Everything we need to do to become 100% sustainable boils down to having two things: enough renewable energy and the time to use it.
The good news is that we have more than enough renewable energy available to us to do everything we need. The question is whether we will have enough time to use it, to clean up our global messes before numerous ecological crises become catastrophes, and enough time to allow everyone access to enough food, water, and energy in equitable ways that will reduce the likelihood of conflicts over our limited resources. We know well enough how to do all this, but will we figure out how to get ourselves to actually do it in time?
Do you believe this? Can it be that simple? Well, it is simple to understand, but it is not so simple to make it happen.
Think of anything that needs to be done. Producing enough clean water for everyone, for example. The water itself is plentiful, but it is not necessarily clean or in the right places where people need it. How do we solve those issues? Energy is required to clean the water, or desalinate it, and energy is required to move it from place to place. The other variable is how long it takes to build the water reclamation facilities or desalination plants, or the time it takes for water to be shipped from flooded Northeastern US to parched South Africa.
What about all the pollution caused by mining and burning coal to get enough energy to do what we need? We know theoretically how to convert the wh*** process over to being 100% clean, using some of the energy generated to remove all of the exhaust pollutants, but there will not be much energy left over for us to use, and there will also be big h***s in the ground where the coal used to be. The same kind of thing applies to all other non-renewable sources of energy.
We should be asking ourselves, exactly how much energy would be required for each non-renewable source of energy to be 100% clean. How much will it cost in energy for us to make those energy production sources have zero footprint, as if they had zero effect on the environment? And then we should compare the true and complete cost of non-renewable sources with that of renewable sources.
We have enormous renewable energy available to us that is ultimately all derived from the sun or from geothermal energy already inside the Earth. Solar energy is still moderately expensive to produce, factoring in just the cost of producing and maintaining solar collectors, compared to the unfair, inaccurate, subsidized cost of producing energy from non-renewable sources. But the economics are much better for wind energy, which is already competitive with non-renewable sources. The total amount of geothermal energy available to us near the surface of the earth is thousands of times more than we need.
All of the renewable sources of energy require some construction of collectors to actually capture that energy, and then we have to consider storage and transmission. This construction requires energy as well, and for that, we may initially use some non-renewable sources, but then the energy produced from renewable sources can be used in further construction. The question of economics is whether the energy cost of construction, factoring in the expected costs over the lifetime of all the facilities, is less than the energy we can expect to gain. If net energy is positive, we are good to go.
As a thought experiment, consider what the world would be like if energy were free, completely free. Then we could do anything we knew how to do very inexpensively, almost as free as the energy itself. The remaining cost is time. And time is money, as you know.