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.

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 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).