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In November 2024, the Western Pacific saw a record four simultaneous named tropical systems—Typhoon Yinxing, Typhoon Toraji, Super Typhoon Usagi, and Super Typhoon Man-Yi—all of which experienced rapid intensification due to warmer-than-average sea surface temperatures. Analysis using the Climate Shift Index: Ocean indicates these temperatures were made up to 40 times more likely by human-caused climate change. The Philippines was severely affected by 16 tropical cyclones or their remnants this season, resulting in at least 160 deaths and the displacement of over 9 million people due to flooding, landslides, and infrastructure damage.

The October 29, 2024, floods in Valencia, Spain, were driven by a low-pressure system (DANA) that utilized an atmospheric river carrying moisture from an unusually warm Tropical Atlantic. Analysis using the Climate Shift Index: Ocean and OISST data indicates that human-caused climate change made these elevated sea surface temperatures 50 to 300 times more likely.

The project utilizes paleotempestology—analyzing sediment cores from lagoons, stalagmite isotopic records, tree rings, and corals—to reconstruct past tropical cyclone activity. Key findings indicate that higher sea surface temperatures in the Atlantic correlate with increased hurricane activity, with notable peaks during the Medieval Warm Period (AD 900-1100) and since 1980. The research also identifies an inverse phase relationship in hurricane landfalls between Central America, the Eastern Caribbean, and the US East Coast, suggesting that the Intertropical Convergence Zone (ITCZ) and tropical anticyclones are critical drivers of coastal risk. Additionally, the study expanded its scope to the Pacific coast of Mexico, identifying an extreme event in Baja California Sur approximately 500 years ago.

The project utilizes paleotempestology—analyzing coastal lagoon sediments, stalagmites, tree-rings, and corals—to reconstruct past hurricane activity in the Caribbean and Mexico. Key findings link increased hurricane activity to warmer sea surface temperatures and specific climate patterns like the Atlantic Multidecadal Oscillation (AMO) and El Niño-Southern Oscillation (ENSO). The research identifies peaks in activity during the Medieval period (AD 900-1100) and since 1980, while also noting an anti-phase relationship in landfall activity between Central America and the eastern Caribbean/U.S. East coast. Additionally, the study assesses coastal vulnerability in the U.S., noting millions of people live in low-elevation areas.

The report finds that human-induced climate change increased the intensity and likelihood of heavy rainfall associated with Hurricane Milton in central Florida. Using the IRIS model, the analysis indicates that climate change increased the frequency of storms with Milton's wind speeds by approximately 40%, meaning the storm would have likely made landfall as a Category 2 rather than a Category 3 hurricane without global warming. Additionally, sea surface temperatures along Milton's track were 1°C warmer than in a world without climate change, making such temperatures 400 to 800 times more likely. The report also assesses Florida's adaptation measures, noting that while building codes are among the toughest in the US, the state's planning remains largely reactive and fails to adequately address social vulnerabilities in low-income and minority communities.

The analysis finds that climate change made rainfall approximately 10% heavier in both the coastal and inland regions affected by Hurricane Helene and increased the likelihood of such rainfall totals by 40% and 70%, respectively. The study also indicates that climate change increased the number of storms with similar wind speeds by about 150% and made the record-hot sea surface temperatures over the storm's track 200-500 times more likely. While the storm was well-forecast, high death tolls occurred inland due to mountainous terrain, poor infrastructure, and a lack of experience with hurricanes.

The document details how rising sea surface temperatures, driven by human-caused climate change, are increasing the frequency and intensity of rapid intensification in tropical cyclones. It highlights that 70% of billion-dollar tropical cyclones in the U.S. since 1980 underwent rapid intensification, contributing to over $1.4 trillion in damages and nearly 7,000 deaths.

The study finds that climate change increased rainfall intensity in Taiwan and Hunan province and contributed to a 7% increase in maximum wind speeds for similar storms in the Western North Pacific basin. While sea surface temperatures as hot as those observed during Typhoon Gaemi were "almost impossible without climate change", the analysis did not identify a significant trend for rainfall in the northern Philippines. The report highlights that existing urban plans and flood infrastructure are unable to withstand climate-driven extreme floods, particularly in areas of unplanned urban development like Metro Manila.

Analysis of 242 U.S. cities shows that fall temperatures have increased by an average of 2.5°F since 1970, with the most intense warming occurring in the Southwest. This trend is characterized by a higher frequency of above-normal temperature days, which prolongs risks related to heat-related illness, wildfires, and allergies, while also affecting agricultural growing seasons and energy demand for cooling.

Hurricane Beryl, the earliest Category 5 hurricane on record, was fueled by ocean temperatures 2°–3°F warmer than normal, conditions made 100–400 times more likely by human-caused climate change.

The document describes La Niña as the cool phase of the El Niño-Southern Oscillation (ENSO) cycle, characterized by the movement of cold water to the central and eastern Pacific surface. For 2024, there is an 85% chance of a transition to neutral conditions between April and June, and a 60% chance of La Niña developing by June to August. The text highlights that multi-year La Niña events are increasing in frequency, with five of the last ten occurring in the past 25 years. While La Niña temporarily lowers global average surface temperatures by about 0.1C, it does not offset human-caused warming; recent La Niña years have been among the top 10 hottest years ever. Regional impacts include drier conditions in East Africa and the southern US, and wetter conditions in Southeast Asia, India, and northern South America, affecting various crop yields and increasing the risk of floods and droughts.

Global sea surface temperatures reached unprecedented levels from April to July 2023, driven primarily by human-caused carbon pollution and El Niño. This warming increases the likelihood of rapid intensification in hurricanes and causes severe heat stress for coral reefs, particularly around Florida and the Caribbean. The document highlights that 48% of the global ocean experienced marine heat waves in July 2023, and warns that 70–90% of tropical coral reefs could disappear even if warming is limited to 1.5°C.

The document reports that while the total number of hurricanes is not increasing, the probability of storms reaching major hurricane status (Category 3-5) has risen significantly, particularly in the North Atlantic. It attributes this trend to rising sea surface temperatures and atmospheric warming, which also contribute to heavier rainfall, slower storm speeds, and deeper coastal flooding due to sea level rise.

Marine heatwaves (MHWs) are prolonged extreme warm water events, defined as temperatures above the 90th percentile for at least five consecutive days. These events have increased since the early twentieth century, driven by a 2.3°F (1.3°C) rise in sea surface temperatures over the last 100 years. MHWs cause severe ecological damage, including coral bleaching, kelp forest collapses, and sea bird die-offs, and can disrupt industries through fishery closures. A notable example is "the Blob" in the Pacific Ocean (2013), which lasted 226 days and was 4.5°F (2.5°C) warmer than average.

The 2016 drought in Kenya was primarily driven by sea-surface temperature patterns, specifically La Niña, rather than human-induced climate change. While climate change did not significantly increase the likelihood of the rainfall deficit, it did lead to hotter temperatures that exacerbated the drought's impact. The event was less severe than the 2010-11 drought but still triggered a national emergency, affecting millions of people in arid and semi-arid lands.

The December 2015 extreme rainfall event in Chennai, India, which saw a record 494 mm of rain in 24 hours, was determined by climate attribution studies to be a 1 in 600–2,500 year event not caused by anthropogenic global warming. While the event's rarity would have overwhelmed most cities, its impact was exacerbated by poor land-use planning, including the encroachment of wetlands and riverbeds, and a clogged drainage system. The document recommends that Indian cities integrate wetland protection, river basin approaches, and vulnerability-focused disaster action plans into their urban development to build resilience against increasing extreme weather trends.

A scientific analysis of the December 2015 Chennai floods found no detectable effect of human-induced climate change on the extreme one-day rainfall event, likely due to the masking effect of aerosol pollution in the region.

The 2016–2017 drought in Kenya, declared a national emergency in February 2017, was primarily driven by sea surface temperature patterns, specifically La Niña. While attribution analysis found no strong climate change signal in rainfall trends, it concluded that temperatures during the drought were hotter than they would have been without human-induced climate change. The drought severely impacted 23 counties, leaving up to 4 million people in need of food aid by April 2017, though it was less extreme than the 2010–2011 event.

The report assesses climate variability and future projections across central, eastern, western, and southern Africa, highlighting a critical gap in observational data and a lack of consensus among climate models. It details regional risks—such as the 'east African climate change paradox' and the vulnerability of the Congo rainforest—while providing country-specific analysis for Malawi, Rwanda, Senegal, Tanzania, Uganda, and Zambia. The document emphasizes the need for improved high-resolution modelling and better communication of scientific uncertainty to support adaptation in agriculture, water, energy, and urban infrastructure.

The analysis found that while human-induced climate change slightly increased the probability of the 2016 record-breaking heat in Rajasthan, the effect was not statistically significant. The study suggests that the warming effect of greenhouse gases in India is being partially offset by the cooling effects of aerosols and increased irrigation. Despite the lack of a strong temperature trend, the combination of high heat, pollution, and humidity is increasing the health risks and mortality associated with heat waves.