Energy & environment

Click the links below for various work on sustainable energy, especially cost-effective solutions for limiting global warming & its escalating impacts:



Meat consumption
Current animal farming practices are environmentally unsustainable and unethical (see this documentary about how farm animals are treated), and always will be under pressure to remain so, in order to keep the cost of food low.  Half of global greenhouse-gas emissions are caused by animal agriculture and meat also requires huge amounts of water - e.g. 15,000 litres per kg of beef (vs 1000 litres/kg grain) - which means water use for food could be reduced 33-55% by switching to a vegetarian & fish diet (from typical levels of about 3,000 litres per person/day, though commonly 50% higher for the French as they need 7x more water per kg of wine than the 111 litres required for a kg of beer).
Therefore public policy should support sustainable farming (including less intensive free-range livestock) & non-meat substitutes that could feed everyone with much less land and environmental impact, such as Beyond Meat's veggie-burger, the McVegan and other artificial meat (like fake bacon & even seafood), sustainable ocean fish-farms, as well as alternatives to cow-milk like soy, oat or pea (but not all alternatives are environmentally better) and even real lab-grown meat (such as Memphis Meats, backed by Bill Gates & Richard Branson, which produces beef, chicken and duck directly from animal cells in the lab), which could be in our supermarkets very soon & help us avoid all animal slaughter within 30 years.



https://sites.google.com/site/drdavidcthorp/energy/Stemming%20the%20tide%20cover.jpg?attredirects=0
Ocean Plastic Pollution
Whilst there is thankfully increasing attention being paid to ocean plastic pollution, current community & government actions - mainly focussed on banning certain things like plastic bags & straws (the latter comprising a mere 0.025% of ocean plastic waste) - are largely tokenistic and not informed by the evidence of where the problem comes from - which as New Scientist reports, is substantially due to poor waste management in developing countries (like this open plastic dump island in the Maldives).  A 2015 McKinsey study found that 20% of ocean plastic waste comes from ocean-based sources like fishing vessels (nearly half of the Great Pacific Garbage Patch is fishing nets), but of the dominant 80% of ocean plastic that leaks from land sources, 75% is from uncollected waste and the rest due to leakage from poor waste management systems.  Clearly waste collection is the big problem, and moreover, 55-60% of all land-sourced ocean plastic comes from just 5 Asian countries, where waste systems are poor or non-existent (e.g. only 5% of waste is collected in rural China (40% overall) vs 90%+ in Philippines & developed countries).  Also this study found that 90-95% of river-borne plastic in the world’s oceans comes from just 10 rivers - 8 of them Asian (e.g. the Yangtze, Indus, Ganges & Mekong) and two in Africa (the Nile & Niger) - with all having large populations and poor waste management along their catchments.

My concern is that as recent public reaction to bag bans in Australia shows, there is a limit to what people are willing to "pay" (in $ & inconvenience) to address the problem of ocean plastic, so we need to ensure maximum "bang-for-buck".  I for one have already had enough of not being able to drink the last of my cocktail through a paper straw that's turned to mush, and that makes me more resistant to the next daft ban that's proposed.  At some point, the community will say, "Enough!", but we will have done precious little to actually reduce ocean plastic. 
So, given 80% of ocean plastic comes from countries suffering extreme poverty, if we are going to be rational and focus on the most effective measures, then top & urgent priorities over the short-medium term (more importantly than promoting recycling) should be for richer countries to help poorer countries improve (& actually have!) waste collection & management (perhaps with financial support being part of broader trade dealswhich seems fair given how much global wealth & polluting consumption is concentrated in the hands of a small wealthy % of the population).

Technologies for collecting existing plastic waste may also be part of the solution, although mainly in areas of high concentration within rivers & harbours and coastal beaches, since about 95% of ocean plastic is below the surface.  The chart below indicates 94% is on the sea floor, with just 1% on the surface and the remaining 4% on coastal beaches, but the concentration on beaches - which are a constant new source for ocean plastic - is about 30 times that on the sea floor.  However this video suggests 92% of ocean plastic that is concentrated in five major ocean garbage patches is large, so although these patches hold a relatively small percentage of total ocean plastic (the largest patch in the Pacific contains 80,000 tonnes) we need to understand whether they are also a constant source of microplastics that result from light degradation and then fall to the sea floor.

In beach clear-ups, plastic cigarette butts are said to comprise about a third of all items collected, although this data suggests 12% (about the same as bags, straws & stirrers combined), with the next most common items of food wrappers, bottles & tops accounting for 22%.  This implies cigarette butts may be responsible for between 0.5 and 1.4 million tonnes of ocean plastic p.a. globally (scaled from 64kt p.a. in the US), which is some 6-17% of the estimated 8m tonnes p.a. of plastic entering the world's seas (although note the chart below indicates 12m tonnes p.a., as there is a large uncertainty of some +/-40% in these total tonnage estimates).  To address these major pollutants, tobacco (& other) companies need to be pressured/incentivised to develop biodegradable alternatives.  However, such regulation needs to be prioritised on the major culprits; for example, microplastics in cosmetics don't appear to be a significant problem (see chart below from a European Commission Study, and this industry link, although of course the latter isn't a neutral source).

For the longer term, the use of plastics may have relevance to oil & energy-use (unless replaced by bio-plastics), so we do also need to support innovation for more efficient reuse & recycling, but initiatives in these areas need to balance competing issues, like the benefits of plastic for food hygiene & waste reduction, energy use, cost etc., so it's not simply a case of plastic = bad & re-use/recycling = good.  For example, many people previously reused so-called single-use plastic bags from supermarkets as bin liners, but will now have to buy truly single-use bags for this purpose (& may throw out the more resource-intensive thick bags that supermarkets are now issuing instead).  Depending on your assumptions and objectives, thick plastic bags and even paper bags need to be reused more than 3 times for a net environmental benefit vs a thin single-use plastic bag, whilst supposedly "green" cotton tote bags need to be used at least 130 times and perhaps more than 7000 times.  Single-use plastic shopping bags and drinking straws make up less than 1% of the more than 100 kg of plastic that each Australian uses every year, which if saved up over a year would only form the size of a volleyball, which (if the bags weren't used as bin liners) could be then thrown in the local recycling bin.  We would do better to focus on reducing and recycling the two-thirds of the plastic we use for packaging.  And of course things that cause problems also have benefits (e.g. faster check-out & hence lower grocery costs), so we need to be careful about banning things.  For example, any parent knows how beneficial disposable nappies are, and actually cloth nappies may be worse for the environment than disposables if they use non-renewable energy for washing & drying.  More broadly, dogs have a bigger carbon footprint than a 4WD, so should we ban dogs?

Funding to support an evidence-based strategy like this should come from small, pragmatic levies on the worst culprits for plastic waste, e.g. retail bags, bottles & fast-food packaging (which of course isn't possible if you simply ban these items) and maybe a general virgin-plastic production tax.  Such price signals will also help to make recycling and bio-plastics (such as seaweed) more commercially viable.  As a relatively poor multi-island nation that is struggling with ocean plastic waste ("drowning in plastic"), Indonesia is also leading the way with major investment in the development of bio-plastics (which in the near term may still cost 30% more than virgin plastic), including biodegradable bags, coffee cups & edible/soluble food packaging, and even edible water balls or bottles based on seaweed, which unlike other bio-plastic sources doesn't require land that's needed for other purposes (such as food production), and may be a major source of economic growth for Indonesia.
And as a final option (or until bio-plastics can replace non-biodegradable plastic), since unfortunately so many people in our wealthy society are so wasteful & careless (whatever it costs them), yes, bans on certain items may be necessary - if the evidence clearly supports it.

http://www.eunomia.co.uk/reports-tools/plastics-in-the-marine-environment/