The correct answer is - greenhouse gases.
The humans have been having a very big impact on the composition of the atmosphere in the past century, and that has started to result into changes in the climate patters all over the globe.
The main problem appears with the huge amounts of greenhouse gases released into the atmosphere, mostly carbon dioxide, but also methane. These two gases have properties that enable the greenhouse effect, which means that they are able to trap bigger amount of heat in the Earth's atmosphere, thus making it warmer.
If the ongoing trend continuous with the release of the greenhouse gases there will for sure be devastating effects on everyone and everything on the planet not so far in the future.
Reception (sensation) sensory receptors detect the presence of a stimulus.
transduction (sensation) sensory receptors convert stimulus energy into electrochemical energy.
transmission (sensation) ...
selection (perception) ...
organisation (perception) ...
interpretation (perception) ...
sensation. ...
perception.
South Asia is a really difficult place to try and centralize the countries. A big problem are the large populations in the countries, with the likes of India, Pakistan, and Bangladesh all being in one of the most populated countries in the world, so centralizing them would mean that hundreds of millions of people will either live on the verge of existence (even worse than it is now), or will be moving towards the city where the centralization will be taking place, and there's no such place that can function properly if that amount of people flood in it. Another problem is that there's multiple cities that are very big, with millions of people living in them, and if centralization takes place, they will start to decline in every aspect, and that will cause huge problems of all sorts on national level.
