    Grade 2.66 words / sentenceThreat 0Hopeful proxy 6.7Actionability 0
Sea level / C. Meaning5 messages
  1. Coastlines hold our memories: the boardwalk, the family beach, the neighborhood where we grew up. Since 1880, the sea has risen about 8 inches, and it may climb 1 to 4 feet more by 2100. Protecting these places means protecting the stories they hold.
    Grade 6.813 words / sentenceThreat 0Hopeful proxy 10.3Actionability 0
  2. For millions of people, the ocean's edge is home. Seas have risen roughly 20 cm since 1880 and are projected to rise further. Behind every inch is a community that cares deeply about its shoreline, and that care is a powerful force for good.
    Grade 714 words / sentenceThreat 4.8Hopeful proxy 14.3Actionability 0
  3. Imagine your favorite shoreline in the year your grandchild turns ninety. NASA projects another 1 to 4 feet of sea level rise by 2100, on top of 8 inches since 1880. What we value most is worth defending, and many are already rising to do it.
    Grade 7.313.7 words / sentenceThreat 0Hopeful proxy 17.1Actionability 0
  4. The sea has risen 8 inches since 1880, quietly reshaping the places where people live, fish, and gather. Hopeful communities everywhere are showing that a future with healthy coasts is something we can build together.
    Grade 10.116.5 words / sentenceThreat 0Hopeful proxy 9.1Actionability 3
  5. Every harbor town has a story. Rising seas, up 8 inches since 1880 with up to 4 feet more projected by 2100, are changing how those stories continue. Our love for these places can become the energy that carries us toward a safer shore.
    Grade 7.313.3 words / sentenceThreat 0Hopeful proxy 15Actionability 0
Sea level / D. Action5 messages
  1. Sea level has risen about 8 inches since 1880 and may rise 1 to 4 feet more by 2100. Check your address on a free sea-level or flood map this week, and share it with your family so you can plan ahead.
    Grade 6.919 words / sentenceThreat 2.6Hopeful proxy 15.8Actionability 13.2
  2. NASA reports 20 cm of sea level rise since 1880, with more coming. Start with one step: look up whether your community has a coastal resilience plan, and attend one public meeting to ask how you can help.
    Grade 8.318 words / sentenceThreat 0Hopeful proxy 13.9Actionability 19.4
  3. The ocean is 8 inches higher than in 1880 and projected to rise another 1 to 4 feet by 2100. You can lower emissions that drive this rise. Replace one car trip a week with a bus ride or a walk.
    Grade 4.712 words / sentenceThreat 0Hopeful proxy 0Actionability 16.7
  4. Global seas have risen roughly 8 inches since 1880. Protect your own home today: check your flood insurance coverage and write an emergency kit list. Then ask your town what it plans to do about rising water.
    Grade 6.111.7 words / sentenceThreat 5.7Hopeful proxy 5.7Actionability 14.3
  5. Seas are 20 cm higher than in 1880, and more rise is projected by 2100. Join a local beach or wetland cleanup this month. Healthy wetlands help buffer coasts, and you can sign up in minutes.
    Grade 4.211 words / sentenceThreat 0Hopeful proxy 3Actionability 15.2
Sea level / E. Integrated5 messages
  1. The sea has risen 8 inches since 1880, and up to 4 feet more is projected by 2100. The places we love are worth protecting. This week, check your address on a free flood map, then talk with your neighbors about a plan. Together, we can be ready.
    Grade 4.111 words / sentenceThreat 2.3Hopeful proxy 9.1Actionability 11.4
  2. Our coastlines are changing: seas are 20 cm higher than in 1880. But communities are already adapting, and you can too. Attend one local meeting on flood planning this month and ask how you can help protect your shoreline.
    Grade 6.412.3 words / sentenceThreat 2.7Hopeful proxy 5.4Actionability 16.2
  3. Think of the beach where you learned to swim. Seas have risen about 8 inches since 1880 and may climb 1 to 4 feet more. Here is a way to help: sign up for a wetland or beach cleanup this month. It protects the coast we all share.
    Grade 2.411 words / sentenceThreat 2.3Hopeful proxy 15.9Actionability 6.8
  4. Rising seas are changing the coasts we cherish, up 20 cm since 1880. We can respond with care. Choose one trip this week to walk or bike instead of drive. Fewer emissions slow ocean warming, and that protects every shoreline.
    Grade 4.29.5 words / sentenceThreat 0Hopeful proxy 13.2Actionability 18.4
  5. Seas are 8 inches higher than in 1880, with more rise coming by 2100. Home is worth defending. Start today: look up your flood risk, share it with one family member, and ask your town about its coastal plan. Hope grows when we act together.
    Grade 410.5 words / sentenceThreat 4.8Hopeful proxy 23.8Actionability 16.7
Extreme heat / A. Baseline5 messages
  1. The IPCC's Sixth Assessment Report concludes that hot extremes, including heatwaves, have become more frequent and more intense across most land regions since the 1950s. Several recent extreme heat events would have been extremely unlikely to occur without human influence on the climate system.
    Grade 12.622 words / sentenceThreat 2.3Hopeful proxy 9.1Actionability 0
  2. According to the IPCC, heatwaves and other hot extremes have increased in frequency and intensity over most land areas since the 1950s. The assessment further finds that some recent hot extremes were extremely unlikely in the absence of human-induced climate change.
    Grade 1221 words / sentenceThreat 4.8Hopeful proxy 2.4Actionability 0
  3. IPCC findings indicate that across most land regions, hot extremes have grown both more common and more severe since the 1950s, while human influence has substantially contributed to this trend, to the extent that certain recent events would have been extremely unlikely otherwise.
    Grade 20.443 words / sentenceThreat 0Hopeful proxy 0Actionability 0
  4. Observational evidence assessed by the IPCC shows an increase in the frequency and intensity of heatwaves across the majority of land regions since the 1950s. Attribution analyses suggest that certain recent extreme heat events would have been extremely unlikely without anthropogenic influence.
    Grade 15.921 words / sentenceThreat 0Hopeful proxy 7.1Actionability 0
  5. As reported in the IPCC's Sixth Assessment Report, hot extremes including heatwaves have become more frequent and more intense over most land regions since the 1950s, and human influence is a key factor, with some recent events extremely unlikely without it.
    Grade 19.741 words / sentenceThreat 2.4Hopeful proxy 7.3Actionability 0
Extreme heat / B. Clarity5 messages
  1. Heatwaves are happening more often. They are also getting hotter. This has been true on most land since the 1950s. Some recent heat events would have been very unlikely without human-caused warming.
    Grade 5.28.2 words / sentenceThreat 0Hopeful proxy 6.1Actionability 0
  2. The IPCC found a clear trend. Hot days are more common. Heatwaves are stronger. This is true across most of the world's land. People's emissions are a big reason why.
    Grade 1.76 words / sentenceThreat 0Hopeful proxy 13.3Actionability 0
  3. Extreme heat is rising. Since the 1950s, heatwaves have become more frequent and more intense in most places. Some recent ones almost surely would not have happened without human influence.
    Grade 610 words / sentenceThreat 3.3Hopeful proxy 13.3Actionability 0
  4. Here is what the science says. Heatwaves now come more often than in the 1950s. They are also hotter. Human-caused climate change helped make recent heat events far more likely.
    Grade 3.57.8 words / sentenceThreat 3.2Hopeful proxy 0Actionability 0
  5. Heat is getting worse. Most land areas now see more heatwaves than in the 1950s. They last longer and burn hotter. Some recent ones would have been extremely unlikely without human influence.
    Grade 4.98 words / sentenceThreat 3.1Hopeful proxy 0Actionability 0
Extreme heat / C. Meaning5 messages
  1. Summer used to mean long evenings and open windows. Now, across most of the world's land, heatwaves arrive more often and burn hotter than they did in the 1950s. Behind each one are neighbors, workers, and children whose well-being matters, and caring for them is something we can do together.
    Grade 7.417 words / sentenceThreat 0Hopeful proxy 3.9Actionability 2
  2. Heat is not just a number. It is an older neighbor in a stuffy apartment, a farmworker in the afternoon sun. The IPCC finds heatwaves have grown more frequent and intense since the 1950s, with human influence behind recent extremes. Our compassion for each other is our greatest strength.
    Grade 712.2 words / sentenceThreat 4.1Hopeful proxy 16.3Actionability 0
  3. A generation ago, a heatwave like today's might have been a rare event. The IPCC finds that human influence has made recent extremes far more likely. That truth carries responsibility, and also hope, because what we helped create, we can help calm.
    Grade 7.914 words / sentenceThreat 0Hopeful proxy 11.9Actionability 4.8
  4. Across most continents, hot extremes have grown more frequent and intense since the 1950s. Every community that looks after its most vulnerable people in the heat is writing a more hopeful story about what we can become.
    Grade 10.118.5 words / sentenceThreat 2.7Hopeful proxy 13.5Actionability 2.7
  5. Imagine a city that protects everyone from the heat. Today, heatwaves are more common and more intense than in the 1950s, and human influence is a major reason. Such cities can only exist because people care enough to build them.
    Grade 7.613.3 words / sentenceThreat 2.5Hopeful proxy 5Actionability 2.5
Extreme heat / D. Action5 messages
  1. Heatwaves have become more frequent and intense since the 1950s, according to the IPCC. Prepare today: find your nearest cooling center, save its address in your phone, and check on one elderly neighbor during the next heat alert.
    Grade 8.919 words / sentenceThreat 2.6Hopeful proxy 21.1Actionability 13.2
  2. Hot extremes are rising across most land. Here is one step: during the next heat alert, close blinds by midday, drink water regularly, and avoid strenuous activity from noon to 4 p.m.
    Grade 8.716 words / sentenceThreat 3.1Hopeful proxy 6.2Actionability 12.5
  3. The IPCC finds heatwaves are more common and more intense than in the 1950s. You can plan ahead. Sign up for your local heat alerts and make a short list of cool places you can go.
    Grade 3.212 words / sentenceThreat 5.6Hopeful proxy 11.1Actionability 11.1
  4. Since the 1950s, heatwaves have grown stronger and more frequent. Take two minutes now to check that your fan or air conditioner works, and ask your landlord to fix it if it does not.
    Grade 5.617 words / sentenceThreat 0Hopeful proxy 0Actionability 14.7
  5. More frequent heatwaves are now a fact of life on most land. Call one friend or relative who lives alone and agree to check in on every hot day. Add their number to your favorites today.
    Grade 4.812 words / sentenceThreat 0Hopeful proxy 11.1Actionability 16.7
Extreme heat / E. Integrated5 messages
  1. Heatwaves are now more frequent and more intense than in the 1950s, and human influence is a key reason. But we can protect each other. This week, text an older neighbor and offer to check on them during the next heat alert.
    Grade 5.614 words / sentenceThreat 2.4Hopeful proxy 9.5Actionability 14.3
  2. The IPCC finds that hot extremes have grown since the 1950s. That is worrying, yet communities that prepare get through it together. Start today: save your nearest cooling center's address, and share it with three friends.
    Grade 5.512 words / sentenceThreat 2.8Hopeful proxy 22.2Actionability 13.9
  3. More heat is here, but so is our ability to care for one another. Heatwaves have become stronger since the 1950s. Sign up for local heat alerts and invite a family member to do the same. Preparing together keeps everyone safer.
    Grade 6.510.2 words / sentenceThreat 2.4Hopeful proxy 9.8Actionability 4.9
  4. Extreme heat is more common than in the 1950s, partly because of human choices. Better choices are possible. Ask your city council to plant shade trees in your neighborhood. Shade protects the people we love.
    Grade 58.8 words / sentenceThreat 0Hopeful proxy 11.4Actionability 8.6
  5. Hotter, more frequent heatwaves are changing summer, yet people are responding with care. You can join them. Check on one neighbor each heat alert, keep water handy, and tell a friend to do the same. Small acts protect whole communities.
    Grade 4.810 words / sentenceThreat 0Hopeful proxy 10Actionability 20

Descriptive evidence, with clear boundaries

The supplied Python analysis tokenizes text with [A-Za-z']+, splits sentences after terminal punctuation, assigns NRC emotion tags, and calculates cue counts per 100 words. Condition-level summaries use the mean and a 95% Student’s t-interval.

Interval half-width = t0.975, n−1 × s / √n   (n = 15)
  • Messages are nested within three topics and were generated by one model.
  • Each prompt directly instructs the target communication design.
  • The source reports descriptive results. Although the supplied code computes Kruskal–Wallis p-values, inferential statistics are not interpreted.
  • Reading metrics and lexical proxies do not establish comprehension, felt emotion, efficacy, intentions, or behavior.
  • The source does not specify the model version, generation settings, generation date, or random seeds.
View the supplied Python analysis

Transcribed from the PDF with line wrapping repaired. The original output directory is retained. The code has been checked for Python syntax; it has not been executed or used to recompute the reported results here. To run it, place messages.py alongside it, install its imported packages, and choose an existing writable output directory.

Download analysis · Download messages.py

import re, json, numpy as np, pandas as pd, textstat, nrclex, os
from importlib import resources
from scipy import stats
import matplotlib; matplotlib.use("Agg")
import matplotlib.pyplot as plt
from matplotlib import font_manager
from messages import M

OUT = "/mnt/user-data/outputs/pilot"
LEX = json.load(resources.files("nrclex.data").joinpath("nrc_en.json").open(encoding="utf-8"))
THREAT = {"fear"}                                #NRC fear-tagged words
HOPE = {"joy", "trust", "anticipation"}          #NRC proxy for hopeful/positive-future language
ACTION_VERBS = set("""switch set lower check sign call email ask join walk bike take replace unplug
find save share text invite


plant attend look write start try choose tell talk track protect prepare add close drink avoid keep support
reduce cut install vote
volunteer donate fix offer agree plan send repair drive""".split())
EFFICACY = re.compile(r"\b(you|we) can\b|\byou could\b|\blet's\b|\bcan too\b|\bpossible\b|\bpower to\b", re.I)
SPECIFIC = re.compile(r"\b(this week|this month|today|each week|every week|a week|minutes?|each heat alert|one (trip|step|action|neighbor|friend|family member))\b", re.I)

rows = [ ]
for (topic, cond), msgs in M.items():
    for i, t in enumerate(msgs, 1):
        words = re.findall(r"[A-Za-z']+", t.lower())
        n = len(words)
        sents = [s for s in re.split(r"(?<=[.!?])\s+", t.strip()) if s]
        tags = [e for w in words for e in LEX.get(w, [])]
        per100 = lambda x: 100 * x / n
        av = sum(w in ACTION_VERBS for w in words)
        ef = len(EFFICACY.findall(t)); sp = len(SPECIFIC.findall(t))
        rows.append(dict(topic=topic, condition=cond, run=i, text=t, words=n,
            fk_grade=textstat.flesch_kincaid_grade(t), sent_len=n/len(sents),
            threat_per100=per100(sum(e in THREAT for e in tags)),
            hope_per100=per100(sum(e in HOPE for e in tags)),
            action_verbs_per100=per100(av), efficacy_per100=per100(ef), specific_per100=per100(sp),
            actionability=per100(av+ef+sp)))
df = pd.DataFrame(rows); df.to_csv(f"{OUT}/messages_metrics.csv", index=False)



metrics = ["fk_grade","sent_len","threat_per100","hope_per100","actionability","words"]
def ci(x):
    x = np.asarray(x); return stats.t.ppf(.975, len(x)-1) * x.std(ddof=1)/np.sqrt(len(x))
summ = df.groupby("condition")[metrics].agg(["mean", ci]); summ.columns = ["_".join([a, b if b=="mean" else "ci95"]) for a,b in summ.columns]
summ.round(2).to_csv(f"{OUT}/summary_by_condition.csv"); print(summ.round(2).T.to_string())
for m in ["fk_grade","threat_per100","hope_per100","actionability"]:
    print(m, "Kruskal-Wallis p=%.2g" % stats.kruskal(*[g[m].values for _, g in df.groupby("condition")]).pvalue)

Explore the supporting material

References

  1. Gifford, R. (2011). The dragons of inaction. American Psychologist, 66(4), 290–302.
  2. Sweller, J. (1988). Cognitive load during problem solving. Cognitive Science, 12(2), 257–285.
  3. O’Neill, S., & Nicholson-Cole, S. (2009). “Fear won’t do it.” Science Communication, 30(3), 355–379.
  4. Feinberg, M., & Willer, R. (2011). Apocalypse soon? Psychological Science, 22(1), 34–38.
  5. Bandura, A. (1977). Self-efficacy. Psychological Review, 84(2), 191–215.
  6. Matz, S. C., Teeny, J. D., et al. (2024). The potential of generative AI for personalized persuasion at scale. Scientific Reports, 14, 4692.

Climate sources cited in the study: NASA (GISS; Earth Observatory) and IPCC AR6 Working Group I Summary for Policymakers (2021).