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1.5 Degrees C: Understanding World’s Critical Warming Threshold

Climate change

Published online June 18, 2025

  • Date (DD-MM-YYYY)

    10-07-2025 to 10-01-2026

    Available on-demand until 10th January 2026

  • Cost

    Free

  • Education type

    Article

  • CPD subtype

    On-demand

Description

Nearly a decade ago, the world rallied around the Paris Agreement on climate change and the goal of holding global temperature rise to 1.5 degrees C (2.7 degrees F). Since then, the “1.5C goal” has become the world’s North Star for climate action — a critical benchmark against which policies are set and progress is measured. But an alarming wave of recent data underscores just how close we are to surpassing this widely cited threshold.

Atmospheric concentration of carbon dioxide reached its highest level in 2 million years last year. 2024 also marked the first single year in which global average surface temperature rose more than 1.5 degrees C above pre-industrial levels. While the Paris Agreement goal refers to a long-term average, not a single year, scientists warn that we may be at the beginning of a full breach — and with it, increasingly dangerous floods, droughts, fires and other climate impacts.

So what exactly is the 1.5 degrees C goal, how was it set, and what happens if we exceed it? Here’s what to know.

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