Additional Warming Research Articles

Assimilating urban heat island effects into climate projections

An urban heat island (UHI) effect is identified in Reno, Nevada by analyzing regional temperature trends calculated from seven long-term observation stations for the summer and winter seasons between 1950 and 2014. The UHI is maximized during summer (June–August) and characterized by asymmetric increases in minimum (∼1.1 °C/decade, p < 0.01) versus maximum temperature (∼0.1 °C/decade, p < 0.01) trends in excess of trends from regional climate stations. Comparisons of historical Reno temperatures with an ensemble of 66 bias-corrected and downscaled global climate model (GCM) outputs spanning 1950–2014 demonstrates cold biases of 1.5–4.5 °C during summer with minimum temperature having the largest bias. We show that a secondary bias correction step utilizing the statistical downscaling method of quantile–quantile mapping (QQM) can reduce biases in future climate projections assuming no changes to the UHI. The QQM results in an additional total warming of ensemble mean temperatures by ∼3 °C for downscaled GCM output and ∼4 °C for re-gridded 1° grid resolution GCM output for 2030–2049 under the RCP8.5 emissions scenario. These temperature differences produce additional increases in summer potential evapotranspiration of 10% compared to non-QQM bias-corrected GCM output. It was shown that the QQM method represents a useful and computationally efficient method for bias correction of temperature projections for cities where UHI effects exist. Planning and impacts studies of urban water resources can benefit from these improved climate projections, particularly in regions where downscaled GCM output is unavailable.

Efficacy of external warming in attenuation of hypothermia in surgical patients.

Hypothermia in surgical patients can be the consequence of long duration of surgical intervention, general anaesthesia and low temperature in operating room. Postoperative hypothermia contributes to a number of postoperative complications such as arrhythmia, myocardial ischemia, hypertension, bleeding, wound infection, coagulopathy, and prolonged effect of muscle relaxants. External heating procedures are used to prevent this condition. The aim of this study was to evaluate the efficiency of external warming system in alleviation of cold stress and hypothermia in patients who underwent major surgical procedures. The study was conducted in the Military Medical Academy in Belgrade. A total of 30 patients of both genders underwent abdominal surgical procedures, randomly divided into two equal groups: the one was externally warmed using warm air mattress (W), while in the control group (C) surgical procedure was performed in regular conditions, without additional warming. Oesophageal temperature (Te) was used as indicator of changes in core temperature, during surgery and awakening postoperative period, and temperature of control sites on the right hand (Th) and the right foot (Tf) reflected the changes in skin temperatures during surgery. Te and skin temperatures were monitored during the intraoperative period, with continuous measurement of Te during the following 90 minutes of the postoperative period. Heart rates and blood pressures were monitored continuously during the intraoperative and awakening period. In the W group, the average Te, Tf and Th did not change significantly during the intraoperative as well as the postoperative period. In the controls, the average Te significantly decreased during the intraoperative period (from 35.61 ± 0.35 °C at 0 minute to 33.86 ± 0.51°C at 120th minute). Compared to the W group, Te in the C group was significantly lower in all the observed periods. Average values of Tf and Th significantly decreased in the C group (from 30.83 ± 1.85 at 20th minute to 29.0 ± 1.39°C at 120th minute, and from 32.75 ± 0.96 to 31.05 ± 1.09°C, respectively). The obtained results confirm that the external warming using warm air mattress was able to attenuate hypothermia, i.e. substantial decrease in core temperature, compared with the similar exposure to cold stress in the control group.

How did ocean warming affect Australian rainfall extremes during the 2010/2011 La Niña event?

AbstractExtreme rainfall conditions in Australia during the 2010/2011 La Niña resulted in devastating floods claiming 35 lives, causing billions of dollars in damages, and far‐reaching impacts on global climate, including a significant drop in global sea level and record terrestrial carbon uptake. Northeast Australian 2010/2011 rainfall was 84% above average, unusual even for a strong La Niña, and soil moisture conditions were unprecedented since 1950. Here we demonstrate that the warmer background state increased the likelihood of the extreme rainfall response. Using atmospheric general circulation model experiments with 2010/2011 ocean conditions with and without long‐term warming, we identify the mechanisms that increase the likelihood of extreme rainfall: additional ocean warming enhanced onshore moisture transport onto Australia and ascent and precipitation over the northeast. Our results highlight the role of long‐term ocean warming for modifying rain‐producing atmospheric circulation conditions, increasing the likelihood of extreme precipitation for Australia during future La Niña events.

Source apportionment of PM10 mass and particulate carbon in the Kathmandu Valley, Nepal

The Kathmandu Valley in Nepal is a bowl-shaped urban basin in the Himalayan foothills with a serious problem of fine particulate air pollution that impacts local health and impairs visibility. Particulate carbon concentrations have reached severe levels that threaten the health of 3.5 million local residents. Moreover, snow and ice on the Himalayan mountains are melting as a result of additional warming due to particulate carbon, especially high black carbon concentrations. To date, the sources of the Valley's particulate carbon and the impacts of different sources on particulate carbon concentrations are not well understood. Thus, before an effective control strategy can be developed, these particulate carbon sources must be identified and quantified. Our study has found that the four primary sources of particulate carbon in the Kathmandu Valley during winter are brick kilns, motor vehicles, fugitive soil dust, and biomass/garbage burning. Their source contributions are quantified using a recently developed new multivariate receptor model SMP. In contrast to other highly polluted areas such as China, secondary contribution is almost negligible in Kathmandu Valley. Brick kilns (40%), motor vehicles (37%) and biomass/garbage burning (22%) have been identified as the major sources of elemental carbon (black carbon) in the Kathmandu Valley during winter, while motor vehicles (47%), biomass/garbage burning (32%), and soil dust (13%) have been identified as the most important sources of organic carbon. Our research indicates that controlling emissions from motor vehicles, brick kilns, biomass/garbage burning, and soil dust is essential for the mitigation of the particulate carbon that threatens public health, impairs visibility, and influences climate warming within and downwind from the Kathmandu Valley. In addition, this paper suggests several useful particulate carbon mitigation methods that can be applied to Kathmandu Valley and other areas in South Asia with similar sources and high particulate carbon concentrations.

Investigation of aerosol optical, physical, and radiative characteristics of a severe dust storm observed over UAE

Abstract This work presents a detailed study of the dynamical processes triggering the occurrence of the two heavy dust storms which occurred between 18 and 22 March 2012 over the Middle East. The dynamics of this event are related to the coupling of subtropical jet and polar jet over the Saudi Arabia region, resulting in massive dust storm generation and dust transport through Rub’ al Khali and the Persian Gulf to the UAE region. AOD and PM10 values showed a fourfold increase during the event reaching a maximum of 1.8 and 1653 μg/m3 respectively. The spatial extent of the dust storm is evident from high values of MODIS AOD (~ 1.5) and OMI aerosol index (4.5) covering the entire Middle East. The total attenuated backscatter at 550 nm from CALLIPSO showed the vertical extent of dust up to 8 km. In addition, surface temperature showed a decrease of almost 15 °C during the event signifying the intensity of the dust storm. Aerosol radiative forcing estimates during the dust storm showed a cooling at the surface and warming in the atmosphere, with a maximum forcing value reaching up to ~− 210 Wm− 2 (185 Wm− 2). Hence, it is evident from the present study that the dust layer caused an additional warming of ~ 150 Wm− 2 in the atmosphere over this region. The present event showcases the importance of dust storm induced aerosol optical and physical processes, and associated atmospheric dynamics over UAE as well as other affected regions.

Early-Holocene warming in Beringia and its mediation by sea-level and vegetation changes

Abstract. Arctic land-cover changes induced by recent global climate change (e.g., expansion of woody vegetation into tundra and effects of permafrost degradation) are expected to generate further feedbacks to the climate system. Past changes can be used to assess our understanding of feedback mechanisms through a combination of process modeling and paleo-observations. The subcontinental region of Beringia (northeastern Siberia, Alaska, and northwestern Canada) was largely ice-free at the peak of deglacial warming and experienced both major vegetation change and loss of permafrost when many arctic regions were still ice covered. The evolution of Beringian climate at this time was largely driven by global features, such as the amplified seasonal cycle of Northern Hemisphere insolation and changes in global ice volume and atmospheric composition, but changes in regional land-surface controls, such as the widespread development of thaw lakes, the replacement of tundra by deciduous forest or woodland, and the flooding of the Bering–Chukchi land bridge, were probably also important. We examined the sensitivity of Beringia's early Holocene climate to these regional-scale controls using a regional climate model (RegCM). Lateral and oceanic boundary conditions were provided by global climate simulations conducted using the GENESIS V2.01 atmospheric general circulation model (AGCM) with a mixed-layer ocean. We carried out two present-day simulations of regional climate – one with modern and one with 11 ka geography – plus another simulation for 6 ka. In addition, we performed five ~ 11 ka climate simulations, each driven by the same global AGCM boundary conditions: (i) 11 ka Control, which represents conditions just prior to the major transitions (exposed land bridge, no thaw lakes or wetlands, widespread tundra vegetation), (ii) sea-level rise, which employed present-day continental outlines, (iii) vegetation change, with deciduous needleleaf and deciduous broadleaf boreal vegetation types distributed as suggested by the paleoecological record, (iv) thaw lakes, which used the present-day distribution of lakes and wetlands, and (v) post-11 ka All, incorporating all boundary conditions changed in experiments (ii)–(iv). We find that regional-scale controls strongly mediate the climate responses to changes in the large-scale controls, amplifying them in some cases, damping them in others, and, overall, generating considerable spatial heterogeneity in the simulated climate changes. The change from tundra to deciduous woodland produces additional widespread warming in spring and early summer over that induced by the 11 ka insolation regime alone, and lakes and wetlands produce modest and localized cooling in summer and warming in winter. The greatest effect is the flooding of the land bridge and shelves, which produces generally cooler conditions in summer but warmer conditions in winter and is most clearly manifest on the flooded shelves and in eastern Beringia. By 6 ka continued amplification of the seasonal cycle of insolation and loss of the Laurentide ice sheet produce temperatures similar to or higher than those at 11 ka, plus a longer growing season.

A Conceptual Framework for Planning Systemic Human Adaptation to Global Warming.

Human activity is having multiple, inter-related effects on ecosystems. Greenhouse gas emissions persisting along current trajectories threaten to significantly alter human society. At 0.85 °C of anthropogenic warming, deleterious human impacts are acutely evident. Additional warming of 0.5 °C–1.0 °C from already emitted CO2 will further intensify extreme heat and damaging storm events. Failing to sufficiently address this trend will have a heavy human toll directly and indirectly on health. Along with mitigation efforts, societal adaptation to a warmer world is imperative. Adaptation efforts need to be significantly upscaled to prepare society to lessen the public health effects of rising temperatures. Modifying societal behaviour is inherently complex and presents a major policy challenge. We propose a social systems framework for conceptualizing adaptation that maps out three domains within the adaptation policy landscape: acclimatisation, behavioural adaptation and technological adaptation, which operate at societal and personal levels. We propose that overlaying this framework on a systems approach to societal change planning methods will enhance governments’ capacity and efficacy in strategic planning for adaptation. This conceptual framework provides a policy oriented planning assessment tool that will help planners match interventions to the behaviours being targeted for change. We provide illustrative examples to demonstrate the framework’s application as a planning tool.

Wave like signatures in aerosol optical depth and associated radiative impacts over the central Himalayan region

Doppler Lidar and Multi-Filter Rotating Shadowband Radiometer (MFRSR) observations are utilized to show wave like signatures in aerosol optical depth (AOD) during daytime boundary layer evolution over the Himalayan region. Fourier analysis depicted 60–80min periods dominant during afternoon hours, implying that observed modulations could be plausible reason for the AOD forenoon–afternoon asymmetry which was previously reported. Inclusion of wave amplitude in diurnal variation of aerosol radiative forcing estimates showed ~40% additional warming in the atmosphere relative to mean AOD. The present observations emphasize the importance of wave induced variations in AOD and radiation budget over the site.

High-resolution distributed analysis of climate and anthropogenic changes on the hydrology of an Alpine catchment

Summary A fully distributed hydrological analysis at scales significant for water management for present-day, and projected future climate conditions is presented for a catchment in the Alps. We selected the upper Rhone basin (Switzerland) as a test case for understanding anthropogenic impacts including climate change on water resources and flood risk in the Alpine area. The upper Rhone basin contains reservoirs, river diversions and irrigated areas offering the opportunity to study the interaction between climate change effects and hydraulic infrastructure. Anthropogenic disturbances of the flow regime were implemented in detail in the hydrological analysis. We downscaled climate model realizations using a methodology that accounts for the uncertainty in climate change projections related to the stochastic variability of precipitation and air temperature. We showed how climate change effects on streamflow propagate from high elevation headwater catchments to the river in the main valley by analyzing changes in several hydrological metrics and at various temporal scales across 297 control sections. Changes in the natural hydrological regime imposed by the existing hydraulic infrastructure are likely larger than climate change signals expected by the middle of the 21st century in most of the river network. Despite a strong uncertainty induced by stochastic climate variability, we identified an elevational dependence of climate change impacts with a severe reduction in streamflow due to the missing contribution of water from ice melt at high-elevation and a dampened effect downstream. Reduced ice cover and ice melt are likely to have significant implications for hydropower production. The impacts can emerge without any additional climate warming. A decrease of August–September discharge and an increase of hourly and daily maximum flows appear as plausible projected change for the most part of the catchment. However, it is unlikely that major changes in total runoff for the entire upper Rhone basin will occur in the next four decades.

Widespread gas hydrate instability on the upper U.S. Beaufort margin

AbstractThe most climate‐sensitive methane hydrate deposits occur on upper continental slopes at depths close to the minimum pressure and maximum temperature for gas hydrate stability. At these water depths, small perturbations in intermediate ocean water temperatures can lead to gas hydrate dissociation. The Arctic Ocean has experienced more dramatic warming than lower latitudes, but observational data have not been used to study the interplay between upper slope gas hydrates and warming ocean waters. Here we use (a) legacy seismic data that constrain upper slope gas hydrate distributions on the U.S. Beaufort Sea margin, (b) Alaskan North Slope borehole data and offshore thermal gradients determined from gas hydrate stability zone thickness to infer regional heat flow, and (c) 1088 direct measurements to characterize multidecadal intermediate ocean warming in the U.S. Beaufort Sea. Combining these data with a three‐dimensional thermal model shows that the observed gas hydrate stability zone is too deep by 100 to 250 m. The disparity can be partially attributed to several processes, but the most important is the reequilibration (thinning) of gas hydrates in response to significant (~0.5°C at 2σ certainty) warming of intermediate ocean temperatures over 39 years in a depth range that brackets the upper slope extent of the gas hydrate stability zone. Even in the absence of additional ocean warming, 0.44 to 2.2 Gt of methane could be released from reequilibrating gas hydrates into the sediments underlying an area of ~5–7.5 × 103 km2 on the U.S. Beaufort Sea upper slope during the next century.

Key factors for assessing climate benefits of natural gas versus coal electricity generation

Assessing potential climate effects of natural gas versus coal electricity generation is complicated by the large number of factors reported in life cycle assessment studies, compounded by the large number of proposed climate metrics. Thus, there is a need to identify the key factors affecting the climate effects of natural gas versus coal electricity production, and to present these climate effects in as clear and transparent a way as possible. Here, we identify power plant efficiencies and methane leakage rates as the factors that explain most of the variance in greenhouse gas emissions by natural gas and coal power plants. Thus, we focus on the role of these factors in determining the relative merits of natural gas versus coal power plants. We develop a simple model estimating CO2 and CH4 emissions from natural gas and coal power plants, and resulting temperature change. Simple underlying physical changes can be obscured by abstract evaluation metrics, thus we focus our analysis on the time evolution of global mean temperature. We find that, during the period of plant operation, if there is substantial methane leakage, natural gas plants can produce greater near-term warming than coal plants with the same power output. However, if methane leakage rates are low and power plant efficiency is high, natural gas plants can produce some reduction in near-term warming. In the long term, natural gas power plants produce less warming than would occur with coal power plants. However, without carbon capture and storage natural gas power plants cannot achieve the deep reductions that would be required to avoid substantial contribution to additional global warming.

A Randomized Controlled Trial to Improve Outcomes Utilizing Various Warming Techniques during Cesarean Birth

To examine the effect of various warming methods during cesarean birth (CB) on maternal core body temperature, maternal hypothermia, and other maternal and neonatal outcomes. Three-arm randomized controlled trial. Perinatal unit in a large community hospital in the mid-Atlantic United States. Two hundred twenty-six (226) pregnant women undergoing planned CB. Women were randomly assigned to one of three groups (usual care, warmed fluids, or warmed underbody pad). Warming treatments began preoperatively and continued for 2hours postoperatively. Study nurses measured outcomes at defined intervals. Both warming techniques affected maternal temperatures and the incidence of hypothermia. The warmed fluids group had significantly higher temperatures in the operating room, whereas the warmed underbody pad group had significantly higher temperatures in the recovery room. Although none of the other outcomes was statistically different among groups, the findings have implications for practice. Apgar scores were proportionately lower in the usual care group, and maternal request for additional warming was proportionately higher in the usual care group. This study adds information on ways to maintain maternal normothermia during surgery. By understanding maternal hypothermia during CB, nurses can use best practice to obtain optimal maternal and neonatal outcomes.

Intensified Arctic warming under greenhouse warming by vegetation–atmosphere–sea ice interaction

Observations and modeling studies indicate that enhanced vegetation activities over high latitudes under an elevated CO2 concentration accelerate surface warming by reducing the surface albedo. In this study, we suggest that vegetation-atmosphere-sea ice interactions over high latitudes can induce an additional amplification of Arctic warming. Our hypothesis is tested by a series of coupled vegetation-climate model simulations under 2xCO2 environments. The increased vegetation activities over high latitudes under a 2xCO2 condition induce additional surface warming and turbulent heat fluxes to the atmosphere, which are transported to the Arctic through the atmosphere. This causes additional sea-ice melting and upper-ocean warming during the warm season. As a consequence, the Arctic and high-latitude warming is greatly amplified in the following winter and spring, which further promotes vegetation activities the following year. We conclude that the vegetation-atmosphere-sea ice interaction gives rise to additional positive feedback of the Arctic amplification.

The Changing Arctic: New Realities and Players at the Top of the World

On December 6, 2012, the liquefied natural gas carrier Ob River arrived in the northern Japanese port of Tobata. Port arrivals by various types of cargo ships happen routinely every day around the world, but this voyage and arrival were special. The Ob River had departed November 7 from the northern Norwegian port of Hammerfest, sailed east across the Barents Sea, continued along Russia's Northern Sea Route, and finally exited the Arctic Ocean through the Bering Strait on its way to Japan. Escorted in ice-covered waters by Russian nuclear icebreakers, this large, ice-capable ship had forged a late season, trans-Arctic maritime route from the Atlantic to the Pacific.1 The voyage symbolized the ongoing globalization of the Arctic-the connection of Arctic natural resources to global markets-in an era when the region is also undergoing profound environmental changes as a result of anthropogenic warming at rates twice that of lower latitudes.This essay argues that globalization, climate change, and regional geopolitics are intersecting and strongly influencing the future of the top of the world. No less important, the voice of the Arctic's indigenous people, who have lived in the North for millennia, is being heard amid all the extraordinary change in the region. The eight states that have sovereign areas above the Arctic Circle-Canada, Denmark (Greenland), Finland, Iceland, Norway, Russia, Sweden, and the United States-are challenged to protect their Arctic peoples and the environment while also developing their northern lands and seas in sustainable ways. The Arctic states have created and nurtured the Arctic Council and have in May 2013 admitted five Asian observers. The roles these Asian observers can play in Arctic affairs within the council and at large in the world are a key focus of this essay.A Melting Arctic and Growing GlobalizationExtraordinary changes in the Arctic's physical environment have been observed. Arctic sea ice is undergoing a historic transformation of thinning and reduction in area that has implications for potentially longer seasons of navigation and access to once remote coastal seas.2 The changes in the sea ice area and observed reduction in snow-cover duration in Eurasia and North America mean that smaller Arctic areas are less reflective of incoming sunlight, causing the exposed land and sea to absorb more heat. Permafrost is melting and releasing methane (a greenhouse gas), which could result in additional warming of the atmosphere. Of importance for the rise of global sea levels, the Greenland ice sheet (as well as Canadian and Alaskan glaciers) has been losing mass because of the melting of the surface ice sheet and iceberg calving. The Arctic's ecosystems have been observed to be highly sensitive to such temperature increases, which have caused the loss of sea ice habitat for marine mammals, changes to the marine food chain, and increases in tundra greenness and biomass. The marine and terrestrial ecosystem changes, increasing coastal erosion, and overall warming present serious challenges to all Arctic indigenous peoples.3While these physical changes have been occurring, the globalization of the Arctic has begun as a result of new economic pressures to link Arctic natural resources to global markets. Higher global commodities prices and improving Arctic access have been drivers of increased attention to what is viewed by many as a global storehouse of desirable natural resources, including hydrocarbons; fisheries; hard minerals such as nickel, palladium, zinc, platinum, diamonds, and coal; rare earths; and freshwater. These strong climatic and economic forces present an array of unique challenges to the existing legal and regulatory structures, which cannot meet today's needs for protecting Arctic peoples and the environment.The Changing Role of the Arctic CouncilThe Arctic Council is an intergovernmental forum, established by the Arctic states in the 1996 Ottawa Declaration, that plays a central role today in managing and shaping international relations in the Arctic. …

Riscaldamento globale e rischio di calcolosi renale

Numerosi studi hanno dimostrato il possibile ruolo della temperatura ambientale e del clima nella patogenesi della calcolosi urinaria. Il rischio di calcolosi è fortemente aumentato dalla disidratazione cronica associata al clima molto caldo, al lavoro all'aperto in aree tropicali o al servizio militare in aree desertiche. La variazione stagionale dell'incidenza delle coliche renali è stata descritta frequentemente, anche se non in modo unanime, ed è stata più volte dimostrata un'associazione positiva delle manifestazioni acute della calcolosi con la temperatura media ambientale e le ore di irraggiamento solare, anche se non con il tasso di umidità. La diuresi, il pH delle urine e l'escrezione urinaria di sodio sono significativamente più bassi nei mesi estivi, con il conseguente aumento dei valori di saturazione urinaria per l'acido urico e l'ossalato di calcio (soprattutto nel sesso maschile). Oltre alle variazioni climatiche stagionali, sono riscontrabili variazioni storiche delle temperature sulla superficie terrestre. Esistono stime abbastanza affidabili delle temperature della superficie terrestre per gli ultimi 12.000 anni, che hanno fatto seguito all'ultima glaciazione. Sono stati osservati periodi più caldi o più freddi, tuttavia le temperature medie della superficie terrestre negli ultimi 25 anni sono state superiori a quelle rilevate nell'ultimo millennio. Questa tendenza climatica, chiamata “riscaldamento globale” sembra essere correlabile alle emissioni dell'attività umana, che creano il cosiddetto “effetto serra”. Si ritiene che, nel 21° secolo, assisteremo a un ulteriore incremento della temperatura media di 2°C o più. Uno dei possibili effetti secondari del “global warming” potrebbe essere un incremento della prevalenza della nefrolitiasi, che si stima, con modelli di calcolo matematico computerizzato, che potrebbe arrivare sino al 10% in più.

Regional climate response to land surface changes after harvest in the North China Plain under present and possible future climate conditions

AbstractIn this study, we investigated the impacts of land use alterations from harvesting practices on the regional surface climate over the North China Plain. The surface climate responses after harvest in June in regions where double‐cropping is practiced were evaluated using observations and model simulations with the global climate model HadGEM2‐Atmosphere. Responses were modeled under both present and possible future climate conditions. In the model, double‐cropping was represented using the monthly varying fraction of vegetation. This contributed to an improvement in the model simulation over East Asia. Modeling results showed that the land surface was warmer and drier after harvest, and these simulation results were consistent with observations. The bare soil surface after harvest in June had biophysical impacts on the surface climate that were mediated by decreasing evapotranspiration and latent heat flux effects, which increased surface air temperatures and decreased surface humidity. An increase in shortwave radiation also contributed to the rise in temperatures. Under two Representative Concentration Pathways (RCP) scenarios for possible future climate conditions, land conversion induced additional warming in addition to greenhouse gases induced global warming. The RCP 8.5 and RCP 2.6 scenarios demonstrated a warming of 1.0°C and 1.4°C due to harvesting practices in June, respectively. The response magnitude was affected by the climate conditions in each RCP. Our results suggest that potential impacts of harvest on the local climate need to be considered in future projections of CO2‐induced warming on a regional scale.

Tiny warming of residual anthropogenicCO2

The residual fraction of anthropogenic CO2emissions which has not been captured by carbon sinks and remains in the atmosphere, is estimated by two independent experimental methods which support each other: the13C /12C ratio and the temperature-independent fraction of d( CO2)/dt on a yearly scale after subtraction of annual fluctuations the amplitude ratio of which reaches a factor as large as 7. The anthropogenic fraction is then used to evaluate the additional warming by analysis of its spectral contribution to the outgoing long-wavelength radiation (OLR) measured by infrared spectrometers embarked in satellites looking down. The anthropogenic CO2additional warming extrapolated in 2100 is found lower than 0.1°C in the absence of feedbacks. The global temperature data are fitted with an oscillation of period 60 years added to a linear contribution. The data which support the 60-year cycle are summarized, in particular sea surface temperatures and sea level rise measured either by tide gauge or by satellite altimetry. The tiny anthropogenic warming appears consistent with the absence of any detectable change of slope of the 130-year-long linear contribution to the temperature data before and after the onset of large CO2emissions.

Global Warming and Risk of Renal Stone Formation

A possible role of ambient temperature and climate as significant risk factors for urinary lithogenesis has been confirmed by several studies. Chronic dehydration associated to hot climate, outdoor working in the tropics, and military duty in a desert environment, all strongly increase the risk of developing kidney stones. Seasonal variation of the number of kidney stone-related colic attacks was frequently, although not consistently, reported; similarly, ambient temperature and hours of sunshine, but not humidity, were found to be positively associated with acute presentations of urinary calculi. Urine volume, sodium content, and pH are significantly lower in summertime and, consequently, the relative saturation of uric acid and calcium oxalate are higher (particularly in men). In addition to seasonal changes, there are also evident historical variations of the temperature at Earth's surface. There are numerous estimations of the temperatures during the previous 12,000 years that followed the last glacial period. During this era there have been warmer as well as cooler periods, although the mean global surface temperatures over the last 25 years have been higher than those of any comparable period in the last millennium. This climatic trend, named “global warming”, seems to be caused primarily by human-induced emissions of greenhouse gases. There is a growing consensus about the fact that during the 21st century we will indeed see a change of 2C° or more in additional warming. A secondary effect of the “global warming” may be an increase in the prevalence rate of kidney stones, which computer models estimate will be up to 10%.

Controls on the Archean Climate System Investigated with a Global Climate Model

The most obvious means of resolving the faint young Sun paradox is to invoke large quantities of greenhouse gases, namely, CO2 and CH4. However, numerous changes to the Archean climate system have been suggested that may have yielded additional warming, thus easing the required greenhouse gas burden. Here, we use a three-dimensional climate model to examine some of the factors that controlled Archean climate. We examine changes to Earth's rotation rate, surface albedo, cloud properties, and total atmospheric pressure following proposals from the recent literature. While the effects of increased planetary rotation rate on surface temperature are insignificant, plausible changes to the surface albedo, cloud droplet number concentrations, and atmospheric nitrogen inventory may each impart global mean warming of 3-7 K. While none of these changes present a singular solution to the faint young Sun paradox, a combination can have a large impact on climate. Global mean surface temperatures at or above 288 K could easily have been maintained throughout the entirety of the Archean if plausible changes to clouds, surface albedo, and nitrogen content occurred.

Signatures of Rossby wave modulations in aerosol optical depth over the central Himalayan region

Abstract. Long-period modulations are shown in aerosol optical depth measured by the Microtops II Sun photometer over a high-altitude site the central Himalayan region (Nainital, 29.4° N, 79.5° E, 1958 m a.m.s.l.) for the first time. Fourier analysis of aerosol optical depth showed dominant 25–45 day oscillations observed in MODerate-resolution Imaging Spectro radiometer data. Further, a Hovmiller diagram showed westward (northward) propagation at a different longitude (latitude), confirming that the modulations are associated with Rossby waves. It is also shown that the Rossby wave amplitude causes an additional warming of 4.16 ± 0.98 W m−2 over the observational site. Hence, the present study illustrates the importance of wave-induced aerosol dynamics and the corresponding radiative effects.