Contributions of individual variation in temperature, solar radiation and precipitation to crop yield in the North China Plain, 1961–2003

An understanding of the relative impacts of the changes in climate variables on crop yield can help develop effective adaptation strategies to cope with climate change. This study was conducted to investigate the effects of the interannual variability and trends in temperature, solar radiation and precipitation during 1961–2003 on wheat and maize yields in a double cropping system at Beijing and Zhengzhou in the North China Plain (NCP), and to examine the relative contributions of each climate variable in isolation. 129 climate scenarios consisting of all the combinations of these climate variables were constructed. Each scenario contained 43 years of observed values of one variable, combined with values of the other two variables from each individual year repeated 43 times. The Agricultural Production Systems Simulator (APSIM) was used to simulate crop yields using the ensemble of generated climate scenarios. The results showed that the warming trend during the study period did not have significant impact on wheat yield potential at both sites, and only had significant negative impact on maize yield potential at Beijing. This is in contrast with previous results on effect of warming. The decreasing trend in solar radiation had a much greater impact on simulated yields of both wheat and maize crops, causing a significant reduction in potential yield of wheat and maize at Beijing. Although decreasing trends in rainfed yield of both simulated wheat and maize were found, the substantial interannual variability of precipitation made the trends less prominent

On the use and misuse of climate change projections in international development

Climate resilience is increasingly prioritized by international development agencies and national governments. However, current approaches to informing communities of future climate risk are problematic. The predominant focus on end-of-century projections neglects more pressing development concerns, which relate to the management of shorter-term risks and climate variability, and constitutes a substantial opportunity cost for the limited financial and human resources available to tackle development challenges. When a long-term view genuinely is relevant to decisionmaking, much of the information available is not fit for purpose. Climate model projections are able to capture many aspects of the climate system and so can be relied upon to guide mitigation plans and broad adaptation strategies, but the use of these models to guide local, practical adaptation actions is unwarranted. Climate models are unable to represent future conditions at the degree of spatial, temporal, and probabilistic precision with which projections are often provided, which gives a false impression of confidence to users of climate change information. In this article, we outline these issues, review their history, and provide a set of practical steps for both the development and climate scientist communities to consider. Solutions to mobilize the best available science include a focus on decision-relevant timescales, an increased role for model evaluation and expert judgment and the integration of climate variability into climate change service

Innovations in Climate Risk Management: Protecting and Building Rural Livelihoods in a Variable and Changing Climate

We argue that more effective management of climate risk must be part of the response of the international agriculture community to the double crisis of persistent poverty and a changing climate. The most promising opportunities to adapt to climate change involve action on shorter time scales that also contributes to immediate development challenges. Climate risk management (CRM) combines systematic use of climate information, and technology that reduces vulnerability and policy that transfers risk. The cost of climate risk comes both through damaging extreme events and through forfeited opportunity in climatically-favorable years. Effective CRM therefore involves managing the full range of variability, balancing hazard management with efforts to capitalize on opportunity. We discuss several innovations for managing climate risk in agriculture, which have not yet been fully mainstreamed in international agricultural research-for-development. First, effective rural climate information services enable farmers to adopt technology, intensify production, and invest in more profitable livelihoods when conditions are favorable; and to protect families and farms against the long-term consequences of adverse extremes. Second, information and decision support systems synthesize historic, monitored and forecast climate information into forms that are directly relevant to institutional decisions (planning, trade, food crisis response) that impact farmer livelihoods. Third, innovations in index-based insurance and credit overcome some of the limitations of traditional insurance, and are being applied to pre-financing food crisis response, and to removing credit constraints to adopting improved technology. We present a typology of CRM interventions around the concept of dynamic poverty traps

Tropical Oceanic Causes of Interannual to Multidecadal Precipitation Variability in Southeast South America over the Past Century

Observations, atmosphere models forced by historical SSTs, and idealized simulations are used to determine the causes and mechanisms of interannual to multidecadal precipitation anomalies over southeast South America (SESA) since 1901. About 40% of SESA precipitation variability over this period can be accounted for by global SST forcing. Both the tropical Pacific and Atlantic Oceans share the driving of SESA precipitation, with the latter contributing the most on multidecadal time scales and explaining a wetting trend from the early midcentury until the end of the last century. Cold tropical Atlantic SST anomalies are shown to drive wet conditions in SESA. The dynamics that link SESA precipitation to tropical Atlantic SST anomalies are explored. Cold tropical Atlantic SST anomalies force equatorward-flowing upper-tropospheric flow to the southeast of the tropical heating anomaly, and the vorticity advection by this flow is balanced by vortex stretching and ascent, which drives the increased precipitation. The 1930s Pampas Dust Bowl drought occurred, via this mechanism, in response to warm tropical Atlantic SST anomalies. The atmospheric response to cold tropical Pacific SSTs also contributed. The tropical Atlantic SST anomalies linked to SESA precipitation are the tropical components of the Atlantic multidecadal oscillation. There is little evidence that the large trends over past decades are related to anthropogenic radiative forcing, although models project that this will cause a modest wetting of the climate of SESA. As such, and if the Atlantic multidecadal oscillation has shifted toward a warm phase, it should not be assumed that the long-term wetting trend in SESA will continue. Any reversal to a drier climate more typical of earlier decades would have clear consequences for regional agriculture and water resources

A farm-level evaluation of nitrogen and phosphorus fertilizer use and planting density for pearl millet production in Niger

Mineral fertilizer use is increasing in West Africa though little information is available on yield response in farmers' fields. Farmers in this region plant at low density (average 5,000 pockets ha−1, 3 plants pocket−1), which can affect fertilizer use efficiency. A study was conducted with 20 farmers in Niger to assess the response of pearl millet [Pennisetum glaucum (L.) R. Br.] to phosphorus and nitrogen fertilizers under farm conditions. In each field, treatments included control, single superphosphate (SSP) only, SSP plus N (point placed near plant), and either SSP or partially acidulated phosphate rock (PAPR) plus N broadcast. N and P were applied at 30 kg N ha−1 and 30 kg P2O5 ha−1. Farmers were allowed to plant, weed, etc., as they wished and they planted at densities ranging from 2,000 to 12,000 pockets ha−1. In the absence of fertilizer, increasing density from 2,000 to 7,000 pockets ha−1 increased yield by 400%. A strong interaction was found between fertilizer use and density. Farmers planting at densities less than 3,500 pockets ha−1 had average yields of 317 kg grain ha−1 while those planting at densities higher than 6,500 pockets ha−1 showed average yields of 977 grain ha−1. Though phosphate alone increased yields significantly at all densities, little response to fertilizer N was found at densities below 6,000 pockets ha−1. Significant residual responses in 1987 and 1988 were found to P applied in high-density plots in 1986. Depending on fertilizer and grain prices, analysis showed that fertilizer use must be be combined with high plant density (10,000 pockets ha−1) or no economic benefit from fertilizer use will be realize

The International Research Institute for Climate and Society: why, what and how

A climate-informed and climate-ready world is possible. Large investments are being made toward adaptation and resilience to climate change, but many of those investments are separated from the more immediate climate-related vulnerabilities and opportunities that society faces. Information is increasingly available that could be used to guide action; however, information alone is not sufficient. Research at the International Research Institute for Climate and Society (IRI) since 1996 has led to the identification of the several guiding principles to scope and address climate-related challenges to decision- and policy-makers at local-to-regional scale. These include climate-related information, such as assessment of the main vulnerabilities to climate variability and change in countries or regions, and the provision of climate information, products and tools to support decisions, including financial tools that are appropriate to the climate-related risk and that can mediate residual risk. The guiding principles also include identifying the technologies and practices that optimize results in coming years, demonstration of the usefulness of climate information to support climate-related decisions, training and capacity building, and partnerships for research and implementation. This essay introduces the evolution of the IRI and its work that is then elaborated through a series of articles that constitute a special issue of Earth Perspectives: Transdisciplinarity Enabled. The collection of articles provides insight into the science and process that lead to better climate-informed choices. Part of the collection of articles in the special issue covers specific stories of local-to-regional engagement with partners to address climate-related problems. Other articles represent how we do what we do, in particular highlighting the research, the climate forecast effort, and the IRI Data Library. Finally, there are two papers offered from partners that have long-time engagement with the IR

The International Research Institute for Climate and Society: why, what and how

A climate-informed and climate-ready world is possible. Large investments are being made toward adaptation and resilience to climate change, but many of those investments are separated from the more immediate climate-related vulnerabilities and opportunities that society faces. Information is increasingly available that could be used to guide action; however, information alone is not sufficient. Research at the International Research Institute for Climate and Society (IRI) since 1996 has led to the identification of the several guiding principles to scope and address climate-related challenges to decision- and policy-makers at local-to-regional scale. These include climate-related information, such as assessment of the main vulnerabilities to climate variability and change in countries or regions, and the provision of climate information, products and tools to support decisions, including financial tools that are appropriate to the climate-related risk and that can mediate residual risk. The guiding principles also include identifying the technologies and practices that optimize results in coming years, demonstration of the usefulness of climate information to support climate-related decisions, training and capacity building, and partnerships for research and implementation. This essay introduces the evolution of the IRI and its work that is then elaborated through a series of articles that constitute a special issue of Earth Perspectives: Transdisciplinarity Enabled. The collection of articles provides insight into the science and process that lead to better climate-informed choices. Part of the collection of articles in the special issue covers specific stories of local-to-regional engagement with partners to address climate-related problems. Other articles represent how we do what we do, in particular highlighting the research, the climate forecast effort, and the IRI Data Library. Finally, there are two papers offered from partners that have long-time engagement with the IR

Cross–Time Scale Interactions and Rainfall Extreme Events in Southeastern South America for the Austral Summer. Part I: Potential Predictors

The physical mechanisms and predictability associated with extreme daily rainfall in southeastern South America (SESA) are investigated for the December–February season in a two-part study. Through a k-mean analysis, this first paper identifies a robust set of daily circulation regimes that are used to link the frequency of rainfall extreme events with large-scale potential predictors at subseasonal-to-seasonal scales. This represents a basic set of daily circulation regimes related to the continental and oceanic phases of the South Atlantic convergence zone (SACZ) and wave train patterns superimposed on the Southern Hemisphere polar jet. Some of these recurrent synoptic circulation types are conducive to extreme rainfall events in the region through synoptic control of different mesoscale physical features and, at the same time, are influenced by climate phenomena that could be used as sources of potential predictability. Extremely high rainfall (as measured by the 95th and 99th percentiles) is associated with two of these weather types (WTs), which are characterized by moisture advection intrusions from lower latitudes and the Pacific Ocean; another three WTs, characterized by above-normal moisture advection toward lower latitudes or the Andes, are associated with dry days (days with no rain). The analysis permits the identification of several subseasonal-to-seasonal scale potential predictors that modulate the occurrence of circulation regimes conducive to extreme rainfall events in SESA. It is conjectured that a cross–time scale interaction between the different climate drivers improves the predictive skill of extreme precipitation in the region

A framework for priority-setting in climate smart agriculture research

Climate-smart agriculture (CSA) is widely promoted as an approach for reorienting agricultural development under the realities of climate change. Prioritising research-for-development activities is crucial, given the need to utilise scarce resources as effectively as possible. However, no framework exists for assessing and comparing different CSA research investments. Several aspects make it challenging to prioritise CSA research, including its multi-dimensional nature (productivity, adaptation and mitigation), the uncertainty surrounding many climate impacts, and the scale and temporal dependencies that may affect the benefits and costs of CSA adoption. Here we propose a framework for prioritising agricultural research investments across scales and review different approaches to setting priorities among agricultural research projects. Many priority-setting case studies address the short- to medium-term and at relatively local scales. We suggest that a mix of actions that span spatial and temporal time scales is needed to be adaptive to a changing climate, address immediate problems and create enabling conditions for enduring change