All this month the BBC World Service is travelling along the rivers of Bangladesh as part of a major project to track and debate climate change.
Ben Sutherland is among those on board the vessel, the MV Aboshar.
5 November - ADAPTATION
The question of what to do about climate change really has two answers.
In the West, it is all about greenhouse gases, and the political processes involved in trying to get countries to cut their carbon emissions.
But in countries like Bangladesh - where emissions are comparatively minimal but the potential impact of climate change is enormous - it is about anticipating what will happen and preparing in advance for a world where the sea levels are higher and the weather is more extreme.
Class Two are among the pupils who have to be taught outside
This is known as "adaptation."
We have already seen some ways this is being done as we travelled around the country.
In Bhola, for example, we saw people growing crops in large wooden frames designed to float should the land be covered by water.
In some ways, adaptation is effectively something Bangladeshis have been doing for some time - because one thing predicted is an increase in floods and cyclones, weather events that have long been a way of life here.
This is obvious in the town of Galachipa, down on the southern coast.
Stepping off the boat, the first houses we saw were all built on stilts, to give them some protection from the flood water.
There is also a well-established Red Crescent operation here which monitors the weather and warns people when a cyclone is imminent. They broadcast the warning on the radio and ride through the town in a rickshaw with a loudspeaker mounted on the roof.
One student we met in the town explained how he had been trained to teach his family what to do when a cyclone comes, such as wrapping food in polythene bags and burying it - not forgetting to mark the spot so that it can be found again - and herding livestock to higher ground.
They have around an hour to then get to the cyclone shelter - in this case, the local school.
But were a cyclone to strike now, the school would be the worst place to come.
When we visited, we found that it was badly damaged and had not been repaired after being battered in previous storms.
The building is quite large but only two classrooms can be used, the rest of the lessons have to take place outside.
One child, Hassan - the star pupil of Class Four - told me how part of the ceiling had recently fallen down on his friend's head.
The head teacher made it clear to me that the school is unsafe in any weather, let alone a cyclone, and that he does the best he can with no money whatsoever.
It is nevertheless worrying that most local residents still consider this the best place to be when cyclones strike.
6 November - ENTERING THE SUNDARBANS
Galachipa turned out to be our last town before the Sundarbans - the largest mangrove forest on earth and a place of vast biodiversity.
There are over 270 species of birds, 50 species of reptile, and 32 species of mammal - including the famous Royal Bengal Tiger.
Even as we entered the forest - a World Heritage Site - the uniqueness of the place is breathtakingly apparent.
From the deck of the MV Aboshar there were gasps of excitement as two crocodiles were sighted on the riverbank opposite.
Bangladesh is doing its best to protect the Sundarbans.
As we approached, suddenly the river traffic disappeared. People do not live here, and fishing is banned in many areas.
Forest stations, every 10-20km along the river, monitor the boats that do come in.
At the first one we reached we got off, partially to have our documentation checked and partially to have a look round.
We spotted a tree full of flying foxes, who took off and shrieked around in the air above our heads.
Later, we took a "silent boat trip" along some of the narrow tracts of the rivers. We saw a king cobra, a monitor lizard and a tree full of rhesus monkeys.
But, whatever measures Bangladesh takes to preserve these animals, the country will be powerless in the face of climate change.
A Unesco report published this year suggests that a 45cm rise in sea levels, predicted by the Intergovernmental Panel on Climate Change to occur by the end of the century - will wipe out 75% of the Sundarbans.
Were that to happen, the effect on the animal population would be catastrophic.
And there is another reason the Sundarbans is so important.
The densely-packed trees along the coastline shield the rest of the country from the worst effects of cyclones and especially tidal waves - precisely the type of weather predicted to become more common in a climate changed world.
Thus, the climate change-induced loss of the Sundarbans would expose the country even more to the problem.
7 November - THE TIGER SURVIVOR
As we got deeper into the Sundarbans, everyone secretly hoped we would see one of the Bengal tigers - albeit from a safe distance.
While we would be disappointed, we did get the story of one man who had got rather too close.
"We were in a boat when the tiger attacked," recalled Abdul Gaffar, a local shopkeeper with a huge scar on his forehead.
"I jumped over the tiger to save my brother and held the tiger's head under my belly. The tiger hit me with his left front foot - that's where the scar comes from.
"Then my brother started to beat the tiger. I had to pull my hand out of the tiger's mouth, but it started to go away.
"The tiger's face was so fearsome - but when I was holding it under my body, it was so soft that I could not understand how it could be so fierce."
8 November - DOLPHIN HOTSPOT
Thursday was our third day in the Sundarbans, but this time our focus was on the animals living not in the forests, but in the water.
The waterways account for nearly a third of the Sundarbans area; the entire area is ultimately the delta of the Ganges, with rivers, streams and canals criss-crossing and meandering through the mangroves.
The flying foxes shrieked as they flew overhead
They are an ideal home for dolphins - Bangladesh is a global "hotspot" for the creatures, including the Irrawaddy dolphin, finless porpoises, and the shushuk, also known as the Ganges River dolphin, and something of an iconic creature.
We have spotted several ourselves as we have travelled along the rivers.
Experts from the Bangladesh Cetacean Diversity Project - including Mowgli Mansur, the son of our guide Hassan - came aboard the MV Aboshar to talk to us about their efforts to monitor and protect the dolphins.
Their work has been an extra urgency by the apparent extinction of the Yangtze River dolphin in nearby China.
They told us that their studies suggest that there are many more dolphins that they had expected. There is genuine optimism but again, climate change is a real worry.
A sea level rise would see tides push in with greater strength, disturbing the placid areas in the rivers where the dolphins gather and spend most of their time.
It is an example of how even animals for whom a sea level rise might seem relatively benign could come under threat from climate change.