Malaria control programs in Amazonian Peru helped reduce the incidence of the deadly parasitic disease by 78 percent. That is, until the programs ceased to operate. Within four years of the programs being de-funded, malaria rates where right back where they started. The rebound was driven not only by the removal of prevention programs, but also by climate change. Average temperatures in Peru have risen a half-degree Centigrade in the last 20 years.