The 1990 IPCC First Assessment Report laid out how a warming world would unfold and, overall, has been vindicated by later data, with the main shortcoming being underestimating human emissions rather than errors in the physics.

Sea level rise has tracked a near-term trajectory of roughly six centimeters per decade, but the rate is accelerating as ice loss in Greenland and Antarctica speeds up.

The author argues that the gap between predictions and reality reflects political decisions more than scientific failures, noting that proven technologies—solar, wind, efficiency, and storage—exist but have not been deployed at the necessary scale.

Hurricane projections were limited in the original report, but modern attribution science shows warming climate intensifies peak winds and rainfall in storms, even if the total number of storms isn’t clearly rising.

Atmospheric CO2 rose from about 354 ppm in 1990 to around 429 ppm today, surpassing the IPCC’s business-as-usual pathway and signaling insufficient emission cuts.

The report projected roughly 0.3°C of warming per decade under business as usual; current temperatures sit about 1.4–1.5°C above pre-industrial levels, with 2024 the warmest year on record since then and 2025 ranking as the third warmest.

The core takeaway remains: climate physics are solid, and the dominant gaps lie in political will and policy choices rather than in scientific understanding or modeling capability.