The question is a little broad.
In the US, the standard of living is very good. But it would take 4 earths for all to live the way we do. Also, in the
US, suicide is the leading cause of death for people between the ages of 10 to 50. Also, the factory farming of animals is hidden, as it contains incredable cruelity. It was not like that 50-75 years ago.
There is also the Malthusian point of view, where the sheer numbers of those suffering are increasing. According the the WHO, every 8 seconds a child under the age of 5 dies, related to the lack of access clean water.
Aren't I a little ray of sunshine?