Search

Mitigation and adaptation represent two solutions to the issue of global warming. While mitigation aims at reducing $$\hbox {CO}_2$$ emissions and preventing climate change, adaptation encompasses a broad scope of techniques used to reduce the impacts of climate change once they have occurred. Both have direct costs on a country's gross domestic product, but costs also arise from temperature increases due to inaction. This paper introduces a tipping point in a real options model and analyzes optimal investment choices in mitigation and their timing. [ABSTRACT FROM AUTHOR]

The Murray dairy region produces approximately 1.85 billion litres of milk each year, representing about 20 % of Australia's total annual milk production. An ongoing production challenge in this region is the management of the impacts of heat stress during spring and summer. An increase in the frequency and severity of extreme temperature events due to climate change may result in additional heat stress and production losses. This paper assesses the changing nature of heat stress now, and into the future, using historical data and climate change projections for the region using the temperature humidity index (THI). Projected temperature and relative humidity changes from two global climate models (GCMs), CSIRO MK3.5 and CCR-MIROC-H, have been used to calculate THI values for 2025 and 2050, and summarized as mean occurrence of, and mean length of consecutive high heat stress periods. The future climate scenarios explored show that by 2025 an additional 12-15 days (compared to 1971 to 2000 baseline data) of moderate to severe heat stress are likely across much of the study region. By 2050, larger increases in severity and occurrence of heat stress are likely (i.e. an additional 31-42 moderate to severe heat stress days compared with baseline data). This increasing trend will have a negative impact on milk production among dairy cattle in the region. The results from this study provide useful insights on the trends in THI in the region. Dairy farmers and the dairy industry could use these results to devise and prioritise adaptation options to deal with projected increases in heat stress frequency and severity. [ABSTRACT FROM AUTHOR]

Daily precipitation and temperature records at 13 stations for the period 1960-2008 were analyzed to identify climatic change and possible effects of urbanization on low-temperature precipitation [LTP, precipitation of ⩾ 0.1 mm d occurring under a daily minimum temperature (Tmin) of ⩽ 0°C] in the greater Beijing region (BJR), where a rapid process of urbanization has taken place over the last few decades. The paper provides a climatological overview of LTP in BJR. LTP contributes 61.7% to the total amount of precipitation in BJR in the cold season (November-March). There is a slight increasing trend [1.22 mm (10 yr)] in the amount of total precipitation for the cold season during 1960-2008. In contrast, the amount of LTP decreases by 0.6 mm (10 yr). The warming rate of Tmin in BJR is 0.66°C (10 yr). Correspondingly, the frequency of LTP decreases with increasing Tmin by −0.67 times per °C. The seasonal frequency and amount of LTP in southeast BJR (mostly urban sites) are 17%-20% less than those in the northwestern (rural and montane sites). The intensity of LTP for the urban sites and northeastern BJR exhibited significant enhancing trends [0.18 and 0.15 mm d (10 yr), respectively]. The frequency of slight LTP (<0.2 mm d) significantly decreased throughout BJR [by about 5.74% (10 yr) in the urban area and northeast BJR], while the contribution of the two heaviest LTP events to total LTP amount significantly increased by 3.2% (10 yr). [ABSTRACT FROM AUTHOR]

Increasing atmospheric concentrations of greenhouse gases are widely expected to cause global warming and other climatic changes. It is important to establish priorities for reducing greenhouse-gas emissions, so that resources can be allocated efficiently and effectively. This is a global problem, and it is possible, on a global scale, to identify those activities whose emissions have the greatest potential for enhancing the greenhouse effect. However, perspectives from smaller scales must be appreciated, because it is on scales down to the local level that response measures will be implemented. This paper analyzes the relative importance of emissions from the many individual sources, on scales ranging from global to national to subnational. Individual country perspectives and proposed policy measures and those of subnational political entities exhibit some commonalities but differ among themselves and from a global-scale perspective in detail. [ABSTRACT FROM AUTHOR]

Egypt, a predominantly arid and hyper-arid country, is one of the environmentally most fragile regions of the world. The country became a hot spot for climatic extremes and aridity change in the global warming context. The unavailability of a detailed and reliable climate zonation map is a major hindrance to climatic studies in Egypt. This study attempted to generate a high-resolution climate zone map of Egypt based on a novel image analysis technique. For this purpose, a colored image representing Egypt's composite climatology was developed using three high-resolution (1-km) climate variables: rainfall, maximum temperature and minimum temperature during 1979–2013. A spherical evolution algorithm was used to classify the image into different climate zones. Subsequently, the climate zones representing similar climate distribution were merged to generate the climate map of Egypt. The study revealed that Egypt's distinguishable climate zones could be recognized when the land area was classified into nine zones using the image analysis technique. The statistical analysis of climate variables of each zone revealed similar climatology only in two pairs of zones. The merging of similar climate zones yielded seven climate zones having distinct climate characteristics. The validation of climate zonation using various statistical tests revealed the robustness of the proposed method in classifying climate. The climate zone map generated in the study can be used as a reference for climate change analysis in Egypt. [ABSTRACT FROM AUTHOR]

Lynne Cherry Brandwein Lecture March 2010 National Science Teachers Association (NSTA) Conference, Philadelphia, PA. Young Voices on Climate Change: Inspired and Empowered Youth Tackle Climate Science and Find Climate Solutions. As a child, Lynne Cherry was profoundly connected to the natural world and a special place. She watched the destruction of her world. Now, through her Young Voices on Climate Change project, she is trying to give teachers and young people the tools to prevent planetary meltdown on a greater scale. Global climate change is upon us and the need for education and action is immediate. Outreach, visual storytelling, and scientific understanding are especially necessary in light of the recent polls that show that the public is becoming more confused and less concerned about climate change. Cherry's climate book, co-authored with photojournalist Gary Braasch, and her Young Voices on Climate Change films feature climate solutions. They're about win-win-save the environment, protect human health, reduce global warming gases, demonstrate youth making a difference with practical tools, motivate engagement in climate science, take pride in increased science literacy, reach young people through their hearts as well as their minds, and save money. Although young people can help their parents, peers and communities understand climate science, they can also show them that reducing CO is in their economic interest, and spur them to take action. School carbon reduction initiatives are spilling over into communities yielding measurable results in both global warming gas reductions and significant monetary savings. [ABSTRACT FROM AUTHOR]

In a warming climate, permafrost is likely to be significantly reduced and eventually disappear from the sub-Arctic region. This will affect people at a range of scales, from locally by slumping of buildings and roads, to globally as melting of permafrost will most likely increase the emissions of the powerful greenhouse gas methane, which will further enhance global warming. In order to predict future changes in permafrost, it is crucial to understand what determines the presence or absence of permafrost under current climate conditions, to assess where permafrost is particularly vulnerable to climate change, and to identify where changes are already occurring. The Torneträsk region of northern sub-Arctic Sweden is one area where changes in permafrost have been recorded and where permafrost could be particularly vulnerable to any future climate changes. This paper therefore reviews the various physical, biological, and anthropogenic parameters that determine the presence or absence of permafrost in the Torneträsk region under current climate conditions, so that we can gain an understanding of its current vulnerability and potential future responses to climate change. A patchy permafrost distribution as found in the Torneträsk region is not random, but a consequence of site-specific factors that control the microclimate and hence the surface and subsurface temperature. It is also a product of past as well as current processes. In sub-Arctic areas such as northern Sweden, it is mainly the physical parameters, e.g., topography, soil type, and climate (in particular snow depth), that determine permafrost distribution. Even though humans have been present in the study area for centuries, their impacts on permafrost distribution can more or less be neglected at the catchment level. Because ongoing climate warming is projected to continue and lead to an increased snow cover, the permafrost in the region will most likely disappear within decades, at least at lower elevations. [ABSTRACT FROM AUTHOR]

The study area, with arid to semi-humid climates, is located in northern Fars Province, southern Iran. Daily precipitation and temperature data from 22 models of the Coupled Model Inter-comparison Project Phase 5 (CMIP5) are used to study climate change for period 2026–2085 under RCP2.6, RCP4.5, and RCP8.5. Daily outputs of each CMIP5 model are downscaled to climatic stations over the study area using LARS-WG tool and transient change factors approach. Daily precipitation is downscaled to seven climatic stations while daily temperature downscaled to two stations. Downscaling results indicate that temperature will increase by + 1.85, + 2.5, and + 3.45 °C under the RCP2.6, RCP4.5, and RCP8.5, respectively, while precipitation will reduce by 14, 22, and 20.8%, respectively, within the study area. Standardized precipitation index (SPI) analysis, performed for 3-, 6-, 9-, and 12-month time scales, shows that frequency (duration) of normal periods will increase (decrease) under climate change, however, 12-month SPI analysis shows decreased frequency and increased duration for normal periods. Frequency, duration, severity, and intensity of wet periods may increase, decrease, or not change under climate change, depending on the SPI time scale. The study area will experience more frequent, longer-duration, severed, intensified droughts in the future due to global warming. Extreme storm analysis shows that precipitation depth of most frequent storms (2-year return period storms) will increase, but precipitation depth of less frequent storms (10- and 20-year return period storms) will decrease under climate change. Temperature enhancement, precipitation reduction, and longer-duration, severed, intensified droughts will increase water shortage in the future, resulting in water crisis and reduced security of food production over northern Fars Province. [ABSTRACT FROM AUTHOR]

Contrary to expectations that global warming will be accompanied by an increase in terrestrial evaporation, pan evaporation (PE) has decreased in several parts of the world during the last decades. This opposing relationship is known as the pan evaporation paradox phenomenon that can be affected by climate change. For this purpose, this study identifies spatial and temporal trends in PE and its associated climate variables (Cvars) in Iran at seasonal and annual time scales. Hence, PE and Cvars data from 68 meteorological stations distributed over Iran during the period 1987–2016 were selected. The analyses of the temporal and spatial trends in PE, Cvars, and relationships among them were examined using the statistical techniques to identify the causes of PE trends. Results indicated that stations located in the subtropical region (latitude below 32°), which is mostly located in the southern half of Iran, showed significant negative PE trends (about 20–30% of stations) in spite of an increasing trend in temperatures indicating the "pan paradox" phenomenon. However, stations with significant positive PE trends (about 40% of stations), which are mostly located in the northern half of Iran, are placed at latitudes above 32°. Trend analysis of other Cvars indicated significant increases in temperatures, sunshine duration, and wind speed in more than half of the stations on all time scales. In addition, minimum, maximum, and mean temperatures, and sunshine duration were the most dominant variables affecting PE in annual, spring, autumn, and summer, respectively, in Iran. [ABSTRACT FROM AUTHOR]

This study presents the results of the ERTDF S-12 project for searching an optimum reduction scenario of the short-lived climate pollutants (SLCPs) to simultaneously mitigate the global warming and environmental problems. The study utilized REAS emission inventory, Asia-Pacific Integrated Model-Enduse (AIM/Enduse), MIROC6 climate model, NICAM non-hydrostatic atmospheric model, and models for estimating environmental damages to health, agriculture, and flood risks. Results of various scenario search indicate that it is difficult to attain simultaneous reduction of global warming and environmental damages, unless a significant reduction of CO2 is combined with carefully designed SLCP reductions for CH4, SO2, black carbon (BC), NOx, CO, and VOCs. In this scenario design, it is important to take into account the impact of small BC reduction to the surface air temperature and complex atmospheric chemical interactions such as negative feedback between CH4 and NOx reduction. We identified two scenarios, i.e., B2a and B1c scenarios which combine the 2D-scenario with SLCP mitigation measures using End-of-Pipe (EoP) and new mitigation technologies, as promising to simultaneously mitigate the temperature rise by about 0.33 °C by 2050 and air pollution in most of the globe for reducing damages in health, agriculture, and flood risk. In Asia and other heavy air pollution areas, health-care measures have to be enhanced in order to suppress the mortality increase due to high temperature in hot spot areas caused by a significant cut of particulate matter. For this situation, the B1b scenario is better to reduce hot spot areas and high-temperature damage to the public health. [ABSTRACT FROM AUTHOR]

It has been challenging to project the tropical cyclone (TC) intensity, structure and destructive potential changes in a warming climate. Here, we compare the sensitivities of TC intensity, size and destructive potential to sea surface warming with and without a pre-storm atmospheric adjustment to an idealized state of Radiative-Convective Equilibrium (RCE). Without RCE, we find large responses of TC intensity, size and destructive potential to sea surface temperature (SST) changes, which is in line with some previous studies. However, in an environment under RCE, the TC size is almost insensitive to SST changes, and the sensitivity of intensity is also much reduced to 3% °C−1-4% °C−1. Without the pre-storm RCE adjustment, the mean destructive potential measured by the integrated power dissipation increases by about 25% °C−1 during the mature stage. However, in an environment under RCE, the sensitivity of destructive potential to sea surface warming does not change significantly. Further analyses show that the reduced response of TC intensity and size to sea surface warming under RCE can be explained by the reduced thermodynamic disequilibrium between the air boundary layer and the sea surface due to the RCE adjustment. When conducting regional-scale sea surface warming experiments for TC case studies, without any RCE adjustment the TC response is likely to be unrealistically exaggerated. The TC intensity-temperature sensitivity under RCE is very similar to those found in coupled climate model simulations. This suggests global mean intensity projections under climate change can be understood in terms of a thermodynamic response to temperature with only a minor contribution from any changes in large-scale dynamics. [ABSTRACT FROM AUTHOR]

Copyright of Advances in Atmospheric Sciences is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Climate projection data were applied to two commonly used pome fruit flowering models to investigate potential differences in predicted full bloom timing. The two methods, fixed thermal time and sequential chill-growth, produced different results for seven apple and pear varieties at two Australian locations. The fixed thermal time model predicted incremental advancement of full bloom, while results were mixed from the sequential chill-growth model. To further investigate how the sequential chill-growth model reacts under climate perturbed conditions, four simulations were created to represent a wider range of species physiological requirements. These were applied to five Australian locations covering varied climates. Lengthening of the chill period and contraction of the growth period was common to most results. The relative dominance of the chill or growth component tended to predict whether full bloom advanced, remained similar or was delayed with climate warming. The simplistic structure of the fixed thermal time model and the exclusion of winter chill conditions in this method indicate it is unlikely to be suitable for projection analyses. The sequential chill-growth model includes greater complexity; however, reservations in using this model for impact analyses remain. The results demonstrate that appropriate representation of physiological processes is essential to adequately predict changes to full bloom under climate perturbed conditions with greater model development needed. [ABSTRACT FROM AUTHOR]

During ice-age cycles, continental ice volume kept pace with slow, multi-millennial scale, changes in climate forcing. Today, rapid greenhouse gas (GHG) increases have outpaced ice-volume responses, likely committing us to > 9 m of long-term sea-level rise (SLR). We portray a context of naturally precedented SLR from geological evidence, for comparison with historical observations and future projections. This context supports SLR of up to 0.9 (1.8) m by 2100 and 2.7 (5.0) m by 2200, relative to 2000, at 68% (95%) probability. Historical SLR observations and glaciological assessments track the upper 68% limit. Hence, modern change is rapid by past interglacial standards but within the range of 'normal' processes. The upper 95% limit offers a useful low probability/high risk value. Exceedance would require conditions without natural interglacial precedents, such as catastrophic ice-sheet collapse, or activation of major East Antarctic mass loss at sustained CO2 levels above 1000 ppmv. [ABSTRACT FROM AUTHOR]

Subfossil chironomid and sediment geochemistry data from Lugu Lake, a large high-elevation lake in southwest China, were used to assess the influences of climate warming and direct human impacts on the lake through time. A 95-year-long sediment record was recovered from the lake. Principal components analysis (PCA) and redundancy analysis of fossil chironomid data were performed to determine the controlling factors on the chironomid community. The four prominent environmental controls were summer air temperature, organic matter C:N ratio (C:N), dry mass accumulation rate (DMAR), and total nitrogen. C:N proved to be the most important controlling factor through time. However, C:N and summer air temperature were highly co-linear, possibly due to temperature directly impacting lake productivity (and thus C:N ratios) through increased stratification and a longer growing season. PCA Axis 1 scores were a strong predictor of summer temperatures even after DMAR was factored out to account for direct human influences. The strong temperature-chironomid relationship over the last 50 years could be due to the lake becoming more responsive to climate warming after cultural eutrophication of the 1950s, as lakes with higher nutrient loads are shown to be more responsive to the effects of climate warming. [ABSTRACT FROM AUTHOR]

Most trees from temperate climates require the accumulation of winter chill and subsequent heat during their dormant phase to resume growth and initiate flowering in the following spring. Global warming could reduce chill and hence hamper the cultivation of high-chill species such as cherries. Yet determining chilling and heat requirements requires large-scale controlled-forcing experiments, and estimates are thus often unavailable. Where long-term phenology datasets exist, partial least squares (PLS) regression can be used as an alternative, to determine climatic requirements statistically. Bloom dates of cherry cv. 'Schneiders späte Knorpelkirsche' trees in Klein-Altendorf, Germany, from 24 growing seasons were correlated with 11-day running means of daily mean temperature. Based on the output of the PLS regression, five candidate chilling periods ranging in length from 17 to 102 days, and one forcing phase of 66 days were delineated. Among three common chill models used to quantify chill, the Dynamic Model showed the lowest variation in chill, indicating that it may be more accurate than the Utah and Chilling Hours Models. Based on the longest candidate chilling phase with the earliest starting date, cv. 'Schneiders späte Knorpelkirsche' cherries at Bonn exhibited a chilling requirement of 68.6 ± 5.7 chill portions (or 1,375 ± 178 chilling hours or 1,410 ± 238 Utah chill units) and a heat requirement of 3,473 ± 1,236 growing degree hours. Closer investigation of the distinct chilling phases detected by PLS regression could contribute to our understanding of dormancy processes and thus help fruit and nut growers identify suitable tree cultivars for a future in which static climatic conditions can no longer be assumed. All procedures used in this study were bundled in an R package ('chillR') and are provided as Supplementary materials. The procedure was also applied to leaf emergence dates of walnut (cv. 'Payne') at Davis, California. [ABSTRACT FROM AUTHOR]

Increases in temperature as a result of anthropogenically generated greenhouse gas (GHG) emissions are likely to impact key aspects of horticultural production. The potential effect of higher temperatures on fruit and nut trees' ability to break winter dormancy, which requires exposure to winter chilling temperatures, was considered. Three chill models (the 0-7.2°C, Modified Utah, and Dynamic models) were used to investigate changes in chill accumulation at 13 sites across Australia according to localised temperature change related to 1, 2 and 3°C increases in global average temperatures. This methodology avoids reliance on outcomes of future GHG emission pathways, which vary and are likely to change. Regional impacts and rates of decline in chilling differ among the chill models, with the 0-7.2°C model indicating the greatest reduction and the Dynamic model the slowest rate of decline. Elevated and high latitude eastern Australian sites were the least affected while the three more maritime, less elevated Western Australian locations were shown to bear the greatest impact from future warming. [ABSTRACT FROM AUTHOR]

Current global warming necessitates a detailed understanding of the relationships between climate and global ice volume. Highly resolved and continuous sea-level records are essential for quantifying ice-volume changes. However, an unbiased study of the timing of past ice-volume changes, relative to polar climate change, has so far been impossible because available sea-level records either were dated by using orbital tuning or ice-core timescales, or were discontinuous in time. Here we present an independent dating of a continuous, high-resolution sea-level record in millennial-scale detail throughout the past 150,000 years. We find that the timing of ice-volume fluctuations agrees well with that of variations in Antarctic climate and especially Greenland climate. Amplitudes of ice-volume fluctuations more closely match Antarctic (rather than Greenland) climate changes. Polar climate and ice-volume changes, and their rates of change, are found to covary within centennial response times. Finally, rates of sea-level rise reached at least 1.2?m per century during all major episodes of ice-volume reduction. [ABSTRACT FROM AUTHOR]

Soil respiration, RS, the flux of microbially and plant-respired carbon dioxide (CO2) from the soil surface to the atmosphere, is the second-largest terrestrial carbon flux. However, the dynamics of RS are not well understood and the global flux remains poorly constrained. Ecosystem warming experiments, modelling analyses and fundamental biokinetics all suggest that RS should change with climate. This has been difficult to confirm observationally because of the high spatial variability of RS, inaccessibility of the soil medium and the inability of remote-sensing instruments to measure RS on large scales. Despite these constraints, it may be possible to discern climate-driven changes in regional or global RS values in the extant four-decade record of RS chamber measurements. Here we construct a database of worldwide RS observations matched with high-resolution historical climate data and find a previously unknown temporal trend in the RS record after accounting for mean annual climate, leaf area, nitrogen deposition and changes in CO2 measurement technique. We find that the air temperature anomaly (the deviation from the 1961–1990 mean) is significantly and positively correlated with changes in RS. We estimate that the global RS in 2008 (that is, the flux integrated over the Earth’s land surface over 2008) was 98 ± 12 Pg C and that it increased by 0.1 Pg C yr-1 between 1989 and 2008, implying a global RS response to air temperature (Q10) of 1.5. An increasing global RS value does not necessarily constitute a positive feedback to the atmosphere, as it could be driven by higher carbon inputs to soil rather than by mobilization of stored older carbon. The available data are, however, consistent with an acceleration of the terrestrial carbon cycle in response to global climate change. [ABSTRACT FROM AUTHOR]

Significant changes in physical and biological systems are occurring on all continents and in most oceans, with a concentration of available data in Europe and North America. Most of these changes are in the direction expected with warming temperature. Here we show that these changes in natural systems since at least 1970 are occurring in regions of observed temperature increases, and that these temperature increases at continental scales cannot be explained by natural climate variations alone. Given the conclusions from the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report that most of the observed increase in global average temperatures since the mid-twentieth century is very likely to be due to the observed increase in anthropogenic greenhouse gas concentrations, and furthermore that it is likely that there has been significant anthropogenic warming over the past 50 years averaged over each continent except Antarctica, we conclude that anthropogenic climate change is having a significant impact on physical and biological systems globally and in some continents. [ABSTRACT FROM AUTHOR]

Under the warmer climate, predicted for the future, northern peatlands are expected to become drier. This drying will lower the water table and likely result in reduced emissions of methane (CH4) from these ecosystems. However, the prediction of declining CH4 fluxes does not consider the potential effects of ecological succession, particularly the invasion of sedges into currently wet sites (open water pools, low lawns). The goal of this study was to characterize the relationship between the presence of sedges in peatlands and CH4 efflux under natural conditions and under a climate change simulation (drained peatland). Methane fluxes, gross ecosystem production, and dissolved pore water CH4 concentrations were measured and a vegetation survey was conducted in a natural and drained peatland near St. Charles-de-Bellechasse, Quebec, Canada, in the summer of 2003. Each peatland also had plots where the sedges had been removed by clipping. Sedges were larger, more dominant, and more productive at the drained peatland site. The natural peatland had higher CH4 fluxes than the drained peatland, indicating that drainage was a significant control on CH4 flux. Methane flux was higher from plots with sedges than from plots where sedges had been removed at the natural peatland site, whereas the opposite case was observed at the drained peatland site. These results suggest that CH4 flux was enhanced by sedges at the natural peatland site and attenuated by sedges at the drained peatland site. However, the attenuation of CH4 flux due to sedges at the drained site was reduced in wetter periods. This finding suggests that CH4 flux could be decreased in the event of climate warming due to the greater depth to the water table, and that sedges colonizing these areas could further attenuate CH4 fluxes during dry periods. However, during wet periods, the sedges may cause CH4 fluxes to be higher than is currently predicted for climate change scenarios. [ABSTRACT FROM AUTHOR]

A large number of studies have documented 20th century climate variability and change at the global, hemispheric, and regional levels. However, understanding the implications of climate change for environmental management necessitates information at the level of the ecosystem. Historical monitoring data from the Chesapeake Bay estuary were used to identify temporal patterns of estuarine temperature anomalies in the surface (≤1 m) and subsurface (≥15 m) between 1949 and 2002. Data indicated a trend in surface and subsurface warming of +0.16°C and +0.21°C per decade, respectively, driven by warming during winter and spring. These trends suggest warming of the estuary since the mid-20th century of approximately 0.8–1.1°C. Estuarine temperatures correlated well with other independent data records for sea surface and surface air temperatures in the region and to a lesser extent, the northern hemisphere. Gross long-term temperature variability in the estuary was consistent with North Atlantic climate variability associated with the prolonged positive North Atlantic Oscillation/Arctic Oscillation and increased anthropogenic radiative forcing, although localized environmental drivers likely are important as well. A simple spatial analysis revealed strong seasonal latitudinal and longitudinal gradients in estuarine temperature as well as a north–south gradient in long-term temperature trends. Continued warming of the estuary will have important implications for ecosystem structure and function as well as attempts to manage existing challenges such as eutrophication and benthic hypoxia. However, such management efforts must be cognizant of the effects of various climate and nonclimate drivers of environmental variability and change operating over different spatial and temporal scales. [ABSTRACT FROM AUTHOR]

It is expected that a change in climatic conditions due to global warming will directly impact agricultural production. Most climate change studies have been applied at very large scales, in which regions were represented by only one or two weather stations, which were mainly located at airports of major cities. The objective of this study was to determine the potential impact of climate change at a local level, taking into account weather data recorded at remote locations. Daily weather data for a 30-year period were obtained for more than 500 sites, representing the south-eastern region of the USA. Climate change scenarios, using transient and equilibrium global circulation models (GCM), were defined, created and applied to the daily historical weather data. The modified temperature, precipitation and solar radiation databases corresponding to each of the climate change scenarios were used to run the CERES v.3.5 simulation model for maize and winter wheat and the CROPGRO v.3.5 model for soybean and peanut. The GCM scenarios projected a shorter duration of the crop-growing season. Under the current level of CO2, the GCM scenarios projected a decrease of crop yields in the 2020s. When the direct effects of CO2 were assumed in the study, the scenarios resulted in an increase in soybean and peanut yield. Under equilibrium 2 × CO2, the GCM climate change scenarios projected a decrease of maize and winter wheat yield. The indirect effects of climate change also tended to decrease soybean and peanut yield. However, when the direct effects of CO2 were included, most of the scenarios resulted in an increase in legume yields. Possible changes in sowing data, hybrids and cultivar selection, and fertilization were considered as adaptation options to mitigate the potential negative impact of potential warming. [ABSTRACT FROM AUTHOR]

Presents research which showed that recent climate change can be interpreted in terms of the changes in natural atmospheric circulation regimes. Questions about the role of anthropogenic forcing or natural climate variability in climate change; Use of atmospheric circulation data; Recent Northern Hemisphere warming tied to the thermal structure of circulation regimes; Applications for research.

The article comments on the Kyoto Protocol, which is an agreement made under the United Nations Framework Convention on Climate Change (UNFCCC). The author stresses that this agreement did not produce demonstrable reductions in emissions or even in anticipated emissions growth. It is cited that Kyoto Protocol has failed not only in achieving success in slowing global warming, but also because this agreement has concealed discussion of alternative policy approaches that could contend climate change and adapt to its unavoidable consequences.

A large-ensemble climate simulation database, which is known as the database for policy decision-making for future climate changes (d4PDF), was designed for climate change risk assessments. Since the completion of the first set of climate simulations in 2015, the database has been growing continuously. It contains the results of ensemble simulations conducted over a total of thousands years respectively for past and future climates using high-resolution global (60 km horizontal mesh) and regional (20 km mesh) atmospheric models. Several sets of future climate simulations are available, in which global mean surface air temperatures are forced to be higher by 4 K, 2 K, and 1.5 K relative to preindustrial levels. Nonwarming past climate simulations are incorporated in d4PDF along with the past climate simulations. The total data volume is approximately 2 petabytes. The atmospheric models satisfactorily simulate the past climate in terms of climatology, natural variations, and extreme events such as heavy precipitation and tropical cyclones. In addition, data users can obtain statistically significant changes in mean states or weather and climate extremes of interest between the past and future climates via a simple arithmetic computation without any statistical assumptions. The database is helpful in understanding future changes in climate states and in attributing past climate events to global warming. Impact assessment studies for climate changes have concurrently been performed in various research areas such as natural hazard, hydrology, civil engineering, agriculture, health, and insurance. The database has now become essential for promoting climate and risk assessment studies and for devising climate adaptation policies. Moreover, it has helped in establishing an interdisciplinary research community on global warming across Japan. [ABSTRACT FROM AUTHOR]

Historical series of monthly mean temperatures from 27 Italian stations, updated to 1993, are analysed. Building on previous analysis thefollowing new results were obtained: there is an upward trend in seasonal and annual temperatures during the last 20 years; a positive trend, stronger at southern stations compared to northern stations, is apparent from 1920 to 1950, after when temperature shows no significant trend until 1985 when it starts to increase again. Data from Northern Italy show similar characteristics to a subset of data from a global climatic database, for the period 1881-1988. This comparison, however, suggests that good station coverage is important for the construction of a more detailed picture of seasonal climate variability." [ABSTRACT FROM AUTHOR]

Changes in solar activity are regularly forwarded as an hypothesis to explain the observed global warming over the last century. The support of such claims is largely statistical, as knowledge of the physical relationships is limited. The statistical evidence is revisited. Changing solar activity is a statistically plausible hypothesis for the observed warming, if short-term natural variability is the only alternative explanation. Compared to the enhanced greenhouse effect, thesolar hypothesis looses a substantial part of its plausibility. Reversely, the size and significance of the estimated impact of the enhanced greenhouse effect on the global mean temperature is hardly affected by solar activity. [ABSTRACT FROM AUTHOR]

Four coupled atmosphere-ocean general circulation models were examined for the ability of their control runs to simulate present climate given present forcings. The area of study is mainly Cameroon and someof its surrounding areas (0-25 deg. E, 5 deg. S-30 deg. N). Thesemodels are from the UK Meteorological Office Hadley Centre (HadCM2),the German Max-Planck-Institut fur Meteorologie (ECHAM4), the Canadian Centre for Climate Modelling and Analysis (CGCM1) and the Australian Commonwealth Science and Industrial Research Organisation (CSIRO-Mk2). The ability of the models to reproduce the observed spatial and temporal patterns was studied. ECHAM4 and HadCM2 were found to reproduce the spatial pattern well, with a correlation of more than 90%. They also simulated the main annual features of both temperature and rainfall. The CSIRO-Mk2 model was slightly less successful and the CGCM1 had the worst results for the area, especially as concern rainfall.In view of these results, ECHAM4 and HADCM2 were used to evaluate projected changes in rainfall and temperature resulting from increased concentration of greenhouse gases in the atmosphere for the 30 year period 2040 to 2070. [ABSTRACT FROM AUTHOR]