These include
1. Population- The world's population has tripled within the last 60 years placing stress on literally every aspect of the environment.
2.Climate- due to indiscriminate burning of fossil fuels, it is thought greenhouse effects have been created causing undesirable climate changes.
3. Loss of biodiversity - humans have continually and steadily destroyed habitats of species which may result in adverse effects on the food chain.
4.Water- it is estimated that by 2050, two thirds of the world's population will be unable to have clean water. This is due to abuse of the environment by man.