A report by PricewaterhouseCoopers LLP forecast that higher temperatures could lead to a doubling of the world pharmaceutical market in 13 years , with sales of medicines increasing to $1.3 trillion US from about $600 billion last year – provided drug makers find innovative treatments.

The New York-based accounting and consulting company, citing the Intergovernmental Panel on Climate Change, said the average temperature is projected to increase by 0.4 degrees Celsius during the next two decades and the increase could be greater if greenhouse-gas emissions increase.

Climate change may already be playing a role in reports of malaria in countries such as Turkey and Georgia where it was eradicated, the report said.