Alternatives can, and will, be found for fossil fuels but there is one natural resource that can't be replicated and is in increasing demand. Wars used to be fought over land. Now they're fought over oil. Soon they will be fought over water.
Havent we got the same amount of water we've always had?
At the moment yes, but access to clean drinkable water per person will decrease with increasing population. In my lifetime (44 years and counting) the global population had increased by over 1 billion people. The time taken for the previous 1 billion population increase was over a century.
The current prediction is that we'll have grown by another billion before I start drawing a pension, and have exceeded the critical mass of 9 billion people within a further 10 years. The critical mass figure is based on supplying the population with around 2000 calories a day of a balanced diet with fully optimised agriculture. (And pretty much a vegetarian diet to maximise food output per acre.)
That's before you take into account the effects of climate change.
The cause of all these bush / forest fires in California and Australia? Drought like nothing experienced in human memory.
We're already seeing growing insect populations here that 20 years ago were almost exclusive to North Africa and occasionally Mediterranean Europe as temperatures rise. The extreme flooding that is now seen regularly in Central Europe doesn't increase the availability of drinking water, rather contaminates the water already present.
Someone I know had a business supplying temporary damming equipment and high capacity pump systems.
10 years ago most of his business was in Asia and China.
Today over 50% of his business is here in Europe.
Desert states like Kuwait rely almost entirely on desalination of sea water. All of their infrastructure (which for obvious reasons is located on the coast) is at risk from rising sea levels.
The list of problems facing water supply is almost as long as the reasons Lambert should have been sacked at least 5 times over the last 2 1/2 years.