Good afternoon Diego~!^^ Thanks for having an impressive understanding and depth of knowledge about your interests in writing topics. 

>>> TEACHER GEMMA

Scientists have been warning for many years already that in order to protect the environment people should use less energy. 
However, most people do not change their ways of living. What is causing this behavior? How can people be encouraged to change?

There's a great apologue which is called 'Boiling frog.' 

>>> CORRECT~!^^

The frog won't jump out from the pot because it boils slowly. 

>>> CORRECT~!^^
However frog will jump out when suddenly pot becomes hot. 

>>> However, [the] frog [tried jumping] out when suddenly [the] pot becomes hot. 

This story tells us, people don't aware the changing  environment when it goes slowly. 

>>> This story tells us that people aren't aware of the changing  environment when it goes slowly. 

They need sudden impact or else they will stay dull. 

>>> CORRECT~!^^

Some people might still, there is hope, but I don't think people can change themselves.

>>> Some people might think that there is still hope, but I don't think people can change themselves.

 We are already paying the debt for what we have done for centuries. 

>>> CORRECT~!^^

Around the world, so many disasters coming up.

>>> Around the world, so many disasters [occur].

Floods, abnormal temperature, typhoon, hurricanes and etc, but still, we recognize as simple events, unconnected phenomena.

>>> CORRECT~!^^
The main course of the environment pollution is China and America. 

>>> CORRECT~!^^

They are powerful nations, other countries spend their products.

>>> They are powerful nations that other countries [consume] their products.

Their products inevitably accompany environment pollutions. 

>>> CORRECT~!^^

So we cannot just blame them however, we have to make them concerned about the environment. 

>>> CORRECT~!^^
Both countries are not even joining in 'Paris Climate Agreement'.

>>> CORRECT~!^^

 It is time to unite and make one voice to both countries. 

>>> CORRECT~!^^

 This problem cannot be solved by individuals.

>>> CORRECT~!^^

 It should be treated by the government and companies.

>>> CORRECT~!^^

 The forceful measure is the effective way to change our behavior.

>>> CORRECT~!^^