Global demand for transport (for both passenger and freight) is growing rapidly, and it is predicted to triple between 2019 and 2050 (OECD 2019). The global vehicle fleet is projected to more than double from 1.2 billion to 2.5 billion between 2015 and 2050, with most of the growth occurring in Low- and  Middle-Income Countries (World Bank 2017).Despite progress made on fuel efficiency and el...

Crop Residue Burning (CRB) or open burning of vegetation to prepare land for resowing remains a persistent issue globally. This practice is especially prevalent among farmers growing paddy, wheat, sugarcane, and maize (FAOSTAT, 2023).  Between 2003 and 2020, an average of 81 million hectares (Hall et al., 2024) of cropland area was burned annually. Deeply rooted in agricultural traditions, CR...

By systematically reviewing over 10,000 publications using a large-language-model-based framework, the authors provide a large-scale quantitative assessment of the global research landscape on climate change’s impact on air quality. Particulate matter (PM) and ozone (O3) are the most frequently studied pollutants, with a notable shift in focus from O3 to PM in recent years. Temperature, as a prima...

The air quality forecasting system is an essential tool widely used by environmental managers to mitigate adverse health effects of air pollutants. This work presents the latest development of the next-generation regional air quality model (AQM) forecast system within the Unified Forecast System (UFS) framework in the National Oceanic and Atmospheric Administration (NOAA). The UFS air quality mode...

Forecast verification is an essential function of National Meteorological and Hydrological Services (NMHSs), underpinning their ability to deliver accurate, reliable, and actionable weather, climate, and water-related information. As NMHSs face increasing demands for transparency, accountability, and continuous improvement, they require robust systems to assess and enhance the quality of their for...

Extreme heat and particulate matter (PM2.5) pollution are among the deadliest environmental hazards that threaten humans and ecosystems. Their co-occurrence, known as compound heat-pollution events, can amplify risks far beyond those posed by either hazard alone, but their global patterns and physical mechanisms are yet to be understood. Here, the authors present a global assessment of compound he...

The online version of the Regional Air Quality Deterministic Prediction System (RAQDPS) is a chemical weather forecast system that has been employed operationally by Environment and Climate Change Canada (ECCC) since 2009. It is run twice per day to produce 72 h forecasts of hourly 10 km abundance fields of three key predictands, NO2, O3, and PM2.5 total mass, as well as other gas-phase chemical s...

The National Oceanic and Atmospheric Administration recently sponsored the New England Forecasting Pilot Program to serve as a “test bed” for chemical forecasting by providing all of the elements of a National Air Quality Forecasting System, including the development and implementation of an evaluation protocol. This Pilot Program enlisted three regional-scale air quality models, serving as protot...

The National Air Quality Forecast Capability (NAQFC) currently provides next-day forecasts of ozone concentrations over the contiguous United States. It was developed collaboratively by NOAA and Environmental Protection Agency (EPA) in order to provide state and local agencies, as well as the general public, air quality forecast guidance. As part of the development process, the NAQFC has been eval...

Short-term exposure to air pollution can result in acute health effects, particularly for individuals with respiratory and cardiovascular disease. Air quality alert programs that notify the public about high air pollution days are critical for susceptible populations. The authors assessed how U.S. adults receive air quality alerts and whether it varies by demographic or health characteristics. The...