Not far from Phuket's idyllic beaches are salt-drenched mangroves and dense vegetation brimming with life and quietly working their magic. Once regarded by many as nothing more than swamps, these mangroves are today being increasingly recognized as a "secret weapon" in the fight against climate change. This is largely due to a growing awareness of their ability to store carbon. Martin Lowe traveled to Thailand's mangroves to find out what makes mangroves so valuable.