Everything is energy.
To understand the grave threat that humanity faces to its survival is to understand energy, energy systems and the laws of thermodynamics.
The universe is energy. You are energy. Your thoughts, words and actions are energy. What you hear, see and smell is energy. All change and motion is energy. All matter is energy. How you look and how you behave is energy. Your dreams, hopes and fears are energy. There is nothing mystical about energy, it is a scientific fact that everything is energy.
You are composed of an energy field, through which energy flows, which together form an energy system. You are an energy system, interconnected with other energy systems.
All energy desires to return to its primordial chaotic state, this gives rise to entropy. The ancient Egyptians personified entropy as a snake, calling it Apophis . The ancient Celts called entropy Gwyn ap Nudd. In the modern world entropy is recognised as the personification of Death, or the Grim Reaper. Entropy is the most powerful authority in the cosmos, for it existed before this universe, and will devour this universe at its ending.
You are dying. Entropy is stealing your energy from you. As your energy is lost you decay into disorder in a process called old age. At a certain point the energy deficit will be so great in your energy system it will collapse, you will die. Game over. Your doom is to die, but you have the ability to delay this fate through a process of energy renewal and conservation. You can cheat entropy by sending part of your energy out into a new energy system by having children, but you yourself are fated to be obliterated by entropy.
All energy systems have mass, and this mass can resist the immediate impact of entropy. Mass creates energy fields such as gravity and magnetism that can trap, organise and give order to energy. At all times entropy is stealing energy from the energy fields, reducing their mass, reducing their energy fields, to a point that they will decay to disorder faster and faster as they diminish in energy.
Energy systems have a capacity for renewal in that they can steal some of the energy back from entropy via their energy fields. Energy systems are in a state of becoming through a constant state of strife and renewal. The flow of energy at work within the energy systems increases mass and the energy field through energy conservation. All energy systems are temporary in nature in that they are running at an energy deficit, their doom is delayed only through their ability to steal energy and conserve that energy as work available to the energy system. It is through the creative capacity of energy systems that new energy systems arise to replace the ones that die.
A healthy energy system has an abundant flow of energy coming into the system, and an abundant energy available as work within the system through conservation. Energy systems that are overly abundant with energy become creative throwing out new energy systems, for instance in human society this is marked by a blaze of art and scientific progress.
Energy systems lacking energy both as an input and as available within the system will move to a state of increasing disorder and decay. Decay is identifiable in that infrastructure falls apart and processes malfunction. In the UK the widespread pot holes in roads are an example of decay of infrastructure, and the death of patients in UK hospitals from hunger and thirst is due to decay of process. Disorder can manifest in many forms from violence, to anarchy, to fragmentation of infrastructure and processes within an energy system. Syria is an example of an energy system that is collapsing to disorder. Egypt is an example of an energy system that is about to collapse into disorder.
All energy systems have a tipping point. If there is lots of energy in a system in excess to its needs, it turns creative churning out new energy systems until it returns to a state of deficit. If there is too little energy in a system it will collapse. Whilst the decline of an energy system may appear steady through increasing manifestations of decay and disorder, when it hits the tipping point the collapse is rapid and total.
For me the question is no longer if energy systems that humanity depends upon will fail, rather it is when and how many energy systems will collapse. An energy system like the Earth has sufficient potential energy to recover from a collapse, however the recovery after an energy system collapse can be slow, for the Earth hundreds to millions of years, which is not enough time for humanity to derive enough energy to survive as a species.