Plastics made from plants could be the answer to the world’s waste problem

Oh, well, that is depressing. Image: Getty.

Plastics are incredibly useful materials with extremely diverse properties, allowing a multitude of different applications that benefit our lives.

Bottles and forks aside, in the medical field alone plastics have been used for artificial heart valves, medical implants and devices, controlled drug release, specialist surfaces and coatings that repel water, organic batteries – the list is endless.

But, with marine plastic debris estimated to reach 250m tonnes by 2025, governments across the globe are starting to think about how to overcome this significant problem.

A fundamental part of this issue is that non-sustainable, single-use plastics account for up to 40 per cent of global plastic production. This equates to around 128m tonnes. The vast majority of these plastics have low recycling rates and do not biodegrade in an acceptable time span – polypropylene can take millennia to break down properly.

Worse still, if these plastics find their way into the marine environment, the motion of the sea along with sunlight can cause the plastics to fracture into small particulates called “microplastics”.

The presence of macro and microplastics in our oceans has been shown to have a detrimental effect on marine life. But the potential effect on human health is much less well understood.

A ban on the production of cosmetics and personal care products containing plastic microbeads came into effect at the beginning of the year. Realistically, though, this only accounts for an estimated 680 tonnes of microplastics per year in the UK.

The problem with plastics

It is clear then that plastic waste is a complicated problem – spanning economics, sustainability, social pressures and recycling infrastructure in both developed and developing countries. But while it’s widely known that plastics can be an issue for the environment, what isn’t often known is that the persistence of plastics in the environment is actually closely linked to how they are made.

The overwhelming majority of plastics are made using oil-based materials, meaning that, by their chemical nature, many plastics have no oxygen content. This makes them very hydrophobic (water hating) and, as such, it is very difficult for common bacteria or enzymes to break them down if they enter the environment.

Over the past few decades, there has been increased awareness of our dependence on a limited oil supply and this has driven research into alternative, sustainable sources of chemicals. In particular, the concept of using bio-based materials as a resource rather than oil-based materials has really gained momentum. Sustainable bio-based material can be waste crops, waste wood, waste food – in fact, any waste biological matter.

Most importantly, these natural, bio-based materials can easily be broken down into smaller chemical building blocks – called “platform molecules” – which in turn, can be used to make other useful chemicals, including plastics.


Nature’s building blocks

Using these platform molecules, the Green Chemistry Centre of Excellence at the University of York, has been working with the plastics industry to create a new generation of bio-based polyesters. These are often used to make fibres for clothing, as well as films and containers for liquids and foods. The resulting materials are entirely plant based, recyclable and – importantly – fully biodegradable.

Aside from sustainability, the huge benefit of using biomass as a resource is the high quantity of oxygen that is incorporated into nature’s chemical structures (celluose, glucose etc). By using bio-based materials to make bio-based plastics, the oxygen content is kept in the material. The hope is that by having a high oxygen content, the bio-based plastics will have high, but controlled biodegradability. This means that the bio-based plastic can totally and safely break down into benign starting materials.

But although this new generation of sustainable plastics is a huge step forward, and a compostable plastic is of huge benefit, this is by no means the end goal for all bio-based plastics.

Circular economy

The circular economy is all about keeping resources in a constant loop, reusing and recycling them as many times as possible. This helps to minimise waste and reduce the need for brand new resources.

Treating plastic waste as a resource rather than a problem is an important change than needs to happen over the coming decades. This will help to preserve our remaining chemical materials, as well as protect our environment.

Enough plastic is thrown away each year to circle the earth four times. Image: Pexels.

Plastics are a fundamental part of modern society and they are here to stay. Ultimately, society has to move away from oil-based products towards sustainable bio-based alternatives. But regardless of whether a plastic is oil-based or plant-based, the biggest impact you can have on the life cycle of a plastic product is to reuse and recycle it.

As a consumer, this means you have a choice and the power to make a positive impact. Find out where your nearest plastic waste recycling point is and look to promote home collection and the proper recycling of all types of plastic waste.

The ConversationSo next time you use the last of the ketchup, help to preserve our resources by making sure your plastic waste stays in the recycling loop.

James William Comerford, Postdoctoral Research Associate, University of York.

This article was originally published on The Conversation. Read the original article.

 
 
 
 

Here are eight thoughts on TfL’s proposed cuts to London’s bus network

A number 12 bus crosses Westminster Bridge. Image: Getty.

In 2016, the urbanism blog City Observatory had a modest proposal for how American cities could sort out their transport systems: “Londonize”.

Its theory, the name of which referenced another popular urbanism blog, Copenhagenize, was that the key plank of Transport for London’s success was something that even transport nerds did not consider very sexy: its buses.

Though the Tube might get more glamorous press, London’s bus service really is impressively massive: It carries roughly 2.3bn passengers per year—much more than the Tube (1.3bn), close to the New York City subway (2.8bn), and nearly half as much as every bus service in America combined (5.1bn), while serving a population roughly 1/35 as large.

How has TfL done this? By making its bus network high frequency, reliable, relatively easy to understand and comprehensive. We rarely talk about this, because the tube map is far more fun – but the reason it’s so difficult to fall off the transport network in Greater London is because you’re never that far from a bus.

Given all that, we should probably talk about TfL’s plans to rethink – and in most cases, cut – as many as 36 different central London bus services over the next few months.

I’m not going to rehash details of the changes on which TfL is consulting from next month: there are just too many of them, and anyway it’s someone else’s scoop. The story was originally broken by Darryl Chamberlain over on 853 London; there’s also some fascinating analysis on Diamond Geezer’s blog. You should read both of those stories, though preferably not before you’ve finished reading this one.

Before offering my own analysis of the proposed changes, though, I should offer a few examples. More than a dozen routes are facing a trim: the 59 from King’s Cross back to Euston, the 113 from Oxford Circle to Marble Arch, the 171 from Holborn all the way down to Elephant & Castle and so on. A couple – the 10, the 48, the C2, and at most times the special routemaster version of the 15 – are being withdrawn altogether.

On, and one new route is planned – the 311, from Fulham Broadway to Oxford Circus. This will help plug some of the cuts to the 11, 19 and 22.

So, what does all this mean? Some thoughts:

1) This might not quite be as awful as it initially sounds

TfL says that demand for buses has fallen by around 10 per cent in London in recent years. It predicts it’ll fall further when Crossrail opens, as passengers switch to the new line, or to the tube routes relieved by the new line. So: the idea of taking some unwanted capacity out of the system is not, in itself, terrible.

Striping out unnecessary buses should also improve air quality in some of London’s worst pollution hot spots, and improve traffic flow, hopefully speeding up journeys on those buses that remain. 

A map from the presentation in which TfL explained its plans, showing the reduction in bus numbers on key arteries. Hilariously, notes Darryl Chamberlain, “It no longer produces its own maps, so has had to use one prepared by a bus enthusiast”.

The plans might even free up buses and staff to increase frequencies in outer London where demand hasn’t fallen – though these plans won’t be unveiled until next year and, for reasons I’ll come to below, I’ll believe it when we see it.

2) For many bus users, a lot of these changes will pass almost unnoticed

By my count, I use nine of the affected routes with any regularity – but only three of the changes are things that I’m likely to be at all inconvenienced by. Most of the changes either affect a part of the route I don’t take, or one where there are easy, and pain free alternatives.

This is anecdotal, obviously – perhaps I’m just lucky. But my suspicion is that a lot of these changes will go unnoticed by most passengers. It’s only the sheer number of them happening at once that makes this look like a big deal.

3) The Hopper fare makes this easier...

Once upon a time, if you had to switch buses, you had to pay a second fare. This isn’t true of journeys on the tube or railways – and since bus passengers have, on average, less money than tube passengers, it amounted to a pretty unfair tax on poorer Londoners.

But in January, in what is probably his most notable policy achievement of his two years in office so far, London’s mayor Sadiq Khan changed the rules. Now you can take as many buses as you want within an hour, for a single fare: that means you can switch buses without paying a penalty.

That will have made it easier for TfL to cut routes back: replacing a direct bus journey with one that requires a change no longer means imposing a financial penalty on passengers.


4) ...but not that easy

That’s about where the good news stops, though – because there are reasons other than cost why people prefer direct bus routes. Needing to change buses will be difficult for anyone with any form of mobility impairment, for example. Even for those of us lucky enough not to fall into that category, it’ll be annoying: it’s just easier to stay in one seat for 40 minutes than to get turfed off and have to fight for a new one halfway through.

More than that, from the passengers’ point of view, excess capacity feels quite good a lot of the time: it means your bus may well be nice and empty. Reducing the number of buses along those key corridors will also make those that remain more crowded.

5) The motive is almost certainly financial

Another of Sadiq Khan’s big policy promises was to freeze fares. He made this promise at a time when central government is massively reducing the financial support it gives TfL (the work, Chamberlain notes, of Evening Standard editor George Osborne, back when he was chancellor). And the Hopper fare, while a great idea in many ways, means a further reduction in income.

So: TfL is scrambling for cash: this is why I remain cynical about those new outer London bus routes. I would be amazed if money wasn’t a motivation here, not least because...

6) TfL thinks no one will notice

Any attempt to reduce tube frequencies, let alone close a station, would result in uproar. Hashtag campaigners! Angry people pointing at things in local newspapers! Damning reports on the front of the Evening Standard from the bloke who made it happen!

Buses, though? Their routes change, slightly, all the time. And do you really notice whether your local route comes every 10 minutes or every 12? That’s not to mention the fact that bus passengers, as previously noted, tend to be poorer – and so, less vocal – than tube passengers.

So cuts, and the savings they bring, are much easier to sneak through. TfL probably would have gotten away with it, too, if it hadn’t been for those meddling bloggers.

Although...

7) Scrapping the C2 might be a mistake

The C2 runs from Parliament Hill, through Kentish Town and Camden to Oxford Circus. In other words, it links north London, where a lot of journalists live, to the offices of the BBC and Buzzfeed.

As occasional New Statesman writer James Ball notes, this is probably not the easiest route to quietly shelve.

8) None of this is set in stone

The consultation doesn’t even begin until next month and then will run for six weeks – so all these plans may yet be forgotten. We shall see.

Anyway – here’s Darryl Chamberlain’s original scoop, and here’s some detailed analysis on Diamond Geezer. Please support your local bloggers by reading them.

Jonn Elledge is the editor of CityMetric. He is on Twitter as @jonnelledge and on Facebook as JonnElledgeWrites.

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