Search

Abstract Using 40 countries’ subnational data, we estimate age-specific mortality-temperature relationships and extrapolate them to countries without data today and into a future with climate change. We uncover a U-shaped relationship where extre6me cold and hot temperatures increase mortality rates, especially for the elderly. Critically, this relationship is flattened by higher incomes and adaptation to local climate. Using a revealed-preference approach to recover unobserved adaptation costs, we estimate that the mean global increase in mortality risk due to climate change, accounting for adaptation benefits and costs, is valued at roughly 3.2% of global GDP in 2100 under a high-emissions scenario. Notably, today’s cold locations are projected to benefit, while today’s poor and hot locations have large projected damages. Finally, our central estimates indicate that the release of an additional ton of CO2 today will cause mortality-related damages of $36.6 under a high-emissions scenario, with an interquartile range accounting for both econometric and climate uncertainty of [−$7.8, $73.0]. These empirically grounded estimates exceed the previous literature’s estimates by an order of magnitude.

In North China (NC), heat stress, which can be quantitatively characterized by wet-bulb globe temperature (WBGT), is closely related to specific humidity. This study focuses on the total days for NC average daily maximum WBGT exceeding 26°C (WGBT26) per summer (June–August) from 1979 to 2017. Rather than local precipitation or evaporation in NC, the NC WBGT26 is significantly related to the nonlocal evaporation around the Yangtze River valley (YR). The abnormal positive evaporated water vapor in YR, associated with anomalously high water vapor flux from south to north at 925 hPa, is continuously transported to NC in the above-normal WBGT26 years. Such an abnormal "evaporation and transportation" process can significantly increase the water vapor in NC and therefore enhance WBGT26. The evaporation in YR peaks in mid- to late July and is closely associated with the occurrence days for daily maximum WBGT exceeding 26°C and maximum daily mean specific humidity at 925 hPa in summer. The main driver for the strongest YR evaporation anomaly from 15 July to 15 August is the simultaneous surface air temperature rather than the simultaneous or earlier soil moisture, precipitation, and vapor pressure deficit (VPD) anomaly. This condition is due to the continuously abundant soil moisture in the YR from April to September. The results of this study provide new ideas for studying heat stress in NC, indicating that nonlocal land–atmosphere interactions are crucial. [ABSTRACT FROM AUTHOR]

Humid heat extremes, taking account of both temperature and humidity, have adverse impacts on society, particularly on human health. It has been suggested that quasi-stationary waves (QSWs) with anomalously high amplitudes contribute to the occurrence of near-surface precipitation extremes and temperature extremes in the midlatitudes of the Northern Hemisphere. However, little attention has been paid to the linkages between amplified QSWs and humid heat extremes. Using the ERA5 dataset, we identify amplified QSWs of zonal wavenumbers 5–7 (Wave 5–7) in summer months from 1979 to 2020. These amplified QSWs show clear circumglobal wave patterns horizontally and nearly barotropic structure vertically. Linking amplified Wave 5–7 to wet-bulb temperature (WBT) extremes, we find that amplified QSWs preferentially induce prominently prolonged WBT extremes in specific regions: north-central North America for amplified Wave 5; western United States, south-central Asia, and eastern Asia for amplified Wave 6; and western Europe and the Caspian Sea region for amplified Wave 7. Analyses of physical processes indicate that, accompanied by the amplification of Wave 5–7, the changes in horizontal temperature advection, adiabatic heating associated with descending motion, downward solar radiation, moisture transport and moisture flux convergence, and surface latent heat fluxes largely account for the increase in persistence of WBT extremes. Significance Statement: In the context of climate change, humid heat extremes exhibit different changes and impacts from high-temperature extremes, but the physical processes that may cause them remain unclear. This study aims to explore the atmospheric dynamic processes leading to the concurrence of humid heat extremes, which may exacerbate the risk from heat stress in today's interconnected world. In specific regions over the Northern Hemisphere midlatitudes, durations of humid heat extremes are found to be elevated simultaneously by amplified quasi-stationary waves. We further identify the physical connections between amplified quasi-stationary waves and humid heat extremes over targeted regions. This would help in better understanding the role of changing atmospheric circulations in the humid heat extremes. [ABSTRACT FROM AUTHOR]

In the early summer (late June–early July) of 2021, a prolonged and extremely high temperature event was observed in the Northwest United States and Southwest Canada. In this study, a connection was found between the subseasonal variations of the East Asian monsoon system and the anomalous heat dome over western North America (WNA). Around 2–3 pentads prior to the period of maximum heat, a northward‐propagating rain belt and abnormally intensified jet stream in East Asia excited a Rossby wave train, causing the high‐pressure anomaly over WNA that was responsible for the occurrence of this heat wave in 2021. Multivariate singular value decomposition analysis results using historical data and a series of numerical experiments further supported the finding of this East Asia–western North America teleconnection. The results provide precursor signals for better monitoring and predicting heat waves over WNA. Plain Language Summary: A persistent and extremely high temperature event was observed in several states in the Northwest United States and Southwest Canada in summer 2021. This severe heat wave resulted in the hottest early‐summer season in western North America (WNA) since 1979 and huge social and economic losses. Although the heat dome (high‐pressure anomaly) over WNA was the factor responsible for this mega heat wave, the cause of this high‐pressure anomaly was unclear. The present study reveals the importance of an atmospheric wave train emanating from East Asia toward North America in inducing the heat dome over WNA. The generation of the wave train is attributable to a northward‐propagating rain belt and abnormally enhanced jet stream over East Asia from 10 to 15 days before the peak of this heat wave. Thus, monitoring the East Asian summer monsoon and associated wave train activity may help in predicting heat waves in WNA, and therefore in knowing when to put measures in place to mitigate against their effects. Key Points: An extreme heat wave occurred in western North America (WNA) in the early summer of 2021, causing huge socioeconomic losses in several big citiesThe subseasonal activity of East Asian summer monsoon contributed to the occurrence of the heat wave via excitation of a Rossby wave trainThe East Asia‐North America teleconnection can provide precursor signals for forecasting heat waves in WNA [ABSTRACT FROM AUTHOR]

Coastal tidal wetlands produce and accumulate significant amounts of organic carbon (C) that help to mitigate climate change. However, previous data limitations have prevented a robust evaluation of the global rates and mechanisms driving C accumulation. Here, we go beyond recent soil C stock estimates to reveal global tidal wetland C accumulation and predict changes under relative sea level rise, temperature and precipitation. We use data from literature study sites and our new observations spanning wide latitudinal gradients and 20 countries. Globally, tidal wetlands accumulate 53.65 (95%CI: 48.52–59.01) Tg C yr−1, which is ∼30% of the organic C buried on the ocean floor. Modeling based on current climatic drivers and under projected emissions scenarios revealed a net increase in the global C accumulation by 2100. This rapid increase is driven by sea level rise in tidal marshes, and higher temperature and precipitation in mangroves. Countries with large areas of coastal wetlands, like Indonesia and Mexico, are more susceptible to tidal wetland C losses under climate change, while regions such as Australia, Brazil, the USA and China will experience a significant C accumulation increase under all projected scenarios. [ABSTRACT FROM AUTHOR]

Ocean dynamic sea level (DSL) change is a key driver of relative sea level (RSL) change. Projections of DSL change are generally obtained from simulations using atmosphere‐ocean general circulation models (GCMs). Here, we develop a two‐layer climate emulator to interpolate between emission scenarios simulated with GCMs and extend projections beyond the time horizon of available simulations. This emulator captures the evolution of DSL changes in corresponding GCMs, especially over middle and low latitudes. Compared with an emulator using univariate pattern scaling, the two‐layer emulator more accurately reflects GCM behavior and captures non‐linearities and non‐stationarity in the relationship between DSL and global‐mean warming, with a reduction in global‐averaged error during 2271–2290 of 36%, 24%, and 34% in RCP2.6, RCP4.5, and RCP8.5, respectively. Using the emulator, we develop a probabilistic ensemble of DSL projections through 2300 for four scenarios: Representative Concentration Pathway (RCP) 2.6, RCP 4.5, RCP 8.5, and Shared Socioeconomic Pathway (SSP) 3–7.0. The magnitude and uncertainty of projected DSL changes decrease from the high‐to the low‐emission scenarios, indicating a reduced DSL rise hazard in low‐ and moderate‐emission scenarios (RCP2.6 and RCP4.5) compared to the high‐emission scenarios (SSP3‐7.0 and RCP8.5). Plain Language Summary: As climate warms, sea‐level rise poses a major threat to coastal communities and ecosystems. A key driver of local sea level change is ocean dynamic sea level change, which is associated with changes in ocean density and circulation. The primary tools used to project changes in dynamic sea level are atmosphere‐ocean general circulation models, which are computationally expensive. Here we develop an emulator for dynamic sea level changes that is, built upon a two‐layer energy balance model. Considering both the rapid response of well‐mixed surface layer and the delayed response of the deep ocean to forcing, the emulator facilitates the estimation of probability distributions of future dynamic sea level change under different emission scenarios and the extension of projections beyond the time horizon of available simulations from some atmosphere‐ocean general circulation models. This emulator captures the evolution of dynamic sea level changes in the atmosphere‐ocean general circulation models to which it is tuned, including the non‐linear and non‐stationary relationship between the dynamic sea level and global warming. The emulator thus facilitates the estimation of future local sea‐level changes. Key Points: An emulator for DSL changes is developed based on a two‐layer energy balance model and a two‐layer pattern scaling techniqueThe two‐layer emulator can better capture the evolution of DSL in corresponding coupled GCMs than scaling of global mean surface temperatureThe two‐layer emulator allows estimation of the probability of future DSL changes in various emission scenarios over multiple centuries [ABSTRACT FROM AUTHOR]

Background: Heatwaves kill more people than floods, tornadoes, and earthquakes combined and disproportionally affect older persons and those with chronic conditions. Commonly used medications for chronic conditions, e.g., diuretics, antipsychotics disrupt thermoregulation or fluid/electrolyte balance and may sensitive patients to heat. However, the effect of heat-sensitizing medications and their interactions with heatwaves are not well-quantified. We evaluated effects of potentially heat-sensitizing medications in vulnerable older patients. Methods: US Medicare data were linked at the zip code level to climate data with surface air temperatures for June-August of 2007–2012. Patients were Medicare beneficiaries aged ≥65 years with chronic conditions including diabetes, dementia, and cardiovascular, lung, or kidney disease. Exposures were potentially heat-sensitizing medications including diuretics, anticholinergics, antipsychotics, beta blockers, stimulants, and anti-hypertensives. A heatwave was defined as ≥2 days above the 95th percentile of historical zip code-specific surface air temperatures. We estimated associations of heat-sensitizing medications and heatwaves with heat-related hospitalization using self-controlled case series analysis. Results: We identified 9,721 patients with at least one chronic condition and heat-related hospitalization; 42.1% of these patients experienced a heatwave. Heatwaves were associated with an increase in heat-related hospitalizations ranging from 21% (95% CI: 7% to 38%) to 33% (95% CI: 14% to 55%) across medication classes. Several drug classes were associated with moderately elevated risk of heat-related hospitalization in the absence of heatwaves, with rate ratios ranging from 1.16 (95% CI: 1.00 to 1.35) to 1.37 (95% CI: 1.14 to 1.66). We did not observe meaningful synergistic interactions between heatwaves and medications. Conclusions: Older patients with chronic conditions may be at heightened risk for heat-related hospitalization due to the use of heat-sensitizing medications throughout the summer months, even in the absence of heatwaves. Further studies are needed to confirm these findings and also to understand the effect of milder and shorter heat exposure. [ABSTRACT FROM AUTHOR]

The impacts of heat waves in a warming climate depend not only on changing temperatures but also on changing humidity. Using 35 simulations from the Community Earth System Model Large Ensemble (CESM LENS), we investigate the long‐term evolution of the joint distribution of summer relative humidity (RH) and daily maximum temperature (Tmax) near four U.S. cities (New York City, Chicago, Phoenix, and New Orleans) under the high‐emissions Representative Concentration Pathway (RCP) 8.5. We estimate the conditional quantiles of RH given Tmax with quantile regression models, using functions of temperature for each city in July for three time periods (1990–2005, 2026–2035, and 2071–2080). Quality‐of‐fit diagnostics indicate that these models accurately estimate conditional quantiles for each city. As expected, each quantile of Tmax increases from 1990–2005 to 2071–2080, while mean RH decreases modestly. Conditional upon a fixed quantile of Tmax, the median and high quantiles of RH decrease, while those of the Heat Index (HI) and dew point both increase. This result suggests that, despite a modest decrease in median relative humidity, heat stress measured by metrics considering both humidity and temperature in a warming climate will increase faster than that measured by temperatures alone would indicate. For a fixed Tmax, the high quantiles of RH (and thus of HI and dew point) increase from 1990–2005 to 2071–2080 in all four cities. This result suggests that the heat stress of a day at a given Tmax will increase in a warming climate due to the increase of RH. Key Points: The quantile‐regression models accurately estimate the conditional distribution of relative humidity given temperatureIncorporating the effect of relative humidity, heat stress in a warming climate will increase faster than temperatures alone would indicateThe heat stress of a day at a fixed daily maximum temperature will increase due to the increase of relative humidity as climate warms [ABSTRACT FROM AUTHOR]

The literature on the costs of climate change often draws a link between climatic 'tipping points' and large economic shocks, frequently called 'catastrophes.' The phrase 'tipping points' in this context can be misleading. In popular and social scientific discourse, 'tipping points' involve abrupt state changes. For some climatic 'tipping points,' the commitment to a state change may occur abruptly, but the change itself may be rate-limited and take centuries or longer to realize. Additionally, the connection between climatic 'tipping points' and economic losses is tenuous, although emerging empirical and process-model-based tools provide pathways for investigating it. We propose terminology to clarify the distinction between 'tipping points' in the popular sense, the critical thresholds exhibited by climatic and social 'tipping elements,' and 'economic shocks.' The last may be associated with tipping elements, gradual climate change, or nonclimatic triggers. We illustrate our proposed distinctions by surveying the literature on climatic tipping elements, climatically sensitive social tipping elements, and climate-economic shocks, and we propose a research agenda to advance the integrated assessment of all three. [ABSTRACT FROM AUTHOR]

This study examines the physical mechanisms that drive the poleward propagation of zonal-mean flow anomalies over the North Atlantic during the boreal winter with ECMWF ERA40 reanalysis data that spans the years 1958-2001. An empirical orthogonal function (EOF) analysis is performed on the zonal wind anomalies for the North Atlantic domain. Based on time-lag correlations between the first two EOFs, 14 poleward propagation events are identified. A series of lagged composite calculations of the poleward propagation events reveals the following processes: midlatitude synoptic-scale Rossby waves propagate equatorward and break when they encounter their critical latitudes in the Tropics and Subtropics; a new critical latitude is generated slightly poleward of the previous critical latitude, and the subsequent wave breaking occurs at this new critical latitude. This interaction between the wave breaking and the critical latitude drives the poleward propagation of zonal-mean zonal wind anomaly. A comparison between the poleward propagation events and zonal index events indicates that the poleward propagation is associated with a relatively weak potential vorticity gradient over the Subtropics. These North Atlantic poleward propagation events are found to be preceded by anomalously strong transient eddy activity over the subtropical North Pacific, and by anomalously weak tropical convection over the tropical Atlantic Ocean and the Amazon. Copyright © 2012 Royal Meteorological Society [ABSTRACT FROM AUTHOR]

The environment influences brain and mental health, both detrimentally and beneficially. Existing research has emphasised the individual psychosocial 'microenvironment'. Less attention has been paid to 'macroenvironmental' challenges, including climate change, pollution, urbanicity, and socioeconomic disparity. Notably, the implications of climate and pollution on brain and mental health have only recently gained prominence. With the advent of large-scale big-data cohorts and an increasingly dense mapping of macroenvironmental parameters, we are now in a position to characterise the relation between macroenvironment, brain, and behaviour across different geographic and cultural locations globally. This review synthesises findings from recent epidemiological and neuroimaging studies, aiming to provide a comprehensive overview of the existing evidence between the macroenvironment and the structure and functions of the brain, with a particular emphasis on its implications for mental illness. We discuss putative underlying mechanisms and address the most common exposures of the macroenvironment. Finally, we identify critical areas for future research to enhance our understanding of the aetiology of mental illness and to inform effective interventions for healthier environments and mental health promotion., (© 2024. The Author(s).)

Coastal tidal wetlands produce and accumulate significant amounts of organic carbon (C) that help to mitigate climate change. However, previous data limitations have prevented a robust evaluation of the global rates and mechanisms driving C accumulation. Here, we go beyond recent soil C stock estimates to reveal global tidal wetland C accumulation and predict changes under relative sea level rise, temperature and precipitation. We use data from literature study sites and our new observations spanning wide latitudinal gradients and 20 countries. Globally, tidal wetlands accumulate 53.65 (95%CI: 48.52-59.01) Tg C yr -1 , which is ∼30% of the organic C buried on the ocean floor. Modeling based on current climatic drivers and under projected emissions scenarios revealed a net increase in the global C accumulation by 2100. This rapid increase is driven by sea level rise in tidal marshes, and higher temperature and precipitation in mangroves. Countries with large areas of coastal wetlands, like Indonesia and Mexico, are more susceptible to tidal wetland C losses under climate change, while regions such as Australia, Brazil, the USA and China will experience a significant C accumulation increase under all projected scenarios., (© The Author(s) 2020. Published by Oxford University Press on behalf of China Science Publishing & Media Ltd.)