What Causes pandemics?

I think that there are many causes but the ones I can most easily wrap my head around are these:

First, you have human overpopulation here on earth. There are just too many people to sustain them for thousands of years. Likely, only around 1 billion people or less can be sustained for thousands of years living on the surface of the planet while enough flora and fauna or the earth also survive to prevent human extinction.

For example, neurotoxins in insecticides to prevent crops from being eaten in the fields by insects made honeybees get sort of Alzheimers (and maybe people too who eat non-organic foods worldwide) so they couldn't find their nests and bees began to go extinct worldwide (at least domesticated honeybees were going extinct).

But, without pollinators most or all human grown crops cannot be grown without something pollinating them by taking the pollen from male plants to female plants. So, as honey bees started to go extinct worldwide we were jeapordizing our future crops. And since human life depends upon what we grow and what we feed our livestock, human extinction looked like it might be coming for us.

Of course there are also other pollinators like Bumble Bees which I notice are still a lot everywhere too. But, there are usually many more honeybees generally speaking than bumblebees I would think (even though I'm not entirely sure about that on a worldwide basis. But, as far as I know bumble bees are not domesticated simply because they live in much smaller family groupings than do honeybees who have Queen bees and have thousands of baby bees and make large quantities of honey.

So, what causes pandemics? It could be said that we are causing pandemics by living in big cities close to each other alongside of actions like the neurotoxins in insecticides causing these infinite chain reactions up and down the food chain.

This also started with DDT which has been outlawed (at least in the U.S.) because all wild bird species especially Raptors (hawks and eagles) were dying because the DDT got into the food that Raptors ate and made their baby chicks egg shells so thin that they broke so their babies all died when they sat on their nests.

Then Rachel Carson wrote "Silent Spring" which made people more aware of this which got DDT outlawed here in the U.S. this helped the hawks and eagles survive here in the U.S. This was in the 1950s.

But, you also notice that countries that didn't outlaw DDT there are no birds to speak of because their birds all died in those countries (or at least their hawks and eagles all died).

Whenever you upset the balance of nature beyond a certain point you are going to get pandemics.

If you notice also during the coronavirus New York City was hit the hardest so far and Wuhan, China and other big cities around the world.

This is because large cities from an ecological point of view are completely unnatural and when a pandemic hits kills more people there than anywhere else usually.

Because out more in the country you notice there are usually less coronavirus infections now (except when tourists from big cities spread the virus by traveling).

So, pandemics are caused by ecological imbalances and fostered by Big Cities and traveling by tourists into more country areas.

As a result the more mobile people are the more pandemics will spread around the world like now.

Also as a result we might see this coronavirus be in pockets of areas for the next 100 years or more slowly killing different groups of people.

Because to try to get ANY vaccine that everyone trusts now will likely be impossible or improbable here on earth.

People are not as gullible or as easily misled as they once were in the 1940s and 1950s regarding vaccines at this point in earth's history.

Trust is gone ever since President Kennedy was assassinated people realize they cannot trust their governments anymore (especially here in the U.S.).

I think trust in Congress is less than 11% here in the U.S. now.

It's like right now with up to 1/2 of all people out of work nationwide, the Congress (especially the Republicans) can not help the people to survive their lives.

If the Congress cannot help the people to actually survive the next month financially without any jobs how can the people trust ANY vaccine this stupid congress comes up with?

So, to summarize, pandemics have many factors but the biggest two I see are caused by Big Cities and imbalances in the food chain and mass extinctions caused by human overpopulation (especially in areas where big cities are worldwide).