USCGA · The Science
Climate Change —
Talk About It
Start with a claim you can check tonight
The Coast Guard Academy runs the Center for Arctic Study and Policy. This program is built around a region that’s changing fast enough to affect where ships can go, where search-and-rescue happens, and where the Coast Guard itself operates. Don’t take our word for how fast. Below is the actual satellite record of the Arctic’s summer sea ice minimum, year by year since 1985. Drag the timeline yourself.
2026 · 4.60M km²
1985
← drag →
2026
Million square kilometers: Arctic sea ice extent at its annual September minimum (5-day average), every year since 1985. NSIDC Sea Ice Index, version 4.
A study and a petition are not the same kind of evidence
One side of this argument points to a review of 88,125 peer-reviewed climate papers published from 2012 to 2020, which found a consensus of more than 99% that humans are causing climate change (Environmental Research Letters, 2021). The other points to petitions signed by tens of thousands of people, including the 1998 Oregon Petition. These aren’t comparable. A petition is a signature. A peer-reviewed paper is data, method, and analysis that other scientists tried to find fault with before it was allowed to publish, and can still challenge after.
PEER-REVIEWED PAPER
Submitted
Reviewers object
Revised
Published
PETITION
Signed
What’s well-established, and what isn’t
“If it disagrees with experiment it is wrong.”
Well-established
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CO2 traps heat — measured directly since Tyndall’s 1859 experiments. See the mechanism →Venus has a CO2-thick atmosphere and is the hottest planet in the solar system — hotter than Mercury, which is closer to the sun. Distance doesn’t explain that. CO2 does.
- Ice cores show CO2 cycled between roughly 180–300 ppm over the last 800,000 years. It’s now above 420 ppm — already outside that entire natural range, reached in a geological instant. Live CO2 data →
- Most of ExxonMobil’s own internal projections, made between 1977 and 2003, accurately predicted the warming that has since been observed (Science, 2023).
- Warmer air holds more water vapor — about 7% more per 1°C. Basic physics, not a projection.
Still being worked out
- The exact rate of sea-level rise beyond the next few decades — model spread is genuinely wide. Boston tide-gauge trend →
- Cloud feedback effects — by climate scientists’ own account, one of the largest remaining sources of uncertainty. IPCC synthesis, not original research →
- Precise regional and local impacts — much harder to pin down than global averages.
- Whether the total number of hurricanes is increasing — the historical data doesn’t support a clear trend either way (NOAA’s own assessment →). Intensity is a different story: the share of storms reaching Category 3–5 has likely increased over the past four decades, though tying that specifically to human-caused warming carries only medium confidence (IPCC AR6, Chapter 11 →).
Read more, directly from the source
Straight from the agencies and societies that publish the underlying data and peer-reviewed research.