At night it takes longer for the water to cool and then it takes longer for the water to heat up in the daytime. Just because of the way the wind is blowing and such
The answer you are looking for is ozone I think
The problem of waste can be tackled in many ways, such as:
producing less waste (the most important way of reducing waste)
reusing the objects rather than throwing them away after one use
recycling the objects that have to be thrown away
so all the options are correct - all of the above!
