More than 8 billion people could be at risk of malaria and dengue fever by 2080 if greenhouse gas emissions continue to rise unabated, a new study says. Malaria and dengue fever will spread to reach billions of people, according to new projections. Researchers predict that up to 4.7 billion more people could be threatened by the world’s two most prominent mosquito-borne diseases, compared with 1970-99 figures. The figures are based on projections of a population growth of about 4.5 billion over the same period, and a temperature rise of about 3.7C by 2100. The study, led by the London School of Hygiene & Tropical Medicine (LSHTM) and published in the Lancet Planetary Health journal, found that if emission levels continue to rise at current rates, the effect on global temperatures could lengthen transmission seasons by more than a month for malaria and four months for dengue over the next 50 years.