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Climate Central analyzed data from 476 weather stations to track fire weather trends in the contiguous U.S. between 1973 and 2025. The analysis reveals a significant increase in fire weather days, particularly in the western U.S., where conditions are intensifying in spring and summer. While the eastern U.S. has seen smaller increases, some areas in the Southeast and Northeast are experiencing more frequent fire weather. The report highlights that climate change is driving these trends through warming temperatures and decreasing relative humidity, which prime landscapes for wildfires to ignite and spread.

In 2025, the U.S. experienced 23 billion-dollar weather and climate disasters costing $115 billion, ranking it the third-highest year on record. The year was dominated by a record 21 billion-dollar severe storm events and the costliest wildfire in U.S. history, the Los Angeles wildfires. Since 1980, the frequency of such disasters has surged, with the average time between events dropping from 82 days in the 1980s to just 10 days in 2025.

An analysis of 240 UK cities from 1970 to 2024 shows that 85% have experienced an increase in the average number of days per year exceeding 27°C. In cities such as Cambridge, Luton, and Bedford, the average number of such days rose from 1 per year in the early 1970s to 11-13 per year between 2020 and 2024, with human-caused climate change responsible for the majority of this increase.

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.

An analysis of 476 weather stations from 1973 to 2023 shows that fire weather seasons are lengthening and intensifying across the contiguous United States, with the most significant increases occurring in the West. While the East has seen more modest increases, both regions are experiencing a notable rise in fire weather days during the spring. The Southwest has seen the most dramatic growth, with some areas experiencing fire weather twice as often as they did 50 years ago.

Climate change is increasing the intensity of extreme precipitation across the U.S., with the Northeast and Midwest seeing the largest increases since 1958. Under 2°C of global warming, 85% of U.S. counties are projected to experience a 10% or higher increase in precipitation on the heaviest 1% of days. This intensification contributes to flash flooding and landslides, disproportionately affecting racial minorities and those in mobile homes, particularly in the South and rural areas. Between 1988 and 2021, warming-induced rainfall intensification caused an estimated $84 billion in inland flood damages.

The report details a decade of significant growth in U.S. solar and wind power, noting that solar generation increased more than eight-fold and wind more than doubled between 2014 and 2023. It highlights the leading roles of states like California and Texas, the emergence of small-scale solar, and the potential for these technologies to drive the U.S. toward its 2035 goal of 100% carbon pollution-free electricity, although current projections suggest the 2030 emissions target may be missed.

Climate Central analyzed 2,041 U.S. monitoring stations from 1970 to 2023, finding that 64% of locations experienced a decrease in annual snowfall. The report highlights regional disparities, noting that while the western U.S. faces shrinking snowpack and increased snow drought, the Great Lakes region sees a trend toward more lake effect snow due to reduced ice cover, though the overall snow season is projected to shorten. These shifts threaten water security in the West, the winter recreation industry in the Northeast, and aquatic ecosystems in the Northern Great Plains.

Climate Central analyzed precipitation data from 1969-70 to 2022-23 for the contiguous U.S., finding that while some regions have balanced seasonal rainfall, others rely heavily on a single season. Specifically, the West and Northwest are dominated by winter precipitation, while the Plains and Upper Midwest rely on summer rainfall. Climate change is altering these patterns, with a general increase in precipitation east of the Rockies and a decrease to the west. Warmer temperatures are increasing atmospheric moisture—approximately 10% more since 1970—which enhances extremes such as heavy downpours and intensifying droughts.

The report analyzes the evolution of biological weapons threats from the 1940s to the 2010s, noting a shift from battlefield utility to 'gray zone' and asymmetric warfare. It argues that the COVID-19 pandemic acts as a 'game changer' that could either drive nations toward biological weapons as a low-cost deterrent or catalyze a new era of international cooperation. The authors identify critical gaps in U.S. policy, including an over-emphasis on bioterrorism over state-based threats and declining biodefense funding, recommending a 'deterrence by denial' strategy and increased international collaboration.

Climate Central's analysis of weather station data from 225 locations across 17 U.S. states reveals a significant increase in fire weather days since the 1970s, driven primarily by warming and decreasing relative humidity. The report highlights that interior regions have seen higher increases than coastal areas, with some parts of New Mexico experiencing two additional months of fire weather compared to nearly 50 years ago. Beyond increasing wildfire risk, these conditions have led utilities like PG&E to implement public safety power shutoffs (PSPSs) to prevent equipment-related ignitions, resulting in significant economic impacts and health risks. The document argues that while land management and localized grids can mitigate risk, long-term stabilization requires reducing carbon pollution to net zero by 2050.

The document describes the humid continental climate of the lower Winnipeg River basin and details historical increases in river discharge. It presents climate projections for the 2050s, indicating rising temperatures, precipitation, and runoff, which may impact hydroelectric development and aquatic ecosystems.

China is the world's largest primary energy consumer and energy-related CO2 emitter. While the country is on track to meet most 2020 targets from its 13th Five-Year Plan, energy-related CO2 emissions continued to grow through 2018, surpassing 10 GtCO2. The report's 'Continuous Improvement Scenario' projects that primary energy consumption will peak in 2029 at 5,400 Mtce and CO2 emissions will peak in 2025 at 10,930 MtCO2, subsequently declining to 5,010 MtCO2 by 2050. This outlook assumes the maximum adoption of commercially available energy efficiency and renewable energy technologies, leading to a power system where non-fossil sources generate 89% of electricity by 2050.

Climate Central's analysis of U.S. weather data from 1970 to 2018 reveals a broad warming trend, with 91% of assessed stations seeing winter temperatures rise by at least 1°F. This warming threatens the winter sports economy, which supported over 191,000 jobs and contributed $11.3 billion to the national economy in the 2015-16 season. The report highlights a decline in below-freezing days and divergent snowfall trends, with significant decreases in the Western U.S. and increases in the Great Lakes region. Future projections suggest that unchecked emissions could rob states like Colorado of more than a month of below-freezing days by midcentury.

The Union of Concerned Scientists reports that cities in the US Midwest have experienced an increase in heat waves and dangerously hot, humid days over the last six decades. Analysis of ten cities, including St. Louis, Chicago, Detroit, and the Twin Cities, shows a rise in the frequency of heat waves and a corresponding loss of cool, comfortable summer days. These trends increase the risk of hyperthermia and dehydration, particularly for vulnerable populations such as the elderly, children, and those with pre-existing medical conditions. The document advocates for city-level preparedness and the reduction of fossil fuel emissions to mitigate these health risks.

The report finds that dangerously hot summer days and heat waves have become more common in the US Midwest since the 1940s and 1950s. It highlights that nighttime temperatures have risen, reducing the cooling relief necessary to prevent heat-related illness. The analysis, covering 10 cities, indicates that these trends are not solely due to urban heat island effects, as smaller cities showed similar increases. Future projections suggest a significant increase in days over 90°F and 100°F by the end of the century if high carbon emissions continue.

The report finds that the US Midwest has experienced a significant increase in dangerously hot and humid summer days since the 1940s and 1950s. This trend increases the risk of heat-related illnesses and deaths, particularly for vulnerable populations such as the elderly, children, and urban residents. The analysis, covering 10 cities across eight states, indicates that rising nighttime temperatures and more frequent heat waves exacerbate health risks. Projections suggest that without significant carbon emission reductions, the region will face a substantial increase in days exceeding 90°F and 100°F by the end of the century.

Hourly rainfall intensity in 126 U.S. cities has increased by an average of 15% since 1970, with the heaviest 1% of downpours intensifying most in the Northeast (+60%) and Midwest (+45%) between 1958 and 2021. Future warming of 2°C is projected to increase precipitation during the heaviest events by an average of 17% across U.S. counties. The document highlights that flood risks disproportionately affect people of color, those in mobile homes, and Black communities along the Atlantic and Gulf coasts, noting that rainfall changes between 1988 and 2017 caused approximately $73 billion in flood damages.

The document analyzes energy efficiency as a 'first fuel' for decarbonization, detailing the historical decline in energy intensity for both the US and China. It outlines specific national targets, such as China's goal to reduce energy intensity by 13.5% by 2025 and the US goal of net-zero emissions by 2050. Additionally, it reviews the history of US-China bilateral cooperation, including the Energy Efficiency Action Plan and the US-China Clean Energy Research Center, noting a recent agreement in November 2023 to restart the US-China Energy Efficiency Forum.

The document details the energy efficiency trajectories of the U.S. and China, noting that the U.S. has seen a steady decline in energy intensity since 1950, while China experienced significant fluctuations, including a sharp increase between 2000 and 2005 before implementing binding reduction targets. It outlines current targets, such as the U.S. goal of net-zero by 2050 and China's goal of carbon neutrality by 2060, and highlights the history of U.S.-China cooperation through initiatives like the Energy Efficiency Action Plan and the Energy Efficiency Forum.