New Delhi, May 15 -- On a hot, sultry afternoon, I made my way to Charkop in Mumbai's western suburbs. All through the journey from Dahisar, a distance of around 10km, I couldn't shake the intense, consuming worry about just how hot it was. It was only February, but already 35 degrees Celsius. Worse, I could barely see buildings even 200m away. The smog was too thick. And still, they want to cut all these trees? I kept thinking. Despite living barely 30 minutes away all my life, I had never explored the mangroves of Charkop. Or those of Gorai, Dahisar, Versova or Bandra, for that matter. So when I heard that Rajneesh Sharma, a 22-year-old naturalist, was leading a nature walk through the area, I decided to join. Sharma runs The Mumbai Wil...