I watched it when it first aired on BBC, and I have the box-set. Good stuff!
On the subject of airplane travel and littering and such. Littering is mainly aesthetic pollution, discounting animals that happen upon it and are harmed by it (which is a huge thing to "discount" because many animals are harmed by it.)
Airplane travel is necessary for some people. I'm from England, and return twice a year to visit my family. Many people have to use planes for business trips. However there has been an enormous increase in the volume of jet travel in european countries in the last decade with the advent of really cheap package-holiday deals. I think you'll find the majority of flights going out of Gatwick are holiday liners going to the mediterranean, turkey, and so on. Having autonomy doesn't excuse us from the fact that we should be morally conscious, and we do have moral responsibility to the earth, its inhabitants, and other humans, as well as the future. An environmentally detrimental practice having a "purpose" (read: human pleasure/leisure) does not necessarily justify it.
I'm very concerned about dead-zones, which are the result of irresponsible agricultural practices. Excessive use of pesticides, storing the highly toxic waste of pigs in huge lagoons beside rivers in factory farming operations, waste dumped from all sorts of plants and factories.
There is a lot to consider, a lot to weigh up in regards to environment, ethics, and the economy. However we have to learn as much as we can about practices we find irresponsible and cast our votes with our wallets and actions. If you don't agree with something and have the option of buying/supporting it or not, don't support it.
It's just where each individual draws their own line
