Encyclopedia of contested claims
Current climate science indicates that human-caused warming is increasing the frequency or intensity of several kinds of extreme weather, especially heat extremes, heavy rainfall, and some drought and fire-weather conditions. The pattern is not uniform for every hazard or every region, and trends are harder to establish for some events such as tornadoes and certain storm measures.
10 reviewing models concluded the claim is mixed by the available evidence.
The Adjudged panel has not yet completed its full review of this claim. This draft is an initial evidence map prepared for review, summarizing major scientific findings, key uncertainties, and candidate sources the panel may evaluate before issuing a final assessment.
Current climate science indicates that human-caused warming is increasing the frequency or intensity of several kinds of extreme weather, especially heat extremes, heavy rainfall, and some drought and fire-weather conditions. The pattern is not uniform for every hazard or every region, and trends are harder to establish for some events such as tornadoes and certain storm measures.
The claim asks whether extreme weather events are becoming more frequent because of climate change. In this context, “extreme weather” can include heat waves, heavy rainfall, droughts, wildfire-conducive conditions, tropical cyclones, coastal flooding, winter storms, and severe convective storms such as tornadoes and hail.
The wording is broad, so a careful assessment needs to distinguish between different event types. Climate change can make some extremes more frequent, others more intense, and others more damaging by raising baseline temperatures, increasing atmospheric moisture, changing snow and ice conditions, or increasing sea level.
The strongest version of the claim would be that all categories of extreme weather are becoming more frequent everywhere because of climate change. The more supportable version is that climate change is already increasing the frequency or intensity of several major categories of extremes, with the clearest evidence for heat extremes and heavy precipitation.
Major climate assessments report that hot extremes have become more frequent and more intense across most land regions since the mid-20th century, and that human-caused greenhouse gas emissions are the main driver of this change. Heat waves are one of the clearest examples because a warmer baseline climate makes unusually hot days and nights more common.
Heavy precipitation has also increased in many regions, consistent with the physical expectation that a warmer atmosphere can hold more water vapor. This does not mean every rainstorm is caused by climate change, but it means the odds and intensity of heavy rainfall events have increased in many places.
For drought, wildfire weather, and tropical cyclones, the evidence is more regionally specific. Some regions have seen increased agricultural or ecological drought linked to warming, and many fire-prone areas experience hotter, drier conditions that can raise fire risk. Tropical cyclones are not generally assessed as clearly more frequent globally, but evidence supports increases in the proportion of very intense storms and in rainfall rates associated with them.
Event-attribution research increasingly estimates how much climate change altered the likelihood or severity of individual events. These studies often find large climate-related increases in the probability or intensity of extreme heat events and, in some cases, heavy rainfall and drought-related extremes.
Uncertainty varies by event type, region, and data quality. Long-term records for heat and precipitation are generally stronger than records for tornadoes, hail, small-scale storms, or events in regions with sparse historical observations.
A change in damages from extreme weather is not the same as a change in weather frequency. Rising losses can also reflect more people and property in exposed areas, changes in infrastructure, insurance coverage, land use, and reporting practices.
The phrase “extreme weather events” can obscure important differences. The overall answer is strongest when focused on well-studied hazards such as heat extremes and heavy precipitation, and more cautious when applied to every category of weather extreme.
The umbrella claim is actually several claims bundled into one. Each needs its own evaluation.
| Model | Part 1 | Part 2 | Part 3 | Overall |
|---|---|---|---|---|
| Grok 4.3 | Yes · 92% | Yes · 82% | Mixed · 78% | Mixed · 70% |
| OpenAI GPT-5.4 | Yes · 92% | Yes · 82% | Mixed · 78% | Mixed · 85% |
| Mistral Medium 3.5 | Yes · 92% | Yes · 82% | Mixed · 78% | Mixed · 35% |
| Llama 4 Maverick | Yes · 92% | Yes · 82% | Mixed · 78% | Mixed · 85% |
| Gemini 3.1 Pro | Yes · 92% | Yes · 82% | Mixed · 78% | Mixed · 85% |
| Claude Opus 4.7 | Yes · 92% | Yes · 82% | Mixed · 78% | Mixed · 85% |
| DeepSeek V4 Pro | Yes · 92% | Yes · 82% | Mixed · 78% | Mixed · 85% |
| GLM 5.1 | Yes · 92% | Yes · 82% | Mixed · 78% | Mixed · 75% |
| Qwen 3.7 Max | Yes · 92% | Yes · 82% | Mixed · 78% | Mixed · 85% |
| Kimi K2.6 | Yes · 92% | Yes · 82% | Mixed · 78% | Mixed · 70% |
The current evidence leans one way. But we're not committed to the conclusion, we're committed to the evidence.
Some extreme weather events are increasing in frequency or intensity due to human-caused climate change, particularly heat extremes and heavy precipitation in many regions, while others show no clear global tre...
Mostly true, with an important caveat: climate change is increasing the frequency and/or intensity of several major types of extreme weather, but not all types everywhere, and not always in frequency rather tha...
The claim that extreme weather events are becoming more frequent due to climate change is **partially true but requires nuance**. **Confidence**: High for heat extremes and heavy precipitation; moderate for droughts and fire-weather conditions; low for tornadoes and some storm measures. **Key evidence**: - **Heat extremes**: Multiple authoritative sources (IPCC, NOAA, USGCRP) confirm that human-caused warming has significantly increased the frequency, intensity, and duration of heatwaves in most regions. Observatio...
Extreme weather events are becoming more frequent or intense in certain categories due to climate change, but not uniformly across all types or regions. Confidence: High for heat extremes and heavy precipitatio...
Many, but not all, types of extreme weather events are becoming more frequent and intense due to climate change. I have high confidence in this assessment based on the consensus of major climate science organiz...
Yes, but with important qualifications. The claim is true for several categories of extreme weather and overstated if applied universally. The evidence is strongest and most consistent for heat extremes. The IP...
The claim that extreme weather events are becoming more frequent due to climate change is partially supported by current science, but it is not accurate as a blanket statement for all types of extreme weather g...
The claim is partially true but requires critical qualification. Human-caused climate change is definitively increasing the frequency and intensity of specific extreme weather events, particularly heat extremes...
Yes, many types of extreme weather events are becoming more frequent and intense due to human-caused climate change, but it is scientifically inaccurate to claim that all types of extreme weather are increasing...
Human-caused climate change has increased the frequency and intensity of specific extreme weather events—notably heat extremes, heavy precipitation, and some drought and fire-weather conditions in many regions—...
