In my point of view each one of the problem named before: Climate Change, lost in Biodiversity, Fresh water scarcity, Pollution, Deforestation are consequences of mainly 2 causes: population growth, economic growth. And that 2 causes are rooted in one external factor: the lack of awareness.
Climate Change is caused by the release of gases that yield to greenhouse effect, but this gases are produced by the industry, mediated by the consumption of a growing population with growing wants, and they are produced also by the behavior of each individual in every choice she or he takes.
The lost in Biodiversity is a clear consequence of the change in land use which brings us to the industry again – agriculture in this case, to produce more food for a growing population. Lost in Biodiversity is caused also for the deforestation which has the same base, deforest in order to have more land so we can produce more food.
Fresh water scarcity, on the other hand is due to the over use for industry, the reduce in its amount due to global warming, and the reduce in its availability due to pollution. So one more time we come back to economic growth (industry, production, consumption) and population growth: the water is reduced because the same amount is needed to be share in many more than before.
With Pollution the issue is pretty clear, pollution is due to industry and production and bring us to economic growth one more time, however, through the consumption is due to a population growth too. If there are many less people to supply then the production will reduce andÂ pollution with it.
Of course, one important point is missing: if there were enough awareness of the problems, we can try to stop climate change, reduce the change in land use and not lose more biodiversity, use water more efficient and make it available were is needed and use more technologies in order to reduce pollution. But if we really were aware of the situation we are living in, we simple control the world population growth and stop the economic growth and change it for economic development. There is enough wealthy in the world now to make a pretty good life for everyone if we don’t have this huge gap between the richest and the poorest.