Rapid buildup of greenhouse gases is expected to increase the Earth surface mean temperature, with unclear effects on temperature variability1–3. This adds urgency to better understand the direct effects of the changing climate on human health. However, the effects of prolonged exposures to temperatures, which are important for understanding the public health burden, are unclear. Here we demonstrate that long-term survival was significantly associated with both seasonal mean values and standard deviations (SDs) of temperature among the Medicare population (aged 65+) in New England, and break that down into long-term contrasts between ZIP codes and annual anomalies. A rise in summer mean temperature of 1 °C was associated with 1.0% higher death rate whereas an increase in winter mean temperature corresponded to 0.6% lower mortality. Increases in temperature SDs for both summer and winter were harmful. The increased mortality in warmer summers was entirely due to anomalies, while it was long term average differences in summer SD across ZIP codes that drove the increased risk. For future climate scenarios, seasonal mean temperatures may in part account for the public health burden, but excess public health risk of climate change may also stem from changes of within season temperature variability.

Summertime HONO concentrations were synchronously measured at two (an agricultural and a non-agricultural) sites in the North China Plain (NCP). Daytime HONO (1.4±0.6 ppbv) and HONO/NO2 ((12±8)%) over the agricultural field after fertilization were found to be remarkably higher than those before fertilization, implying strong HONO emission from the fertilized fields.Synchronous enhancements of HONO and O3 after fertilization at both sites suggested that the emitted HONO accelerated the local and the regional O3 pollution. HONO budget analysis further revealed that its emission was significantly enhanced after fertilization. Soil HONO emission flux and its uncertainty were estimated and discussed. The estimated emission flux exhibited a distinct diurnal variation with a noontime maximum. Net OH production rate from HONO photolysis greatly exceeded that from O3 photolysis over the agricultural field, and their maximum ratio of 4.7 was obtained after fertilization. We provide field evidence that fertilized fields in the NCP act as a strong HONO source, which accelerates daytime photochemistry, leading to an increase of regional photo-oxidants such as O3. Considering the severe O3 pollution in the summer NCP and that the large area of the agricultural field is regularly treated with high fertilization amount in this region, HONO emission should be taken into account in the regional air quality deterioration.

Climate change may affect human health, particularly for elderly individuals who are vulnerable to temperature changes. While many studies have investigated the acute effects of heat, only a few have dealt with the chronic ones. We have examined the effects of seasonal temperatures on survival of the elderly in the Southeastern USA, where a large fraction of subpopulation resides. We found that both seasonal mean temperature and its standard deviation (SD) affected long-term survival among the 13 million Medicare beneficiaries (aged 65+) in this region during 2000–2013. A 1 °C increase in summer mean temperature corresponded to an increase of 2.5% in death rate. Whereas, 1 °C increase in winter mean temperature was associated with a decrease of 1.5%. Increases in seasonal temperature SD also influence mortality. We decomposed seasonal mean temperature and its temperature SD into long-term geographic contrasts between ZIP codes and annual anomalies within ZIP code. Effect modifications by different subgroups were also examined to find out whether certain individuals are more vulnerable. Our findings will be critical to future efforts assessing health risks related to the future climate change.