SciDev.Net

This Nature paper reviews evidence that a changing climate poses significant health risks and that global warming over the past few years has already increased illness and death worldwide.

Infectious diseases are strongly affected by climatic variations because the vectors that carry the bacteria or viruses do not have thermoregulatory mechanisms, say the authors. One of the most important existing sources of climatic variability is El Niño. This weather system has been shown to influence malaria in South America, rift valley fever in east Africa, cholera in Bangladesh and dengue fever in Thailand. If, as some scientists have suggested, climate change alters El Niño, the consequences will be significant.

The authors say there are some promising early warning systems for infectious disease. In Botswana, for example, two-thirds of the inter-annual variability of malaria can be predicted from sea surface temperatures and monthly rainfall.

A population's immunity to disease can greatly affect outbreaks of vector-borne disease, and isolating the influence of climate variability has proven difficult. This research study sets out to evaluate the effect of climate by accounting for population immunity.

The authors collated data on cholera cases from a predominant strain in the rural area of Matlab, Bangladesh, from 1966–2002. They used a model to incorporate immunity from previous infections and also potential cross-immunity from previous infections by other strains. They found that both forms of immunity were long-lasting — over 10 years in some cases. Yet the variation in transmission did not always match variations in immunity; at several points, it coincided with severe weather change such as monsoon rains or river overflow.

The authors suggest that forecasting disease will require considering climate variability alongside population susceptibility.

This extensive report from the Institute of Medicine of the US National Academies takes on the considerable challenge of understanding how, and to what extent, climate change will affect infectious diseases.

The report provides detailed summaries of current knowledge on diseases such as cholera and rift valley fever. Several pages are devoted to reviewing the latest climate science to contextualise the effect on infectious disease; it also includes several maps on climate anomalies to show how they are linked to disease.

One section highlights methods to assess climate change impacts on infectious diseases. These include analyses of historical records; monitoring programs, especially those that track disease in wild animals; and comparisons of satellite-derived environmental measurements with epidemiological data.

The report concludes with an analysis of the challenges facing policymakers. In many cases, it says, the best public health measures against climate change are those that strengthen health systems in general, such as better training for professionals and better disease surveillance. Policymakers will need to move away from the traditional thinking of individual policies for individual diseases, towards a joined-up approach aimed at tackling "systemic, long-term" stresses that cause a range of effects.

Paul Reiter, a researcher on insects and infectious disease at the Institut Pasteur in France, is not convinced that climate change will cause a rise in malaria in tropical regions. In this opinionated review he sets out to dispel widely held "common misconceptions" about the effect of climate variability on future transmission.

To do so, he examines the history of malaria. He finds that in the past, contrary to expectations, climate has often not affected the transmission of the malaria parasite. Researchers claim that the Anopheles mosquito that carries the parasite cannot survive extreme temperatures, yet Reiter cites examples of the mosquito finding ways to adapt. In Sudan, for example, they can survive temperatures of over 55 degrees Celsius by hiding in buildings in daytime and only feeding after midnight.

Reiter's main disagreement with prediction models is that they only look at how one climate variable, temperature, is likely to interact with mosquito populations. Temperature, rainfall and humidity are interconnected and cannot be analysed separately, he says. The ecology of mosquitoes and humans is too complex to predict future malaria prevalence and incidence from temperature alone, he adds.

As global temperatures rise, vector-borne disease is set to increase in the developing world but patterns will vary across countries. This review looks at how the prevalence of vector-borne disease will change in Africa, Asia, Australia, Europe, North America and South America.

As the authors explain, urbanisation levels will determine which diseases are likely to hit hardest. For example, dengue fever is a largely urban disease and will affect South America, where over 70 per cent of the population live in cities, far more than it will Sub-Saharan Africa, where less than 30 per cent of people live in urban areas. Malaria, by contrast, will have a bigger impact in Africa.

As ecosystems change, so will the distribution of vector species. Some will find their habitats expanded. A positive note is that most vectors cannot survive above about 40 degrees Celsius, so regions in which warming tips the temperature over this level could well see a drop in vector-borne disease — this is starting to be seen in Senegal, for example.

But the precise extent to which climate variability affects vector-borne disease is yet unknown, say the authors, which hampers evidence-based policy change.

This report provides a policy framework for assessing the impacts of climate change on health, including vector-borne disease, by considering five challenges: informational, poverty and equity-related, technological, sociopolitical and institutional.

It begins with a detailed outline of climate science so far and the financial cost of adaptation. The informational challenges relate to better monitoring and surveillance to gather urgently needed data on disease and mortality in different regions, and early warning systems to predict extreme weather events and associated disease outbreaks. Technological challenges include the development of vaccines for diseases such as malaria and dengue fever.

How do policymakers tackle such challenges? A key move will be for government and non-government agencies, academia and civil society to collaborate internationally. Surveillance and primary health information systems in developing countries must be improved and local communities need to share adaptation strategies.

Adapting to climate change also means investing in food security, clean water supplies and reforestation. Policymakers also need to stimulate industry to develop low-cost methods for recycling wastewater and desalinating sea water. Mitigating and adapting to climate change, say the authors, has become inextricable from policies to eradicate poverty or closing the gap on social inequalities and health.

This report, published by the Food and Agricultural Organization of the UN and Policy Innovation Systems for Clean Energy Security (PISCES), presents fifteen case studies of small-scale bioenergy initiatives across Africa, Asia and Latin America.

The authors assess to what extent these initiatives are both providing clean and convenient energy access in developing countries, as well as supporting rural livelihoods.

The case studies focus on a range of bioenergy resources including forestry, agriculture and industrial activities used to meet local energy needs such as cooking, lighting and communication.

The authors conclude that small initiatives can, in some instances, improve energy efficiency as well as increase employment, promote economic growth and improve standards of living. But they highlight concerns with corruption and a lack of local governance.

This report, published by the Food and Agricultural Organization of the UN and Policy Innovation Systems for Clean Energy Security (PISCES), presents fifteen case studies of small-scale bioenergy initiatives across Africa, Asia and Latin America.

The authors assess to what extent these initiatives are both providing clean and convenient energy access in developing countries, as well as supporting rural livelihoods.

The case studies focus on a range of bioenergy resources including forestry, agriculture and industrial activities used to meet local energy needs such as cooking, lighting and communication.

The authors conclude that small initiatives can, in some instances, improve energy efficiency as well as increase employment, promote economic growth and improve standards of living. But they highlight concerns with corruption and a lack of local governance.

This feature article, published in the Environmental Science and Technology journal, uses the Cordillera Azul national park in Peru as an example to introduce mechanisms for reducing emissions from deforestation and forest degradation (REDD) that are under global discussion. 

The author discusses both the potential importance of and challenges associated with REDD projects. For example, although Cordillera Azul has been established as a national park by the Peruvian Government, funds for conserving it are still needed.

The article outlines some important milestones in progressing to an international framework for REDD, but notes that important details are yet to be resolved, such as how to ensure that beneficiaries of REDD funds deploy them effectively to protect forests.

The article suggests that active forest management is important and concludes with a brief introduction to the principle of proactive investment in natural capital (PINC) — the idea, promoted by the Global Canopy Programme, that forests should be regarded not only as a source of emissions, but rather as a public utility providing global ecosystem services that should be paid for.

This book, written by researchers at the Center for International Forestry Research (CIFOR), poses several critical questions that must be addressed in designing a global framework for reducing emissions from deforestation and forest degradation (REDD) to be implemented after 2012, when the first commitment period of the Kyoto Protocol runs out.

The authors frame their discussion within the 3E criteria, first proposed in the Stern Review on the Economics of Climate Change, of carbon effectiveness, cost efficiency and equity/co-benefits. Questions posed include how to set scales and baselines, deal with leakage, ensure permanence, and achieve co-benefits.

They examine various technical solutions for monitoring, reporting and verifying REDD projects, including remote sensing techniques and forest inventories. The political implications of implementing different technical options to distribute REDD income across different countries are also addressed.

The book highlights the need for flexibility in REDD strategies due to differences between countries and the need to allow for room to adapt to changes to the mechanisms as lessons are learned from initial implementation.

This information briefing, published by the Center for International Forestry Research (CIFOR), focuses on the implications of different country circumstances for measuring and monitoring forest degradation within activities for reducing emissions from deforestation and forest degradation (REDD).

The authors introduce forest degradation as a set of activities that can have different driving forces than deforestation, highlighting the fact that forests can remain degraded for a long time before becoming deforested. Degradation is typically caused by selective logging, fire and fuel wood collection.

The authors discuss monitoring, reporting and verifying (MRV) options for projects aiming to reduce forest degradation, emphasising the need to consider changes in both forest area and average carbon stocks per unit area. Based on a framework for forest transition with varying rates of deforestation and degradation, the relative importance for including degradation within REDD mechanisms for different countries is also outlined.

The briefing concludes that although monitoring and measuring degradation is more complicated than deforestation, developing a flexible MRV framework for including degradation in REDD mechanisms could be important for international equity. In particular, they expect that many African countries could benefit from the inclusion of degradation within REDD frameworks.

This policy brief, published by the Global Canopy Programme, proposes a system called Proactive Investment in Natural Capital (PINC), to reward countries for conserving large areas of tropical forest that act as 'global utilities' providing ecosystem services essential for preserving global food and energy security.

The authors suggest that the system, could complement current proposals for reducing emissions from deforestation and forest degradation (REDD). They argue that REDD could encourage countries with historically low deforestation rates to destroy their forests. They point out that if REDD successfully brings deforestation rates down — to zero eventually — then in the long-term, countries will not be able to receive payments for reducing deforestation.

The alternative, PINC, would build on existing systems that pay for ecosystem services, such as eco-certification, although scaling-up funding for standing forests is still a challenge, say the authors. To be effective, PINC requires capacity building and improved governance across the world. Land tenure reform will be needed in many countries, as will local participation in decision making and training in forest management. But, if appropriately designed, PINC could provide local communities with co-benefits such as poverty alleviation and biodiversity conservation.

This guide to reducing emissions from deforestation and forest degradation (REDD), published by the Global Canopy Programme, reviews many of the REDD proposals under discussion in global climate change negotiations.

The authors highlight why strategies for REDD are needed, then outline and compare the 32 government and nongovernmental proposals being considered by the UN Framework Convention on Climate Change (UNFCCC). They frame their analysis by examining the proposals in terms of scope, reference level, distribution mechanisms and financing options.

Visual comparisons are included to show where proposals agree and differ, and highlight areas with emerging consensus. For example, the proposals generally agree that reference levels should be set at a national level, and that a phased approach using a combination of different financing approaches could be most appropriate. Some challenges for reaching agreement on REDD measures and areas of current research are also highlighted.

The book includes a chapter summarising key research on REDD, including the Meridian Institute's Options Assessment Report, written for the Norwegian government, and several papers published by the Center for International Forestry Research (CIFOR).

This opinion article, published by the Overseas Development Institute (ODI), argues that the real challenges to effective preparation for reducing emissions from deforestation and forest degradation (REDD) are creating robust governance and funding structures, not just capacity building.

The authors outline the practicalities of developing REDD mechanisms. They note that REDD could potentially mitigate the risk of climate change, conserve biodiversity and support development in forest areas. They express concern, however, that some approaches to implementing REDD projects have had limited success and note that reducing degradation can be particularly challenging.

The report concludes with suggestions for ensuring that REDD frameworks move from preparation to successful deployment. These include careful consideration of development implications for measures taken to promote reduced forest dependence and improve links between public and private finance to encourage complementary use of funds.

This guide, published by Tebtebba (Indigenous Peoples' International Centre for Policy Research and Education), outlines the expected impacts of climate change on indigenous peoples around the world, and showcases traditional methods of climate change mitigation and adaption.

Following a basic introduction to climate change and the bodies, mechanisms and processes used for addressing it, the authors outline how climate change is impacting indigenous peoples in diverse ecosystems. For example, food and water insecurity arising from increased flooding or drought, and loss of biodiversity and traditional knowledge from rising temperatures.

The authors discuss the likely impacts of climate change mitigation measures highlighting, for example, the limitations of market-based strategies such as the Clean Development Mechanism. They discuss a range of alternative adaptation measures already being practiced by indigenous people, providing several case studies and examples of innovative strategies used in different regions. For example, African farmers using zero-tillage practices to moderate soil temperatures, Asian farmers growing varieties of crops to minimise the risk of harvest failure, and Honduran farmers using agroforestry and terracing to reduce erosion.

The authors go on to discuss measures for reducing emissions from deforestation and forest degradation (REDD) and emphasise the need for indigenous people to be fully engaged in the debate.

This policy paper, published by the World Resources Institute (WRI), suggests a range of sustainable development policies within frameworks for reducing emissions from deforestation and forest degradation (REDD).

The authors argue that there can be significant barriers to countries providing guaranteed quantified measures of emissions reductions for use in carbon trading schemes. They propose that a broader range of sustainable development policies and measures, such as building institutional capacity to reduce fires or combat illegal logging, should be included within REDD measures.

The authors recommend that developed countries encourage developing nations to reduce forest degradation, including measures that do not produce tradable carbon credits, and support a range of approaches to measure, report and verify nationally appropriate mitigation actions.

Further work is urgently needed, they say, to develop and refine these approaches, including specifying acceptable metrics, determining how to make different countries' activities comparable, and exploring alternative sources of sustainable funding.

This comprehensive report on the options for reducing emissions from deforestation and forest degradation (REDD) under consideration for an international deal on climate change was prepared by the Meridian Institute for the Government of Norway.

The authors focus on four critical areas for successfully developing REDD measures: finance, reference levels, monitoring, reporting and verification (MRV) and promoting indigenous peoples' effective participation. They propose a three-phased approach for REDD projects, to account for countries' widely varying capacities. This would start with countries receiving funds to develop national REDD strategies, followed by support to implement those strategies, which finally leads to payment for verified performance compared to agreed reference levels.

The report concludes that successful REDD implementation requires global partnership, led by REDD countries, in which indigenous peoples and local communities are fully engaged.

This paper, published in the New England Journal of Medicine, examines how the Internet can help monitor, prevent and control emerging diseases. The authors argue that the emergence of influenza A(H1N1), or 'swine flu', in April 2009 shows the value web-based information holds for early disease monitoring.

Informal internet channels such as blogs, chat rooms and search engine request analyses can help identify outbreaks more quickly, prevent governments suppressing information and facilitate public health responses. Google and Yahoo data searches can be used to generate epidemic curves that show the number of new infections plotted against time, and are comparable to those derived from traditional influenza surveillance methods.

The Internet also connects experts — through wikis and social networks — to quickly disseminate reports and responses. There is also great potential from public information.

The authors give examples of approaches being taken to monitor infectious diseases, including swine flu, and highlight some of the online resources available, including Google Flu Trends, HealthMap and ProMED.

This article, written by the WHO Rapid Pandemic Assessment Collaboration and published in the journal Science, examines the spread of A(H1N1) influenza, or 'swine flu', and assesses its potential to cause a pandemic.

Analysing surveillance data from Mexico, the authors suggest the geographical spread of swine flu will likely be comparable to other twentieth century pandemics, although the associated impact on human health is difficult to predict.

The authors suggest that the outbreak originated in mid-February 2009 in the village of La Gloria, Veracruz, where over half the population suffered acute respiratory illness. They calculate that the virus transmissibility — the number of cases that one case generates on average — is between 1.4 and 1.6, similar to the transmissibility of previous flu viruses including those that led to the 1918, 1957 and 1968 pandemics. The authors estimate that by 30 April 2009, 6,000–32,000 people will have been infected, with 0.4–1.4 per cent of cases being fatal.

This article, published by the WHO, answers frequently asked questions about the A(H1N1) influenza virus, or 'swine flu'. It provides information on the availability, production and effectiveness of A(H1N1) vaccines.

The WHO says that no effective A(H1N1) vaccines are currently available (May 2009) but adds that work is underway to develop one. The Centers for Disease Control and Prevention in the United States, for example, has identified and prepared candidate vaccine strains and is distributing them to all interested parties on request.

A vaccine could be available in five to six months after a pandemic strain has been identified but the WHO notes that more than 90 per cent of the global capacity for vaccine production lies in Europe or the United States — which may have implications for vaccinating people in developing countries. While these countries are well-versed in distributing vaccines through mass campaigns, they may face difficulties in ensuring timely access to enough supplies of vaccine.