Local Warming Effect Research Articles

The Conditional Nature of the Local Warming Effect

Abstract The local warming effect occurs when perceived deviations in the day’s temperature affect individuals’ global warming beliefs. When people perceive the day to be warmer than usual, they tend to overestimate the number of warm days throughout the year, and to report increased belief in and worry about global warming. For many, this is normatively concerning because a single day’s perceived temperature fluctuation is not representative of longer-term, large-scale climate patterns. It thus makes for a poor basis for global warming judgments. Recent work shows that the local warming effect might disappear when people receive a reminder to think about weather patterns over the past year (i.e., a correction). This paper employs a survey experiment that extends past research by exploring the generalizability, conditionality, and durability of the corrective information. It identifies the conditions under which a local warming effect is more or less likely to occur.

Comparison of the effects of lidocaine pre-administration and local warming of the intravenous access site on propofol injection pain: Randomized, double-blind controlled trial

BackgroundLidocaine reduces pain that occurs upon the intravenous injection of propofol. But, there are few non-pharmacological nursing interventions to reduce propofol injection pain. ObjectiveTo compare the effects of lidocaine pre-administration and local warming of the intravenous access site on propofol injection pain. DesignProspective, double-blind, randomized controlled trial. SettingThe 555 bed, non-teaching National Cancer Center in Kyunggido, South Korea. ParticipantsA total of 96 patients who underwent thyroidectomy under total intravenous general anesthesia with propofol were randomly allocated to the control, lidocaine pre-administration (LA) or local warming (LW) group. MethodsAll three groups received 2% propofol with an effect-site target at 3μg/mL for induction dose. The control group received 2% propofol with no intervention. The lidocaine pre-administration group received 2% propofol 30s after 1% lidocaine 30mg. The local warming group received 2% propofol after warming of the intravenous access site for 1min using 43°C forced air. Propofol injection pain was assessed by four-point verbal categorial scoring (VCS), numerical rating scale (NRS) and surgical pleth index (SPI). ResultsPain VCS of the LA group (mean±SD, 1.11±0.45) was significantly reduced (U=−3.92, p<.001) compared to the control group (mean±SD, 1.71±0.74). Pain VCS of the LW group (mean±SD, 0.76±0.44) was significantly reduced (U=−5.17, p<.001) compared to the control group (mean±SD, 1.71±0.74). Pain VCS of the LW group was significantly reduced compared to the LA group (U=−3.33, p=.001]. Pain NRS of the LA group (mean±SD, 4.31±2.32) was significantly reduced (mean difference, 1.82; 95% CI, 0.63–3.00; p=.003) compared to the control group (mean±SD, 6.13±2.39). Pain NRS of the LW group (mean±SD, 3.06±2.37) was significantly reduced (mean difference, 3.07; 95% CI, 1.63–4.51; p<.009) compared to the control group. There were significant differences in pain NRS between the LA group and the LW group (mean difference, 1.25; 95% CI, 0.09–2.42; p=.035). SPI of the LA group (mean±SD, 64.1±16.3) was significantly reduced (mean difference control versus LA, 8.36; 95% CI, 1.64–15.1; p=.016) compared to the control group (mean±SD, 72.5±9.56). SPI of the LW group (mean±SD, 55.0±16.2) was significantly reduced (mean difference control versus LW, 17.4; 95% CI, 10.8–24.0; p<.001) compared to the control group. There was a significant difference in SPI between the LA group and LW group (mean difference, 9.06; 95% CI, 1.02–17.1; p=.028). ConclusionLocal warming of the intravenous access site by 43°C forced air for 1min is slightly more effective in reducing propofol injection pain compared to lidocaine pre-administration.

Disruption of the European climate seasonal clock in a warming world

The application of a new metric of seasonal onset over Europe to existing observational data sets indicates that the start of summer has advanced significantly over recent decades, a trend expected to continue under global warming. Temperatures over Europe are largely driven by the strength and inland penetration of the oceanic westerly flow. The wind influence depends on season: blocked westerlies, linked to high-pressure anomalies over Scandinavia, induce cold episodes in winter1 but warm conditions in summer2,3. Here, we propose to define the onset of the two seasons as the calendar day on which the daily circulation/temperature relationship switches sign. We have assessed this meteorologically based metric using several observational data sets and we provide evidence for an earlier onset of the summer date by ∼10 days between the 1960s and 2000s. Results from a climate model show that internal variability alone cannot explain this calendar advance. Rather, the earlier onset can be partly attributed to anthropogenic forcings. The modification of the zonal advection due to earlier disappearance of winter snow over Eastern Europe, which reduces the degree to which climate has continental properties, is mainly responsible for the present-day and near-future advance of the summer date in Western Europe. Our findings are in line with phenological-based trends (earlier spring events) reported for many living species over Europe4,5,6, for which we provide an alternative interpretation to the traditionally evoked local warming effect. Based on the Representative Concentration Pathway (RCP) 8.5 scenario, which assumes that greenhouse gas emissions continue to rise throughout the twenty-first century, a summer advance of ∼20 days compared with pre-industrial climate is expected by 2100, whereas no clear signal arises for winter onset.

Optical and thermal characteristics of carbonaceous aerosols measured at an urban site in Gwangju, Korea, in the winter of 2011

ABSTRACTCarbonaceous components (organic carbon [OC] and elemental carbon [EC]) and optical properties (light absorption and scattering) of fine particulate matter (aerodynamic diameter <2.5 μm; PM2.5) were simultaneously measured at an urban site in Gwangju, Korea, during the winter of 2011. OC was further classified into OC1, OC2, OC3, and OC4, based on a temperature protocol using a Sunset OC/EC analyzer. The average OC and EC concentrations were 5.0 ± 2.5 and 1.7 ± 0.9 μg C m−3, respectively. The average single-scattering albedo (SSA) at a wavelength of 550 nm was 0.58 ± 0.11, suggesting that the aerosols observed in the winter of 2011 had a local warming effect in this area. During the whole sampling period, “stagnant PM” and “long-range transport PM” events were identified. The light absorption coefficient (babs) was higher during the stagnant PM event than during the long-range transport PM event due to the existence of abundant light-absorbing OC during the stagnant PM event. In particular, the OC2 and OC3 concentrations were higher during the stagnant PM event than those during the long-range transport event, suggesting that OC2 and OC3 might be more related to the light-absorbing OC. The light scattering coefficient (bscat) was similar between the events. On average, the mass absorption efficiency attributed to EC (σEC) was 9.6 m2 g−1, whereas the efficiency attributed to OC (σOC) was 1.8 m2 g−1 at λ = 550 nm. Furthermore, the σEC is comparable among the PM event days, but the σOC for the stagnant PM event was significantly higher than that for the long-range transport PM event (1.7 vs. 0.5).Implications: Optical and thermal properties of carbonaceous aerosol were measured at Gwangju, and carbonaceous aerosol concentration and optical property varied between “stagnant PM” and “long-range transport PM” events. More abundant light absorbing OC was observed during the stagnant PM event.

The Effects of Local Warming on Surgical Site Infection.

Surgical site infections (SSI) account for a major proportion of hospital-acquired infections. They are associated with longer hospital stay, readmissions, increased costs, mortality, and morbidity. Reducing SSI is a goal of the Surgical Care Improvement Project and identifying interventions that reduce SSI effectively is of interest. In a single-blinded randomized controlled trial (RCT) we evaluated the effect of localized warming applied to surgical incisions on SSI development and selected cellular (immune, endothelial) and tissue responses (oxygenation, collagen). After Institutional Review Board approval and consent, patients having open bariatric, colon, or gynecologic-oncologic related operations were enrolled and randomly assigned to local incision warming (6 post-operative treatments) or non-warming. A prototype surgical bandage was used for all patients. The study protocol included intra-operative warming to maintain core temperature ≥36°C and administration of 0.80 FIO2. Patients were followed for 6 wks for the primary outcome of SSI determined by U.S. Centers for Disease Control (CDC) criteria and ASEPSIS scores (additional treatment; presence of serous discharge, erythema, purulent exudate, and separation of the deep tissues; isolation of bacteria; and duration of inpatient stay). Tissue oxygen (PscO2) and samples for cellular analyses were obtained using subcutaneous polytetrafluoroethylene (ePTFE) tubes and oxygen micro-electrodes implanted adjacent to the incision. Cellular and tissue ePTFE samples were evaluated using flow cytometry, immunohistochemistry, and Sircol™ collagen assay (Biocolor Ltd., Carrickfergus, United Kingdom). One hundred forty-six patients participated (n=73 per group). Study groups were similar on demographic parameters and for intra-operative management factors. The CDC defined rate of SSI was 18%; occurrence of SSI between groups did not differ (p=0.27). At 2 wks, warmed patients had better ASEPSIS scores (p=0.04) but this difference was not observed at 6 wks. There were no significant differences in immune, endothelial cell, or collagen responses between groups. On post-operative days one to two, warmed patients had greater PscO2 change scores with an average PscO2 increase of 9-10 mm Hg above baseline (p<0.04). Post-operative local warming compared with non-warming followed in this study, which included intra-operative warming to maintain normothermia and FIO2 level of 0.80, did not reduce SSI and had no effect on immune, endothelial cell presence, or collagen synthesis. PscO2 increased significantly with warming, however, the increase was modest and less than expected or what has been observed in studies testing other interventions.

Transport of anthropogenic and biomass burning aerosols from Europe to the Arctic during spring 2008

Abstract. During the POLARCAT-France airborne campaign in April 2008, pollution originating from anthropogenic and biomass burning emissions was measured in the European Arctic. We compare these aircraft measurements with simulations using the WRF-Chem model to investigate model representation of aerosols transported from Europe to the Arctic. Modeled PM2.5 is evaluated using European Monitoring and Evaluation Programme (EMEP) measurements in source regions and POLARCAT aircraft measurements in the Scandinavian Arctic. Total PM2.5 agrees well with the measurements, although the model overestimates nitrate and underestimates organic carbon in source regions. Using WRF-Chem in combination with the Lagrangian model FLEXPART-WRF, we find that during the campaign the research aircraft sampled two different types of European plumes: mixed anthropogenic and fire plumes from eastern Europe and Russia transported below 2 km, and anthropogenic plumes from central Europe uplifted by warm conveyor belt circulations to 5–6 km. Both modeled plume types had undergone significant wet scavenging (&gt; 50% PM10) during transport. Modeled aerosol vertical distributions and optical properties below the aircraft are evaluated in the Arctic using airborne lidar measurements. Model results show that the pollution event transported aerosols into the Arctic (&gt; 66.6° N) for a 4-day period. During this 4-day period, biomass burning emissions have the strongest influence on concentrations between 2.5 and 3 km altitudes, while European anthropogenic emissions influence aerosols at both lower (~ 1.5 km) and higher altitudes (~ 4.5 km). As a proportion of PM2.5, modeled black carbon and SO4= concentrations are more enhanced near the surface in anthropogenic plumes. The European plumes sampled during the POLARCAT-France campaign were transported over the region of springtime snow cover in northern Scandinavia, where they had a significant local atmospheric warming effect. We find that, during this transport event, the average modeled top-of-atmosphere (TOA) shortwave direct and semi-direct radiative effect (DSRE) north of 60° N over snow and ice-covered surfaces reaches +0.58 W m−2, peaking at +3.3 W m−2 at noon over Scandinavia and Finland.

Eliminating the local warming effect

A growing body of work shows that perceived deviations in daily local temperatures alter individuals’ global warming beliefs and concerns (e.g., Krosnick et al. 2006, Semenza et al. 2008, Li et al. 2011, Zaval et al. 2014). Little research, however, explores the conditions under which this “local warming” effect occurs. Here, Druckman presents an experiment that shows how a simple prompt—that reminds individuals to remember how the weather felt over the past year—eliminates the local warming effect. Specifically, the prompt severs the relationship between perceptions of the daily temperature with estimates of last year’s temperature deviations, which is the basis on which many base their global warming opinions. While the results do not reveal the frequency that local warming effects occur overall, they do demonstrate the limits of the effect. Additionally, the findings suggest ways to rhetorically counteract the effect. Public opinion about the existence and salience of global warming plays an important role in the construct of public policy. Elected oriented politicians rarely implement new policies in the face of public opposition. A sizable literature has sought to explain the origins and nature of global warming opinions. One notable finding is that individuals often base their beliefs about global warming on their present assessments of local temperature: relatively warm temperatures lead individuals to increase their belief in and concern about global warming. Egan and Mullin (2014: 89) state that the “evidence for the effect of weather on public opinion regarding climate change is now overwhelming.” Perhaps the most compelling demonstration of the “local warming” phenomenon comes from Zaval et al. (2014). The authors present a series of ingenious studies that show, rather conclusively, that when individuals perceive the day’s local temperature to be warmer than usual, they then overestimate the number of warm days through the year, which, in turn, leads them to increase their beliefs about the existence of global warming and their concern about global warming (also see, e.g., Krosnick et al. 2006, Semenza et al. 2008, Li et al. 2011). Moreover, information about the distinction between weather (e.g., a constantly changing dynamic) and climate (e.g., average weather over time and space), or changes in terminology (e.g., global warming versus climate change) do not vitiate the impact of local temperatures on beliefs. The effect is substantively significant, rivaling the impact of age, race, and education on global warming attitudes (Egan and Mullin 2012: 796). For many this dynamic is concerning; Egan and Mullin (2012: 806) state, “[g]lobal climate change is one of the most important public policy challenges of our time... [people] use fluctuations in local temperature to reassess their beliefs about the existence of global warming... a discovery 1 Others find mixed evidence on the impact of climate changes on beliefs; however, much of the inconsistent evidence concerns actual and not perceived climate shifts: “studies tend to find that perceptions of weather have greater influence on climate change perceptions than do actual weather” (Marquart-Pyatt et al. 2014: 249).

Satellite Observations of Wind Farm Impacts on Nocturnal Land Surface Temperature in Iowa

Wind farms (WFs) are believed to have an impact on lower boundary layer meteorology. A recent study examined satellite-measured land surface temperature data (LST) and found a local nighttime warming effect attributable to a group of four large WFs in Texas. This study furthers their work by investigating the impacts of five individual WFs in Iowa, where the land surface properties and climate conditions are different from those in Texas. Two methods are used to assess WF impacts: first, compare the spatial coupling between the LST changes (after turbine construction versus before) and the geographic layouts of the WFs; second, quantify the LST difference between the WFs and their immediate surroundings (non-WF areas). Each WF shows an irrefutable nighttime warming signal relative to the surrounding areas after their turbines were installed, and these warming signals are generally coupled with the geographic layouts of the wind turbines, especially in summer. This study provides further observational evidence that WFs can cause surface warming at nighttime, and that such a signal can be detected by satellite-based sensors.

The biogeophysical effects of extreme afforestation in modeling future climate

Afforestation has been deployed as a mitigation strategy for global warming due to its substantial carbon sequestration, which is partly counterbalanced with its biogeophysical effects through modifying the fluxes of energy, water, and momentum at the land surface. To assess the potential biophysical effects of afforestation, a set of extreme experiments in an Earth system model of intermediate complexity, the McGill Paleoclimate Model-2 (MPM-2), is designed. Model results show that latitudinal afforestation not only has a local warming effect but also induces global and remote warming over regions beyond the forcing originating areas. Precipitation increases in the northern hemisphere and decreases in southern hemisphere in response to afforestation. The local surface warming over the forcing originating areas in northern hemisphere is driven by decreases in surface albedo and increases in precipitation. The remote surface warming in southern hemisphere is induced by decreases in surface albedo and precipitation. The results suggest that the potential impact of afforestation on regional and global climate depended critically on the location of the forest expansion. That is, afforestation in 0°–15°N leaves a relatively minor impact on global and regional temperature; afforestation in 45°–60°N results in a significant global warming, while afforestation in 30°–45°N results in a prominent regional warming. In addition, the afforestation leads to a decrease in annual mean meridional oceanic heat transport with a maximum decrease in forest expansion of 30°–45°N. These results can help to compare afforestation effects and find areas where afforestation mitigates climate change most effectively combined with its carbon drawdown effects.

The effects of general warm up, specific warm up and taping on electrical activity of lower limb's muscles in reaction to sudden unloading while walking

Background Ability of balance maintenance and postural control is important to prevent falling and injuries when balance perturbations occurs during walking. Injuries due to unloading of the base of support in walking and running such as ankle sprain has high incidence. Poor muscle function may put the joint in unstable condition. The association of the unloading and poor muscle function in the ankle joint may increase the rate and the intensity of the ankle sprain. Various techniques have been applied to maximize the joint’s stability. The objectives of this study was to compare the effects of general warming, local warming and taping of the ankle joint on the electrical activity of few muscles during a sudden unloading of the base of support during walking.

A Temporal Multiscale Analysis of the Waters off the East Coast of South Korea over the Past Four Decades

We address the trends in water temperature variability to understand the local global warming effects through different time scales using daily sea surface temperature (SST) measurements from 1966-2004. The abrupt SST changes off of the east coast of Korea are related to similar changes observed in the North Pacific. Seasonal water temperatures have increased by at least a factor of two or more in winter than in summer. While SSTs on annual timescales have increased significantly, SSTs on interannual timescales have decreased slightly at all stations. The anomalies in SST decadal time scales reveal maxima in temperature occurring in the mid-to-late 1970's, circa 1990 and circa 2000. These maxima coincide with major peaks in the North Pacific Gyre Oscillation (NPGO) with a lag of 4-7 months. The most significant warming appears in the long-term SST trends at each station where it approaches +0.05°C yr^(-1). Overall, the SST off the east coast of Korea has increased at rates that are far greater than what is reported in many other marginal seas.

Examining vegetation feedbacks on global warming in the Community Earth System Model

Leaves close their stomates in response to increases of CO2. Such a rapid physiological response is included in the land component of comprehensive climate models. However, observational studies have shown that they can further close their stomates as a consequence of “down‐regulation,” further reducing canopy conductance. However, they may also increase the area of their leaves, hence increasing their canopy conductance. Changes of canopy conductance change surface ET, a reduction leading to surface warming. A simulation considering these mechanisms of modifying canopy conductance is carried out for the assumption of a doubled atmospheric CO2concentration, using the Community Earth System model. It finds that down‐regulation as formulated in previous studies could have as large a warming impact on land temperatures as the standard leaf physiological response. Increases in LAI, if they were to occur, appear to have but a small cooling effect. The reduction of latent cooling in the model is amplified by a reduction of low‐level cloud cover, hence enhanced net absorption of solar radiation. Reduction of low level cloudiness appears to be necessary to maintain global radiation balance as reported in a previous study. Over mid to high latitudes, decreases in surface albedo associated with reduced snow cover also contribute to amplifying the warming. The physiological feedbacks of leaf stomates in the simulation increase warming by 0.6 ± 0.2°C over land and 0.3 ± 0.1°C globally, not inconsistent with previous studies. Enhanced interhemispheric temperature differences weaken the southward shift of the ITCZ associated with CO2radiative warming. Regions with relatively high LAI tend to have greater vegetation feedback; but increases in large‐scale precipitation may weaken this local warming effect.

First-aid with warm water delays burn progression and increases skin survival

First aid treatment for thermal injuries with cold water removes heat and decreases inflammation. However, perfusion in the ischemic zone surrounding the coagulated core can be compromised by cold-induced vasoconstriction and favor burn progression. The aim of this study is to evaluate the effect of local warming on burn progression in the rat comb burn model. 24 male Wistar rats were randomly assigned to either no treatment (control) or application of cold (17 °C) or warm (37 °C) water applied for 20 min. Evolution of burn depth, interspace necrosis, and microcirculatory perfusion were assessed with histology, planimetry, respectively with Laser Doppler flowmetry after 1 h, as well as 1, 4, and 7 days. Consistent conversion from a superficial to a deep dermal burn within 24 h was obtained in control animals. Warm and cold water significantly delayed burn depth progression, however after 4 days the burn depth was similar in all groups. Interspace necrosis was significantly reduced by warm water treatment (62±4% vs. 69±5% (cold water) and 82±3% (control); p<0.05). This was attributed to the significantly improved perfusion after warming, which was present 1 h after burn induction and was maintained thereafter (103±4% of baseline vs. 91±3% for cold water and 80±2% for control, p<0.05). In order to limit damage after burn injury, burn progression has to be prevented. Besides delaying burn progression, the application of warm water provided an additional benefit by improving the microcirculatory perfusion, which translated into increased tissue survival.

Enhanced poleward moisture transport and amplified northern high-latitude wetting trend

Observations and climate change projections forced by greenhouse gas emissions have indicated a wetting trend in northern high latitudes, evidenced by increasing Eurasian Arctic river discharges1, 2, 3. The increase in river discharge has accelerated in the latest decade and an unprecedented, record high discharge occurred in 2007 along with an extreme loss of Arctic summer sea-ice cover4, 5, 6. Studies have ascribed this increasing discharge to various factors attributable to local global warming effects, including intensifying precipitation minus evaporation, thawing permafrost, increasing greenness and reduced plant transpiration7, 8, 9, 10, 11. However, no agreement has been reached and causal physical processes remain unclear. Here we show that enhancement of poleward atmospheric moisture transport (AMT) decisively contributes to increased Eurasian Arctic river discharges. Net AMT into the Eurasian Arctic river basins captures 98% of the gauged climatological river discharges. The trend of 2.6% net AMT increase per decade accounts well for the 1.8% per decade increase in gauged discharges and also suggests an increase in underlying soil moisture. A radical shift of the atmospheric circulation pattern induced an unusually large AMT and warm surface in 2006–2007 over Eurasia, resulting in the record high discharge.

Effect of local warming versus local cooling on injection pain after propofol administration during anaesthesia induction

Ministry of Health, Ankara Training and Research Hospital, Department of Anaesthesiology and Intensive Care, Ankara, Turkey

Phenology of trees and urbanization: a comparative study between New York City and Ithaca, New York

The ‘global warming’ effect has been found to influence vegetation phenological processes. Heat island phenomenon associated with urbanized area presents a unique place to investigate its local warming effects. This study compares the date of budburst (DOBB) of street London plane trees (Platanus × acerifolia) between highly urbanized New York City (NYC) and relatively less urbanized Ithaca, New York in 2007 and 2008. It also linked DOBB with land surface temperature and fractional vegetation cover derived from Landsat satellite images. The DOBB in NYC and Ithaca differed significantly as budburst occurred 3 and 4 days earlier in NYC than in Ithaca in 2007 and 2008, respectively. The intensity of the heat island effect and its effect on tree phenology were greater in NYC. Results show that DOBB can be explained by temperature, and findings could be extrapolated to make inferences on the potential impact of global warming on vegetation communities.

The impact of natural versus anthropogenic aerosols on atmospheric circulation in the Community Atmosphere Model

The equilibrium response of atmospheric circulation to the direct radiative effects of natural or anthropogenic aerosols is investigated using the Community Atmosphere Model (CAM3) coupled to two different ocean boundary conditions: prescribed climatological sea surface temperatures (SSTs) and a slab ocean model. Anthropogenic and natural aerosols significantly affect the circulation but in nearly opposite ways, because anthropogenic aerosols tend to have a net local warming effect and natural aerosols a net cooling. Aerosol forcings shift the Intertropical Convergence Zone and alter the strength of the Hadley circulation as found in previous studies, but also affect the Hadley cell width. These effects are due to meridional gradients in warming caused by heterogeneous net heating, and are stronger with interactive SST. Aerosols also drive model responses at high latitudes, including polar near-surface warming by anthropogenic aerosols in summer and an Arctic Oscillation (AO)-type responses in winter: anthropogenic aerosols strengthen wintertime zonal wind near 60°N, weaken it near 30°N, warm the troposphere, cool the stratosphere, and reduce Arctic surface pressure, while natural aerosols produce nearly opposite changes. These responses are shown to be due to modulation of stratospheric wave-driving consistent with meridional forcing gradients in midlatitudes. They are more pronounced when SST is fixed, apparently because the contrast in land-ocean heating drives a predominantly wavenumber-2 response in the northern hemisphere which is more efficient in reaching the stratosphere, showing that zonal heating variations also affect this particular response. The results suggest that recent shifts from reflecting to absorbing aerosol types probably contributed to the observed decadal variations in tropical width and AO, although studies with more realistic temporal variations in forcing would be needed to quantify this contribution.

Accelerated human activities affecting the spatial pattern of temperature in the Yangtze River Delta

A zigzag city belt along the Yangtze River and Hangzhou rim has formed in the Yangtze River Delta in China due to the accelerated development of human activities and urbanization. Local climate change in the belt has affected the spatial patterns of surface air temperature (SAT). (1) There exist six major warmer centers with increasing rates of SAT from 0.28 to 0.54 °C per decade during 1961–2006 along the belt, namely Yangzhou, Nanjing, Jiangyin, Shanghai, Hangzhou and Ningbo. As the greatest areas of human activities and rapid urbanization in the Yangtze River Delta, Shanghai metropolitan areas have the maximum rates of increases in annual and seasonal mean SAT, which range from 0.23 to 0.50 °C per decade, and the strongest urban heat island effects, which are increasing at rates in the range of 0.11–0.15 °C per decade. (2) Local warming and urban heat island effects have created the largest and warmest SAT core in the Shanghai metropolitan areas, contributing to spatial pattern changes in SAT over the Yangtze River Delta. The spatial patterns of SAT for 2001–2006 and 1971–2000 significantly differ in the typical latitudinal pattern for 1971–2000 that has changed, mainly in Shanghai metropolitan areas. (3) The annual mean of the regional SAT will increase from 15.4 °C in 1961–1990 to 18.5 °C in 2071–2100 due to global warming and urban heat island effects according to the IPCC SRES A2 Scenario. This increase is notably higher than the increment of 2.5 °C from 15.4 °C to 17.9 °C due to global warming alone. The spatial distribution of the projected SAT with global warming and urban heat island effects is markedly different from that for global warming alone. In 2071–2100, the Shanghai metropolitan areas will have summer average temperatures of about 30.0–30.5 °C, which are higher than summer average temperatures of about 28.7 °C that would be expected from global warming alone. Higher average temperatures can have negative implications for energy and water consumption, human health and local ecosystems. The development and implementation of adaptation strategies are important and required by the policy makers from local government and city planning departments.

Forcings and feedbacks by land ecosystem changes on climate change

Vegetation change is involved in climate change through both forcing and feedback processes. Emissions of CO 2 from past net deforestation are estimated to have contributed approximately 0.22 -0.51 Wm -2 to the overall 1.46 Wm -2 radiative forcing by anthropogenic increases in CO 2 up to the year 2000. Deforestation-induced increases in global mean surface albedo are estimated to exert a radiative forcing of 0 to -0.2 Wm -2 , and dust emissions from land use may exert a radiative forcing of between approximately +0.1 and -0.2 Wm -2 . Changes in the fluxes of latent and sensible heat due to tropical deforestation are simulated to have exerted other local warming effects which cannot be quantified in terms of a Wm -2 radiative forcing, with the potential for remote effects through changes in atmospheric circulation. With tropical deforestation continuing rapidly, radiative forcing by surface albedo change may become less useful as a measure of the forcing of climate change by changes in the physical properties of the land surface. Although net global deforestation is continuing, future scenarios used for climate change prediction suggest that fossil fuel emissions of CO 2 may continue to increase at a greater rate than land use emissions and therefore continue to increase in dominance as the main radiative forcing. The CO 2 rise may be accelerated by up to 66% by feedbacks arising from global soil carbon loss and forest dieback in Amazonia as a consequence of climate change, and Amazon forest dieback may also exert feedbacks through changes in the local water cycle and increases in dust emissions.

Effects of Local and Systemic Warming on Postoperative Infections

There is increasing recognition that attention to optimal perfusion and oxygenation, normothermia, and normoglycemia is associated with low postoperative infection rates. The results of several studies on temperature maintenance will be presented. In a test of the value of systemic warming, patients undergoing major orthopedic, general, or urologic surgery were randomized to standard care with or without systemic warming using a disposable forced warm-air blanket. The addition of perioperative warming using a conductive carbon polymer mattress and overblanket to intraoperative warming was studied in patients undergoing major elective abdominal surgery. In a study of local warming, patients undergoing elective clean-wound surgery were randomized to local warming or non-warming. To determine the contribution of heat to eradication of methicillin-resistant Staphylococcus aureus, patients with stage III-IV pressure sores were randomized to receive or not receive local warming along with standard care. The intraoperative improvement of cutaneous blood flow and oxygen tension in the systemically warmed group improved tissue viability and reduced the incidence of pressure sores. A statistically significant reduction in morbidity and mortality was found in the patients having the conductive mattress as well as an overblanket. Similar findings are being reported from studies of systemic warming as an adjunct to resuscitation of patients presenting with abdominal pain and elderly patients admitted after a fall or with a suspected fractured femoral neck. Local warming with non-contact radiant heat was as good as systemic warming in preventing surgical site infections. Attention to keeping patients warm, together with maintenance of optimal perfusion and oxygenation and euglycemia, represents a simple effective guideline. Several methods of warming are available for use during transport and resuscitation and to achieve perioperative normothermia.