- Possibly as many as two-fifths of the world is peoples live under conditions where small changes to climate, water availability and access to fuelwood will have disproportionate effects on their chances of survival. Climate change may be a century away in terms of truly noticeable departures from temperature norms. But relatively small fluctuations in the form of precursors to that change will almost certainly adversely affect many millions of people, despite their in-built resilience to environmental change< this matter is also covered in Chapter 6>.