Next year is the 100th anniversary of the opening of the Panama Canal, which revolutionised trade between the Pacific and Atlantic, saving about 8,000 miles from journeys around Cape Horn in South America. Imagine the amount of fuel and time it saves by cutting the distance.

It was also one of the greatest engineering feats in the world, in which the Americans built the canal over the hills of Panama in a series of great locks, a system that relies entirely on rain.

Around 52 million gallons of fresh water is lost to the sea each time a ship enters or leaves the canal. That water is replaced from a vast reservoir built high in the hills, which in turn is replenished by heavy rainfall – but if the rains dry up so does the canal, and in 1997-98 the canal experienced its worst recorded drought that restricted shipping.

The fresh water which is fed to the reservoir is critical for the operation of the Panama Canal. No commercial activity is allowed on the 80 kms long Panama canal banks.

The tree cover is maintained on the both sides of the canal and the hills adjoining the canal so that tropical rain can be good and the reservoir is always full. All the wonderful engineering and innovation would come to a standstill without the rain which is supported by the forest cover. So plant trees, they stand still but silently move the world.