SciDev.Net

The third IPCC assessment report, Climate Change 2001, includes this section on the links between climate change and health. It offers a detailed look at how variations in climate, such as temperature or rainfall, could affect vector-borne disease. In particular, it evaluates computer models that predict climate impact on dengue fever and malaria. The assessment also looks at specific diseases such as leishmaniasis or schistosomiasis, explaining how the disease is spread and how changes in the environment might alter that spread.

The authors take a holistic look at the various factors involved. For example, in assessing schistosomiasis, they also consider the irrigation systems that will likely be needed to cope with expected water shortages resulting from climate change. The schistosomiasis parasite uses water snails as an intermediate host, so irrigation systems will need to be designed in such a way that they do not cause snail populations to multiply.

An update to the research on climate and vector-borne disease is also included in the fourth IPCC assessment report[796kB] although not in as much detail.

This report, written for the Meridian Institute by a team of scientists from South Africa and Sri Lanka, describes the general issues facing projects aimed at improving access to clean water in the developing world, as well as the specific challenges facing nano-based projects.

The authors describe a number of water treatment devices that incorporate nanotechnology, including nanofiltration membranes, attapulgite clays and zeolites, nanocatalysts, magnetic nanoparticles and nanosensors. More importantly, they outline potential opportunities associated with these technologies, and possible risks.

The paper includes two case studies of projects designed to improve access to clean water — one in Bangladesh based on a conventional approach using sari cloth to remove cholera from water, and one in South Africa that incorporates a nanofiltration membrane.

This paper from the Meridian Institute describes a range of well-known and field-tested conventional approaches to removing contaminants from water as well as the current crop of nanotechnologies that could enhance existing — or develop new — water treatment technologies.

For each approach or potential product the authors give a short description of what it is and who has developed it, and report on the product's effectiveness in removing contaminants, the amount of water it can treat, and its cost and ease of use. They also include summary comparative charts of conventional versus nano-based treatments.

Conventional approaches covered include various types of filters, ultraviolet radiation, chemical treatment and desalination. Nano-based water treatments covered include carbon nanotube-based technologies, nanofiltration membranes and devices, nanoporous materials and clays, zeolites, nanocatalysts and magnetic nanoparticles.

This feature article from Nanowerk, written in collaboration with scientists, provides a short introduction to the role nanotechnology could play in resolving water shortage and quality issues.

The authors describe how nanotechnologies are being used in water filtration, especially nanotechnology membranes incorporating carbon nanotubes and dendrimers. They also examine how nanotechnologies and materials such as zeolites, carbon nanotubes and biopolymers can be used to remove, reduce or neutralise heavy metals and other contaminants that pose a threat to human health. And they briefly discuss the issue of using nanotechnology to develop water disinfectants.

This commentary, by South African scientists Thembela Hillie and Mbhuti Hlophe, examines nanoscience's potential to solve the technical challenges associated with removing pollutants from water. The authors describe a range of nano-based water treatment technologies already in the marketplace and discuss how nanofiltration membranes can be used in low-cost methods to produce safe drinking water. They highlight a case study in South Africa where such membranes were used to treat brackish groundwater.

The authors emphasise the importance of technology transfer in getting nano-based solutions to the countries that need them, arguing that direct transfer does not often work. Rather, what developing countries need are approaches that combine technology transfer with technology adaptation and adoption — involving local stakeholders in establishing water treatment devices and developing local capacity to use them.

This report, prepared by the World Water Assessment Programme under UNESCO (UN Educational, Scientific and Cultural Organization), assesses global freshwater resources including what drives the pressures facing them, how water is used, climate change's future effects on water supplies and options for improving water management for sustainable development.

The authors highlight the increasing demand for water, outlining the demographic, economic and social factors — such as population growth, international trade and changing lifestyles. They argue that climate change will undoubtedly affect water resources, impacting water quality and the frequency of extreme events such as droughts or flooding.

Investment in the water sector is important, say the authors — to improve access to clean water as well as decrease pollution from untreated sewage discharge. International donors must play a part in improving water infrastructure in the developing world, they add.

But how individual countries respond will depend on their own development objectives, capacity and political framework. The authors outline options for policymakers to increase supply, manage demand, reduce losses and reallocate resources.

This report from the UN Environment Programme (UNEP) calls for international action to combat the global economic crisis with a stimulus package based on clean energy and environmental protection. The author — Edward B Barbier from the University of Wyoming — argues that while stimulating growth and creating jobs are key objectives, unless new policy initiatives also reduce carbon dependency, protect ecosystems and water resources, and alleviate poverty they will not be enough to avert future crises.

Developed countries must remove subsidies and adopt complementary carbon pricing policies, says Barbier. Developing countries should spend at least one per cent of GDP on improving access to clean water and should also expand educational and health services for the poor. And all economies should consider removing water subsidies to increase water efficiency, he adds.

He concludes that the international community has a central role to play in promoting this global green new deal — through global governance, facilitating access to development assistance and enhancing trade incentives.

This report combines a background paper and summary report from a moderated email conference held by the UN Food and Agriculture Organization in March 2007.

The background paper outlines the current and future challenges for water availability. The authors discuss options for dealing with water scarcity, focusing on agricultural water use, and ask how biotechnologies — from microorganisms for pest control to genetically modified crops — can help.

The summary report highlights the consensus among conference participants that biotechnology has a valuable role to play in addressing water scarcity in developing countries.

It presents examples of biotechnologies being used in the developing world, including marker-assisted selection, genetic modification, biofertilisers and wastewater recycling. But the report calls for increased collaboration and interdisciplinary research, as well as more involvement of stakeholders in designing solutions, to help biotechnologies move from the lab to farmers' fields.

This report published by the IUCN (The World Conservation Union) is based on participatory consultations with stakeholders and provides a comprehensive and in-depth account of West Africa's vulnerability to climate impacts on water resources, wetlands and desertification. 

The report contains two parts; the first section details the regional context, climate impacts on water resources and West Africa's preparedness at present. This is followed by an outline of a potential regional adaptation strategy, its methods and its implementation. 

This report offers recommendations on how African water resources specifically may be affected by climate change, but also ways collaboration for adaptation can be strategic and useful.