Madagascar is the 4th largest island in the world.
Answer: Disease (economic disruptions) Also keep in mind that bacterica, cancer, tumors etc. were not brought up till the 1980's - 2000's
Explanation: Look at my comment because it got cencored for some reason
The most important thing that the designers should take into account are the potential earthquakes - the buildings should be able to withstand the shaking of the ground.
Additionally, Earthquakes often lead to fires, so the buildings should also be fire-proof; especially not made of wood.
Finally, the possibility of a tsunami should be considered.
The main sources are humans which is why it is stated that the global warming is man made. The levels have increased beyond all measure, increasing since the 1950s by a 100 CO2 parts per million, and it keeps increasing by 2ppm on a yearly basis. The statistics from the industrial revolution era are not much different and show how much we've increased the CO2 in modern times.