Sunday, 13 January 2019

One third of microplastic in the oceans comes from washing clothes - really?

I recently heard a claim that a third of microplastic in the ocean comes from laundry, as synthetic clothes shed fibres in the wash. (This was on a radio program called New Year Solutions: clothes, on radio 4.) This struck me as unlikely so I checked and I believe I found the source: a report from the IUCN in 2017[1]. They do indeed estimate that a third of primary microplastics come from laundry – averaged over the world. However this varies hugely in different regions. I found estimates specific to the UK in a report by Eunomia for Friends of the Earth [2]. They found that only 8% of UK primary microplastic is from laundry. The bulk is actually from tyre wear from cars and lorries.

Thursday, 3 January 2019

Some facts about food waste

Michael Gove has announced that we could divert 250 million meals per year to the most needy in society [1]. Is this a lot? There are 67 million people in the UK (approx). If we each eat 2 meals per day, that comes to 49 billion meals per year. The quoted 250 million meals is 0.5% of consumption. That seems a very low level of wastage to me, though we should still redistribute it if that is practical. We waste a lot more food at home. Here are some more facts about food waste.

Friday, 23 November 2018

Are hybrid heat pumps the solution for low carbon heating?

The Committee on Climate Change has just published their view on the role of hydrogen in a low carbon economy [1]. Their recommendation for people currently on gas is to insulate your home as much as possible and then install a hybrid heat pump/boiler system. You can get hybrid systems now, only burning methane gas rather than hydrogen. The idea with a hybrid is that the heat pump supplies all the heat most of the time, but with a boiler for backup when demand is very high or electricity supply is expensive. In theory, a hybrid system should supply around 90% of the heat from the heat pump - however, this is only the case when the system is configured correctly. In field trials the proportion of heat from the heat pump has ranged from 96% down to 30% [2]. No wonder the RHI subsidy requires that hybrid heat pumps have metering to actually measure how much renewable heat is supplied through the heat pump [3]. If hybrid heating systems are to play their part in a sustainable future we have to learn how to manage them properly.

Thursday, 15 November 2018

BAU is not an option. Plus indirect subsidies for indirect benefits.

Last week I went to Low Carbon Britain  and the bit that has stuck in my head all week has been a comment from Patrick Allcorn from the Department for Business, Energy and Industrial Strategy. He said (with a bit of paraphrase from me) we should never compare costs of carbon saving policies with business as usual (BAU) because BAU is not an option. We should be comparing costs of one carbon saving scheme with another to see which is most cost-effective.

In many ways this is spot on. We have to reduce our carbon emissions so we should only consider options that meet this requirement. It isn't a question of electric cars versus fossil fuel cars, it is electric cars (with clean electricity) versus fuel cells (with hydrogen) or other clean vehicles. However, its a bit more complicated than that because how you measure the costs depends on who you are.

Tuesday, 23 October 2018

Should we (and companies) offset our emissions?

Last year I took an airline flight and considered offsetting the carbon emissions. Several of my friends have done so too. Recently I was reminded that companies such as Marks and Spencer offset their emissions so that they are carbon neutral. I would be the first to agree that we all need to reduce our own emissions, not just pay someone else to do it for us. (And M&S have reduced their emissions substantially already [1]). However it seems to me it ought to be better to offset than not. How many people do this? Not many, it seems, as the total voluntary carbon offsetting market is tiny. In 2016, the equivalent of 43 million tonnes of CO2 was offset globally [2]; that is only 0.1% of global GHG emissions [3]. The projects supported by offsetting are clearly worthwhile, but could they be funded another way? How much would it cost to offset our own emissions?

Friday, 10 August 2018

Why I am pulling 100% degradable plastic bags from my compost bin

My organic veg supplier has recently started using plastic bags with this logo on. It says they are '100% degradable'. Perhaps I was naive in assuming that meant it was OK to put the bags in the compost bin. It turns out that they are 'oxo-degradable', a technology which is highly controversial.  They are currently banned in France and Spain [1]. 150 organisations including the World Wildlife Fund, Unilever and British Plastics Federation Recycling Group have signed a statement calling for them to be banned completely [2]. Now the European Commission has called for all member countries to take measures against them [3].

Wednesday, 18 July 2018

Climate change is here - how do we adapt?

Like a lot of people I've been suffering in the hot weather recently as has my work (low productivity) and my partner (due to my grumpiness). June has been a record breaking scorcher for many people. In East Anglia the temperature is several degrees above average and we have had only 12% of the normal rain fall [1]. July so far has been at least as bad. Climate change is going to bring more of this and other weather extremes. We are not suffering as much as other parts of the world but we do not escape entirely. So what can we do?

[By the way I am organising a workshop on this topic: Adapting our homes for Climate Change on 15th October. This will be one of five events to go with this year's OpenEcoHomes house tours. If you have tips to share or would like some advice please put this in your diary.]

The problem weather we need to cope with includes heavy rain and floods as well as heatwaves and drought. As with energy efficiency, there are a whole range of measures we can take from very low cost (e.g. more ice cube trays in the freezer) to higher cost (blinds or solar control film for windows) and requiring little or lots of advance planning (planting trees, politely requesting that potholes in the road should be fixed). Here are some ideas. I am sure you will have lots more.