This discussion paper describes the links between global climate change and ecosystem and animal health that researchers generally agree on and the impacts that, while less certain, are still likely. The author highlights gaps in current knowledge, emphasising the need for better disease surveillance and more localised climatological and ecological data.

The one bright note in global warming is seemingly that higher carbon dioxide levels will make food crops grow faster. More crops should equal more food. But, as this feature article emphasises, the story is not that simple.

Initial tests have shown that plants grown in high carbon dioxide environments could be less nutritious — with lower protein levels and a different type of protein produced. Other scientists have found a drop in key micronutrients such as chromium, selenium and zinc in high carbon dioxide environments.

Mitigating these changes can involve increasing nitrogen levels to offset protein deficiency, although not all scientists agree on this.

What is clear is that there is very little research in this area and past studies have only looked at carbon dioxide concentrations of 550 parts per million, which is lower than levels predicted by the end of this century.

This journal article, written by three researchers in Trinidad and Tobago, looks at malaria in the Caribbean. It asks why there are still outbreaks — including a big one in Jamaica in 2006/2007 — when the disease was allegedly eliminated in the late 1950s. The authors review malaria and vector data from across the Caribbean, summarising the pattern of imported cases as well as indigenous ones.

They identify three essential conditions for malaria transmission: presence of the vector, imported organisms and susceptible human hosts — all of which the authors show still exist across the Caribbean.

The authors suggest specific actions for regional policymakers to combat malaria. These include enhancing vector control skills, strengthening surveillance with new technologies, upgrading malaria therapy, increasing prevention strategies such as bed nets and raising public awareness of malaria. They emphasise that the role of climate change must be considered too, saying that rising temperatures could lead to new malaria vectors entering and colonising Caribbean islands and transmitting malaria on a major scale. But the authors are also careful to point out that the link to climate change is uncertain and remains contested in scientific circles.

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.

This paper discusses likely future changes in tropical cyclones, questioning whether they will become more intense following higher sea surface temperatures. The author outlines the different approaches currently taken to climate modelling and discusses the results of characterising current and future climate using the Max Planck Institute for Meteorology in Hamburg model, comparing them to observations.

Most climate models predict stronger tropical cyclones in a warmer climate, as an increase in latent heat provides more energy for the storms. But the author claims there is less evidence for a reduction in the frequency of storms in a warmer climate. Still, such a reduction could result from a general weakening of large-scale atmospheric circulation (which reduces the number of cyclones) caused by the rapid increase in water vapour that would follow a rise in global temperatures.