Audience: High school Earth Science students with little or no background in statistics.

Storytelling framework: Beginning–Middle–End, guided by the Big Idea approach.

• Beginning: Introduce Earth’s warming and ask whether warmer temperatures mean more storms.
• Middle: Explore 30 years of temperature and storm data through visualizations.
• End: Explain what the evidence tells us and why storm intensity matters.

Main Idea: A warmer planet can influence storms, but frequency and intensity are different questions.

Evidence: 30 years of NASA and NOAA records, 1995–2024.

Today’s idea: Frequency and intensity are different questions.

• A tropical cyclone is a rotating storm that forms over warm ocean water.
• Hurricane is used in the Atlantic; typhoon is used in the western North Pacific.
• We count storms with recorded peak winds of at least 34 knots (tropical-storm strength).
• We separately count major intensity storms with peak winds of at least 96 knots.

Key takeaway: Storm frequency varies considerably between years and regions, showing that rising global temperatures do not produce identical storm patterns in every ocean basin.

Key takeaway: The number of major tropical cyclones fluctuates from year to year, with no consistent increase across both ocean basins.

Key takeaway: Average peak wind speeds vary over time, showing that storm intensity does not follow the same pattern in every region.

• Tornadoes are smaller, short-lived rotating columns of air associated with thunderstorms.
• They are not the same phenomenon as tropical cyclones.
• We examine U.S. reports and separately count strong F/EF2–5 tornadoes.
• Better detection and reporting can change observed totals even without changes in weather.

A positive correlation means warmer years tend to have higher values. A negative correlation means warmer years tend to have lower values. A correlation near zero means little linear relationship.

Important: Correlation does not prove that warming caused a particular storm.

Main finding: None of the eight storm measures showed a statistically significant correlation with global temperature in this analysis.

Pearson r ranges from −1 to +1. A small p-value is not proof of causation.

• Warm ocean surfaces can provide heat and moisture to tropical cyclones.
• Other ingredients such as wind shear and atmospheric circulation also matter.
• The scientific evidence for stronger tropical cyclone rainfall and a higher share of very intense storms is more robust than evidence for increasing total storm counts everywhere.
• Tornado climate trends remain more uncertain.

A storm does not need to become more common to become more dangerous.

A very intense storm can cause severe flooding, destructive winds, and lasting damage to homes and infrastructure. Exposure and preparedness also influence the harm a storm causes.

🌡️ Earth is warming

🌪️ Storm counts vary

💨 Intensity matters

Main takeaway: A warmer planet does not automatically mean more storms everywhere.

• NASA GISTEMP v4: https://data.giss.nasa.gov/gistemp/
• NOAA IBTrACS v04r01: https://www.ncei.noaa.gov/products/international-best-track-archive
• NOAA Storm Prediction Center: https://www.spc.noaa.gov/wcm/
• IPCC AR6, Working Group I: https://www.ipcc.ch/report/ar6/wg1/

Limitations: Global average temperature is not local ocean temperature; storm detection and intensity estimates vary; IBTrACS USA_WIND coverage is incomplete in some basins; storm seasons and calendar years may differ; tornado ratings/reporting have changed; the 30 annual observations are serially related. These descriptive correlations are not causal estimates.