The impact of equilibrating hemispheric albedos on tropical performance in the HadGEM2-ES coupled climate model

Haywood, J., Jones, A., Dunstone, N., Milton, S., Vellinga, M., Bodas-Salcedo, A., Hawcroft, M., Kravitz, B., Cole, J., Watanabe, S. and Stephens, G.

The Earth’s hemispheric reflectances are equivalent to within ± 0.2Wm_2, even though the Northern Hemisphere contains a greater proportion of higher reflectance land areas, because of greater cloud cover in the Southern Hemisphere. This equivalence is unlikely to be by chance, but the reasons are open to debate. Here we show that equilibrating hemispheric albedos in the Hadley Centre Global Environment Model version 2-Earth System coupled climate model significantly improves what have been considered longstanding and apparently intractable model biases. Monsoon precipitation biases over all continental land areas, the penetration of monsoon rainfall across the Sahel, the West African monsoon “jump”, and indicators of hurricane frequency are all significantly improved. Mechanistically, equilibrating hemispheric albedos improves the atmospheric cross-equatorial energy transport and increases the supply of tropical atmospheric moisture to the Hadley cell. We conclude that an accurate representation of the cross-equatorial energy transport appears to be critical if tropical performance is to be improved.

Improving hydropower outcomes through system-scale planning: an example from Myanmar

Report prepared for United Kingdom’s Department forInternational Development (DFID) by The Nature Conservancy, WWF and The University of Manchester

This report examines hydropower development in Myanmar to explore a fundamental challenge: how can governments make informed decisions about infrastructure development that will deliver the broadest range of benefits to their people over the long run? Hydropower provides a clear example of this challenge. For many countries, hydropower is a strategic resource that could increase energy supply at low costs and make important contributions to water resources management and development objectives (potential “co-benefits” of hydropower development and management). However, current approaches to hydropower development often fail to achieve this potential for broad benefits and incur high environmental and social costs. Decisions are often made at the scale of individual projects without a comprehensive understanding of how these projects fit within the larger context of both infrastructure systems and social and environmental resources. Short-term and project-focused decisions are not likely to produce hydropower systems that can fulfill their potential to achieve broad benefits and balanced development. This is because they will be systems in name only. In reality, they are groups of individual projects that are not well coordinated, miss opportunities for more optimal designs, and often cause high social and environmental costs—contributing to conflict and uncertainty for future investment. Most governments do not have a process in place to plan true systems and to strategically select projects that are in the best public interest.

Initial lists of AMMA-2050 user-relevant climate metrics

Dave Rowell, Doug Parker, Ndjido Kane, François Affholder, Adeline Barnaud, Vicky Bell, Andy Challinor, Françoise Gérard, Helen Houghton-Carr, Harouna Karambiri, James Miller, Kathryn Nicklin, Benjamin Sultan, Chris Taylor and Theo Vischel

This is a cross-project output that will inform AMMA-2050 Pillar 1 research.

December 9, 2015

Mainstreaming climate information into sector development

Paul Watkiss

This report demonstrates the use of climate information in assessing adaptation needs and implementing adaptation interventions. It provides an outline of the change in thinking that is happening as adaptation moves from theory to practice, how this translates into a different approach for assessing adaptation needs and the implications of this shift from climate information and services provision. It provides information on the adaptation and decision policy cycle, outlining the sequence of actions associated with practical programming, and the use of climate information within this.

These actions would include immediate actions that address the impacts of current climate variability and extremes such as by early capacity building and the introduction of low- and no-regret actions which are actions, adaptation policies, plans or options that “generate net social and/or economic benefits irrespective of whether or not anthropogenic climate change occurs”. In addition this would integrate adaptation into immediate decisions or activities with long life times, such as infrastructure or planning as well as early planning for the future impacts of climate change, noting uncertainty. This would include a focus on adaptive management, the value of information and future options/ learning, especially when decision life-times are long or future risks are very large or irreversible.

Finally, it demonstrates this sequence using a real case study application on mainstreaming climate adaptation into the sector agricultural development plan in Rwanda by finding relevant entry points, identifying opportunities in national, sector or local planning processes where adaptation can best be integrated. Critically, these entry points vary with the specific adaptation problem. It also requires analysis of existing policies and objectives, to include adaptation in decision-making, especially as climate will be one of many challenges, and not necessarily the dominant one. Complementing the identification of entry points is the identification and engagement of stakeholders.

The role of storage capacity in coping with intra- and inter-annual water variability in large river basins

Gaupp, F., Hall, J. and Dadson, S.

Societies and economies are challenged by variable water supplies. Water storage infrastructure, on a range of scales, can help to mitigate hydrological variability. This study uses a water balance model to investigate how storage capacity can improve water security in the world’s 403 most important river basins, by substituting water from wet months to dry months. We construct a new water balance model for 676 ‘basin-country units’ (BCUs), which simulates runoff, water use (from surface and groundwater), evaporation and trans-boundary discharges. When hydrological variability and net withdrawals are taken into account, along with existing storage capacity, we find risks of water shortages in the Indian subcontinent, Northern China, Spain, the West of the US, Australia and several basins in Africa. Dividing basins into BCUs enabled assessment of upstream dependency in transboundary rivers. Including Environmental Water Requirements into the model, we find that in many basins in India, Northern China, South Africa, the US West Coast, the East of Brazil, Spain and in the Murray basin in Australia human water demand leads to over-abstraction of water resources important to the ecosystem. Then, a Sequent Peak Analysis is conducted to estimate how much storage would be needed to satisfy human water demand whilst not jeopardizing environmental flows. The results are consistent with the water balance model in that basins in India, Northern China, Western Australia, Spain, the US West Coast and several basins in Africa would need more storage to mitigate water supply variability and to meet water demand.

The recent partial recovery in Sahel rainfall: a fingerprint of greenhouse gases forcing?

Serge Janicot, Marco Gaetani, Frederic Hourdin, Alessandra Giannini, Michela Biasutti, Elsa Mohino, Yongkang Xue, Aaron Boone, Amadou Gaye, Seyni Salack and Christophe Lavaysse

In the present context of climate transition under the influence of anthropogenic forcings, a critical issue is proper attribution of climate anomalies, in order to avoid misinterpretations leading to possible maladaptations. Over the last 60 years, the monsoon region of the Sahel has been coping with some of the most severe climate variability in the world, including two decades of persistent excessive rainfall in the 1950s–1960s, followed by two decades of rainfall deficits (see figure on page 12). Recently, there has been a partial recovery with annual rainfall amounts fluctuating around the long-term mean, more evident over the central Sahel than over the western Sahel (Lebel and Ali, 2009). The current period is also characterized by a deficit of rainy days with a rise in extreme rainfall occurrences, indicating the intensification of the hydrological cycle (Giannini et al., 2013; Panthou et al., 2014). This climate is drier in the sense of persistent dry spells compared to the 1950s–1960s, while at the same time there is an increased probability of floods.

Recent observed and simulated changes in precipitation over Africa

Ross I. Maidment, Richard P. Allan, and Emily Black

Multiple observational data sets and atmosphere-only simulations from the Coupled Model Intercomparison Project Phase 5 are analysed to characterise recent rainfall variability and trends over Africa focusing on 1983–2010. Datasets exhibiting spurious variability, linked in part to a reduction in rain gauge density, were identiﬁed. The remaining observations display coherent increases in annual Sahel rainfall (29 to 43 mm yr per decade), decreases in March – May East African rainfall (- 14 to – 65 mm yr per decade), and increases in annual Southern Africa rainfall (32 to 41 mm yr per decade). However, CentralAfrica annual rainfall trends vary in sign ( – 10 to +39 mm yr per decade). For Southern Africa, observed and sea surface temperature (SST)-forced model simulated rainfall variability are signiﬁcantly correlated (r~0.5)and linked to SST patterns associated with recent strengthening of the Paci ﬁc Walker circulation.

May 12, 2015
// Climate science

Literature Review: The Economics, Political Economy and Behavioural Science of Accounting for Long-term Climate in Decision Making Today

GCAP, Vivid Economics, UK Met Office and Atkins

This report summarises the findings of Phase 1 of the project ‘Economics, Political Economy and Behavioural Science of Accounting for Long-term Climate in Decisions Making Today’. It includes a literature review of the barriers to long-term decision-making and identifies practical examples of long-term decisions that should be actively accounting for future (10 years+) climate in decisions taken today.

The findings of this report was used to provide initial conclusions and develop a framework and methodology for a series of economic case studies. The overarching aims of the project were to analyse and identify the types of development decisions that should be actively accounting for future (10 years+) climate in decisions taken today, and to advance quantitative evidence on this to help inform decisions made by development practitioners in Africa.

The study was undertaken by the Global Climate Adaptation Partnership working with Vivid Economics, the UK Met Office and Atkins.

Report from the Future Climate for Africa Pilot Country Case Study project

CSAG, START, SEI and University of Ghana

As a precursor to the Future Climate for Africa (FCFA) research activities, CDKN, on behalf of DFID commissioned a series of case study activities with the purposes of exploring the climate science needs of decision makers in Africa. The intention was for the learning gained through these pilot case studies to inform the design and implementation of the broader FCFA research activities over the coming years.

The overarching aim of the case studies was to

Provide users with the state of the art scientific information and build their capacity to use such information to support long term adaptation
Contribute to the identification of climate information needs for real decision-making, with a view to informing the design of the FCFA

The proposed case study rested strongly on the “co-exploration” model of engagement. The primary concept of co-exploration is that the decision-making process is complex and progresses through different stages. Different climate information is required at different stages and the nature of this information is not known beforehand, rather it emerges through the decision process. The process therefore requires the continual engagement of climate scientists and decision makers as the decision is explored, hence the term “co-exploration”. As will emerge through the results of the case study below, the co-exploration approach is diametrically opposite to the dominant approach practised in most real world decision-making contexts.

This report describes the outcomes and activities of the case study, including the desktop study, the initial participant engagements, and the workshop activities itself. It draws out key learning messages that address the guiding questions posed by DFID and CDKN as well as identifying discrete learning points gained from implementation.

Rwanda technical report

GCAP, UK Met Office and Atkins

To help guide the FCFA programme, the Climate and Development Knowledge Network (CDKN) was commissioned by the UK Department for International Development (DFID) to undertake a scoping phase.

The Rwanda FCFA case study was undertaken by the Global Climate Adaptation Partnerships (GCAP), working with the UK Met Office and Atkins. The case study undertook four major activities:

A literature review was undertaken to frame the context for adaptation applications. This identified relevant decisions and support methods, particularly for medium to long‐term decisions.

A country background and policy assessment was undertaken to understand the adaptation context in Rwanda. This included analysis of development plans, the DFID office portfolio, current vulnerability, future climate projections, key future climate risks, and existing climate change/adaptation activities.

An initial country visit was undertaken and a large number of bi‐lateral interviews (25) were held with key stakeholders, to understand the decision context and end‐use applications for existing and potential adaptation activities, and to explore the current/future use of climate information.

A number of practical and policy-relevant medium‐long term adaptation case studies were selected and assessed in detail, considering the problem area, decision processes, current use of climate information, and the opportunities for medium‐to long‐term policy making. New CMIP5 climate projection information (focusing on relevant case study metrics) was developed, and a review of climate‐hydrological information needs was made. The case studies were discussed in a second country visit/interviews.