Why is photosynthesis is so important to life on earth?

It is the key factor to our survival. Photosynthesis is what keeps oxygen flowing and Humanity still alive. First we can look at the process itself. Plants breath in Co2, and releases oxygen which is vital for us. Co2 is a substance found in our atmosphere which too much of it, can kill people. This is why photosynthesis is here. Without the proccess, much of our atmosphere would be filled with unbreathable gases. This will result in many fatalities and eventually the loss of humanity.

We could also look at this at the plants' side. Humans continue to kill many of the much needed plants that hold our future. For them, they require photosynthesis greatly as well. They must "breath" in the Co2 to keep their bodies alive. If plants were to stop "breathing," humans would stop having oxygen, and if humans stop having oxygen, they die.

Another bad effect without it, can last on animals. Animals, much like humans, need oxygen to breath. Whether it is very short, or a large amount, they all need oxygen just like us. It is important for animals to sustance life here on Earth. Not only for the enviroment, but for the future the beholds unknown.

In conclusion, photosynthesis is something every species need. Whether it's plants, animals, or humans, photosynthesis is required for our survival. Without it, no species would exist. This is why humans need to stop destroying vital plant species and realize the true consequences.

true, i don't really know what you're asking but from the info you provided im guessing the answer is true.

they had the law tat factories that produces smoke cannot be built near residential buildings.

building of proper sewage system was done to ensure that the waste is carried away from the humans so that they do not get diseases from it.

also they built water systems to provide water in those areas which are drought prone.