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Basic science of climate change
Abstract
Anthropogenic emissions of greenhouse gases are enhancing the natural greenhouse effect. There is almost universal agreement in the scientific community that this will lead to a warming of the lower atmosphere and of the earth's surface. However, the exact timing, magnitude, and regional distribution of this future warming are very uncertain. Merely taking account of changes in the global mean climate is not enough, especially when considering the impacts of climate change. Man also have to consider the rate and regional distribution of climate change and changes in the frequency of events. An increase in the frequency of extremes, such as droughts and storms, and rapid climate change are two factors which could have dramatic effects on human society and natural ecosystems. However, systems already under stress or close to their climate limits are likely to experience the greatest difficulty in adapting to change. Although human activity has been increasing greenhouse gas concentrations for a hundred years, man cannot yet detect unequivocally a greenhouse gas induced signal in climate records. However, increases in greenhouse gas concentrations are almost bound to continue and are likely to emerge as the dominant perturbation of the earth's climate in the coming decades.
... The magnitude of alterations in temperature and precipitation patterns will differ regionally. The largest increases in surface temperatures are predicted to occur at high northern latitudes (Maskell et al. 1993. Over the next 50 yr, the annual mean temperature is expected to increase by 1.5 -2.5ºC in the northern parts of Europe and the United States (Hadley Center 1995). ...
... Regional climate change models estimate a proportionally higher temperature increase during winter at the high northern latitudes (Maskell et al. 1993, IPCC 1996a. Drawing on the findings of this study, it is likely that milder winters will lead to increases in the abundance of TBE in these regions. ...
"Climatic changes are projected to alter the abundance, dynamics, and geographical distribution of many vectorborne diseases in human populations. Tick-borne diseases such as Lyme disease and tick-borne encephalitis (TBE) are a growing concern in northern Europe and the United States. The impact of a future climate change on the transmission of tick-borne diseases is not known. To make such assumptions, more empirical data are needed on the relations between short-term fluctuations in contemporary weather and disease incidence. This paper analyzes relations between daily minimum and maximum temperatures, monthly precipitation, and TBE incidence during a 36-yr period in Stockholm County, a high-endemic region for TBE in Sweden. Multiple regression analyses were performed, with temperature variables expressed as number of days per winter or spring - summer - fall season with temperatures above, below, or in the interval between different temperature limits. The limits used for daily minimum temperatures represent bioclimatic thresholds of importance for pathogen transmission. To adjust for the length of the tick's life cycle, each TBE incidence rate was related to meteorological data over two consecutive years. Results reveal that increased incidence of tick-borne encephalitis is related to a combination of two successive years of more days with temperatures permitting prolonged seasonal tick activity and, hence, pathogen transmission (i.e., daily minimum temperatures above 5-10 degrees C), and a mild winter preceding the year before the incidence year (i.e., fewer winter days with minimum temperatures below -7 degrees C). Alternative explanations of the results are discussed. Findings of this study suggest that a climate change may extend the seasonal range and intensify the endemicity of tickborne diseases, in particular, at northern latitudes."
... Maskell et al stated that nitrous oxide contributes to the greenhouse effect by approximately 6%; however, it has been estimated that only 1% of this is due to anaesthetic use. 19,20 ...
This article highlights an alternative sedation technique by providing inhalation sedation with nitrous oxide and oxygen alongside intravenous sedation with midazolam as an additional option for patients within special care dentistry. Two case reports are described, as well as a short overview of the available literature on this technique and the indications, advantages and disadvantages. This technique should be considered alongside other sedation techniques. As with all treatment for which sedation is provided, each case needs to be considered on an individual basis and the most appropriate option selected following discussion with the patient.
CPD/Clinical Relevance: Although single sedation techniques provide a good level of sedation to facilitate dental treatment for the majority of patients, it is desirable to have an awareness of alternative sedation options that may be available for patients.
... No hay registros locales de observaciones astronómicas y ante la compleja situación que plantea el cambio climático global (Maskell et al., 1993), los ángulos solares son puntos de referencia con ables por su estabilidad para entender mejor las alteraciones, si las hubiera. Por ello, también pueden funcionar como variables independientes contra las que se re eran o comparen otros factores medibles o estimados dentro de un contexto anual de variación local o bien asociada con cambios a mayor escala, como los que afectan la salud humana y la de los ecosistemas naturales mencionados por Haines et al. (1993). ...
Annual changes on the sun’s apparent bearing (azimuth) and on its relative height on the sky, expressed as Altitude and Declination for Santa Marta’s Latitude, are analyzed. Observed azimuth data did not differ signicantly from those calculated. Local daylight duration in minutes was also computed. The parameters for a predictive model as a function of the day’s number and their C.I. at 95 % are estimated. Because of its mountainous topography, the Santa Marta region shows areas where sunlight availability changes throughout the year due to their northern or southern location of promontories and to the respective solar angles. Implications for local living communities are discussed.
... Thus, there hasn't been much research on the subject and most of the research found is on transmission biology and not on ecological and sociological factors 1,12,31 . Studies on ecological changes and infectious Fig. 1: Integrated assessment framework for evaluating research on the association between climate change and infectious diseases diseases discuss habitat destruction, while studies on sociological changes and infectious diseases focus on economic developments, such as nutrition and sanitation 34,1,17 . The integrated assessment framework: means by which cross-disciplinary research could be integrated to identify, target, and initiate investigation in a number of areas, including: systematic understanding of ecologic and epidemiologic responses to climate changes; potential effects of climate changes on food and water supplies; effects of resource availability on human demographic changes (e.g., migration, urbanization), and vice versa; confounding effects of travel, habitat loss and pollution; potentially mitigating effects of increasing wealth, sanitation, nutrition, and disease control, or divergence in standards of these among human populations; effects of human activities on ecosystems; and urbanization and patchy or heterogeneous dynamic ...
Climate change is an occurring phenomenon that creates extreme weather patterns and global warming. These extreme weather patterns and global warming have a direct negative impact on infectious diseases, especially vector-borne infectious diseases. Malaria is one of the vector-borne infectious diseases that are particularly affected by climate change as it is extremely sensitive to meteorological conditions. This extreme sensitivity is creating a resurgence and redistribution of the malaria vector, the mosquito. This resurgence and redistribution of the mosquito puts an extra pressure on the public health system, especially the public health Infrastructure of a developing country. An integrated framework assessment is needed for the public sector to determine the risks of climate change on infectious diseases. Infectious disease may not have affected most developed countries as they have their impact on developing countries, but with climate change this dynamics is rapidly shifting and must be addressed. The key to the integrated framework assessment is the understanding that infectious diseases have multiple determinants that are not just biological, but ecological, sociological, and epidemiological. This paper assesses the climate change impacts on vector-borne infectious diseases. A framework is necessary for the public health sector to determine the risks of epidemics in different demographics and geographic regions. Malaria is an interesting vector-borne disease as it brings up the issue of developing countries versus developed countries.
... The supply of safe water is also endangered by climate changes. Although the average climate conditions have been relatively stable for millennia, the last 50 years have witnessed an acceleration of changes [2,3], so that the average global temperature has increased by 0.7°C and is expected to further increase between 1.8 and 4.0°C by the year 2100 [4][5][6]. The main cause of the ongoing warming of the earth must be sought in the increasing emissions into the lower atmosphere of carbon dioxide (CO 2 ) and other greenhouse gases resulting from human activities (mainly methane and nitrous oxide) [6]. ...
There is increasing evidence that climate is rapidly changing. These changes, which are mainly driven by the dramatic increase of greenhouse gas emissions from anthropogenic activities, have the potential to affect human health in several ways. These include a global rise in average temperature, an increased frequency of heat waves, of weather events such as hurricanes, cyclones and drought periods, plus an altered distribution of allergens and vector-borne infectious diseases. The cardiopulmonary system and the gastrointestinal tract are particularly vulnerable to the adverse effects of global warming. Moreover, some infectious diseases and their animal vectors are influenced by climate changes, resulting in higher risk of typhus, cholera, malaria, dengue and West Nile virus infection. On the other hand, at mid latitudes warming may reduce the rate of diseases related to cold temperatures (such as pneumonia, bronchitis and arthritis), but these benefits are unlikely to rebalance the risks associated to warming.
... No hay registros locales de observaciones astronómicas y ante la compleja situación que plantea el cambio climático global (Maskell et al ., 1993), los ángulos solares son puntos de referencia confiables por su estabilidad para entender mejor las alteraciones, si las hubiera . Por ello, también pueden funcionar como variables independientes contra las que se refieran o comparen otros factores medibles o estimados dentro de un contexto anual de variación local o bien asociada con cambios a mayor escala, como los que afectan la salud humana y la de los ecosistemas naturales mencionados por Haines et al . ...
Annual changes on the sun's apparent bearing (azimuth) and on its relative height on the sky, expressed as Altitude and Declination for Santa Marta's Latitude, are analyzed. Observed azimuth data did not differ significantly from those calculated. Local daylight duration in minutes was also computed. The parameters for a predictive model as a function of the day's number and their C. I. at 95 % are estimated. Because of its mountainous topography, the Santa Marta region shows areas where sunlight availability changes throughout the year due to their northern or southern location of promontories and to the respective solar angles. Implications for local living communities are discussed.
... El Plasmodium sp. se desarrolla sólo desde los 15ºC (23,29), la temperatura mínima de desarrollo de P. falciparum es de 18ºC y de P. vivax es de 15ºC (23). Se observa que ocurre un acortamiento del periodo de incubación extrínseca a temperaturas entre 20º y 27º (27), a los 20ºC P. falciparum demora 26 días en madurar mientras que a 25ºC le toma 13 días (23). ...
Several epidemiological evidence have been correlated with the effect of environmental factors over infectious diseases. Since the El Niño phenomenon in 1973, this event has been incriminated in the onset or trigger of epidemic changes and outbreaks. El Niño, which is responsible for the Ecuatorial Pacific Ocean water warming, produce a global effect, and as a consequence atmospheric humidity and environmental temperature are higher than usual. Currently, there are evidence that those changes have a direct effect on the biological life cycle of infectious diseases vectors and some microorganisms with a correlation in the epidemiology of those diseases. Recently, the molecular biology and the mathematical model analysis have been improving our understood about biological explanations, allowing the opportunity to predict outbreaks, risky areas, or epidemiological changes. We review the current evidence that may affect infectious diseases, as Malaria, Leishmaniasis, Bartonellosis, Cholera and others. (Rev Med Hered 2004;15:218-224).
... Ao falarmos de poluição atmosférica não podemos deixar de referir a influência do clima, já que existe uma correlação importante entre este e a poluição. As inversões térmicas, por exemplo, estão associadas a níveis mais elevados de TPS, NO 2 e SO 2 , enquanto que as temperaturas diurnas elevadas, os ventos de baixa velocidade e os céus limpos aumentam os níveis dos precursores voláteis do ozono e as taxas de fotólise (16)(17)(18)(19) . ...
Resumo: O organismo humano está exposto às mais diversas agressões do ambiente; acidentes, agressões físicas, químicas e microbiológicas constituem um permanente risco para o organismo. O aparelho respiratório está particularmente exposto às agressões do ambiente e é freqüentemente sede de alterações de maior ou menor intensidade e gravidade. Revêem-se neste trabalho os efeitos da poluição atmosférica sobre o aparelho respiratório. Definem-se poluição atmosférica, poluição do exterior e dos interiores e poluição primária e secundária. Revêem-se sumariamente os mecanismos de defesa do aparelho respiratório e descrevem-se as ações deletérias dos diferentes poluentes atmosféricos para as vias aéreas: SO2, NO2, CO, O3, aerossóis e partículas. Destaca-se a ação do fumo do tabaco atendendo à sua importância para a saúde. Termina-se tecendo alguns comentários sobre a intervenção que a pneumologia e os pneumologistas devem ter nesta área, chamando a atenção para a comunidade e para as autoridades, para os riscos da poluição para a saúde em geral e, em particular, para o aparelho respiratório.
... A growing number of investigators propose that vector-borne diseases (VBDs), (e.g., involving insects and snails as carriers), could shift their range in response to climate change (Leaf 1989;Shope 1991;Patz et al. 1996;McMichael et al. 1996;Carcavallo and de Casas 1996). Models, incorporating vectorial capacity (temperature-dependent insect reproductive and biting rates and microorganism reproductive rates), uniformly indicate the potential for spread of the geographic areas that could sustain VBD transmission to higher elevations and higher latitudes under global warming (2 × CO 2 ) scenarios (Maskell et al. 1993;Martens et al. 1997;Matsuoka and Kai 1994;Martin and Lefebvre 1995;Focks et al. 1995) (see Fig. 3). The transmission season may also be extended. ...
The Intergovernmental Panel on Climate Change concluded that there is
"discernible evidence" that humans-through accelerating changes in
multiple forcing factors-have begun to alter the earth's climate regime.
Such conclusions are based primarily upon so-called "fingerprint"
studies, namely the warming pattern in the midtroposphere in the
Southern Hemisphere, the disproportionate rise in nighttime and winter
temperatures, and the statistical increase in extreme weather events in
many nations. All three aspects of climate change and climate
variability have biological implications.Detection of climate change has
also drawn upon data from glacial records that indicate a general
retreat of tropical summit glaciers. Here the authors examine biological
(plant and insect) data, glacial findings, and temperature records taken
at high-elevation, mountainous regions. It is concluded that, at high
elevations, the overall trends regarding glaciers, plants, insect range,
and shifting isotherms show remarkable internal consistency, and that
there is consistency between model projections and the ongoing changes.
There are implications for public health as well as for developing an
interdisciplinary approach to the detection of climate change.
... Regional predictions from a global climate change are difficult to make. However, the highest increases in surface air temperature, especially during the winter season, are expected to occur over the higher northern latitudes (Maskell et al., 1993; The Hadley Center, 1995). Disturbances in the climatic system would cause a whole range of consequences, including effects on human health (IPCC II, 1996). ...
A future, global, climate change may indirectly lead to changes in the transmission and incidence of several vector-borne diseases. This paper presents an example of a modeling tool for projections of possible changes in the incidence of tick-borne encephalitis (TBE), and the subsequent changes in vaccination needs, during the next half-century in Sweden. The model is based on the Hadley Center’s regional temperature predictions for the year 2050, taking into account the IPCC IS92 ‘non-intervention scenario’. The model has been constructed into STELLA, a graphical dynamic-simulation, soft-ware program.The model project an increase in TBE incidence in Stockholm County, a high-endemic region in Sweden, during the next 50 years. According to this simplified model, the annual vaccination rate need to increase by 3–4-fold during the next half century in order to prevent the projected increases in TBE incidence in the region from a climatic change.
The advent of global environmental change, with all its uncertainties and requirement for long-term prediction, brings new challenges and tasks for scientists, the public and policy makers. A major environmental upheaval such as climate change is likely to have significant health effects. Current mainstream epidemiological research methods do not always adequately address the health impacts that arise within a context in which the ecological and other biophysical processes display non-linear and feedback-dependent relationships. The agenda of research and policy advice must be extended to include the larger-framed environmental change issues. This book identifies the nature and scope of the problem, and explores the conceptual and methodological approaches to studying these relationships, modelling their future realisation, providing estimates of health impacts, and communicating the attendant uncertainties. This timely volume will be of great interest to health scientists and graduate students with an interest in the effects of global environmental change.
Background: Global warming is a consequence of air pollution resulting in
climate change due to trapping of excess greenhouse gases in the earth's
atmosphere that affects biodiversity and constitutes a serious health hazard,
especially tothe respiratory system. These greenhouse gases include carbon
dioxide, water vapor, methane, ozone and nitrous oxide. They hold heat in the
atmosphere thereby creating a greenhouse effect. Thesources of these gases
include human activities like industrial air pollution, burning of human waste,
wood and forests, tobacco, fossil fuels like oil, natural gas and coal, deforestation
and the release of chlorofluorocarbons (CFCs). Climate change brought about by
global warming results in storms, drought, and floods which can be of immediate
threat to life, the respiratory system being particularly vulnerable because of the
background air pollution. Effects of global warming on the respiratory system
include potentially increased incidence (and/or worsening/exacerbations) of the
following: bronchial asthma and other allergic diseases, infection (pneumonia
and tuberculosis), parasitic lung diseases, chronic obstructive pulmonary
disease, hypersensitivity pneumonitis, lung cancer and sudden death.
Aim: To create awareness and increase enlightenment about the very important
subject of global warming and the lung.
Methods: A literature search on global warming and respiratory diseases was
carried out through the internet (Google, Medline) and locally. Data synthesis
was carried out and synchronized under the following headings: introduction,
effects of global warming on respiratory diseases, respiratory diseases, and
recommendations.
Conclusion: There is urgent need for control measures to be taken to mitigate the
effects of global warming on the respiratory system.
Keywords: Global warming, respiratory diseases
Objectives. To explore the relationship between climatic variables with the transmission of malaria in Loreto, in a period of 13 years. Material and methods. Ecological study was conducted with data from the monthly average temperature (º C), relative humidity (%), precipitation (mm) and the level of the Amazon River (meters), with cases of malaria confirmed by thick smear recorded by the Dirección Regional de Salud de Loreto. In addition, it was used simple linear regression and multiple linear regression models to determine relationship between these variables and malaria transmission. Results. We found significant negative correlation between temperature and cases of malaria for five years: 1997, 1999, 2003, 2005 and 2006; river level for four years: 1997, 1998, 2003 and 2005; and humidity for three years: 1996, 2005, 2006. No association was found for any years with rainfall. The multiple regression models were significant in three years (1999, 2003 and 2006) with R 2 values between 0.870 and 0.937. Conclusions. Some climate variables may be associated with the transmission of malaria, but the importance of each one may vary from year to year. The years of El Niño or later years are the best correlation. When the average temperature is low, it's probably that the sporozoite cycle vector and gametocyte cycle vector are advantaged. It is at this time that the potential for transmission of the vector population is high, which favors the transmission of malaria. Keys words: Malaria; Grenhouse effect; Climate effects; Climatic processes; Peru (source: MeSH NLM).
There are many determinants of health and well-being, and they can all interact with one another. Human biological and psychological factors come into play on a personal level, but ecological and global systems are also involved, as are economics and access to health care, which determine the social vulnerabilities to disease. Recently, our chief means of controlling infections — antibiotics and insecticides — have themselves become a source of new, resistant microbes and disease carriers, and the growing number of people with malnutrition or depressed immune systems have helped select and disseminate these emerging organisms.
Objectives. To explore the relationship between climatic variables with the transmission of malaria in Loreto, in a period of 13 years. Material and methods. Ecological study was conducted with data from the monthly average temperature (° C), relative humidity (%), precipitation (mm) and the level of the Amazon River (meters), with cases of malaria confirmed by thick smear recorded by the Dirección Regional de Salud de Loreto. In addition, it was used simple linear regression and multiple linear regression models to determine relationship between these variables and malaria transmission. Results. We found significant negative correlation between temperature and cases of malaria for five years: 1997, 1999, 2003, 2005 and 2006; river level for four years: 1997, 1998, 2003 and 2005; and humidity for three years: 1996, 2005, 2006. No association was found for any years with rainfall. The multiple regression models were significant in three years (1999, 2003 and 2006) with R2 values between 0.870 and 0.937. Conclusions. Some climate variables may be associated with the transmission of malaria, but the importance of each one may vary from year to year. The years of El Niño or later years are the best correlation. When the average temperature is low, it's probably that the sporozoite cycle vector and gametocyte cycle vector are advantaged. It is at this time that the potential for transmission of the vector population is high, which favors the transmission of malaria.
Climatic factors influence the emergence and reemergence of infectious diseases, in addition to multiple human, biological, and ecological determinants. Climatologists have identified upward trends in global temperatures and now estimate an unprecedented rise of 2.0°C by the year 2100. Of major concern is that these changes can affect the introduction and dissemination of many serious infectious diseases.
The incidence of mosquito-borne diseases, including malaria, dengue, and viral encephalitides, are among those diseases most sensitive to climate. Climate change would directly affect disease transmission by shifting the vector's geographic range and increasing reproductive and biting rates and by shortening the pathogen incubation period. Climate-related increases in sea surface temperature and sea level can lead to higher incidence of water-borne infectious and toxin-related illnesses, such as cholera and shellfish poisoning. Human migration and damage to health infrastructures from the projected increase in climate variability could indirectly contribute to disease transmission. Human susceptibility to infections might be further compounded by malnutrition due to climate stress on agriculture and potential alterations in the human immune system caused by increased flux of ultraviolet radiation.
Analyzing the role of climate in the emergence of human infectious diseases will require interdisciplinary cooperation among physicians, climatologists, biologists, and social scientists. Increased disease surveillance, integrated modeling, and use of geographically based data systems will afford more anticipatory measures by the medical community. Understanding the linkages between climatological and ecological change as determinants of disease emergence and redistribution will ultimately help optimize preventive strategies.
(JAMA. 1995;275:217-223)
The United Nation's Intergovernmental Panel on Climate Change estimates an unprecedented global rise of 2.0°C by the year 2100. Such change can affect serious infectious diseases, including dengue fever and malaria. Both large-scale iterative modeling and site-specific microclimatic analysis of disease ecology are needed in tandem to address health effects of climate change scenarios.
In two separate studies of dengue and malaria transmission, both General Circulation Models (GCMs) of global climate change and site-specific climate analysis are used respectively to investigated climate change impacts on dengue fever and malaria transmission risk. For the first study, analysis was conducted using the integrated MIASMA model to link GCM projections of climate with a vectorial capacity model of transmission. Preliminary results indicate climate conditions being more suitable to dengue transmission, given viral introduction. An expansion of potential epidemic risk both geographically and temporally is inferred from this study. In the malaria study, preliminary results from regression analysis show mosquito biting rates to correlate to ambient temperature and rainfall. Parasite development was also shown to relate to temperature and humidity. Further interdisciplinary cooperation and multi-scaled analytical approaches will be required to better assess the potential effect of climate change on malaria and dengue. J Epidemiol, 1996 ; 6 : S145-S148.
Objective:
The aim of this study was to examine whether sevoflurane in oxygen was equivalent to near equipotent concentrations of nitrous oxide in oxygen when used as an inhalation sedation agent in terms of patient and user acceptability.
Method:
Forty anxious dental patients referred to the sedation suite at Cardiff University School of Dentistry received either nitrous oxide to a maximum concentration of 40% or sevoflurane to a maximum concentration of 0.3% for a routine maxillary plastic restoration with articaine infiltration local analgesia. The inhalation sedation agent to be administered was chosen by a random number allocator. Measurements of blood pressure, oxygen saturation, heart rate, respiratory rate and bispectral index were recorded every 5 minutes. At the end of the treatment episode the patient, the operator and an observer who was unaware of the agent used, recorded their impressions about the episode by completing questionnaires.
Results:
In the doses used in this study, sevoflurane was found to be as effective as an inhalation sedation agent as the standard dose of nitrous oxide used in normal inhalation sedation in the treatment of adult anxious dental patients.
Conclusion:
Sevoflurane in low concentrations is equivalent in effect to near equipotent concentrations of nitrous oxide. This would suggest that further research, perhaps with slightly higher concentrations of sevoflurane, is needed. If sevoflurane was shown to be acceptable at slightly higher concentrations, there is scope to explore the development of equipment specifically designed to deliver sevoflurane as an inhalation sedation agent in future.
Global civilisation, and therefore population health, is threatened by excessive inequality, weapons of mass destruction, inadequate economic and political theory and adverse global environmental change. The unequal distribution of global foreign exchange adjusted income is both a cause and a reflection of global social characteristics responsible for many aspects of these inter-related crises. ¶ The global distribution of foreign exchange adjusted income for the period 1964-1999 is examined. Using data for more than 99% of the global population, a substantial divergence in its distribution is found. The global Gini co-efficient, adjusted for national income inequality, increased from an already high value of 71% in 1964 to peak at more than 80% in 1995, before falling, very slightly, to 79% in 1999. The global distribution of purchasing parity power income is also examined, for a similar period. Though also found to be extremely unequal, its trend has not been to increased inequality. Implications of the differences between these two trends are discussed. ...
A review of some of the major issues that may impact global warming and climate change as well as a discussion of global environmental factors and their possible affect on vector-borne and waterborne infectious diseases.
This article presents the basic science of climate change upon which our concern of possible anthropogenic interference with the climate system is based. Where possible, those aspects of particular relevance to the study of climate change impact assessment will be highlighted to set the scene for the remaining articles in this issue, which focus on the effects of climate change on human health.
Growing concern about the possible threat of anthropogenic climate change led to the establishment of the Intergovernmental Panel on Climate Change (IPCC) in 1988 under the auspices of the United Nations Environment Programme (UNEP) and the World Meteorological Organisation (WMO). The IPCC was charged with the task of assessing the latest scientific understanding of climate change, possible impacts, mitigation and adaptation strategies and their economic implications.
The first set of IPCC Assessment Reports were produced in 1990 and were instrumental in the negotiations which led to birth of the United Nations Framework Convention on Climate Change, signed by 155 countries at the 1992 Earth Summit in Rio. The final section reviews the outcome of that meeting and discusses the results of the first Conference of the Parties to the Convention which took place earlier this year to debate the adequacy of the commitments set in 1992.
Emission of various hazardous air pollutants (HAPs) and greenhouse gases including perfluorocompounds (PFCs) from semiconductor industries, which individually may cause great impact on human health and the global environment, has attracted much public attention. In this paper, a potential application of nonthermal plasma technologies as an integrated approach for abating the emission of these gaseous pollutants is critically reviewed. Relevant studies indicate that direct electron impact with PFC molecules to form PFC fragment radicals is the first step leading to the destruction of PFCs in nonthermal plasmas (NTPs) and that further reactions of PFC fragments with radicals are essential for the effective removal of PFCs. Previous studies demonstrate that nonthermal plasma combined with catalyst or adsorbent has a good potential to be used as an integrated technology for abating PFCs from complicated gas streams of semiconductor manufacturing processes.
The rise and fall of the Last Interglacial (LI) sea levels and sea surface temperatures (SSTs) are evaluated using U-series dating combined with Sr/Ca ratios in corals from both stable and tectonically uplifted sites. Along the stable coastal margin of Western Australia, an extensive series of LI coral reefs occur at heights of 2–3 m above present-day sea level. These corals have a very tight cluster of 234U–230Th ages ranging from 129±1 to 119±1 ka, as well as a narrow range of initial δ234U values of 150±5, similar to modern seawater. Bahamas, which is also a stable site, has an essentially identical pattern of U-series ages from 130±1 to 120±1 ka. Barbados and Huon Peninsula are tectonically active sites where the LI terraces are found at elevations of >50 and >200 m, respectively. U-series ages from corals exposed in the lower footwall of these uplifted reefs, allow better constraints to be placed on the rate of sea level rise which initiated the LI. Corals from the Huon Peninsula constrain sea level at −80±10 m at 131±2 ka, and from Barbados, at −30±5 m at 129±1 ka. Combined with constraints from stable sites, these observations require an exceedingly rapid rise in sea level of 30–50 m per 1000 years at 130±1 ka. This indicates that large-scale catastrophic melting of the once massive continental ice sheets occurred in phase with the rapidly increasing northern hemisphere (NH) summer insolation, consistent with the orbital forcing being the main driver of glacial–interglacial climate change. There is also some evidence from Huon Peninsula, although still not conclusive, for a precursor oscillation in sea level during the penultimate deglaciation, that may have been within ∼−20 m of present-day levels at ∼135 ka.
The proportion of travellers who fall ill varies from 15 to 43%. In general, diarrhoea and gastrointestinal infections account for 50–65% of health problems, followed by upper respiratory tract infections (14–30%), fever (12–15%) and skin disorders (10–12%). Sexually transmitted diseases account for 0.5–2% or more. Malaria in travellers remains important and there are approximately 10,000 reported cases of imported malaria each year in Europe alone.Emerging and re-emerging infectious diseases and increasing resistance to antibiotics and malaria are important.While the reasons for international travel are mainly tourism, business and education, in some regions of the world, migrant workers, refugees and asylum seekers contribute substantially to international migration. Migration contributes to the biological interplay between pathogens and their hosts as well as genetic exchange between different infectious agents including altered virulence and sensitivity to therapeutic drugs.The main causes of death in travellers are cardiovascular conditions, road and other accidents, and drowning. Infections appear to be an uncommon cause of death (2–3%).
Escalating global environmental change (GEC) over the past century has been driven largely by rapid industrialization, population
growth, overconsumption of natural resources, and associated waste disposal challenges, as well as the inappropriate uses
of technology. These changes are already having and will increasingly continue to have significant impacts on human health
and well-being. How to tackle these issues is an important challenge to scientists, policy-makers, and the general public.
Scientific consensus now exists that GEC and population health are linked, even though the details and mechanisms underlying
this link remain to be both explicated and quantified. In this article we provide an overview of progress and challenges in
the area of GEC and population health since the late 1980s, highlighting some of the main landmarks in this area and recommending
directions for future research.
Responses of the photosynthetic characteristics to variation in CO2 concentration and temperature of Ginkgo biloba, Eucommia ulmoides, Magnolia denudata and Tilia japonica were measured during the peak growing season. The results show that the ambient CO2 concentration could not meet the requirements for photosynthesis of these four species. The optimal temperatures for photosynthesis
were lower than the average daytime air temperature. Hence, the photosynthesis of these four species was restricted by the
low CO2 concentration and high daytime air temperature at the time of measurement. Marked enhancements in the net photosynthetic
rate were found in all four species when the CO2 concentration was doubled. When the dependency on CO2 and temperature were examined simultaneously, it was seen that for increased CO2 concentrations there was a shift in the optimum temperature for M. denudata and T. japonica towards higher temperatures. Due to their independence on CO2 concentrations, this trend could not be found in the G. biloba and E. ulmoides data sets. The stomatal conductance (G
s) was sensitive to a vapor pressure deficit (VPD) which in turn was sensitive to temperature. An increase in temperature would cause the VPD to increase and plants might be assumed to react by reducing their stomatal apertures. The effect on stomatal resistance
would be most significant at high temperatures. The restriction to stomatal conductance for these four species would increase
if CO2 concentrations were elevated at the same temperature.
General anesthetics are administered to approximately 50 million patients each year in the United States. Anesthetic vapors and gases are also widely used in dentists' offices, veterinary clinics, and laboratories for animal research. All the volatile anesthetics that are currently used are halogenated compounds destructive to the ozone layer. These halogenated anesthetics could have potential significant impact on global warming. The widely used anesthetic gas nitrous oxide is a known greenhouse gas as well as an important ozone-depleting gas. These anesthetic gases and vapors are primarily eliminated through exhalation without being metabolized in the body, and most anesthesia systems transfer these gases as waste directly and unchanged into the atmosphere. Little consideration has been given to the ecotoxicological properties of gaseous general anesthetics. Our estimation using the most recent consumption data indicates that the anesthetic use of nitrous oxide contributes 3.0% of the total emissions in the United States. Studies suggest that the influence of halogenated anesthetics on global warming will be of increasing relative importance given the decreasing level of chlorofluorocarbons globally. Despite these nonnegligible pollutant effects of the anesthetics, no data on the production or emission of these gases and vapors are publicly available. The primary goal of this article is to critically review the current data on the potential effects of general anesthetics on the global environment and to describe possible alternatives and new technologies that may prevent these gases from being discharged into the atmosphere.
Climatic factors influence the emergence and reemergence of infectious diseases, in addition to multiple human, biological, and ecological determinants. Climatologists have identified upward trends in global temperatures and now estimate an unprecedented rise of 2.0 degrees C by the year 2100. Of major concern is that these changes can affect the introduction and dissemination of many serious infectious diseases. The incidence of mosquito-borne diseases, including malaria, dengue, and viral encephalitides, are among those diseases most sensitive to climate. Climate change would directly affect disease transmission by shifting the vector's geographic range and increasing reproductive and biting rates and by shortening the pathogen incubation period. Climate-related increases in sea surface temperature and sea level can lead to higher incidence of water-borne infectious and toxin-related illnesses, such as cholera and shellfish poisoning. Human migration and damage to health infrastructures from the projected increase in climate variability could indirectly contribute to disease transmission. Human susceptibility to infections might be further compounded by malnutrition due to climate stress on agriculture and potential alterations in the human immune system caused by increased flux of ultraviolet radiation. Analyzing the role of climate in the emergence of human infectious diseases will require interdisciplinary cooperation among physicians, climatologists, biologists, and social scientists. Increased disease surveillance, integrated modeling, and use of geographically based data systems will afford more anticipatory measures by the medical community. Understanding the linkages between climatological and ecological change as determinants of disease emergence and redistribution will ultimately help optimize preventive strategies.
Nitrous oxide (N2O) was assayed in 676 urine samples and 101 blood samples provided after exposure by operating theatre personnel from nine hospitals. The blood and urine assays were repeated in 25 subjects 18 h after the end of exposure. For 80 subjects, environmental N2O was also measured during intraoperative exposure. Mean urinary N2O in the 676 subjects at the end of exposure was 40 micrograms/l (range 1-3805 micrograms/l); in 10 of the 676 subjects, urinary N2O was in the range 279-3805 micrograms/l (mean 1202 micrograms/l). The 98th percentile was 120 micrograms/l. Mean blood N2O at the end of exposure, measured in 101 subjects, was 21 micrograms/l (median 16 micrograms/l, range 1-75 micrograms/l). Blood and urine N2O (1.5 micrograms/l and 4.9 micrograms/l, respectively) in 25 subjects, 18 h after exposure, was significantly higher than in occupationally non-exposed subjects (blood 0.91 microgram/l, urine 1 microgram/l). Environmental exposure was significantly related to blood and urinary N2O (r = 0.59 and r = 0.64, respectively). Blood and urinary N2O were significantly related to each other (r = 0.71), and were equivalent to about 25% of the environmental exposure level. The mean urinary N2O of 1202 micrograms/l in 10/676 subjects was not related to environmental exposure in the operating theatre. The highest urinary N2O levels measured in these 10/676 subjects could be explained by an asymptomatic urinary infection.
The paper looks at the phenomenon of global warming and its potential health effects and outlines a number of plausible response by the health sector in developing countries to its threat. It suggests that the health sector should facilitate an international effort at addressing this challenge, mainly through advocacy, epidemiological surveillance and awareness creation.
During recent years the world has experienced the reemergence of old communicable diseases and the emergence of new ones caused by novel pathogens such as the HIV virus and Borrelia burgdorferi. The problem consists mostly in the reemergence of old diseases but specially in industrialized countries new pathogens have also been described. Although the emergence of these infections in rare instances is due to genetic changes of pathogens to more virulent forms, most commonly they are due to changes in the environment and the host. Rapidly deteriorating living standards, disintegration of sanitation and public health infrastructure, cultural changes, migration and variations in behavior are some of the factors involved in the worldwide increase of infectious diseases. The degradation of natural habitats including forests and marine niches accompanied by climatic changes, are also playing an increasing role in the detrimental evolution of these diseases. The global emergence of these diseases calls into question the doctrine of epidemiological transition and directs us to scrutinize the paradigm that bases the prevention of these diseases solely on vaccination. The current situation also highlights the limitations of classical epidemiology in dealing with unexpected problems, and strongly suggests that this discipline should incorporate into its analysis findings from other fields, including ecological, climatological, and economical information. As most of the negative social and economical developments that impinge on the detrimental evolution of these diseases are increasing world-wide, it can be predicted that the problems posed by these infections will continue and perhaps worsen in the near future.
A Leslie matrix population model supported by carbon-14 dating of early occupation layers lacking moa remains suggests that human hunting and habitat destruction drove the 11 species of moa to extinction less than 100 years after Polynesian settlement of New Zealand. The rapid extinction contrasts with models that envisage several centuries of exploitation.
Current climate policy does not take into account that, after greenhouse gas emissions have been reduced to an extent that atmospheric concentrations stabilise and then start to fall, natural decay of greenhouse gases will lead to a global cooling phase spanning several centuries. This cooling will lead to damage to humans and ecosystems that depends on the rate of temperature change. Current climate policy should thus concentrate on the reduction of short- and medium-lived greenhouse gases, while exempting long-lived gases. This reduces the cooling rate. Another policy option is to sequester carbon in geological reservoirs that allow controlled release in the future. Copyright 2003 Organization of the Petroleum Exporting Countries .
Considerable scientific effort has been applied to the question of whether worldwide fossil fuel combustion and the resultant emission of CO2 (as well as emissions of other greenhouse gases) will cause a discernible enhancement of the greenhouse effect in the next century. A more precise understanding of the contribution of human activity to potential global warming (vis-à-vis natural climatic variability) is of critical policy interest. Surprisingly little research has been devoted to establishing the underlying statistical relationship between human activities and CO2 emissions. In this paper, we explore the nature of the relationship between global population growth and CO2 emissions by employing the test of causality developed by Granger on annual data for 1880–1989, as well as more comprehensive error correction and cointegration models. The results suggest a lack of a long-term equilibrium relationship, but imply a short-term dynamic relationship from CO2 to population growth.
A detailed stable-isotope record is presented for the full length of the Greenland Ice-core Project Summit ice core covering the last 250,000 years according to a graduated timescale. It appears that the climatic stability of the Holocene is the exception rather than the rule; the last interglacial is also noted to have lasted longer than is implied by the deep-sea SPECMAP record. This discrepancy may be accounted for if the climate instability at the outset of the last interglacial delayed the melting of the Saalean ice sheets in America and Eurasia.
Book review of the intergovernmental panel on climate change report on global warming and the greenhouse effect. Covers the scientific basis for knowledge of the future climate. Presents chemistry of greenhouse gases and mathematical modelling of the climate system. The book is primarily for government policy makers.
Climate change 1992: the Supplementary Report to the IPCC Scientific Assessment. Cambridge: Cambridge Unversity Press, 1992. 3 Murphy JM. A prediction of the transient response of climate Meteorological Office, 1992. Climate Res Tech Note 1992, no 32 Climate change: the IPCC impacts assessment
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Houghton JT, Callander BA, Varney SK. Climate change 1992: the Supplementary Report to the IPCC Scientific Assessment. Cambridge: Cambridge Unversity Press, 1992. 3 Murphy JM. A prediction of the transient response of climate. Bracknell, UK: Hadley Centre, Meteorological Office, 1992. Climate Res Tech Note 1992, no 32. 4 Tegart WG McG, Sheldon GW, Griffiths DC. Climate change: the IPCC impacts assessment. Canberra: Australian Government Publishing Service, 1990.