Understanding the process of adaptation to climate change by small-holder farmers: The case of east Hararghe Zone, Ethiopia

This study examined smallholder farmers' level of perception about climate change, source of information on climate change, types of adaptation strategies, factors influencing adaptation choices and barriers to adaptation in Eastern Hararghe Zone, Ethiopia. The surveyed farm households in the study area perceived at least one aspect of climate change primarily through their life experience. Planting trees is the major adaptation measure and 89.1 percent of the farmers took this adaptation strategy. Most farmers (96 percent) believe that deforestation is the main cause of climate change and the choice of farmers to plant trees as an adaptation strategy may be partly a mitigation strategy. However, the majority (49.6 percent) of the households employed at least one adaptation response on top of tree planting. The other adaptation strategies include: early planting, terracing, irrigation and water harvesting. The main source of information for these adaptation strategies for 58.4 percent of the respondents is from extension advice. Results of a multinomial logit model showed that non-farm income, farmer- to-farmer extension, access to credit, distance to selling markets, distance to purchasing markets, and income affect the choice of adaptation strategies. Finally, the study identified lack of information as the most important barrier to climate change adaptation. The other barriers include: lack of farm inputs, shortage of land, lack of money, lack of water and shortage of labor

Burden of disease attributable to suboptimal diet, metabolic risks, and low physical activity in Ethiopia and comparison with Eastern sub-Saharan African countries, 1990-2015: findings from the Global Burden of Disease Study 2015

Background: Twelve of the 17 Sustainable Development Goals (SDGs) are related to malnutrition (both under- and overnutrition), other behavioral, and metabolic risk factors. However, comparative evidence on the impact of behavioral and metabolic risk factors on disease burden is limited in sub-Saharan Africa (SSA), including Ethiopia. Using data from the Global Burden of Disease (GBD) Study, we assessed mortality and disability-adjusted life years (DALYs) attributable to child and maternal undernutrition (CMU), dietary risks, metabolic risks and low physical activity for Ethiopia. The results were compared with 14 other Eastern SSA countries. Methods: Databases from GBD 2015, that consist of data from 1990 to 2015, were used. A comparative risk assessment approach was utilized to estimate the burden of disease attributable to CMU, dietary risks, metabolic risks and low physical activity. Exposure levels of the risk factors were estimated using spatiotemporal Gaussian process regression (ST-GPR) and Bayesian meta-regression models. Results: In 2015, there were 58,783 [95% uncertainty interval (UI): 43,653-76,020] or 8.9% [95% UI: 6.1-12.5] estimated all-cause deaths attributable to CMU, 66,269 [95% UI: 39,367-106,512] or 9.7% [95% UI: 7.4-12.3] to dietary risks, 105,057 [95% UI: 66,167-157,071] or 15.4% [95% UI: 12.8-17.6] to metabolic risks and 5808 [95% UI: 3449-9359] or 0.9% [95% UI: 0.6-1.1]to low physical activity in Ethiopia. While the age-adjusted proportion of all-cause mortality attributable to CMU decreased significantly between 1990 and 2015, it increased from 10.8% [95% UI: 8.8-13.3] to 14.5% [95% UI: 11.7-18.0] for dietary risks and from 17.0% [95% UI: 15.4-18.7] to 24.2% [95% UI: 22.2-26.1] for metabolic risks. In 2015, Ethiopia ranked among the top four countries (of 15 Eastern SSA countries) in terms of mortality and DALYs based on the age-standardized proportion of disease attributable to dietary risks and metabolic risks. Conclusions: In Ethiopia, while there was a decline in mortality and DALYs attributable to CMU over the last two and half decades, the burden attributable to dietary and metabolic risks have increased during the same period. Lifestyle and metabolic risks of NCDs require more attention by the primary health care system of in the country

Frequent but Predictable Droughts in East Africa Driven by a Walker Circulation Intensification

During and after recent La Niña events, the decline of the eastern East African (EA) March-April-May (MAM) rains has set the stage for life-threatening sequential October-November-December (OND) and MAM droughts. The MAM 2022 drought was the driest on record, preceded by three poor rainy seasons, and followed by widespread starvation. Connecting these dry seasons is an interaction between La Niña and climate change. This interaction provides important opportunities for long-lead prediction and proactive disaster risk management, but needs exploration. Here, for the first time, we use observations, reanalyses, and climate change simulations to show that post-1997 OND La Niña events are robust precursors of: (a) strong MAM “Western V sea surface temperature Gradients” in the Pacific, which (b) help produce large increases in moisture convergence and atmospheric heating near Indonesia, which in turn produce (c) regional shifts in moisture transports and vertical velocities, which (d) help explain the increased frequency of dry EA MAM rainy seasons. We also show that, at 20-year time scales, increases in atmospheric heating in the Indo-Pacific Warm Pool region are attributable to warming Western V SST, which is in turn largely attributable to climate change. As energy builds up in the oceans and atmosphere, during and after La Niña events, we see stronger heating and heat convergence over warm tropical waters near Indonesia. The result of this causal chain is that increased Warm Pool atmospheric heating and moisture convergence sets the stage for dangerous sequential droughts in EA. These factors link EA drying to a stronger Walker Circulation and explain the predictable risks associated with recent La Niña events

Defining the concept of ‘tick repellency’ in veterinary medicine

Although widely used, the term repellency needs to be employed with care when applied to ticks and other periodic or permanent ectoparasites. Repellency has classically been used to describe the effects of a substance that causes a flying arthropod to make oriented movements away from its source. However, for crawling arthropods such as ticks, the term commonly subsumes a range of effects that include arthropod irritation and consequent avoiding or leaving the host, failing to attach, to bite, or to feed. The objective of the present article is to highlight the need for clarity, to propose consensus descriptions and methods for the evaluation of various effects on ticks caused by chemical substances

Atmospheric and oceanic conditions associated with early and late onset for Eastern Africa short rains

Timing of the rainy season is essential for a number of climate sensitive sectors over Eastern Africa. This is particularly true for the agricultural sector, where most activities depend on both the spatial and temporal distribution of rainfall throughout the season. Using a combination of observational and reanalysis datasets, the present study investigates the atmospheric and oceanic conditions associated with early and late onset for Eastern Africa short rains season (October–December). Our results indicate enhanced rainfall in October and November during years with early onset and rainfall deficit in years with late onset for the same months. Early onset years are found to be associated with warmer sea surface temperatures (SSTs) in the western Indian Ocean, and an enhanced moisture flux and anomalous low-level flow into Eastern Africa from as early as the first dekad of September. The late onset years are characterized by cooler SSTs in the western Indian Ocean, anomalous westerly moisture flux and zonal flow limiting moisture supply to the region. The variability in onset date is separated into the interannual and decadal components, and the links with SSTs and low-level circulation over the Indian Ocean basin are examined separately for both timescales. Significant correlations are found between the interannual variability of the onset and the Indian Ocean dipole mode index. On decadal timescales the onset is shown to be partly driven by the variability of the SSTs over the Indian Ocean. Understanding the influence of these potentially predictable SST and moisture patterns on onset variability has huge potential to improve forecasts of the East African short rains. Improved prediction of the variability of the rainy season onset has huge implications for improving key strategic decisions and preparedness action in many sectors, including agriculture

Correction to: A Fresh Take: Seasonal Changes in Terrestrial Freshwater Inputs Impact Salt Marsh Hydrology and Vegetation Dynamics (Estuaries and Coasts, (2024), 10.1007/s12237-024-01392-1)

In the original online version of the article the following information was missing from the Funding section: Department of Energy, Small Business Innovation Research Award Number DE-SC0021480. In addition, the following was missing from the Acknowledgements: The authors would like to thank Elkhorn Slough Foundation for providing and facilitating the opportunity to conduct this work at the Cowell Ranch site. Also, the study site noted in the Background section was incorrect. The study was conducted at the Elkhorn Slough on the property of the Elkhorn Slough Foundation. The original article was corrected

A Fresh Take: Seasonal Changes in Terrestrial Freshwater Inputs Impact Salt Marsh Hydrology and Vegetation Dynamics

Abstract: Salt marshes exist at the terrestrial-marine interface, providing important ecosystem services such as nutrient cycling and carbon sequestration. Tidal inputs play a dominant role in salt marsh porewater mixing, and terrestrially derived freshwater inputs are increasingly recognized as important sources of water and solutes to intertidal wetlands. However, there remains a critical gap in understanding the role of freshwater inputs on salt marsh hydrology, and how this may impact marsh subsurface salinity and plant productivity. Here, we address this knowledge gap by examining the hydrologic behavior, porewater salinity, and pickleweed (Sarcocornia pacifica also known as Salicornia pacifica) plant productivity along a salt marsh transect in an estuary along the central coast of California. Through the installation of a suite of hydrometric sensors and routine porewater sampling and vegetation surveys, we sought to understand how seasonal changes in terrestrial freshwater inputs impact salt marsh ecohydrologic processes. We found that salt marsh porewater salinity, shallow subsurface saturation, and pickleweed productivity are closely coupled with elevated upland water level during the winter and spring, and more influenced by tidal inputs during the summer and fall. This seasonal response indicates a switch in salt marsh hydrologic connectivity with the terrestrial upland that impacts ecosystem functioning. Through elucidating the interannual impacts of drought on salt marsh hydrology, we found that the severity of drought and historical precipitation can impact contemporary hydrologic behavior and the duration and timing of the upland-marsh hydrologic connectivity. This implies that the sensitivity of salt marshes to climate change involves a complex interaction between sea level rise and freshwater inputs that vary at seasonal to interannual timescales

Simulated response of the climate of eastern Africa to stratospheric aerosol intervention

Eastern Africa is vulnerable to extreme climate events, including droughts and floods, which are expected to become more frequent and intense in the future. This paper evaluates the potential of solar radiation management (SRM) with stratospheric aerosol injection (SAI) to influence the projected climate, including extreme events, over the region. The study utilized climate simulation outputs from the Community Earth System Model version 2 with the Whole Atmosphere Community Climate Model (CESM2-WACCM6) to assess future climate changes under two scenarios: one without Solar Aerosol Injection (SAI) following the SSP2-4.5 emissions pathway, and another with SAI, based on the first set of simulations from the Assessing Responses and Impacts of Solar Climate Intervention on the Earth System with Stratospheric Aerosol Injection (ARISE-SAI) project. The analysis of model performance was conducted for the 1981–2010 period, while future changes were assessed over two climatological periods: the near-term (2035–2054) and the mid-term (2050–2069). Changes in extreme temperatures and rainfall events were evaluated using four extreme indices: two for temperature (WSDI and DTR) and two for rainfall (CDD and CWD). Additionally, the Standardized Precipitation-Evapotranspiration Index (SPEI) was used to assess changes in the frequency of extreme wet and dry events. In the historical period, there is good agreement between the observed and simulated data in representing the spatial distribution of temperature and rainfall over the region, despite the slight overestimation and underestimation by the model in some areas. The model effectively captures the seasonal cycles of rainfall and temperature over the cities of interest. Analysis of future projections indicates that temperatures are projected to rise consistently in the future under the SSP2-4.5 scenario. However, SAI produces a steady trend in the four cities, suggesting SAI’s potential to counteract warming in Eastern Africa. Rainfall is projected to increase in the equatorial region compared to the reference period, while other areas remain stable. ARISE-SAI shows higher increases in rainfall during the MAM season but lower increases during the JJAS and OND seasons compared to SSP2-4.5. Overall, the study’s findings suggest that SAI technology could have a clear effect in reducing temperatures in Eastern Africa, both in the near- and mid-term futures. However, its impact on rainfall varies by region and season, indicating that further simulations with a wider range of scenarios and analyses are required to assess the robustness of these results. The results of this study should be interpreted cautiously since they are specific to the approach of SAI applied, the modelling experiments employed, and the scenarios considered