60 Second with…Paul Parham
Over the past few years, Paul Parham has been studying how global warming could affect malaria, a disease that recently hit the headlines with news of promising vaccine trials. Paul spoke to James Lloyd about his work at Imperial College’s Grantham Institute for Climate Change.
LS: What exactly is malaria, and what are the symptoms?
PP: Malaria is a potentially severe and life-threatening infectious disease transmitted by mosquitoes. There are four main types of parasite responsible for human malaria, although Plasmodium falciparum and Plasmodium vivax are by far the most common and widespread. Symptoms are often quite similar to flu and depend on which parasite is responsible, but generally tend to include fever, headaches, diarrhoea, muscular pain and coughing fits.
LS: Why is malaria of interest to climate change researchers?
PP: Since mosquitoes are cold-blooded, many aspects of their survival, development and behaviour depend strongly on ambient temperature and other climatic conditions. One possibility of climate change is an expansion of those regions where transmission is currently absent or limited, so the global distribution of malaria may change over the coming century. Understanding these changes is important for the planning of interventions and control strategies against malaria.
LS: Presumably the changes in malaria depend on changes in the location of mosquitoes?
PP: Yes that’s true, but these changes will also be driven by the response of the parasite to changing conditions, as well as human demographic factors and any additional human behavioural shifts. It’s the interaction between mosquitoes, parasites and humans, rather than any one in isolation that will ultimately determine what happens in the long-term.
LS: What other factors could affect the spread of malaria?
PP: An important question is the role of climate as a driving factor behind malaria transmission, as there are multiple determinants. Socioeconomic (e.g. poverty), demographic (e.g. changing human distributions), environmental (e.g. land use changes) and epidemiological (e.g. the impact of interventions) factors will also affect malaria, and climate is just one of these – a key question is to better understand its role compared to the others.
LS: Malaria was once common in Europe: Shakespeare mentioned the disease in eight of his plays and the last indigenous case in Britain was as recent as the 1950s. Can we expect to see European malaria making a comeback in the not-too-distant future?
PP: This is probably quite unlikely for malaria in the immediate future, but it remains a possibility on longer timescales.
LS: Despite the overwhelming scientific consensus that our warming climate is caused by humans, there are still a lot of climate change naysayers. Why do you think this is?
PP: There are probably two main reasons for this – (1) uncertainty in the science, and (2) distrust in the science. In the first case, this is solved by the climate science community pulling together to reduce the uncertainties associated with model predictions. Science is often perceived as something that should provide exact and definitive answers to problems, but the reality is that within most scientific disciplines there are almost always unknowns and uncertainties. The science gradually becomes more accepted as evidence is gathered to support theories and predictions, which generally equates to reducing (or at least quantifying) inherent uncertainties in the predictions.
In some sense, the second case is harder to overcome and may require longer! It certainly requires the scientific community to pull together, but also, arguably more importantly, it requires us to better communicate scientific uncertainties to the public.
While considerable progress is still required to address (1), it is perhaps just as, if not more, crucial to ensure we invest substantial time in (2) as well!
Reader Comments