‘Splendid rains have fallen’: links between El Niño and rainfall variability in the Kalahari, 1840–1900

This study uses a range of published and unpublished historical documentary sources to explore the nature of rainfall variability in the Kalahari Desert and adjacent hardveld regions of central southern Africa during the seventeen Pacific El Niño–Southern Oscillation (ENSO) episodes that occurred between 1840 and 1900. Documentary data are used in two ways. First, maps of relative annual rainfall levels are presented for each of the 12 single-year and five protracted ENSO episodes during the period, in order to identify the associated inter-annual rainfall variations. These suggest that the relationship between ENSO episodes and rainfall variability identified for the twentieth century, whereby warm events are frequently preceded by wetter conditions during the austral summer prior to the event year and succeeded by drought in the following summer, has broadly held for much of the last 160 years. This is despite the long-term fluctuations in precipitation and temperature which are known to have occurred over this period. Droughts are identified following at least thirteen of the 17 single-year and protracted ENSO episodes. Pre-ENSO wetter periods are less common, with only nine of the ENSO episodes preceded by above-normal rainfall. Second, the documentary data are analyzed in detail in order to reveal any evidence for high resolution intra-annual variations in the seasonal distribution of rainfall during ENSO events. Seasonal sequences of rainfall/drought appear to have closely followed contemporary patterns, with heavy rainfall commonly occurring late in the pre-ENSO year or early in the ENSO year(s), and drought at the start of the post-ENSO year. This relationship can be seen to hold most strongly for single-year ENSO warm events and for the first year of protracted events, but rainfall conditions were more variable during the later years of protracted events.     

Asymmetric impact of rainfall on India’s food grain production: evidence from quantile autoregressive distributed lag model

This study used a quantile autoregressive distributed lag (QARDL) model to capture asymmetric impact of rainfall on food production in India. It was found that the coefficient corresponding to the rainfall in the QARDL increased till the 75th quantile and started decreasing thereafter, though it remained in the positive territory. Another interesting finding is that at the 90th quantile and above the coefficients of rainfall though remained positive was not statistically significant and therefore, the benefit of high rainfall on crop production was not conclusive. However, the impact of other determinants, such as fertilizer and pesticide consumption, is quite uniform over the whole range of the distribution of food grain production.     

Estimation of global temperature trends: what’s important and what isn’t

In this essay we discuss the development of and estimation of uncertainties in the global surface temperature record. We briefly discuss the similarities in and differences between the records from the institutions that produce such series. We then consider the numerous issues that must be addressed to enable accurate estimates to be derived. We consider these in their order of importance with respect to the record: biases in the sea surface temperature data, exposure of land-based thermometers before about 1900, urbanization effects in some series, and, finally, the homogeneity of individual land-based records.     

Diurnal Evolution and Annual Variability of Boundary-Layer Height and Its Correlation to Other Meteorological Variables in California’s Central Valley

One year of observations from a network of five 915-MHz boundary-layer radar wind profilers equipped with radio acoustic sounding systems located in California’s Central Valley are used to investigate the annual variability of convective boundary-layer depth and its correlation to meteorological parameters and conditions. Results from the analysis show that at four of the sites, the boundary-layer height reaches its maximum in the late-spring months then surprisingly decreases during the summer months, with mean July depths almost identical to those for December. The temporal decrease in boundary-layer depth, as well as its spatial variation, is found to be consistent with the nocturnal low-level lapse rate observed at each site. Multiple forcing mechanisms that could explain the unexpected seasonal behaviour of boundary-layer depth are investigated, including solar radiation, precipitation, boundary-layer mesoscale convergence, low-level cold-air advection, local surface characteristics and irrigation patterns and synoptic-scale subsidence. Variations in solar radiation, precipitation and synoptic-scale subsidence do not explain the shallow summertime convective boundary-layer depths observed. Topographically forced cold-air advection and local land-use characteristics can help explain the shallow CBL depths at the four sites, while topographically forced low-level convergence helps maintain larger CBL depths at the fifth site near the southern end of the valley.     

“A sky of brass and burning winds”: documentary evidence of rainfall variability in the Kingdom of Lesotho, Southern Africa, 1824–1900

Forecasting austral summer rainfall in southern Africa is hampered by a lack of long-term instrumental data. This paper extends the historical record for the subcontinent by presenting the first extensive 19th century climate history for Lesotho derived from documentary evidence. The data sources included unpublished English-, French- and Sesotho-language materials archived in Lesotho, South Africa and the UK. These included letters, journals and reports written by missionaries and colonial authorities, which were supplemented by newspapers, diaries, travelogues and other historical sources. Each source was read in chronological order, with any climate information recorded verbatim. Observations were classified into five categories (Very Wet, Relatively Wet, ‘Normal’, Relatively Dry, and Very Dry) based upon the predominant documented climate during each ‘rain-year’ (July to June). The latter portion of the chronology was then compared for accuracy against available instrumental precipitation records from Maseru (1886–1900). The results yield a semi-continuous record of climate information from 1824 to 1900. Data are restricted to lowland areas, but reveal drought episodes in 1833–34, 1841–42, 1845–47, 1848–51, 1858–63, 1865–69, 1876–80, 1882–85 and 1895–99 (the most severe drought years being 1850–51 and 1862–63) and wet periods or floods in 1835–36, 1838–41, 1847–48, 1854–56, 1863–65, 1873–75, 1880–81, 1885–86 and 1890–94. The rainfall chronology is compared with similar records for South Africa, Botswana and Zimbabwe. Linkages to possible forcing mechanisms, including ENSO teleconnections and historical coral-derived southwest Indian Ocean sea surface temperature variations are also explored.     

The stresses and dynamics of smallholder coffee systems in Jamaica’s Blue Mountains: a case for the potential role of climate services

Access to climate information has the potential to build adaptive capacity, improve agricultural profitability, and help manage risks. To achieve these benefits, knowledge of the local context is needed to inform information development, delivery, and use. We examine coffee farming in the Jamaican Blue Mountains (BM) to understand farmer livelihoods, opportunities for climate knowledge to benefit coffee production, and the factors that impinge on farmers’ ability to use climate information. Our analysis draws on interviews and 12 focus groups involving 143 participants who largely cultivate small plots. BM farmers currently experience stresses related to climate, coffee leaf rust, and production costs that interrelate concurrently and with time lags. Under conditions that reduce income, BM farmers compensate by adjusting their use of inputs, which can increase their susceptibility to future climate and disease stresses. However, farmers can also decrease impacts of future stressors by more efficiently and effectively allocating their limited resources. In this sense, managing climate, like the other stresses, is an ongoing process. While we identify climate products that can help farmers manage climate risk, the local context presents barriers that argue for interactive climate services that go beyond conventional approaches of information production and delivery. We discuss how dialogs between farmers, extension personnel, and climate scientists can create a foundation from which use can emerge.     

Empirical calibration of climate policy using corporate solvency: a case study of the UK’s carbon price support

Emission reductions improve the chances that dangerous anthropogenic climate change will be averted, but could also cause some firms financial distress. Corporate failures, especially if they are unnecessary, add to the social cost of abatement. Social value can be permanently destroyed by the dissolution of organizational capital, deadweight losses paid to liquidators, and unemployment. This article proposes using measures of corporate solvency as an objective tool for policy makers to calibrate the optimal stringency of climate change policies, so that they can deliver the least loss of corporate solvency for a given level of emission reductions. They could also be used to determine the generosity of any compensation to address losses to corporate solvency. We demonstrate this approach using a case study of the UK’s Carbon Price Support (a carbon tax).

Key policy insights

• Solvency metrics could be used to empirically calibrate the optimal stringency of climate policies.

• An idealized solvency trajectory for firms affected by climate change policy would cause corporate solvency to initially decline – approaching but not exceeding ‘distressed’ levels – and then gradually improve to a new ‘steady state’ once the low-carbon transition had been achieved.

• In terms of the UK’s Carbon Price Support, corporate solvency of energy-intensive industries was found to be stable subsequent to its introduction. Therefore, the available evidence does not support its later weakening.

     

Institutional change and the political economy of water megaprojects: China’s south-north water transfer

This paper analyses the relationship between megaproject construction and change in water management institutions. Due to the wide geographical distribution of their costs and benefits, which often spans national and provincial borders, water supply megaprojects frequently prompt intentional or evolutionary institutional change. China’s South-North Water Transfer Project (Middle Route), the world’s largest interbasin transfer project, was completed in December 2014 and is now in operation. Based on extensive fieldwork and analysis of Chinese documents, this paper introduces the government actors involved in, and impacted by, the planning and construction of the project. By detailing the interests of these actors, and the way those interests have been affected by the political, economic and environmental changes wrought by the megaproject, it shows that the Middle Route project has already contributed to change in one major financial institution – water pricing – and is exerting pressure on at least two others—infrastructure financing and compensation. Despite the regulatory efforts of the Chinese central government, incomplete institutional change processes threaten the long-term viability of the megaproject. Megaprojects demand institutional change and this must be factored into policymaking processes; business as usual will not suffice if the real benefits of the South-North Water Transfer are to be fairly distributed and its negative social, economic and environmental effects mitigated and appropriately compensated.     

Integrated assessment of smallholder farming’s vulnerability to drought in the Brazilian Semi-arid: a case study in Ceará

Smallholder farming is among the most vulnerable sectors due to its great social and economic sensitivity. Despite future climate change, current climate variability is already an issue of concern that justifies adaptation efforts. In Brazil, the Semi-Arid Region is a climate hotspot, well known for both historic socioeconomic setbacks, and agriculture failures caused by dry spells and severe droughts. In 2010, the Brazilian government enacted the National Policy on Climate Change, which states as one of its key goals the identification of vulnerabilities and the adoption of adequate measures of adaptation to climate change. The improvement of vulnerability assessment tools is a response to the growing demand of decision makers for regular information and indicators with high spatial and temporal resolution. This article aims at undertaking a comparative assessment of smallholder farming’s vulnerability to droughts. An integrated assessment system has been developed and applied to seven municipalities located in the Brazilian Semi-Arid Region (within the State of Ceará). Results show regional vulnerability contrasts driven by institutional and socioeconomic factors, beyond climatic stressors.     

Unravelling the United Kingdom’s climate policy consensus: The power of ideas,discourse and institutions

As climate change policies and governance initiatives struggle to produce the transformational social changes required, the search for stand out case studies continues. Many have pointed to the period between 2005 and 2008 in the United Kingdom as a promising example of national level innovation. With strong cross-party consensus and a first-of-its-kind legislation the UK established itself as a climate policy leader. However, early warning signs suggest that this institutionalised position is far from secure. Through a novel application of discursive institutionalism this article presents a detailed analysis of the role of ideas in unravelling this ambition under the Conservative-Liberal coalition administration (2010–2015). Discursive interactions among policymakers and other political actors were dominated by ideas about governmental responsibility and economic austerity, establishing an atmosphere of climate policy scepticism and restraint. By situating this conspicuous and influential process of bricolage within its institutional context the importance of how policymakers think and communicate about climate change is made apparent. The power of ideas to influence policy is further demonstrated through their cognitive and normative persuasiveness, by imposing over and excluding alternatives and in their institutional positioning. It can be concluded that despite innovative legislation, institution building and strategic coordination of different types of governance actors the ideational foundations of ambitious climate change politics in the UK have been undermined.     

Hydro-climatic variability over the Andes of Colombia associated with ENSO: a review of climatic processes and their impact on one of the Earth��s most important biodiversity hotspots

The hydro-climatic variability of the Colombian Andes associated with El Ni?o?CSouthern Oscillation (ENSO) is reviewed using records of rainfall, river discharges, soil moisture, and a vegetation index (NDVI) as a surrogate for evapotranspiration. Anomalies in the components of the surface water balance during both phases of ENSO are quantified in terms of their sign, timing, and magnitude. During El Ni?o (La Ni?a), the region experiences negative (positive) anomalies in rainfall, river discharges (average and extremes), soil moisture, and NDVI. ENSO??s effects are phase-locked to the seasonal cycle, being stronger during December?CFebruary, and weaker during March?CMay. Besides, rainfall and river discharges anomalies show that the ENSO signal exhibits a westerly wave-like propagation, being stronger (weaker) and earlier (later) over the western (eastern) Andes. Soil moisture anomalies are land-cover type dependant, but overall they are enhanced by ENSO, showing very low values during El Ni?o (mainly during dry seasons), but saturation values during La Ni?a. A suite of large-scale and regional mechanisms cooperating at the ocean?Catmosphere?Cland system are reviewed to explaining the identified hydro-climatic anomalies. This review contributes to an understanding of the hydro-climatic framework of a region identified as the most critical hotspot for biodiversity on Earth, and constitutes a wake-up call for scientists and policy-makers alike, to take actions and mobilize resources and minds to prevent the further destruction of the region??s valuable hydrologic and biodiversity resources and ecosystems. It also sheds lights towards the implementation of strategies and adaptation plans to coping with threats from global environmental change.     

Erratum to: Simulating the impacts of climate change, prices and population on California’s residential electricity consumption

We discovered an error in the computer code generating the simulation results in section 5 of Auffhammer and Aroonruengsawat (Clim Chang 109(Supplement 1):191–210, 2011). While four out of five main findings are unaffected, the simulated impacts of climate change on annual residential electricity consumption are an order of magnitude smaller, which is consistent with findings in the previous literature.     

Influence of Indian Ocean Dipole and Pacific recharge on following year’s El Niño: interdecadal robustness

The Indian Ocean Dipole (IOD) can affect the El Niño–Southern Oscillation (ENSO) state of the following year, in addition to the well-known preconditioning by equatorial Pacific Warm Water Volume (WWV), as suggested by a study based on observations over the recent satellite era (1981–2009). The present paper explores the interdecadal robustness of this result over the 1872–2008 period. To this end, we develop a robust IOD index, which well exploits sparse historical observations in the tropical Indian Ocean, and an efficient proxy of WWV interannual variations based on the temporal integral of Pacific zonal wind stress (of a historical atmospheric reanalysis). A linear regression hindcast model based on these two indices in boreal fall explains 50 % of ENSO peak variance 14 months later, with significant contributions from both the IOD and WWV over most of the historical period and a similar skill for El Niño and La Niña events. Our results further reveal that, when combined with WWV, the IOD index provides a larger ENSO hindcast skill improvement than the Indian Ocean basin-wide mode, the Indian Monsoon or ENSO itself. Based on these results, we propose a revised scheme of Indo-Pacific interactions. In this scheme, the IOD–ENSO interactions favour a biennial timescale and interact with the slower recharge-discharge cycle intrinsic to the Pacific Ocean.     

Simulations of a Cold-Air Pool in Utah’s Salt Lake Valley: Sensitivity to Land Use and Snow Cover

Obtaining realistic land-surface states for initial and boundary conditions is important for the numerical weather prediction of many atmospheric phenomena. Here we investigate model sensitivity to land use and snow cover for a persistent wintertime cold-air pool in northern Utah during 1–8 January 2011. A Weather Research and Forecast model simulation using the 1993 United States Geological Survey land-use and North American Mesoscale model reanalysis snow-cover datasets is compared to an improved configuration using the modified 2011 National Land Cover Database and a more realistic representation of snow cover. The improved surface specification results in an increase (decrease) in urban land cover (Great Salt Lake surface area), and changes to the snow-cover initialization, depth, extent, and albedo. The results obtained from the model simulations are compared to observations collected during the Persistent Cold-Air Pool Study. The changes in land use and snow cover and the resulting impacts on the surface albedo and surface heat fluxes contributed to near-surface air temperature increases of 1–\(2\,^{\circ }\hbox {C}\) in urban areas and decreases of 2–\(4\,^{\circ }\hbox {C}\) in areas surrounding the Great Salt Lake. Although wind speeds in the boundary layer were overestimated in both simulations, shallow thermally-driven and terrain-forced flows were generally lessened in intensity and breadth in response to the decreased areal extent of the Great Salt Lake and increases in the urban footprint.     

Taming São Paulo’s floods: Dominant discourses,exclusionary practices,and the complicity of the media

Climate change leads to more frequent and severe flooding, urging cities to adapt to protect their populations and assets. Despite exacerbated hazards, governments repeatedly draw on ‘tried-and-true’ approaches to protect the status quo, often with serious adverse effects for the poor and vulnerable. Yet, such dominant approaches do not go unchallenged as the media and other actors prompt public debate to assess flood impacts, scrutinise government decisions, and perhaps even promote alternative practices. News outlets are not, however, balanced or value-free; the events portrayed and the voices (and knowledges) recognised and included in media coverage deeply influence whether and how flooding is incorporated in policy. Focusing on São Paulo, Brazil, we examine how the media framed flood events and conveyed solutions during the city’s worst floods in recorded history. We demonstrate how competing media outlets largely depicted flooding as a natural phenomenon to be solved by governments and experts through existing techno-managerial practices, mirroring governmental partisan plans for adaptive action. In doing so, the media failed to offer a democratic space for public discussion, citizen contestation, and the advancement of alternative trajectories for adaptation. We posit that inclusive trajectories that address entrenched vulnerabilities and projected climate change will benefit from rigorous ethical debates around the media’s role in disaster coverage while strategically leveraging alternative media outlets as public pedagogy and agenda-setting tools.     

Well-being and environmental change in the arctic: a synthesis of selected research from Canada’s International Polar Year program

The social and cultural dimensions of arctic environmental change were explored through Canada??s International Polar Year (IPY) research program. Drawing on concepts of vulnerability, resilience and human security, we discuss preliminary results of 15 IPY research projects (of 52) which dealt with the effects and responses of northern communities to issues of ecological variability, natural resource development and climate change. This paper attempts to determine whether the preliminary results of these projects have contributed to the IPY program goal of building knowledge about well-being in the arctic. The projects were diverse in focus and approach but together offer a valuable pan-northern perspective on many themes including land and resource use, food security, poverty and best practices of northern engagement. Case study research using self-reported measures suggests individual views of their own well-being differ from regional and territorial standardized statistics on quality of life. A large body of work was developed around changes in land and resource use. A decline in land and resource use in some areas and consequent concerns for food security, are directly linked to the effects of climate change, particularly in coastal areas where melting sea ice, erratic weather events and changes in the stability of landscapes (e.g., erosion, slumping) are leading to increased risks for land users. Natural resource development, while creating some new economic opportunities, may be compounding rather than offsetting such stresses of environmental change for vulnerable populations. While the IPY program has contributed to our understanding of some aspects of well-being in the arctic, many other issues of social, economic, cultural and political significance, including those unrelated to environmental change, remain poorly understood.