Fact check: How long has the planet been getting warmer

1. Summary of the results

Based on the analyses provided, the planet has been experiencing measurable warming since the mid-1800s, with the most significant warming occurring in recent decades. The data shows that 2024 was the warmest year on record since temperature measurements began in 1850/1880 ^{[1] [2]}.

The global average surface temperature has risen approximately 2.32°F (1.29°C) above the 20th-century average and 2.63°F (1.46°C) above pre-industrial levels ^[1]. More specifically, the planet's temperature has increased about 2°F (1°C) since the late 19th century, with most warming occurring in the past 40 years ^[3]. One analysis indicates an average yearly temperature increase of 0.0067°C over 172 years since 1850, with acceleration in recent years ^[4].

Critically, the ten warmest years in the 175-year temperature record have all occurred during the last decade ^[1], and the current warming trend is proceeding at a rate not seen in the past 10,000 years ^[3].

2. Missing context/alternative viewpoints

The analyses reveal important geological context missing from a simple timeline question. Earth's temperature has naturally varied between 11°C and 36°C over the past 485 million years, with CO2 being the dominant control on climate throughout this period ^[5]. This long-term perspective shows that while climate has always changed, the current rate of change is unprecedented in recent geological history.

The analyses emphasize that human activities have been the primary driver of warming since the mid-1800s ^{[3] [6]}, distinguishing current warming from natural climate variations. Human activities, principally through greenhouse gas emissions, have unequivocally caused global warming, with temperatures reaching 1.1°C above 1850-1900 levels during 2011-2020 ^[6].

Climate scientists and environmental organizations benefit from emphasizing the urgency and human causation of recent warming, as this supports calls for immediate policy action and funding for climate research and mitigation technologies. Conversely, fossil fuel industries and climate skeptics might benefit from emphasizing natural climate variability over geological timescales to downplay the significance of recent human-caused warming.

3. Potential misinformation/bias in the original statement

The original question "how long has the planet been getting warmer" contains no explicit misinformation but could be misleading in its simplicity. The question fails to distinguish between:

• Natural climate variations over geological timescales versus recent human-caused warming
• The dramatically different rates of warming in recent decades compared to historical patterns
• The critical difference between gradual natural climate changes and the current rapid warming trend

The phrasing could inadvertently support narratives that conflate natural climate variability with current anthropogenic warming, potentially minimizing the significance of recent temperature increases. The question lacks the specificity needed to understand that while Earth's climate has always changed, the current warming trend since the mid-1800s represents an unprecedented rate of change driven by human activities ^[3].