I have seen cut worms, aphids, mites and hoppers destroy crops and the plants that produce them. I have seen how practising mono culture, that is growing huge, unbroken areas of a single crop, has facilitated terrible infestations by providing an almost endless feast of a favoured plant for a pest.
I have seen pest control that did more harm than good by killing not only the targeted pest, but directly or indirectly also many benificial organisms. Collateral damage, so to speak.
Currently I have an issue with aphids, spider mites and white flies. They are not so bad in the summer when natural predators abound in my garden, but in the winter when much of the garden is enclosed there are few predators and the pests can multiply unchecked.
The choices for control of pests are few and not without undesirable side effects. One can use chemicals to control infestation at the expense of using substances that can harm the soil and contaminate the produce. Or, one can let nature take its course and watch the insects destroy the plants.
Pests and most other species are genetically driven to eat and reproduce as much as possible, right up to the point that the food runs out and they follow their host into extinction.
People, of course, are part of the same biological universe as insects and other critters, including those that are pests. Humans are hard wired to consume and reproduce, and the same ecological rules apply. The difference for humans is that many of them also possess a level of intelligence that allows them to understand the dynamics of the ecosystem that they are bound to, and how maintaining balance, not optimizing consumption and procreation, is the best path for survival of the species.
One of my winter crops is chili peppers which will grow in a sunny window provided that the insects do not eat them down to bare sticks. To understand how the world works, lets think of the planet as a big pepper plant. Think of humans as the equivalent of white flies. At present the humans who understand and appreciate how it all works are not in control. The result is that the pepper plant is being devoured by, and over run with white flies who are happily multiplying and munching away. Both the plant and the white flies are travelling a path that will lead to their destruction.
This outcome does not have to be inevitable. If enough people develop and exercise enough common sense to realize that things are out of balance and that too many white flies are eating too much of the pepper plant, and if this realization leads to a change in behaviour that supports leaders and policies that bring back balance between the plant and those that depend upon it, then there might be a decent future for the grandchildren of their grandchildren.
The world is truly like an infested field. The balance between organisms that has provided the ecosystem that maintains life as we know it, has been seriously disrupted. Consumption has gone beyond the amount that the planet can support indefinitely, and consumption now is eating into the systems' ability to produce. Even one quarter of the level of consumption that Canadians enjoy on average is not sustainable in a world of seven billion people.
There is no escaping the fact that if we do not bring back balance to the planet's ecosystem the grandchildren of our grandchildren will have a world that no sane person would wish on anyone, if they have a world at all.