"We run the risk of just coming up with a very accurate warning system without having any capacity to actually respond," said Dr. Diarmid Campbell-Lendrum, a WHO climate change expert. "You can't solve malaria problems in Africa just by providing better risk information."
Even rich countries haven't entirely integrated weather considerations into their health surveillance systems. The heat wave that hit Europe in 2003, killing an estimated 15,000 people in France alone, was a reminder that the West is not immune to weather-related problems.
Global warming trends are likely to have disease consequences for the entire world. Unseasonably warm temperatures this year have already resulted in a spike of malaria and tick-borne encephalitis cases in Italy.
While climate change is likely to bring back tropical diseases to areas not used to them, weather is only one contributing factor.
"The prime determinant of whether or not a health risk translates into dead bodies is how well your public health system is functioning," Campbell-Lendrum said.
But when it comes fighting diseases like Rift Valley Fever, experts say any lead time is valuable.
"It gives us the chance to act before the outbreak instead of panicking during it," said Formenty, who helped Kenyan authorities prepare for an expected malaria outbreak by distributing bednets and bolstering supplies of anti-malarial drugs.
