Millions of dengue cases can be prevented if world limits global warming

Understanding the impacts of warming on human health is crucial for public health preparedness and response, say researchers

An Aedes aegypti mosquito photographed through a microscope

Millions of cases of dengue fever, the world's fastest spreading tropical disease, could be prevented annually if global warming is capped at 1.5°C, says a study that purportedly is the first to show the health benefits of a cooler planet.

Using computer models, researchers from the University of East Anglia in Britain found that capping warming at 2°C could cut annual dengue cases in Latin America and the Caribbean by up to 2.8 million by the end of the century. A further half a million cases could be prevented if the rise in global temperatures is kept down to 1.5°C, the report published in PNAS said, with parts of South America most likely to benefit.

“There is growing concern about the potential impacts of climate change on human health,” said lead author Felipe Colūn-Gonzŕlez. “This is the first study to show that reductions in warming from 2C to 1.5C could have important health benefits.”

Climate change and diseases

Since the year 2000, climate change has caused severe harm to human health by stoking more heatwaves, the spread of some mosquito-borne diseases and under-nutrition as crops fail, according to a Lancet report last October.

Current national pledges to curb emissions put the world on track for a warming of about 3°C above pre-industrial times, far above the goal of “well below” 2C set at a 2015 summit in Paris. The WHO has previously estimated there could be 250,000 extra deaths a year between 2030 and 2050 because of climate change.

“Understanding and quantifying the impacts of warming on human health is crucial for public health preparedness and response,” said co-author Iain Lake in a statement. “Clearly a lot more needs to be done to reduce (carbon dioxide) and quickly if we are to avoid these impacts.”

Dengue infects around 390 million people worldwide each year, with an estimated 54 million cases in Latin America and the Caribbean. There is no cure for dengue and medical experts recommend early detection and expert care as the most effective way of overcoming an infection. The infection causes flu-like symptoms and can be fatal if it develops into severe haemorrhagic form. The annual number of cases has increased 30-fold in the last 50 years, says the World Health Organization (WHO).