Climate Analogues Research Articles

Moderate levels of Eocene pCO2 indicated by Southern Hemisphere fossil plant stomata

Abstract Reducing the uncertainty in predictions of future climate change is one of today’s greatest scientific challenges, with many significant problems unsolved, including the relationship between pCO2 and global temperature. To better constrain these forecasts, it is meaningful to study past time intervals of global warmth, such as the Eocene (56.0–33.9 Ma), serving as climatic analogues for the future. Here we reconstructed pCO2 using the stomatal densities of a large fossil Lauraceae (laurel) leaf database from ten sites across the Eocene of Australia and New Zealand. We show that mostly moderate pCO2 levels of ∼450–600 ppm prevailed throughout the Eocene, levels that are considerably lower than the pCO2 forcing currently needed to recreate Eocene temperatures in climate models. Our data record significantly lower pCO2 than inferred from marine isotopes, but concur with previously published Northern Hemisphere Eocene stomatal proxy pCO2. We argue that the now globally consistent stomatal proxy pCO2 record for the Eocene is robust and that climate sensitivity was elevated and/or that additional climate forcings operated more powerfully than previously assumed.

Climate change likely to reshape vegetation in North America's largest protected areas

AbstractClimate change poses a serious threat to biodiversity and unprecedented challenges to the preservation and protection of natural landscapes. We evaluated how climate change might affect vegetation in 22 of the largest and most iconic protected area (PA) complexes across North America. We use a climate analog model to estimate how dominant vegetation types might shift under mid‐ (2041–2070) and late‐century (2071–2100) climate according to the RCP 8.5 scenario. Maps depicting vegetation for each PA and time period are provided. Our analysis suggests that half (11 of 22) of the PAs may have substantially different vegetation by late‐21st century compared with reference period conditions. The overall trend is toward vegetation associated with warmer or drier climates (or both), with near complete losses of alpine communities at the highest elevations and high latitudes. At low elevation and latitudes, vegetation communities associated with novel climate conditions may assemble in PAs. These potential shifts, contractions, and expansions in vegetation portray the possible trends across landscapes that are of great concern for conservation, as such changes imply cascading ecological responses for associated flora and fauna. Overall, our findings highlight the challenges managers may face to maintain and preserve biodiversity in key PAs across North America.

Economic benefits of blast-resistant biofortified wheat in Bangladesh: The case of BARI Gom 33

The first occurrence of wheat blast in 2016 threatened Bangladesh's already precarious food security situation. The Bangladesh Agricultural Research Institute (BARI), together with the International Maize and Wheat Improvement Center (CIMMYT) developed and released the wheat variety BARI Gom 33 that is resistant to wheat blast and other common diseases. The new variety provides a 5–8% yield gain over the available popular varieties, as well as being zinc enriched. This study examines the potential economic benefits of BARI Gom 33 in Bangladesh. First, applying a climate analogue model, this study identified that more than 55% of the total wheat-growing area in Bangladesh (across 45 districts) is vulnerable to wheat blast. Second, applying an ex-ante impact assessment framework, this study shows that with an assumed cumulative adoption starting from 2019–20 and increasing to 30% by 2027–28, the potential economic benefits of the newly developed wheat variety far exceeds its dissemination cost by 2029–30. Even if dissemination of the new wheat variety is limited to only the ten currently blast-affected districts, the yearly average net benefits could amount to USD 0.23–1.6 million. Based on the findings, international funder agencies are urged to support the national system in scaling out the new wheat variety and wheat research in general to ensure overall food security in Bangladesh and South Asia.

Monsoon Responses to Climate Changes—Connecting Past, Present and Future

Knowledge of how monsoons will respond to external forcings through the twenty-first century has been confounded by incomplete theories of tropical climate and insufficient representation in climate models. This review highlights recent insights from past warm climates and historical trends that can inform our understanding of monsoon evolution in the context of an emerging energetic framework. Projections consistent with paleoclimate evidence and theory indicate expanded/wetter monsoons in Africa and Asia, with continued uncertainty in the Americas. Twentieth century observations are not congruent with expectations of monsoon responses to radiative forcing from greenhouse gases, due to the confounding effect of aerosols. Lines of evidence from warm climate analogues indicate that while monsoons respond in globally coherent and predictable ways to orbital forcing and inter-hemispheric thermal gradients, there are differences in response to these forcings and also between land and ocean. Further understanding of monsoon responses to climate change will require refinement of the energetic framework to incorporate zonal asymmetries and the use of model hierarchies.

Impact of climate change on Ostrinia nubilalis (Lepidoptera: Crambidae) phenology and its implications on pest management

Abstract Climate change can cause negative impacts to the agricultural sector by increasing pest damage to crops. The European corn borer (ECB) is a major insect pest of corn in North America. Its speed of development could potentially accelerate under a warmer climate, leading to an earlier development of the first generation and an increase in the number of generations per year. The main objective of this study was to assess the potential impacts of climate change on ECB management for the future period 2041–2070 in Quebec, Canada, using bioclimatic modelling and climate analogues. First flight of ECB moths could occur about 15 days earlier in the season in 2041–2070 compared to the reference period 1970–1999. The window for insecticide interventions may be reduced under climate change by 15.6% to 27.8% for univoltine ECB and by 13.8% to 52.7% for bivoltine ECB. Climate change could promote the development of an additional generation in the southern region for both races, considering temperature increases and factors inducing the overwintering diapause. ECB management could become more costly both economically and environmentally under the future climate, and it should be revised according to the results of this study.

Contemporary climatic analogs for 540 North American urban areas in the late 21st century

A major challenge in articulating human dimensions of climate change lies in translating global climate forecasts into impact assessments that are intuitive to the public. Climate-analog mapping involves matching the expected future climate at a location (e.g., a person’s city of residence) with current climate of another, potentially familiar, location - thereby providing a more relatable, place-based assessment of climate change. For 540 North American urban areas, we used climate-analog mapping to identify the location that has a contemporary climate most similar to each urban area’s expected 2080’s climate. We show that climate of most urban areas will shift considerably and become either more akin to contemporary climates hundreds of kilometers away and mainly to the south or will have no modern equivalent. Combined with an interactive web application, we provide an intuitive means of raising public awareness of the implications of climate change for 250 million urban residents.

Using a Multiyear Temporal Climate-Analog Approach to Assess Climate Change Impacts on Park Visitation

AbstractBecause of the perceived weather sensitivity of park visitation in Ontario, Canada, several previous assessments have examined the impact of climate change. However, these assessments have predominantly been based on modeling approaches (regression analysis). The current study uses a multiyear temporal climate-analog approach to reassess the impact of climate change on visitation to Pinery Provincial Park in southwestern Ontario based on the observed effects of historical climatic anomalies on park visitation from 2000 to 2016. Consideration was also given to major events such as the North American terror attacks on 11 September 2001 and the confounding effect that events such as this may have had on the results. There were no statistically significant relationships (at the 95% confidence level) between seasonal climatic anomalies and park visitation in Ontario during the winter or spring seasons. There was a weak statistical relationship between anomalously warm summer seasons and park visitation, when compared to summer seasons with climatically normal temperatures; however, the presence of nonclimatic variables may have confounded these results, producing a false positive. Autumn-season park visitation was most sensitive to climatic anomalies, with the warmest temperatures causing visitation to increase by 37%, the wettest conditions causing visitation to decrease by 11%, and the driest conditions resulting in a 24% increase. These observed seasonal temperature anomalies represent temporal climate analogs for projected climate change across the span of the twenty-first century. Thus, the results of this study suggest that previous assessments may have overestimated the positive impacts of projected climate change on park visitation in this region.

Future Climate Analogues of Current Wheat Production Zones in India

The future of agriculture in India will be affected by substantial changes in the environment, although not uniformly across the country. These changes, as projected by the well-known General Circulation Model will grossly impact the food-cropping system. While developing adaptation strategies, it would be useful to understand the current climatic and farming regimes in similar or analogue sites, which have already experienced future conditions. The data used in this paper are from a study using the Climate Analogues tool, a web-based tool developed by the Research Programme on Climate Change, Agriculture and Food Security, which uses spatial and temporal variability in climate projections for different climatic scenarios using the General Circulation Model. Sites with statistically similar climates were thus identified and mapped; these include two sites from four different agro-ecological regions of wheat cropping in India. Comparisons were made specifically for the year 2030, keeping in mind changes in agricultural techniques and mechanisms that could potentially occur over a span of one and a half decades. Temperature was prioritized over other climatic variables in this study, which was conducted using the ECHAM models for the .:42 scenario. A comparison of the current yields of the selected sites with those of the future' analogue sites revealed the former to be at low, moderate or high risk, in accordance with the projected future climatic conditions for wheat cultivation. Most sites appeared to be at moderate risk due to temperature increase at these sites by the year 2030, and except for two sites, had significantly reduced yields.

Projecting Tree Species Composition Changes of European Forests for 2061-2090 Under RCP 4.5 and RCP 8.5 Scenarios.

Climate change poses certain threats to the World’s forests. That is, tree performance declines if species-specific, climatic thresholds are surpassed. Prominent climatic changes negatively affecting tree performance are mainly associated with so-called hotter droughts. In combination with biotic pathogens, hotter droughts cause a higher tree vulnerability and thus mortality. As a consequence, global forests are expected to undergo vast changes in the course of climate change. Changed climatic conditions may on the one hand locally result in more frequent dieback of a particular tree species but on the other hand allow other—locally yet absent species—to establish themselves, thereby potentially changing local tree-species diversity. Although several studies provide valuable insights into potential risks of prominent European tree species, we yet lack a comprehensive assessment on how and to which extent the composition of European forests may change. To overcome this research gap, we here project future tree-species compositions of European forests. We combine the concept of climate analogs with national forest inventory data to project the tree-species composition for the 26 most important European tree species at any given location in Europe for the period 2061–2090 and the two most relevant CMIP5 scenarios RCP 4.5 and RCP 8.5. Our results indicate significant changes in European forests species compositions. Species richness generally declined in the Mediterranean and Central European lowlands, while Scandinavian and Central European high-elevation forests were projected an increasing diversity. Moreover, 76% (RCP 4.5) and 80% (RCP 8.5) of the investigated locations indicated a decreasing abundance of the locally yet most abundant tree species while 74 and 68% were projected an increasing tree-species diversity. Altogether, our study confirms the expectation of European forests undergoing remarkable changes until the end of the 21st century (i.e., 2061–2090) and provides a scientific basement for climate change adaptation with important implications for forestry and nature conservation.

Palynology of Cenozoic successions of Kerala Basin: a review from the perspective of biostratigraphy and palaeoclimatic studies

The Kerala Basin is only onshore opportunity to study Cenozoic palaeoclimate and palaeoenvironment of southwest India encompassing Neogene global events such as Mid Miocene Climate Optimum (MMCO) and even older times of Palaeogene. The global warming during ~17–15 Ma (MMCO), enhanced annual surface temperature 3–4° C higher than the present, is equivalent to the warming predicted for the next century. Since the palaeogeographical and other general conditions have not been much changed from the Miocene Period, Neogene palaeoclimate of Kerala Basin can be considered as a possible analogue for future climate. Many workers have studied the Cenozoic sedimentary successions of surface and subsurface for stratigraphic classification of the rocks, but still, discrepancy persists in the chronostratigraphic relationship in sedimentary successions. The palynological investigations have also been limited mainly to palynofloral and palaeoecological inferences except a few in which palynostratigraphy, correlation and age have been attempted on the basis of spore–pollen only. Major three Cenozones namely, Triangulorites bellus and Crassoretitriletes vanraadshooveni (Eocene–Oligocene) and Malvacearumpollis bakonyensis (Miocene) have been established. The palynological studies done in the region broadly suggest warm and humid climate with heavy rainfall. However, the recent quantitative studies have highlighted the complexity of palaeoclimatic evolution in the tropics in terms of monsoon. A time–constrained quantitative palaeovegetation and palaeoclimate reconstructions on the basis of palynology is required for evaluation of response and changes in the tropical flora of northwestern India across the major climate events. For that, the biostratigraphy of finer resolution based on systematic and integrated multi–biotic proxy is needed to establish an age model for these sedimentary successions.

Reduction in nutritional quality and growing area suitability of common bean under climate change induced drought stress in Africa

Climate change impacts on food security will involve negative impacts on crop yields, and potentially on the nutritional quality of staple crops. Common bean is the most important grain legume staple crop for human diets and nutrition worldwide. We demonstrate by crop modeling that the majority of current common bean growing areas in southeastern Africa will become unsuitable for bean cultivation by the year 2050. We further demonstrate reductions in yields of available common bean varieties in a field trial that is a climate analogue site for future predicted drought conditions. Little is known regarding the impact of climate change induced abiotic stresses on the nutritional quality of common beans. Our analysis of nutritional and antinutritional compounds reveals that iron levels in common bean grains are reduced under future climate-scenario relevant drought stress conditions. In contrast, the levels of protein, zinc, lead and phytic acid increase in the beans under such drought stress conditions. This indicates that under climate-change induced drought scenarios, future bean servings by 2050 will likely have lower nutritional quality, posing challenges for ongoing climate-proofing of bean production for yields, nutritional quality, human health, and food security.

Eemian Greenland SMB strongly sensitive to model choice

Abstract. Understanding the behavior of the Greenland ice sheet in a warmer climate, and particularly its surface mass balance (SMB), is important for assessing Greenland's potential contribution to future sea level rise. The Eemian interglacial period, the most recent warmer-than-present period in Earth's history approximately 125 000 years ago, provides an analogue for a warm summer climate over Greenland. The Eemian is characterized by a positive Northern Hemisphere summer insolation anomaly, which complicates Eemian SMB calculations based on positive degree day estimates. In this study, we use Eemian global and regional climate simulations in combination with three types of SMB models – a simple positive degree day, an intermediate complexity, and a full surface energy balance model – to evaluate the importance of regional climate and model complexity for estimates of Greenland's SMB. We find that all SMB models perform well under the relatively cool pre-industrial and late Eemian. For the relatively warm early Eemian, the differences between SMB models are large, which is associated with whether insolation is included in the respective models. For all simulated time slices, there is a systematic difference between globally and regionally forced SMB models, due to the different representation of the regional climate over Greenland. We conclude that both the resolution of the simulated climate as well as the method used to estimate the SMB are important for an accurate simulation of Greenland's SMB. Whether model resolution or the SMB method is most important depends on the climate state and in particular the prevailing insolation pattern. We suggest that future Eemian climate model intercomparison studies should include SMB estimates and a scheme to capture SMB uncertainties.

Understanding how changing rainfall may impact on urban drainage systems; lessons from projects in the UK and USA

Abstract Urban flooding and wet weather pollution are recognised as significant problems across the world, and changes in rainfall patterns arising as a consequence of climate change are likely to exacerbate these problems. This paper shares learning from a ground-breaking project led by CH2M for UK Water Industry Research and approaches used in other CH2M projects around the world. The UK project has explored the use of very high resolution (1.5 km) climate model output and climate analogues; other projects have used other methods to derive new design rainfall statistics commonly used in modelling wet weather collection systems for flooding and pollution investigations. Estimates of rainfall change have been used within collection system models to estimate the flooding and pollution impact of these changes. The methods applied in these projects can be replicated globally.

Drought and vegetation change in the central Rocky Mountains and western Great Plains: potential climatic mechanisms associated with megadrought conditions at 4200 cal yr BP

Abstract. Droughts are a naturally re-occurring phenomena that result in economic and societal losses. Yet, the most historic droughts that occurred in the 1930s and 1950s in the Great Plains and western United States were both shorter in duration and less severe than megadroughts that have plagued the region in the past. Roughly 4200 years ago, a ∼150-year long megadrought occurred in the central Rocky Mountains, as indicated by sedimentary pollen evidence documenting a brief and unique change in vegetation composition from Long Lake, southeastern Wyoming. Neighbouring the central Rocky Mountains, several dune fields reactivated in the western Great Plains around this time period illustrating a severe regional drought. While sedimentary pollen provides evidence of past drought, paleoecological evidence does not provide context for the climate mechanisms that may have caused the drought. Thus, a modern climate analogue technique was applied to the sedimentary pollen and regional dune reactivation evidence identified from the region to provide a conceptual framework for exploring possible mechanisms responsible for the observed ecological changes. The modern climate analogues of 2002/2012 illustrate that warm and dry conditions persisted through the growing season and were associated with anomalously higher-than-normal geopotential heights centred over the Great Plains. In the spring, higher-than-normal heights suppressed moisture transport via the low-level jet from the Gulf of Mexico creating a more southwesterly component of flow. In the summer, higher-than-normal heights persisted over the northern Great Plains resulting in a wind shift with an easterly component of flow, drawing in dry continental air into the study region. In both cases, lower-than-normal moisture in the atmosphere (via 850 mbar specific humidity) inhibited uplift and potential precipitation. Thus, if the present scenario existed during the 4.2 ka drought, the associated climatic responses are consistent with local and regional proxy data suggesting regional drought conditions in the central Rocky Mountains and western Great Plains.

Distribution and protection of climatic refugia in North America.

As evidenced by past climatic refugia, locations projected to harbor remnants of present-day climates may serve as critical refugia for current biodiversity in the face of modern climate change. We mapped potential climatic refugia in the future across North America, defined as locations with increasingly rare climatic conditions. We identified these locations by tracking projected changes in the size and distribution of climate analogs over time. We used biologically derived thresholds to define analogs and tested the impacts of dispersal limitation with 4 distances to limit analog searches. We identified at most 12% of North America as potential climatic refugia. Refugia extent varied depending on the analog threshold, dispersal distance, and climate projection. However, in all cases refugia were concentrated at high elevations and in topographically complex regions. Refugia identified using different climate projections were largely nested, suggesting that identified refugia were relatively robust to climate-projection selection. Existing conservation areas cover approximately 10% of North America and yet protected up to 25% of identified refugia, indicating that protected areas disproportionately include refugia. Refugia located at lower latitudes (≤40°N) and slightly lower elevations (approximately 2500 m) were more likely to be unprotected. Based on our results, a 23% expansion of the protected-area network would be sufficient to protect the refugia present under all 3 climate projections we explored. We believe these refugia are high conservation priorities due to their potential to harbor rare species in the future. However, these locations are simultaneously highly vulnerable to climate change over the long term. These refugia contracted substantially between the 2050s and the 2080s, which supports the idea that the pace of climate change will strongly determine the availability and effectiveness of refugia for protecting today's biodiversity.

Using climate analogue tools to explore and build smallholder farmer capacity for climate smart agriculture

Background: The phenomenon of climate change (CC) and its attendant challenges in agriculture have been widely document. Climate Smart Agriculture (CSA) focuses on sustainable agriculture intensification for food sovereignty through the adoption of mitigation and adaptation practices. Agriculture provides the livelihood for 70% of rural poor in the developing world, so building farmer capacity in CSA is imperative for food security. Studies show that transformative change must be bottom-up – integrating scientific and ethical dimensions, using participatory research approaches that employ simple comprehensive tools for building participants’ capacity to adapt. Methods: The study uses the “Climate Change Agriculture and Food Security” (CCAFS) climate analogue and weather forecasting tools. These participatory learning tools allow participants to interrogate and explore their own geographical and climatic histories and to draw conclusions on climate variability. This study examined smallholder farmers’ understanding of CC and their resilience to it. The study consisted of 5 stages – selection of tools, planning and training of teams, meetings with community leaders and community members to select participants, focus group discussions, modelling sessions and community dissemination meetings. Results: Participants showed awareness of CC, explained in terms of rainfall variability, decreasing rainforest, increasing temperature and excessively long hot days. Farmers illustrated gendered perception of past and present landscapes, time use, past seasonal trends, vulnerabilities and access to key resources. They also observed that natural resources were declining, while population and social infrastructure increased. Participants modelled the shift in seasons and projected possible future scenarios. Finally, participants were willing to adopt climate smart agronomic practices. Conclusions: After establishing that farmers are aware of CC, follow-on-studies addressing the impediments to adaptation and provision of necessary tools and resources to facilitate adaptation must be carried out. This study can also be replicated among a larger smallholder population for increased capacity to practice CSA.

Climatic, topographic, and anthropogenic factors determine connectivity between current and future climate analogs in North America.

As climatic conditions shift in coming decades, persistence of many populations will depend on their ability to colonize habitat newly suitable for their climatic requirements. Opportunities for such range shifts may be limited unless areas that facilitate dispersal under climate change are identified and protected from land uses that impede movement. While many climate adaptation strategies focus on identifying refugia, this study is the first to characterize areas which merit protection for their role in promoting climate connectivity at a continental extent. We identified climate connectivity areas across North America by delineating paths between current climate types and their future analogs that avoided nonanalogous climates, and used centrality metrics to rank the contribution of each location to facilitating dispersal across the landscape. The distribution of connectivity areas was influenced by climatic and topographic factors at multiple spatial scales. Results were robust to uncertainty in the magnitude of future climate change arising from differing emissions scenarios and general circulation models, but sensitive to analysis extent and assumptions concerning dispersal behavior and maximum dispersal distance. Paths were funneled along north-south trending passes and valley systems and away from areas of novel and disappearing climates. Climate connectivity areas, where many potential dispersal paths overlapped, were distinct from refugia and thus poorly captured by many existing conservation strategies. Existing protected areas with high connectivity values were found in southern Mexico, the southwestern US, and western and arctic Canada and Alaska. Ecoregions within the Isthmus of Tehuantepec, Great Plains, eastern temperate forests, high Arctic, and western Canadian Cordillera hold important climate connectivity areas which merit increased conservation focus due to anthropogenic pressures or current low levels of protection. Our coarse-filter climate-type-based results complement and contextualize species-specific analyses and add a missing dimension to climate adaptation planning by identifying landscape features which promote connectivity among refugia.

Using tetraether lipids archived in North Sea Basin sediments to extract North Western European Pliocene continental air temperatures

The Pliocene is often regarded as a suitable analogue for future climate, due to an overall warmer climate (2–3 °C) coupled with atmospheric CO2 concentrations largely similar to present values (∼400 ppmv). Numerous Pliocene sea surface temperature (SST) records are available, however, little is known about climate in the terrestrial realm. Here we generated a Pliocene continental temperature record for Northwestern Europe based on branched glycerol dialkyl glycerol tetraether (brGDGT) membrane lipids stored in a marine sedimentary record from the western Netherlands. The total organic carbon (TOC) content of the sediments and its stable carbon isotopic composition (δ13Corg) indicate a strong transition from primarily marine derived organic matter (OM) during the Pliocene, to predominantly terrestrially derived OM after the transition into the Pleistocene. This trend is supported by the ratio of branched and isoprenoid tetraethers (BIT index). The marine–terrestrial transition indicates a likely change in brGDGT sources in the core, which may complicate the applicability of the brGDGT paleotemperature proxy in this setting. Currently, the application of the brGDGT-based paleothermometer on coastal marine sediments has been hampered by a marine overprint. Here, we propose a method to disentangle terrestrial and marine sources based on the degree of cyclization of tetramethylated brGDGTs (#rings) using a linear mixing model based on the global soil calibration set and a newly developed coastal marine temperature transfer function. Application of this method on our brGDGT record resulted in a ‘corrected’ terrestrial temperature record (MATterr). This latter record indicates that continental temperatures were ∼12–14 °C during the Early Pliocene, and 10.5–12 °C during the Mid Pliocene, confirming other Pliocene pollen based terrestrial temperature estimates from Northern and Central Europe. Furthermore, two colder (Δ 5–7 °C) periods in the Pliocene MATterr record show that the influence of Pliocene glacials reached well into NW Europe.

A Bayesian modelling method for post-processing daily sub-seasonal to seasonal rainfall forecasts from global climate models and evaluation for 12 Australian catchments

Abstract. Rainfall forecasts are an integral part of hydrological forecasting systems at sub-seasonal to seasonal timescales. In seasonal forecasting, global climate models (GCMs) are now the go-to source for rainfall forecasts. For hydrological applications however, GCM forecasts are often biased and unreliable in uncertainty spread, and calibration is therefore required before use. There are sophisticated statistical techniques for calibrating monthly and seasonal aggregations of the forecasts. However, calibration of seasonal forecasts at the daily time step typically uses very simple statistical methods or climate analogue methods. These methods generally lack the sophistication to achieve unbiased, reliable and coherent forecasts of daily amounts and seasonal accumulated totals. In this study, we propose and evaluate a Rainfall Post-Processing method for Seasonal forecasts (RPP-S), which is based on the Bayesian joint probability modelling approach for calibrating daily forecasts and the Schaake Shuffle for connecting the daily ensemble members of different lead times. We apply the method to post-process ACCESS-S forecasts for 12 perennial and ephemeral catchments across Australia and for 12 initialisation dates. RPP-S significantly reduces bias in raw forecasts and improves both skill and reliability. RPP-S forecasts are also more skilful and reliable than forecasts derived from ACCESS-S forecasts that have been post-processed using quantile mapping, especially for monthly and seasonal accumulations. Several opportunities to improve the robustness and skill of RPP-S are identified. The new RPP-S post-processed forecasts will be used in ensemble sub-seasonal to seasonal streamflow applications.

Application of the climate analogue concept in assessing the probable physiological and haematological responses of Friesian cattle to changing and variable climate in the Kenyan Highlands

Friesian cattle are considered the most sensitive to climate change-induced thermal stress and remain the major dairy breed in Kenya. This study applied the climate analogue concept to predict probable physiological and haematological responses of Friesian cattle in the 2050s to understand their adaptability to a changing and variable climate. Njoro in the Kenya Rift Valley Highlands was used as the reference site and its 2050s climate analogue site was identified in Shawa, based on criteria of a similarity index of 0.8–0.9. Results suggest that Njoro in the 2050s will likely experience increasing temperatures, but changes in rainfall are uncertain. The increasing temperatures will probably be accompanied by mild thermal stress for Friesian cattle during the dry seasons or drought. The thermal humidity index differed between times of day, but not between the analogue sites. Except for rectal temperatures, the physiological and haematological responses differed between the analogue sites, but were within the normal ranges. It is concluded that Friesian cattle in Njoro in the 2050s will probably experience mild thermal stress in the afternoons during the dry seasons, expressed by slight increases in physiological and haematological responses, but will probably remain within the normal margins.Keywords: Dairy cattle, haematimetric, Njoro, Rongai, thermal humidity index