Excessive Warming Research Articles

Diurnal variation in an amplified canopy urban heat island during heat wave periods in the megacity of Beijing: roles of mountain–valley breeze and urban morphology

Abstract. Against the background of global warming and rapid urbanization, heat waves (HWs) have become increasingly prevalent, amplifying canopy urban heat island intensity (CUHII). The megacity of Beijing, characterized by rapid urbanization, frequent high-temperature events, and exceptionally complex terrain, presents a unique case to study the synergies between HWs and canopy urban heat islands (CUHIs). However, research exploring the formation mechanisms of the amplified CUHII (ΔCUHII) during HW periods in the megacity of Beijing from the perspectives of mountain–valley breeze and urban morphology remains scarce. This study found that compared to non-heat-wave (NHW) periods, the average daily CUHII during HW periods significantly increased by 59.33 %. On the urban scale, the wind direction reversal of the mountain–valley breeze might contribute to the north–south asymmetry in the ΔCUHII. On the street scale, wind speed was inversely proportional to the ΔCUHII. In addition, the ΔCUHII was closely related to urban morphology, particularly the three-dimensional indicators of buildings. During the mountain breeze phase, high-rise buildings with lower sky view factors (SVFs) had a more pronounced effect on amplifying CUHII compared to low-rise buildings with higher SVFs. Conversely, during the valley breeze phase, high-rise buildings exerted a dual influence on amplifying CUHII. Our findings provide scientific insights into the driving mechanisms of urban overheating and contribute to mitigating the escalating risks associated with urban excess warming.

The impact of roof systems on cooling and building energy efficiency

The excessive warming in the built environment, due to urbanization and anthropogenic heat emissions, has adverse effects on building energy consumption. Diverse technology using, e.g., vegetated roofs or innovative roof materials, have been proposed and implemented to ameliorate both indoor and outdoor thermal environments and reduce energy consumption. In this study, we apply a state-of-the-art urban canopy model to simulate the thermal performance of multiple roof technology, viz. the white, green, and hybrid roofs, in the contrasting urban environments of Princeton, NJ and Phoenix, AZ, USA. In addition, we estimate the combined energy-water saving potential for green roofs with five different irrigation schemes. It is found that green roofs can achieve a combined energy-water saving of $9.68 m−2 roof area in Phoenix with moisture-controlled irrigation, and $5.23 m−2 in Princeton without irrigation. These results can help to promote building energy efficiency by adapting to flexible and sustainable roof technology for heat mitigation.

Brown Carbon From Biomass Burning Reinforces the Himalayas and Tibetan Plateau Warming

AbstractThe Himalayas and Tibetan Plateau (the HTP), referred to as “the third pole” with an excessive warming rate, exerts strong impacts on the global environment. As one of warming contributors, atmospheric brown carbon (BrC) remains limited scientific understanding in the HTP due to a scarcity of observations. In this study, we present a study of the light‐absorbing properties of methanol‐soluble brown carbon (MeS‐BrC) and water‐soluble brown carbon (WS‐BrC) during 2018–2021. Highly spatiotemporal variations of BrC light absorptions were observed. In the HTP marginal area, elevated BrC absorption coefficients at 365 nm (babs,365) and levoglucosan concentrations were obtained, and MeS‐BrC exhibits approximately 1.3–1.8 times higher absorption compared to WS‐BrC. We determined that BrC light absorptions was largely attributed to biomass burning (29%–35%). BrC can act as a potent warming agent in the HTP marginal area, with high direct solar absorption (25%–47% relative to black carbon).

A mysterious skin rash outbreak over Pescadores Islands in Taiwan Strait: An airborne contact dermatitis by Euproctis taiwana revealed by ultrastructure mapping

Abstract Background: A mysterious skin rash (papular lesions) outbreak broke out for unknown reasons in Taiwan’s Pescadores Islands in mid-autumn 2021, causing much anxiety in the population already nervous about the ongoing COVID-19 epidemic. Objectives: We conducted a field survey for possible culprit agents. Methods: Skin samples were taken with rapid-glue adhesives from the affected skin. Electron microscopy from the skin samples as well as caterpillar seta was performed. Additional neurotransmitter analysis by mass spectrometry (MS) was conducted on the skin samples. Results: A field survey found a large increase in caterpillars, Euproctis taiwana, in September 2021, the warmest September in recent years. Electron microscopy performed on superficial skin samples (3–6 cells thick) of affected and healthy skin (n = 5 and 3, respectively) and caterpillar setae revealed ultrastructural similarities between setae spurs (0.15–0.2 μm) and tiny pits (0.2 μm) on the affected skin as well as similar vegetative debris (0.75 μm) on both setae and affected skin. MS showed large increases in tyrosine, serine, and histamine, known mediators of arthropod insult. Conclusion: The co-occurrence of E. taiwana population growth, excessive warming, and strong monsoon winds may lead to this unusual autumn outbreak in late September. The lifting of COVID-19-related travel restrictions against earlier that month probably exacerbated it.

Research progress on the synergies between heat waves and canopy urban heat island and their driving factors

Under the background of global warming and accelerating urbanization, the interaction between heat waves (HWs) and canopy urban heat island (CUHI) has become one of the focuses in the field of global climate change research. This paper comprehensively reviewed and summarized the research process on the synergies of HWs and CUHI and their influencing mechanism. The coupling effect between HWs and CUHI remains debated, which may be related to the use of different standards to define heat wave events. The spatiotemporal differences in the synergies between HWs and CUHI was also influenced by climate background and local circulation. For instance, scholars have reached different conclusions regarding the stronger synergistic effect between daytime and nighttime in cities with different climate backgrounds. In addition, the modulation of urban morphological structure to the synergies between HWs and CUHI cannot be ignored. In the future, it is necessary to adopt different definitions of HWs to systematically study the formation mechanism of urban excess warming from different climatic backgrounds, local circulation conditions, and urban morphologies.

Causal mediation of urban temperature by geopotential height in U.S. cities

Excessive warming is the source of many environmental challenges in urban areas. Finding causal interactions between urban ambient temperature and other meteorological variables will greatly facilitate our understanding of the underlying mechanisms of urban heat. In this study, we use the data of 2-m air temperature and 500 hPa geopotential height (GPH) in 520 cities in the contiguous United States (CONUS), from 2016 to 2022, to detect their local and nonlocal causal interactions based on the convergent cross-mapping method. For local (within the same city) interactions between temperature and GPH, there are hubs of strong causal interactions in the northern Appalachian Mountain and inland southwestern CONUS, whereas the leeward side of the southern Rocky Mountains exhibit low causation due to the baroclinic in this area. The nonlocal causal networks exhibit potential long-range connections (teleconnections), largely attributable to the influence of the upstream and downstream westerly circulations on local atmospheric variables. This study can be informative to stakeholders in design sustainable countermeasures to mitigate excessive heat in urban areas.

General anesthetic management in two patients with an anaphylaxis history cholinergic urticaria

BackgroundCholinergic urticaria is triggered by an increased body temperature after exercise, passive warming, or emotional stresses. The anesthetic management used for two patients with an anaphylaxis history after cholinergic urticaria is described.Case presentationPatient 1: A 34-year-old female was scheduled for a right-side thyroidectomy. At 27 years old, she experienced post-exercise anaphylaxis and repeated episodes of hives following exercise, sunbathing, mental stresses, and the consumption of spicy foods. Patient 2: A 35-year-old female was scheduled for a laparoscopic ovarian cystectomy. At 19 years old, she experienced anaphylaxis after a long bath and then hives after hot showers, bicycle riding, and long walks. For both patients, intraoperative passive warming was not performed to prevent excessive warming, and prophylactic antiemetics and multimodal analgesia were used to minimize their perioperative stresses.ConclusionCareful anesthetic management is necessary to prevent anaphylaxis during anesthesia in a patient with a history of cholinergic urticaria.

Quantifying the cooling effect of tropical cyclone clouds on the climate system

The net effect on the upwelling radiation caused by tropical cyclone clouds is calculated over a 20-year global data set, and the corresponding contribution to the earth energy balance is analyzed. Tropical cyclone clouds are shown on average to increase the upwelling radiation at the top of the atmosphere compared with the background non-tropical-cyclone-cloud climatology. This increase in upwelling radiation provides an overall cooling effect on the climate system because the increased reflected shortwave radiation (cooling) outweighs the decreased emitted longwave radiation (warming). While the effect neglects the (likely considerable) contribution due to tropical cyclone drying, the amount of cooling by clouds alone represents a considerable fraction of the excess warming energy in the climate system. Thus, any future change in tropical cyclone activity has the potential to impact the overall energy balance if it substantially alters this total. The seasonal and geographic distribution of warming and cooling effects, and the diurnal dynamics that impact whether any particular cyclone is net cooling or net warming are discussed in this study.

Unevenly spatiotemporal distribution of urban excess warming in coastal Shanghai megacity, China: Roles of geophysical environment, ventilation and sea breezes

The complexity and uncertainty of urban excess warming are modulated by the morphology of urban areas, canopy urban heat island (CUHI)–heat wave interactions, the geographical–climatological background and the local circulation. Focusing on the coastal Shanghai megacity, we analyzed the synergistic effects of local climate zones (LCZs), urban ventilation, and sea breezes on the urban excess warming related to the CUHI and heat waves in summer from 2013 to 2018. Over the whole urban areas, the average CUHI intensity (CUHII) increased by 128.91% during heat waves periods relative to non-heat wave periods. Moreover, the spatial-temporal distributions of both CUHII and heat waves exhibited heterogeneously. In dense urban areas (e.g., LCZ 1 and 2), the blocking effect of dense high-rise buildings, and poor ventilation with low wind speeds would exacerbate urban excess warming, which exhibited relatively higher occurrence of heat waves and an increase in the CUHII. By contrast, over open areas of the urban periphery (eg., LCZ5), more heat wave events and stronger CUHII were mainly affected by the horizontal advective transport of urban heat at medium wind speeds. Particularly, the sea breezes could weaken the CUHII and decrease the occurrence frequency of heat wave events during daytime over coastal areas. In addition, the shading effects of high-rise buildings and the evaporative cooling effects of water and vegetation would also mitigate urban warming at the local scale, which would reduce the CUHII as well as the frequency of heat waves.

Marine methods for carbon dioxide removal: fundamentals and myth-busting for the wider community

Abstract To avoid global warming in excess of 1.5°C under the current sluggish adoption of drastic reductions in global greenhouse gas emissions, application of methods to remove carbon dioxide from the atmosphere will become essential in the near future; yet, development of these methods is in its infancy. Land-based methods are further developed than marine methods, but it is likely that similar-scaled application will be necessary in both realms. There are many misconceptions in discussion groups and fora about the ‘simplicity’ or ‘ease’ of proposed marine applications, partly because the complex marine carbon cycle is insufficiently understood by the proponents, having been discussed in largely inaccessible, technical texts only. This review outlines the basic operation of the marine carbon cycle in straightforward terms, with some simplifications, to help advance the debate among the wider community. Break-out boxes provide additional detail where desired, and references (and the sources cited therein) provide avenues for further study. The review then discusses two potential marine methods for atmospheric carbon removal that are thought to offer the greatest potential in terms of carbon removal mass: ocean iron fertilization and ocean alkalinity enhancement. Finally, six statements/arguments that seem to regularly crop up in carbon removal discussion groups are evaluated within the perspective of the compiled and reviewed information.

Qualitative Considerations on the Influence of the Gases Water Vapor and Carbon Dioxide on the Global Environmental Temperature from the Point of View of Textbook Knowledge

The solar radiation that hits the Earth conditions the dynamic equilibrium that prevails on our planet. Consideration of basic physical-chemical knowledge shows that this equilibrium can be changed only by additional energy input or prolongation of the interaction time solar radiation—Earth matter. The contribution of H2O(g) and CO2 to the protection of the earth against excessive warming is experimentally and by basic laws of nature secured. For a greenhouse effect, a part of the earth radiation must be radiated back to the earth and then into space. If one understands the earth radiation as radiation of a black body with the average global environmental temperature, from all vibrations normal modes of the gases H2O(g) and CO2 only the bending mode of CO2 with 4% of the solar constant can contribute beside the rotational modes of the water to the greenhouse effect. The contributions of the normal modes of H2O(g) and CO2 to the heat capacity of the atmosphere are negligible. Therefore, in agreement with studies by K. Ångström, CO2 contributes only to the stabilization of the global environmental temperature. Whether the use of renewable energies can actually at least mitigate the increase of the environmental temperature is by no means certain but must be examined for each individual case. With certainty, this goal can only be achieved by reducing the energy consumption of mankind.

Plant-Soil Mediated Effects of Long-Term Warming on Soil Nematodes of Alpine Meadows on the Qinghai-Tibetan Plateau.

Global warming is one of the most pressing environmental issues today. Our study aimed to investigate how warming affected plant and soil nematode communities in alpine meadows on the Qinghai-Tibetan Plateau over the past seven years. An artificial warming experiment with different gradients was conducted from 2011 to 2018, including temperature increases of 0 °C (CK), 0.53 °C (A), 1.15 °C (B), 2.07 °C (C), and 2.17 °C (D), respectively. Cyperaceae plants were shown to be eliminated by increasing temperature, and plant community composition tended to cluster differently under different warming gradients. The number of nematodes decreased with the increase in soil depth, and the majority of them were observed in the topsoil layer. The individual densities of soil nematodes were 197 ind.·100 g-1 dry soil at 10-20 cm and 188 ind.·100 g-1 dry soil at 20-30 cm in the A treatment, which was significantly higher than the CK (53 and 67 ind.·100 g-1 dry soil) (p < 0.05). The lowest relative abundance of bacterivore nematodes (Ba) was 31.31% in treatment A and reached the highest of 47.14% under the warming gradient of D (p < 0.05). The abundance of plant parasitic nematodes (Pp) was significantly reduced to 26.03% by excessive warming (2.17 °C increase) in comparison to CK (41.65%). The soil nematode community had the highest diversity with a 0.53 °C increase in soil temperature; 1.15 °C warming gradients were lower, and nematode communities tended to be simplified (p < 0.05). All nematode channel ratio (NCR) values were above 0.5, indicating that warming did not change the decomposition pathway of soil organic matter dominated by the bacterial channels. The Wasilewska Index (WI) in the D treatment increased significantly compared to other treatments (p < 0.05), indicating that the mineralized pathway of the food web was primarily involved with Ba and fungivores nematodes (Fu), which is conducive to the growth of micro-biophagous nematodes. The plant parasite index (PPI) decreased significantly in the D treatment compared with other treatments (p < 0.05), indicating that a high warming gradient caused a reduction in the maturity of Pp nematodes. The maturity index (MI) increased in the D treatment compared with A, B, and C treatments, indicating that overheating affected the nematode community in the later stage of succession and caused the soil to be less disturbed. A partial least squares path model (PLSPM) showed that warming indirectly affects Fu and Pp diversity by directly impacting the plant community as well as indirectly affecting Ba by directly affecting soil properties. In conclusion, plant diversity and community composition profoundly affect the soil nematode communities, thus reflecting the dynamic processes and evolution of soil ecosystems.

Earlier ice loss accelerates lake warming in the Northern Hemisphere

How lake temperatures across large geographic regions are responding to widespread alterations in ice phenology (i.e., the timing of seasonal ice formation and loss) remains unclear. Here, we analyse satellite data and global-scale simulations to investigate the contribution of long-term variations in the seasonality of lake ice to surface water temperature trends across the Northern Hemisphere. Our analysis suggests a widespread excess lake surface warming during the months of ice-off which is, on average, 1.4 times that calculated during the open-water season. This excess warming is influenced predominantly by an 8-day advancement in the average timing of ice break-up from 1979 to 2020. Until the permanent loss of lake ice in the future, excess lake warming may be further amplified due to projected future alterations in lake ice phenology. Excess lake warming will likely alter within-lake physical and biogeochemical processes with numerous implications for lake ecosystems.

Mechanisms of Ocean Heat Uptake along and across Isopycnals

Abstract Warming of the climate system accumulates mostly in the ocean and discrepancies in how this is modeled contribute to uncertainties in predicting sea level rise. In this study, regional temperature changes in an atmosphere–ocean general circulation model (HadCM3) are partitioned between excess (due to perturbed surface heat fluxes) and redistributed (arising from changing circulation and perturbations to mixing) components. In simulations with historical forcing, we first compare this excess–redistribution partitioning with the spice and heave decomposition, in which temperature anomalies enter the ocean interior either along isopycnals (spice) or across isopycnals (heave, without affecting the temperature–salinity curve). Second, heat and salinity budgets projected into thermohaline space naturally reveal the mechanisms behind temperature change by spice and heave linked with water mass generation or destruction. Excess warming enters the ocean as warming by heave in subtropical gyres whereas it mainly projects onto warming by spice in the Southern Ocean and the tropical Atlantic. In subtropical gyres, Ekman pumping generates excess warming as confirmed by Eulerian heat budgets. In contrast, isopycnal mixing partly drives warming and salinification by spice, as confirmed by budgets in thermohaline space, underlying the key role of salinity changes for the ocean warming signature. Our study suggests a method to detect excess warming using spice and heave calculated from observed repeat profiles of temperature and salinity.

Potential Impacts of Shade Treatments on Dormancy of Overwintering Redbud (Cercis canadensis L.) Trees at Southeastern Nurseries

Abstract Dormancy accrual is an important process in mitigating the abiotic stressors of overwintering trees at ornamental nurseries, with frost-injured tree crops at heightened risk of ensuing biotic insect and disease attack. As mean global temperatures rise, overwintering nursery crops may lose dormancy earlier. Using potted eastern redbud (Cercis canadensis L.) trees placed under two types of shade cloth, under full sun, or in walk-in coolers, we measured stem, air and root zone temperatures, accrual of chill hours and mean time to bud break at two sites. While there was no significant difference between the two shade treatments, shade cloths did moderate both high and low temperatures to which trees were exposed. Differences in mean time to first bud break were observed from shaded trees versus those in full sun at each site. It may be useful to alter our shading design to continue protection from overnight lows while preventing excess warming from daytime highs, and thus promoting dormancy and preventing frost exposure in some regions, but further tests will be required. Species used in this study: eastern redbud (Cercis canadensis L.).

Projected Air Temperature Extremes and Maximum Heat Conditions Over the Middle-East-North Africa (MENA) Region

This study analyzes projected heat extremes over the Middle-East–North Africa (MENA) region until the end of the twenty-first century with a number of temperature indices based on absolute values and thresholds to describe hot conditions. We use model projected daily near-surface air (2-m) temperature (T_mathrm{{max}} and T_mathrm{{min}}) to derive the indices for the period 1980–2100. The data were taken from 18 CMIP5 models combining historical (1980–2005) and scenario runs (2006–2100 under RCP2.6, RCP4.5, and RCP8.5 pathways). Results show a domain-wide projected warming for all emission scenarios. Our findings for a business-as-usual pathway indicate excessive warming of more than 8 ^circ C in the northern part of the domain (south Europe) for the annual warmest day (TXx) and night (TNx). In the hottest parts of the domain record high temperatures reached 50 ^circ C in the recent past, which could increase to at least 56 ^circ C by the end of the century, while temperatures over 50 ^circ C are expected to occur in a large part of the MENA region. A significant increase is projected in the number of hot days (TX >40^circ C) and nights (TN >30 ^circ C) all over the region. For the period of 2071–2100 excessive hot days and nights will become the normal during summer in large parts of the MENA with some locations expected to exceed 180 and 100 days, respectively. Calculations of the corresponding heat index suggest that several areas across the MENA region may reach temperature levels critical for human survival.

Effects of Aerosol–Induced Snow Albedo Feedback on the Seasonal Snowmelt Over the Himalayan Region

AbstractAerosol‐induced snow darkening and its feedback on seasonal snow cover, snowmelt, and runoff were investigated using the Regional Climate Model (RegCM4.6) coupled with SNow, Ice, and Aerosol Radiation (SNICAR) and aerosol modules over the Himalayas during the melting season (March‐September). The snow albedo reduction due to the deposition of absorbing aerosols increases the 2 m air temperature (1.47°C) and thus decreases the snow cover (10.6%) over the Himalayas during spring. This aerosol‐induced excess warming accelerates the seasonal snowmelt (1.2 mm day−1), which reduces the number of snow‐covered periods by more than 20 days throughout the Himalayas. The accumulated total snowmelt also increased by 41.3% over the Himalayas during the melting season. The early snowmelt and increase in runoff due to aerosol forcing have significant implications on rivers originating from the western Himalayas (Indus Basin). The change in snowmelt distribution and doubling of snowmelt extremes due to aerosol‐induced snow darkening could also translate to an increase in flood risks across the Himalayan river basins. Therefore, the present study highlights the importance of aerosol‐induced snow albedo forcing and its feedback on snowmelt and runoff over the Himalayan region, which has further implications on water availability over the South Asian region.

Improvements on the upper-ocean simulation from 2007 to 2018 in the Canada Basin

The Beaufort Gyre reserves most of the freshwater in the Arctic Ocean. Observation shows that the freshwater content over 2016–2018 far exceeds the level over the plateau period 2008–2012. Modeling the vertical temperature and salinity structure and their changes in the Beaufort Gyre is a way to understand the process related to such step changes. We configured a pan-Arctic sea ice-ocean model with a southern boundary at ∼7°N in the Atlantic Ocean. The numerical simulation with sea surface salinity restoring, a latitude dependent horizontal diffusivity scaled by the squared buoyancy frequency, and a weak vertical diffusivity of 5 × 10−7 m2 s−1 in the Arctic Ocean better reproduces the sea ice extent, the Pacific summer halocline water, and the freshwater variations as observed. The sea surface salinity restoring mitigates the surface desalination in the North Atlantic Ocean, therefore a weaker ocean stratification prevents the excessive warming in the intermediate Arctic Ocean. It is also found that the weak vertical background diffusivity is the major factor in our model to preserve the vertical ocean structure in the Canada Basin and also the step change of freshwater recently. In addition to resolving eddy activities in high resolution models, the success in our low resolution model suggests that tuning the vertical diffusivity serves as another approach to simulate the increasing freshwater content in the recent decade.

The Effectiveness of Environmental Spending in China and the Environmental Kuznets Curve

The aim of this study is to determine whether recent environmental spending in China has enabled it to reduce its emissions of greenhouse gases in the context of an Environmental Kuznets Curve-based model and promote sustainable economic development. Following the Paris Agreement in 2015, there has been a coordinated effort to reduce the consumption of fossil fuels and prevent the excessive warming of the climate. The study uses annual regional data across China and a dynamic panel data approach for estimating an EKC model which includes measures of the increased use of fossil fuels and the spending across China to reduce environmental damage. The results suggest that the policies have been effective in controlling emissions across a variety of pollutants and that the EKC tends to hold in China but varies according to the pollutant. This suggests that these policies should be continued and where possible, extended.

Seeking Nietzsche’s Great Tree of Humanity: The Overhuman and Powers’s The Overstory

This essay reconstructs Nietzsche’s ecological and environmental thought by focusing on his idea of the human-earth (Menschen-Erde) and his deep concern for the natural world. It then articulates these thoughts in a coordinate reading of Richard Powers’s environmentally focused novel The Overstory (2019). Nietzsche understands that the human position on the Earth is precarious and that we are in danger of injuring our fragile environmental surround. I attempt to clarify the contemporary relevance of this thought by showing how his diagnosis chimes with current ecological thinking. Nietzsche saw not only dangers but opportunities in the relation of humans to their environment. His writings as well as his daily life exhibit intense interest in trees and forests. He foresaw that too much forest clearing could endanger the climate, leading to excessive warming. Nietzsche also imagined that the humans might foster a “great tree of humanity” (WS 188-89), a green expansion of their environment, and Zarathustra anticipates living in the world as a garden (Z “The Convalescent”). Richard Powers’s The Overstory speaks to a time that is much more deeply informed about our precarious ecological situation. The novelist dramatizes this in a narrative that brings together a number of disparate individuals, drawn to defend an old-growth US West Coast forest from the state-supported depradations of industrial logging. These figures learn about “the secret life of trees,” their mutual dependence and communication, as they experiment with a new life high among the branches. Their different fates pose a variety of questions relevant to Nietzsche’s ideas for a transvalued Earth.