scholarly journals Malaria trends in Ethiopian highlands track the 2000 ‘slowdown’ in global warming

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xavier Rodó ◽  
Pamela P. Martinez ◽  
Amir Siraj ◽  
Mercedes Pascual

AbstractA counterargument to the importance of climate change for malaria transmission has been that regions where an effect of warmer temperatures is expected, have experienced a marked decrease in seasonal epidemic size since the turn of the new century. This decline has been observed in the densely populated highlands of East Africa at the center of the earlier debate on causes of the pronounced increase in epidemic size from the 1970s to the 1990s. The turnaround of the incidence trend around 2000 is documented here with an extensive temporal record for malaria cases for both Plasmodium falciparum and Plasmodium vivax in an Ethiopian highland. With statistical analyses and a process-based transmission model, we show that this decline was driven by the transient slowdown in global warming and associated changes in climate variability, especially ENSO. Decadal changes in temperature and concurrent climate variability facilitated rather than opposed the effect of interventions.

2021 ◽  
Vol 288 (1963) ◽  
Author(s):  
Marcel E. Visser ◽  
Melanie Lindner ◽  
Phillip Gienapp ◽  
Matthew C. Long ◽  
Stephanie Jenouvrier

Climate change has led to phenological shifts in many species, but with large variation in magnitude among species and trophic levels. The poster child example of the resulting phenological mismatches between the phenology of predators and their prey is the great tit ( Parus major ), where this mismatch led to directional selection for earlier seasonal breeding. Natural climate variability can obscure the impacts of climate change over certain periods, weakening phenological mismatching and selection. Here, we show that selection on seasonal timing indeed weakened significantly over the past two decades as increases in late spring temperatures have slowed down. Consequently, there has been no further advancement in the date of peak caterpillar food abundance, while great tit phenology has continued to advance, thereby weakening the phenological mismatch. We thus show that the relationships between temperature, phenologies of prey and predator, and selection on predator phenology are robust, also in times of a slowdown of warming. Using projected temperatures from a large ensemble of climate simulations that take natural climate variability into account, we show that prey phenology is again projected to advance faster than great tit phenology in the coming decades, and therefore that long-term global warming will intensify phenological mismatches.


2013 ◽  
Vol 9 (2) ◽  
pp. 1237-1257
Author(s):  
W. H. Berger

Abstract. The response of the climate system to external forcing has become an item of prime interest in the context of global warming, especially with respect to the rate of melting land-based ice masses. The deep-sea record of ice-age climate change has been useful in assessing the sensitivity of the climate system to such forcing, notably to orbital forcing, which is well-known for the last several million years. When comparing response and forcing, one finds that sensitivity varies greatly through time, apparently in dependence on the state of the system. The changing stability of ice masses presumably is the underlying cause for the changing state of the system. A buildup of vulnerable ice masses within the latest Tertiary, when going into the ice ages, is conjectured to cause a stepwise increase of climate variability since the early Pliocene.


2014 ◽  
Vol 14 (61) ◽  
pp. 8428-8444
Author(s):  
CJ Stigter ◽  
◽  
E Ofori ◽  

Climate change seriously influences the livelihoods of African farmers. It was, therefore, felt useful to make an inventory of what climate change really means for them. In this review in three parts, climate change is approached by dealing with the three sides from which the danger comes: (i) global warming, (ii) increasing climate variability, (iii) more (and possibly more severe) meteorological and climatological extreme events. These are the three panels of this triptych review. Vulnerable communities already suffer. They are, therefore, urgently in need of assistance aimed at building resilience, and at undertaking climate change adaptation efforts to survive and to maintain their livelihoods. Climate change adaptation projects - especially if implemented in the context of adaptation strategies at the macro level - often mobilize public and private stakeholders, engaging them in the problem-solving process. Scientists have an important role to play in these projects. One of the major problems in guiding rural change, in a rural response to climate change, is the low formal level of education that most farmers have and for which governments have done very little to upgrade it. Improved climate literacy is needed among farmers and a better trained extension that can guide farmers in further rainfall monitoring and rainfall interpretation. Further agro-ecosystem observations that, with the rainfall distribution, explain yields and yield differences are also needed. While it is relatively easy to define technical messages that can be communicated, one must look beyond “adaptation to current climate variability“. The basic vulnerability factors of communities must be targeted. One of the problems faced is that experts on climate variability and climate change do not really know what information the grassroots need in the short- and medium-term. However, people assisting vulnerable communities do not know what science generated products are available and how to use them. In this first part of the paper, the consequences of global warming are dealt with at length. Increasing temperatures and changing rainfall patterns get attention first. Other consequences of increasing atmospheric carbondioxide contents and how they influence agricultural production in Africa are also discussed. Ten text boxes distributed over the three parts illustrate local conditions that must be taken into account to understand the impacts/consequences of climate change for African farmers and how they may cope with them.


2013 ◽  
Vol 9 (4) ◽  
pp. 2003-2011 ◽  
Author(s):  
W. H. Berger

Abstract. The response of the climate system to external forcing (that is, global warming) has become an item of prime interest, especially with respect to the rate of melting of land-based ice masses. The deep-sea record of ice-age climate change has been useful in assessing the sensitivity of the climate system to a different type of forcing; that is, to orbital forcing, which is well known for the last several million years. The expectation is that the response to one type of forcing will yield information about the likely response to other types of forcing. When comparing response and orbital forcing, one finds that sensitivity to this type of forcing varies greatly through time, evidently in dependence on the state of the system and the associated readiness of the system for change. The changing stability of ice masses is here presumed to be the chief underlying cause for the changing state of the system. A buildup of vulnerable ice masses within the latest Tertiary, when going into the ice ages, is thus here conjectured to cause a stepwise increase of climate variability since the early Pliocene.


2019 ◽  
Vol 3 (2) ◽  
pp. 221-231 ◽  
Author(s):  
Rebecca Millington ◽  
Peter M. Cox ◽  
Jonathan R. Moore ◽  
Gabriel Yvon-Durocher

Abstract We are in a period of relatively rapid climate change. This poses challenges for individual species and threatens the ecosystem services that humanity relies upon. Temperature is a key stressor. In a warming climate, individual organisms may be able to shift their thermal optima through phenotypic plasticity. However, such plasticity is unlikely to be sufficient over the coming centuries. Resilience to warming will also depend on how fast the distribution of traits that define a species can adapt through other methods, in particular through redistribution of the abundance of variants within the population and through genetic evolution. In this paper, we use a simple theoretical ‘trait diffusion’ model to explore how the resilience of a given species to climate change depends on the initial trait diversity (biodiversity), the trait diffusion rate (mutation rate), and the lifetime of the organism. We estimate theoretical dangerous rates of continuous global warming that would exceed the ability of a species to adapt through trait diffusion, and therefore lead to a collapse in the overall productivity of the species. As the rate of adaptation through intraspecies competition and genetic evolution decreases with species lifetime, we find critical rates of change that also depend fundamentally on lifetime. Dangerous rates of warming vary from 1°C per lifetime (at low trait diffusion rate) to 8°C per lifetime (at high trait diffusion rate). We conclude that rapid climate change is liable to favour short-lived organisms (e.g. microbes) rather than longer-lived organisms (e.g. trees).


1979 ◽  
Vol 90 (2) ◽  
pp. 372-384 ◽  
Author(s):  
N. P. Goncharov ◽  
A. G. Taranov ◽  
A. V. Antonichev ◽  
V. M. Gorlushkin ◽  
T. Aso ◽  
...  

ABSTRACT Adult baboons (5 males and 5 females) were exposed to immobilization stress by being strapped to a table in a horizontal position for 2 h. In females the experiment was performed during both the follicular and luteal phase. Peripheral blood was withdrawn at frequent intervals, the first sample just before immobilization, and the last one 3 days later. A number of steroids were measured in blood plasma samples by radioimmunoassay (17-hydroxypregnenolone, 17-hydroxyprogesterone, pregnenolone, testosterone, dihydrotestosterone, progesterone, 20α-dihydroprogesterone, oestrone, oestradiol) or competitive protein binding (cortisol) techniques. The cortisol levels exhibited a marked increase in both sexes. This increase was observed already during the immobilization and lasted for approximately 24 h. A similar, even more pronounced increase was seen in 17-hydroxypregnenolone, 17-hydroxyprogesterone and pregnenolone levels. A marked, long-lasting (72 h) decrease of testosterone and dihydrotestosterone levels was a consistent finding in male baboons. This was not observed in the females which, on the other hand, exhibited a marked decrease (duration 48 h) of progesterone and 20α-dihydroprogesterone levels during the luteal phase, and a significant decrease (duration > 24 h) of oestradiol and oestrone concentrations during the follicular phase. It is concluded that stress has a marked inhibitory action on gonadal function both in male and female baboons. In females the inhibition of steroidogenetic function is exerted both on the ovarian follicles and on the corpus luteum.


2012 ◽  
Vol 1 (1) ◽  
Author(s):  
Johnny Chavarría Viteri ◽  
Dennis Tomalá Solano

La variabilidad climática es la norma que ha modulado la vida en el planeta. Este trabajo demuestra que las pesquerías y acuicultura costera ecuatorianas no son la excepción, puesto que tales actividades están fuertemente influenciadas por la variabilidad ENSO (El Niño-Oscilación del Sur) y PDO (Oscilación Decadal del Pacífico), planteándose que la señal del cambio climático debe contribuir a esta influencia. Se destaca también que, en el análisis de los efectos de la variabilidad climática sobre los recursos pesqueros, el esfuerzo extractivo también debe ser considerado. Por su parte, la acción actual de la PDO está afectando la señal del cambio climático, encontrándose actualmente en fases opuestas. Se espera que estas señales entren en fase a finales de esta década, y principalmente durante la década de los 20 y consecuentemente se evidencien con mayor fuerza los efectos del Cambio Climático. Palabras Clave: Variabilidad Climática, Cambio Climático, ENSO, PDO, Pesquerías, Ecuador. ABSTRACT Climate variability is the standard that has modulated life in the planet. This work shows that the Ecuadorian  fisheries and aquaculture are not the exception, since such activities are strongly influenced by ENSO variability (El Niño - Southern Oscillation) and PDO (Pacific Decadal Oscillation), considering that the signal of climate change should contribute to this influence. It also emphasizes that in the analysis of the effects of climate variability on the fishing resources, the extractive effort must also be considered. For its part, the current action of the PDO is affecting the signal of climate change, now found on opposite phases. It is hoped that these signals come into phase at the end of this decade, and especially during the decade of the 20’s and more strongly evidencing the effects of climate change. Keywords: Climate variability, climate change, ENSO (El Niño - Southern Oscillation) and PDO  (Pacific Decadal Oscillation); fisheries, Ecuador. Recibido: mayo, 2012Aprobado: agosto, 2012


2020 ◽  
Author(s):  
Alistair Soutter ◽  
René Mõttus

Although the scientific evidence of anthropogenic climate change continues to grow, public discourse still reflects a high level of scepticism and political polarisation towards anthropogenic climate change. In this study (N = 499) we attempted to replicate and expand upon an earlier finding that environmental terminology (“climate change” versus “global warming”) could partly explain political polarisation in environmental scepticism (Schuldt, Konrath, & Schwarz, 2011). Participants completed a series of online questionnaires assessing personality traits, political preferences, belief in environmental phenomenon, and various pro-environmental attitudes and behaviours. Those with a Conservative political orientation and/or party voting believed less in both climate change and global warming compared to those with a Liberal orientation and/or party voting. Furthermore, there was an interaction between continuously measured political orientation, but not party voting, and question wording on beliefs in environmental phenomena. Personality traits did not confound these effects. Furthermore, continuously measured political orientation was associated with pro-environmental attitudes, after controlling for personality traits, age, gender, area lived in, income, and education. The personality domains of Openness, and Conscientiousness, were consistently associated with pro-environmental attitudes and behaviours, whereas Agreeableness was associated with pro-environmental attitudes but not with behaviours. This study highlights the importance of examining personality traits and political preferences together and suggests ways in which policy interventions can best be optimised to account for these individual differences.


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