The outbreak of Schmallenberg disease amongst sheep and cattle on British farms has provided a powerful reminder of how novel infections can develop, spread and kill before the authorities have a chance to react.

Scientists are still working hard to fully understand the virus and a vaccine is still some way off so what can we do to protect ourselves against future disease outbreaks?

And how can we discover what diseases could be heading our way? Tom Heap heads to the Kent marshes in search of one of the potential carriers of nasty illnesses: Culex modestus. It's known to be a successful carrier of West Nile Virus - a paricularly nasty illness - and while the mosquito has been found on the marshes of Kent the disease has not made it's way to the UK yet.

Costing The Earth also discovers the vital role social media could play in monitoring future epidemics.

Intensive farming, international travel, global trade and climate change are all playing a role in changing the diseases we encounter. In 'Costing the Earth' Tom Heap asks what epidemics we should expect in the future and examines the readiness of government, the medical profession and the pharmaceutical industry.

Producer: Martin Poyntz-Roberts.