When I was young I would be given toffees. These came in sensual, waxed paper wrappers, and, once the toffee was exposed and the wrappers briefly explored, these wrappers would simply drop from the fingers to land, who cared where? Well, my parents cared: "Don't do that, pick it up"; "What would happen if everyone did that?" And there, it turns out, was my first lesson in scaling: what might, perhaps, be ok in small numbers becomes unacceptable for larger quantities. So, what to do? Do you ban toffees? Unthinkable. Do you limit visitor numbers? Doesn't apply to public streets. Provide waste bins? Could work, but people have to be conscious of littering, and the bins might overflow if whoever is looking after them is not up to the mark. Suggest people take their rubbish home? Also works, and they don't have to search for a bin.

The problem of scale is key to the issues that people talk about. These issues are variously named under headings such as decline in pollinators, fertiliser run-off, flooding, food shortages, and on, and on. In a list like that, the problems seem just about addressable one by one, but there is always another one, and we are loosing any opportunity to see parallels. I prefer a shorter list; pollution and extraction.

Pollution is putting too much of something into an environmental system. Too much, in this case, being something more than the environment can cope with. What is too much? That depends. In the case of escapes of heavy metals from factories we might say that any amount is too much. For a more debatable limit we could look at, say, particulates from diesel fuel, too much might be measured in observable population health deterioration. These examples are local and near immediate; they have a restricted geographical impact, and the effect of either more or less pollutant can be seen in a reasonably short time span. At the other end we could consider greenhouse gasses. Release of excess CO2 causes climate disruption over the whole globe, so it is certainly not local, but the effect is also delayed. It takes decades for us to see the change, and, importantly, decades for any mitigation to take effect.

Extraction is taking too much out of an environmental system. Just as for pollution, too much is something more than the environment can cope with. Mining springs easily to mind here; taking too much of a non-renewable resource means that we run out of it - eventually. Running out of iron may not happen too soon, and may or may not matter. Running out of helium is a current worry, and matters for, among other things, medical devices. Taking too much from wild life populations means changing a renewable resource into a non-renewable one. Think fish. Think snow leopard. More subtly, farming, too, can be extractive. Any farming activity, by definition, takes nutrients from the ground and delivers them to humans. These nutrients are, currently, not returned to the farm - hence extraction. Using chemical fertilisers is a technical fix with its own problems - adding chemistry does not change the fundamental problem.

Which brings us back to toffee papers and scaling. My primitive analysis of what to do seems to be conflating the goal we want to achieve with a mechanism for achieving it. Looking at it a bit closer suggests three types of mechanism: law - international agreements, laws, regulation, taxation, by-laws, contractual conditions; social change - education, introduction of new narratives, provision (and presentation) of relevant information; and technical fix. Each of these options may be more or less available to us, singly or together, depending on the problem. But it may be difficult to decide what to do without first deciding what the goal is. We have three options. Suppose we have some thing that is happening too much, either polluting or extracting. We can reduce the occurrence of the thing. We can change the thing to reduce its impact on the environment. We can change the environment to change its response to the thing.

So far so good, but there are some caveats with these goals.