Importance Of Climate Change Research Articles

Zoonoses and Climate Variability

Leishmaniasis in the Americas is transmitted by Lutzomyia spp., which have many animal reservoirs. Previous studies indicated potential changes in vectors of climate-related distribution, but impact outcomes need to be further studied. We report climatic and El Niño events during 1985-2002 that may have had an impact on leishmaniasis in 11 southern departments of Colombia: Amazonas, Caquetá, Cauca (Ca), Huila, Meta (Mt), Nariño, Putumayo (Py), Tolima, Valle (Va), Vaupes (Vp), and Vichada. Climatic data were obtained by satellite and epidemiologic data were obtained from the Health Ministry. NOAA climatic classification and SOI/ONI indexes were used as indicators of global climate variability. Yearly variation comparisons and median trend deviations were made for disease incidence and climatic variability. During this period there was considerable climatic variability, with a strong El Niño for 6 years and a strong La Niña for 8. During this period, 19,212 cases of leishmaniasis were registered, for a mean of 4756.83 cases/year. Disease in the whole region increased (mean of 4.98%) during the El Niño years in comparison to the La Niña years, but there were differences between departments with increases during El Niño (Mt 6.95%, Vp 4.84%), but the rest showed an increase during La Niña (1.61%-64.41%). Differences were significant in Va (P= 0.0092), Py (P= 0.0001), Ca (P= 0.0313), and for the whole region (P= 0.0023), but not in the rest of the departments. The importance of climate change is shown by shifts in insect and animal distributions. These data reflect the importance of climate on transmission of leishmaniasis and open further investigations related to forecasting and monitoring systems, where understanding the relationship between zoonoses and climate variability could help to improve the management of these emerging and reemerging diseases.

The importance of climate change when considering the role of forests in the alleviation of poverty

SUMMARY Forests could play a major role in the alleviation of poverty in many different parts of the world. However, forests are dynamic, and their rate of change is accelerating as a result of anthropogenic activities. Climate change, for example, will alter the nature of many protection forests in mountainous areas, exposing the inhabitants to increased risk from natural hazards. It will also affect the viability of plantation forests established in drier areas to combat desertification. Many forests are showing increased productivity, although the causes remain unclear. Sea-level change will destabilize coastal forests, particularly mangroves, reducing their effectiveness in coastal protection. Air pollution has already destabilized many forests, and is likely to be an increasing problem in the forests surrounding urban areas in developing countries. Many impacts remain uncertain, and there remains a great need to integrate the biophysical knowledge that currently exists with socioeconomic information ...

Large-scale atmospheric circulation biases and changes in global climate model simulations and their importance for climate change in Central Europe

Abstract. The quality of global sea level pressure patterns has been assessed for simulations by 23 coupled climate models. Most models showed high pattern correlations. With respect to the explained spatial variance, many models showed serious large-scale deficiencies, especially at mid-latitudes. Five models performed well at all latitudes and for each month of the year. Three models had a reasonable skill. We selected the five models with the best pressure patterns for a more detailed assessment of their simulations of the climate in Central Europe. We analysed observations and simulations of monthly mean geostrophic flow indices and of monthly mean temperature and precipitation. We used three geostrophic flow indices: the west component and south component of the geostrophic wind at the surface and the geostrophic vorticity. We found that circulation biases were important, and affected precipitation in particular. Apart from these circulation biases, the models showed other biases in temperature and precipitation, which were for some models larger than the circulation induced biases. For the 21st century the five models simulated quite different changes in circulation, precipitation and temperature. Precipitation changes appear to be primarily caused by circulation changes. Since the models show widely different circulation changes, especially in late summer, precipitation changes vary widely between the models as well. Some models simulate severe drying in late summer, while one model simulates significant precipitation increases in late summer. With respect to the mean temperature the circulation changes were important, but not dominant. However, changes in the distribution of monthly mean temperatures, do show large indirect influences of circulation changes. Especially in late summer, two models simulate very strong warming of warm months, which can be attributed to severe summer drying in the simulations by these models. The models differ also significantly in the simulated warming of cold winter months. Finally, the models simulate rather different changes in North Atlantic sea surface temperature, which is likely to impact on changes in temperature and precipitation. These results imply that several important aspects of climate change in Central Europe are highly uncertain. Other aspects of the simulated climate change appear to be more robust. All models simulate significant warming all year round and an increase in precipitation in the winter half-year.

Phytogeography of the bryophyte floras of oak forests and páramo of the Cordillera de Talamanca, Costa Rica

AbstractAim Central America is a biogeographically interesting area because of its location between the rich and very different biota of North and South America. We aim to assess phytogeographical patterns in the bryophyte floras of oak forests and páramo of the Cordillera de Talamanca, Costa Rica.Location Tropical America, in particular the montane area of Cordillera de Talamanca, Costa Rica.Methods The analysis is based on a new critical inventory of the montane bryophyte flora of Cordillera de Talamanca. All species were assigned to phytogeographical elements on the basis of their currently known distribution. Absolute and percentage similarities were employed to evaluate floristic affinities.Results A total of 401 species [191 hepatics (liverworts), one hornwort, 209 mosses] are recorded; of these, 251 species (128 hepatics, one hornwort, 122 mosses) occur in oak forests. Ninety‐three per cent of all oak forest species are tropical in distribution, the remaining 7% are temperate (4%) and cosmopolitan (3%) species. The neotropical element includes almost 74% of the species, the wide tropical element (pantropical, amphi‐atlantic, amphi‐pacific) only 19%. A significant part of the neotropical species from oak forests are species with tropical Andean‐centred ranges (27%). As compared with bryophyte species, vascular plant genera in the study region are represented by fewer neotropical, more temperate and more amphi‐pacific taxa. Bryophyte floras of different microhabitats within the oak forest and epiphytic bryophyte floras on Quercus copeyensis in primary, early secondary and late secondary oak forest show a similar phytogeographical make‐up to the total oak forest bryophyte flora. Comparison of oak forest and páramo reveals a greater affinity of the páramo bryophyte flora to temperate regions and the great importance of the páramo element in páramo. Surprisingly, oak forests have more Central American endemics than páramo.Main conclusions (1) Providing first insights into the phytogeographical patterns of the bryophyte flora of oak forests and páramo, we are able to confirm general phytogeographical trends recorded from vascular plant genera of the study area although the latter were more rich in temperate taxa. (2) Andean‐centred species are a conspicuous element in the bryophyte flora of Cordillera de Talamanca, reflecting the close historical connection between the montane bryophyte floras of Costa Rica and South America. (3) High percentages of Central American endemics in the bryophyte flora of the oak forests suggest the importance of climatic changes associated with Pleistocene glaciations for allopatric speciation.

A long-term evaluation of fruiting phenology: importance of climate change

Within the last decade the study of phenology has taken on new importance because of its contribution to climate-change research. However, phenology data sets spanning many years are rare in the tropics, making it difficult to evaluate possible responses of tropical communities to climate change. Here we use two data sets (1970–1983 and 1990–2002) to describe the fruiting patterns of the tropical tree community in Kibale National Park, Uganda. To address variation in spatial patterns, we describe fruiting over 2–3 y among four sites each separated by 12–15 km. Presently, the Kibale region is receiving c. 300 mm more rain than it did at the start of the century, droughts are less frequent, the onset of the rainy season is earlier, and the average maximum monthly temperature is 3.5 °C hotter than it was 25 y ago. The 1990–2002 phenology data illustrated high temporal variability in the proportion of the populations fruiting. Interannual variation in community-wide fruit availability was also high; however, the proportion of trees that fruited has increased over the past 12+y. At the species level a variety of patterns were exhibited; however, a number of the most common species currently rarely fruit, and when they do, typically <4% of the individuals take part in fruiting events. Combining the data set from 1990 to 2002 with that from 1970 to 1983 for specific species again reveals an increase in the proportion of trees fruiting between 1990 and 2002; however, the proportion of the populations fruiting decreased during the earlier period. When one examines particular species over this whole period a variety of patterns are evident. For example, Pouteria altissima exhibited a relatively regular pattern of fruiting during the 1970s; however, it rarely fruited in the 1990s. Contrasting phenological patterns at four sites revealed that at the community level the fruiting patterns of only one of the six pair-wise site combinations were correlated. Relationships between rainfall and fruiting were variable among sites. Contrasting changes in fruiting patterns over the 30 y with differences among the four sites varying in rainfall, suggests that the changes observed in fruiting may be due to climate change. Responses to this climate change are likely complex and will vary among species. However, for some species, current conditions appear unsuitable for fruiting.

Biological Impacts of Climatic Change on a Beringian Endemic: Cryptic Refugia in the Establishment and Differentiation of the Rock Sandpiper (Calidris Ptilocnemis)

The importance of climatic change on the establishment and differentiation of high-latitude species is largely unknown. Biological effects of historic climate change can be determined from historic signals in genetic data. The rock sandpiper (Calidris ptilocnemis) is a good test case for examining these biological effects because it has a known sister species, the purple sandpiper (Calidris maritima), and it is the only endemic Beringian bird with multiple described subspecies, suggesting a process of initial establishment and subsequent differentiation in the high-latitude regions of Beringia. We sequenced 2,074 bp of mitochondrial DNA from 40 rock sandpipers from nine breeding locations and four purple sandpipers. We used phylogenetic and coalescence methods to reconstruct trees and to evaluate the population demography, migration rates, and relative times of population divergence. Phylogenetic trees show that purple and rock sandpipers are monophyletic sister species. Within the rock sandpiper, clade branching patterns and coalescence estimates suggest that there were multiple refugial populations in Beringia, which correspond loosely to different glacial cycles. Rock sandpipers show the establishment, persistence, and accumulation of partitioned genetic diversity across several glacial cycles, implicating the presence of multiple cryptic biological refugia in this region through repeated cycles of climate change.

Stommel transitions in shallow coastal basins

The theory of Stommel transitions is presented, and their importance discussed, for both shallow coastal systems and large-scale ocean circulation (where they are predicted to have major importance for climate change). The transitions occur in systems driven by buoyancy fluxes, and for coastal basins, involve jumps between classical and inverse states. Data are examined for Tomales Bay (California) in 1988 and suggest a Stommel transition in early autumn at a time which is consistent with the predictions of the Stommel model. The transition in Tomales Bay is primarily induced by changes in ocean and air temperatures. Stommel transitions have previously been seen in a variety of models, and laboratory simulations, but the present observation may be the first in a natural system.

UK adaptation strategy and technical measures: the impacts of climate change on buildings

This paper discusses the importance of climate change for the UK building stock and reviews the predictions of the United Kingdom Climate Impacts Programme 2002 (UKCIP02) scenarios for the future climate that are of relevance to buildings and construction. The possible impacts of these changes on flooding, wind damage, driving rain impact, subsidence and the internal environment of buildings are reviewed and the steps that might be taken to mitigate these impacts discussed. The current response of regulators, standardisation bodies, building owners and the insurance industry to these impacts is examined, and it is shown that each body acts in different ways to different impacts. Some bodies, such as government departments responsible for building regulations and the insurance industry, are taking the possibility of climate change very seriously. However, the uncertainty of future climate predictions, especially as regards wind speed, means that it is not easy to incorporate these issues in formal legislation. The whole culture of standardisation, which is based on well-established data, such as mean climate data over the last 30 years, makes it difficult for British and European Standards, which underpin regulations, to react to the changing climate. Les auteurs examinent l'importance des changements climatiques pour le parc immobilier du Royaume-Uni et passent en revue les prévisions des scénarios du Programme 2002 sur les impacts du climat au Royaume-Uni (UKCIP02); ces questions intéressent le secteur du bâ timent et de la construction. Ils analysent les conséquences possibles des changements climatiques en termes d'inondations, de dégâts causés par le vent, de précipitations, d'affaissements; ils étudient également l'impact sur l'environnement interne des bâ timents ainsi que les mesures qui pourraient être prises pour atténuer les conséquences de ces changements. Ils examinent ensuite la réponse actuelle donnée par les organismes de régulation, les agences de normalisation, les propriétaires de bâ timents et les compagnies d'assurance; il apparaît que chaque entité réagit de fac,on différente à des impacts différents. Certaines, comme des services gouvernementaux responsables de la réglementation en matière de bâtiments et des compagnies d'assurance prennent très au sérieux les conséquences possibles des changements climatiques. Toutefois, l'incertitude des prévisions climatiques, notamment en ce qui concerne la vitesse du vent, signifie qu'il est difficile d'intégrer ces problèmes dans la législation officielle. L'ensemble du paysage normatif, qui repose sur des données bien établies, comme les données climatiques moyennes sur les 30 dernières années, rend difficile pour les normes britanniques et européennes, qui sont le fondement de la réglementation, de réagir aux changements climatiques.

The last occurrence of Pleistocene megafauna in the Ecuadorian Andes

The latest Pleistocene—Holocene megafauna extinction is a global event, particularly dramatic in the Americas. In a previous paper the authors hypothesised a scenario for this extinction event in South America, where mastodonts first suffered from the changing climate environment, followed by the mylodonts and equids. These different latest Pleistocene—Holocene megafauna extinction “waves” in Ecuadorian Andes have been dated using 14C methods on material from selected sites in north and central Ecuadorian Interandean Depression. An outline of the physiographic evolution of the Interandean Depression in Ecuador is offered and the stratigraphic setting of the fossiliferous sites is discussed. The present results confirm the author's hypothesis on the megafauna extinction pattern, previously published in terms of relative age. The importance of climatic changes during Last Glacial Maximum at low latitudes is discussed.

Climate response, migrational lag, and pollen representation: The problems posed byRhododendronandAcer

Views have changed as to the relative importance of climate change and human activity on the composition of Holocene temperate forest. The ‘climate school’ maintains that temperate arboreal taxa responded swiftly to changes in Holocene climate, irrespective of dispersal mechanism, with no evidence for migrational lag or for human influence; taxa moved individualistically according to their climate response. This paper tests these tenets in two case studies. The present‐day distributions of Rhododendron and Acer in Europe are compared with earlier records, and discussed in the context of migrational lag and pollen‐climate response. Distributional data emphasise the importance of humans as a vector in aiding the spread of both Rhododendron ponticum and some Acer species in the very late Holocene. Arguably, the species concerned have exhibited extreme migrational lag; they re‐open the question as to whether the natural distributions of temperate arboreal species are in equilibrium with climate.

A climate model study of indirect radiative forcing by anthropogenic sulphate aerosols

ANTHROPOGENIC sulphate aerosols are believed to affect the radiation budget of the Earth in two ways. Through the direct effect they scatter solar radiation back to space, producing a radiative forcing whose global annual mean has been estimated to lie in the range −0.3 to −0.9 W m−2 (refs 1–3). This is significant compared to the longwave forcing due to increases in anthropogenic trace gases since the beginning of the industrial era, estimated at +2 to +2.5 W m−2 (ref. 4). Aerosols also have an indirect effect, altering the distribution and concentration of cloud condensation nuclei (CCN) and hence the number density and size distribution of cloud droplets, thus affecting the solar radiative characteristics of clouds5,6. This is harder to quantify than the direct effect, because it depends on complex and poorly understood interactions between aerosols, CCN and cloud properties. Here we use sulphate aerosol data derived from a three-dimensional chemical transport model7 to estimate the indirect radiative forcing by low-level water clouds using a general circulation model. We estimate that the indirect aerosol effect at the top of the atmosphere is approximately −1.3 W m−2 in the global annual mean. Although this value is subject to a high level of uncertainty, even if the effect is only half as large it would still exceed many estimates of the direct effect, demonstrating its potential importance in climate change.

Determinants of Plant Distribution: Evidence from Pine Invasions

The question of which factors limit the occurrence of a plant species to a particular site is addressed by considering 53 cases in which the distribution of pines (Pinus species; Pinaceae) has changed in the last century. We consider expansions of pines in and adjacent to their natural ranges in the Northern Hemisphere and the spread from sites of introduction in the Southern Hemisphere well outside the contemporary range of pines. We first consider a neutral hypothesis (with respect to climate or biological interactions as determinants of invasion): invasion simply requires that a species is present in sufficient numbers, with sufficient propagules over sufficient time to invade. We then explore the relative importance of climatic changes, disturbance, competition (including competition between seedlings and herbaceous plants during early establishment), herbivory, pathogens, and other agents that might influence pine membership in communities. Determinants of susceptibility to invasion often interact in a complex fashion. Environmental stresses created by moisture and temperature appear to exercise primary control on invasibility at xeric and high-elevation sites, respectively, but play a smaller role at intermediate locations At these sites, range limits are determined principally by interactions between pine seedlings and the resident biota in adjacent communities. This suggests that the effects of predicted global warming on the distribution of pines are unlikely to be simple functions of temperature or precipitation, except at climatic extremes. Pine invasions are most prevalent where there is limited competition in the regeneration niche and occur more easily in habitats where the dominant growth form is most different from that of pines, namely, in grasslands. The disturbance regime in the receiving habitat is important and interacts directly and indirectly with the "inherent" susceptibility to invasion Severe disturbances may initiate pine invasions at any latitude, but are essential for reducing the cover of vigorous plant growth (and hence competition in the regeneration niche) in tropical and near-tropical regions Contemporary practices such as deforestation and increased grazing pressure and those practices leading to accelerated erosion, modified fire regimes, and climate amelioration essentially duplicate ice-age stresses and disturbances that shaped plant communities in the Holocene. The fundamental role of biotic factors (either direct or indirect) in regulating the distribution of pines is discussed with reference to aspects of land husbandry including the management of biological invasions.

The Emerging Political Importance of Climate Change as an Energy and Environment Issue

The Emerging Political Importance of Climate Change as an Energy and Environment Issue