{"query_echo":{"q":"","filters":{"analysis_type":["detection and attribution"]},"warnings":[{"code":"facet_value_not_in_vocabulary","message":"Value 'detection and attribution' for facet 'analysis_type' is not in the controlled vocabulary."}]},"total":{"value":1,"relation":"eq"},"page":1,"page_size":20,"self":"https://climateinsightsdirectory.org/api/v1/search?analysis_type=detection+and+attribution","stability":"beta","ai_marking":{"digital_source_type":{"uri":"http://cv.iptc.org/newscodes/digitalsourcetype/trainedAlgorithmicMedia","name":"Created using Generative AI"},"notice":"Summary and key insights are generated using artificial intelligence."},"results":[{"id":"wwatt-000095","url":"https://climateinsightsdirectory.org/document/wwatt-000095","title":"U.S. Heat February 2017","publisher":{"name":"World Weather Attribution","organization":"world-weather-attribution"},"document_type":"research paper","language":"en","date_published":"2017-03-08","source_url":"https://www.worldweatherattribution.org/u-s-heat-february-2017/","generator":"Climate Insights Directory","generated_fields":["summary","key_insights","climate_tags","geography_discussed","analysis_type"],"summary":{"text":"The analysis finds that February 2017 was the second warmest February on record for the contiguous United States, with temperatures 3.1°C above the 1981–2010 normal. By combining historical observations with CMIP5, HadGEM3-A, and Weather@Home model ensembles, the study concludes that the probability of such a warm event has increased more than threefold due to human-induced greenhouse gas emissions. While the 2017 event had a return period of approximately 12 years in the current climate, it would have been a 1-in-160-year event around 1900. Projections suggest that by 2050, temperatures like those seen in February 2017 will be 'completely normal', occurring roughly every three years.","ai_generated":true,"unit":"wwatt-000095#summary","date_modified":"2026-10-23"},"key_insights":[{"text":"February 2017 was the second warmest February on record for the contiguous United States (CONUS), with a temperature of 4.9 °C, which was 3.1°C warmer than the 1981–2010 normal. It was the warmest February on record for the area east of the Rocky Mountains.","ai_generated":true,"unit":"wwatt-000095#insight-1","date_modified":"2026-10-23"},{"text":"The frequency of record-breaking high temperatures was extreme in February 2017, with over 6,300 record daily highs tied or broken compared to fewer than 130 record lows, resulting in a ratio of 49 high records for every one low record.","ai_generated":true,"unit":"wwatt-000095#insight-2","date_modified":"2026-10-23"},{"text":"Observational data indicates that the likelihood of a February as warm as 2017 has increased significantly since 1900; the return period has shifted from approximately 160 years (0.6% annual probability) around 1900 to about 12 years (8% annual probability) in the current climate.","ai_generated":true,"unit":"wwatt-000095#insight-3","date_modified":"2026-10-23"},{"text":"A weighted average of observational trends and three model ensembles (CMIP5, HadGEM3-A, and Weather@Home) concludes that human-caused climate change has increased the probability of such warm February events by more than a factor of three.","ai_generated":true,"unit":"wwatt-000095#insight-4","date_modified":"2026-10-23"},{"text":"Climate model simulations indicate that without human-induced increases in greenhouse gases, the return period for a February as warm as 2017 would be approximately 60 years, compared to the current 18-year return period estimated by CMIP5 models.","ai_generated":true,"unit":"wwatt-000095#insight-5","date_modified":"2026-10-23"},{"text":"Projections for the year 2050, based on the RCP8.5 scenario of continued intensive fossil fuel use, suggest that temperatures similar to February 2017 will occur on average every three years.","ai_generated":true,"unit":"wwatt-000095#insight-6","date_modified":"2026-10-23"},{"text":"While the overall trend is toward warming, the study notes that natural weather fluctuations will continue to produce cold events, although their probability is reduced.","ai_generated":true,"unit":"wwatt-000095#insight-7","date_modified":"2026-10-23"}],"climate_tags":["greenhouse gas emissions","extreme weather event","extreme event attribution"],"geography_discussed":["Pacific Northwest","California","Washington"],"frame_perspective":[],"analysis_type":["detection and attribution","trend analysis","climate modeling"]}]}