Welcome
A Hands-On Introduction to Python, Climate Data, and Our Planet
Understanding Climate Change Using Data Science
The Earth is running a fever. Don't take our word for it — in this book, you can download the data and see it for yourself.
First version: 2024. Updated with new data and analysis in 2026.
One stripe per year since 1850: blue years were cooler than the 20th-century average global temperature, red years warmer. Notice anything? (Data: NOAA NCEI, fetched live when this page was built — with the very same Python code you will learn in the opening chapters.)
3
The three warmest years in this 176-year record: 2024, 2023 and 2025 — the very stripes above
≈10 in
Global sea level rise since 1880, per the NOAA record through 2021 — and accelerating
90%
Share of the excess heat from global warming absorbed by the oceans (NASA)
−28 m
Water equivalent lost by the world's reference glaciers since 1970 (WGMS, through 2025)
Every chart in this book — including the stripes above — is built from free public data with a few lines of Python. No experience needed: we learned to code writing this book, mistakes and all, and we will show you exactly how. Grab a laptop. Let's look at the evidence together.