How I shrank my carbon footprint

carbon footprint

Shrink That Footprint

Writing a blog about reducing your carbon footprint is much, much easier than actually cutting your footprint.

This post is where the rubber meets the road.  It details my carbon footprint from 2012, the things I did, the things I didn’t do and my struggles along the way.

I did the data back for this post back in January but didn’t publish then as the blog was brand new. Now that 2013 is coming to an end and I’ve almost got another year of data, I though I should dust it off and walk you through my footprint.

Btw: this post is a whopper so don’t be scared to scroll to what interests you.  It goes through a summary, housing, travel, food, products and services.

My Carbon Footprint in 2012

In 2012 my carbon footprint was about 4.67 t CO2e.  This is a little bit under the global average for personal emissions.

In this calculation I include all the emissions that result from my share of spending on housing, travel, food, products and services.  This includes the full climate impact of my spending by accounting for length of the supply chains associated with purchases of energy, food, products and services.

The calculation is done with our own carbon calculator, using adjustments to the carbon intensities where necessary.

My Carbon Footprint

The breakdown of my 4.67 t CO2e is as follows.  Housing (1.2 t), travel (0.9 t), food (1.4 t), products (0.6 t) and services (0.6 t).

The three biggest components of my 2012 footprint are natural gas (653 kg), driving (663 kg) and electricity (312 kg).  This is similar to a typical UK resident, though my emissions are quite a bit lower.

In terms of the calculation both the housing and travel numbers should be very accurate, as I’ve done them using units of fuel.  I think I’ve done a pretty decent job with the food calculations, and services are quite homogeneous so not too bad either.  The product figures are likely to be the most inaccurate as you can’t be sure your purchases have similar emissions to typical products in those groups.

Finally, as a calculation of my personal footprint this figure does not account for my share of government and construction emissions in the UK.  This would add about 3 t CO2e to my figure.  Net UK land use emissions are pretty negligible.

Now to explain what we are doing, what we aren’t doing, and why . . .

My Housing Footprint

In our house the main challenge is keeping warm while avoiding a big emissions.  Throughout 2012 we were a 3 person household. So my emissions above are a third of our total household footprint.

This picture below is our place.  It is pretty standard ex-council semi from the 1950s, although it has been nicely refurbished and we have added some solar panels.

Our house

The major sources of household emissions in 2012 were natural gas (653 kg), electricity (312 kg) and waste (170 kg).  Together in the house we used 9,300 kWh of natural gas for heating and hot water, 1500 kWh of grid electricity and generated about 10kg of waste a week, less after composting.

Heating and Hot Water Emissions:

Reducing heating emissions is the biggest struggle in our house.  Since buying our house 3 years ago we have insulated floors, the loft (attic) and walls, replaced a few windows, and also replaced the old boiler with a more efficient one (still natural gas).  We keep the house pretty cold (around 12-15 C), with the exception of the main living area which we heat well (18-20 C).

We also have a wood burner which we use pretty regularly. We use straw briquettes (CO2 absorber last summer) and waste wood kindling, as I don’t like the idea of burning virgin wood that is decades old.  As is the standard I don’t count these emission here (if I did they would add 400 kg). This said I still have mixed feelings about burning biomass, even short rotation stuff, both on a CO2 and particulate level.

I have investigated in detail the possibility of externally cladding our house with insulation.  I really like this idea, and aiming for the passivhaus retrofit standard, but it would require a new roof and the payback time is horrendous for us as our heating bill is currently pretty low.  So for us it is a super expensive way to cut carbon that I’m unlikely to do any time soon.  I can much more bang for my buck elsewhere.

Hot water actually accounts for a little over a third of our gas use.  The only strategy we use to reduce this is to use less, and to ensure the boiler temperature isn’t too high.  This is becoming an increasing struggle now we have little kids who have regular baths.

Electricity Emissions

We’ve had solar panels on our house since August 2011.  The solar (3.29 kWp, Sanyo panels, Fronius Inverter) has produced almost exactly 3,300 kWh each of the last two years.  This is 50% more electricity than we use over the year, but of course our production occurs at different times to use.  I’ll show you what I mean using some data.

Over the two days of December 8 and 9 our solar panels produced 8.6 kWh of electricity while we used 9.3 kWh of electricity. Seemly pretty good.  But if you look at the hourly data below, you can see that most of the solar electricity was exported during the day and that consumption occurred primarily from 4-11pm when the panels were not producing.

Our solar production

Click on the image to expand it.

You’ll see the solar production in green, with Monday the 9th being a pretty sunny day for December in England.  In the red you can see our usage, with a spike at 5-6pm each day as we prepare dinner.  The nighttime usage is the fridge cycling on and off.

It is obviously better in the summer when production hours extend, but you get the picture.  As we are grid-tied on the feed-in tariff that isn’t going to change.

In 2012 we used 1,950 kWh of electricity.  575 kWh of this was solar power, with the remaining 1,375 kWh from the grid.  We exported 2,725 kWh to the grid, which does our bit to improve the fuel mix on the grid.

In my calculation of our emissions I use the grid factors (including upstream emissions) for our grid share, and a typical solar value (50 g CO2e/kWh) for our solar stuff.  I don’t subtract the grid export from our numbers, because I think negative values for export are a little silly  (unless you can make short rotation biomass work with carbon capture).

We don’t really do anything with the solar, other than to make sure it hasn’t tripped and to use the washing machine while the sun shines (that is the red spike at 11am Sunday).  Instead we focus on our uses of electricity by actively using an energy monitor and improving the efficiency of our lights or appliances where possible.

My Travel Footprint

2012 was one of my best years for travel emissions at just under 1t CO2e.  More than two-thirds of this came from car travel, the rest was mostly a monthly train trip to London.  I managed to avoid flying in 2012, something that doesn’t always happen.

I have two main modes of transport that I use on a weekly basis, our car and my bike (pictured below).

My car

I love my fabulous old dutch bike from my time in Holland.  It is great for trips around the town we live in.  And my 3 year old son yells weeeeeee from the back seat as we go down the hill, which makes me cycle more. I also walk a lot, as the town isn’t that big and everything is within 20 mins walk.

Driving Emissions

Our only family car is the 1.4 L diesel Skoda Fabia Estate in the picture.  I read a review once that called it the perfect car for two kids and a vasectomy.  This is spot on.  It is a very thin car with a surprisingly roomy boot for its size.  But between two car seats you are lucky to fit a hand bag, let alone a passenger.

In 2012 the Skoda clocked 6,780 miles, which is pretty similar to previous years.  Because we don’t need it much in our small town these were mostly highway miles, generally with two and often with three people in the car.

Because it is pretty small and efficient car, and we drive mostly on highways, we average about 60 MPG (UK), that’s 50 MPG (US) or 4.7 L/100km.  When you look at these numbers it’s worth remembering diesel emissions are about 15% higher per unit of fuel than gasoline.  The downside from the diesel is higher particulate emissions, even with a filter.

Given we have 2,700 kWh of solar electricity that goes to the grid we could have an electric car.  This is something I might look at in the long run, but given how much we currently drive and the UK grid mix I don’t feel having an electric car at the moment would do much to reduce emissions in a cost-effective way.  Moreover, we are pretty frugal and have never owned a car newer than 4 years old, so an electric is a little decadent for us at this point.

Flying Emissions

Although I managed to avoid flying in 2012, flying is and remains my biggest problem when it comes to my carbon footprint.

Back in the year 2000 I was on holiday and drove from my home in Sydney up to see my brother in Brisbane.  It was my first break in a while so I stopped in Byron Bay for a week to try and learn to Surf.  I never made it to see my brother.

I met this English girl travelling with some friends, gave them a lift back to Sydney, ended up in New Zealand . . .

13 years later I live in the UK, with two little English kids.  My parents live in Australia.  I’ve got a brother and sister there too, and another brother in New York.  My five closest friends live in New York, Tel Aviv, Geneva, Sydney and Canberra (they are all Australian). I’m suffering an acute case of what George Monbiot would call love miles.

Although we happily use high-speed trains in Europe there is no practical low carbon alternative to flying when it comes to trips like London to Sydney to see family.  It is what it is, and I hate that. I will fly more in the future, and each time that I do I will completely blow my carbon budget for that year.

Let me show you what I mean:

Flying

No prizes for guessing in which of the last three years I flew to Australia.  In 2011 my emissions from one return flight between London and Sydney were equal to all my other emissions that year.

The problem with flying isn’t that it is a huge footprint on a per mile basis.  It is simply that you can travel such vast distances so quickly.  It you fly a lot it will quickly dominate your carbon footprint.

If you notice me starting to write posts about offsetting in the future it probably means I’ve got a flight looming. To me it really is the hardest part about cutting my footprint.

In all other areas of life I feel like there is a clever mix of behavior and technology that allows me to cut carbon without sacrificing my lifestyle too much.  With flying I feel the opposite, it is hugely constraining and stops me going places I would like go to see people I dearly miss.

My Foodprint

In 2012 my foodprint was about 1.4 t CO2e, decent by UK standards but a little over the global average. Here is my foodprint from 2012 broken down into food groups:

Food carbon footprint

Dairy is my major source of emissions, although my foodprint is quite well spread.  The majority of my Calorie intake comes from breads, grains, snacks, fruit and vegetables.  The beef and lamb emissions come from just one or two serves a month, such is their high carbon intensity.

I have three basic tactics for reducing my foodprint.  They are to eat more low carbon foods, to waste less food and to grow my own food.  I also take steps to avoid food that is flown in from abroad, but as I have detailed before food miles are not a good thing to make your primary focus when it comes to food emissions, as they are not nearly as important as what you eat or what you waste.

1: Eat more low carbon food

In terms of food choices I still eat meat and dairy, but am trying to cut down.  I’ve found it pretty easy to reduce beef and lamb (the most carbon intensive foods) consumption but have had less success with reducing dairy.  Although my cereals, vegetables and fruit emissions are moderate these supply a great deal of calories. So going forward tackling dairy and further reducing meat consumption are my best options.

2: Waste less food 

We are pretty hot on food waste in our home, and I’ve documented the system we use in our how to save money on food waste video series.  The project we did this year weighing it has reduced our food waste further.

You can watch me demonstrate the global food waste problem (by wasting tomatoes) below:

carbon footprint

3: Grow your own

By far the most enjoyable part of tackling my foodprint has been the chance to grow my own.  In 2012 year we had strawberries, corn, beans, broccoli, salads, various herbs, aubergine (eggplant), peppers (capsicum), carrots, courgettes (zucchini), and a huge load of tomatoes.

Most of all I adore growing tomatoes.  I grow them from seed, in peat-free compost using only natural light.  They need to be watered each day, and looked after.  But from July through till the end of November we swim in tomatoes.  I end up giving them away, making passatas, chutneys, sauces . . .

My Stuff Footprint

According to my calculations the emissions that resulted from purchases of stuff were about 600kg CO2e in 2012.  This is the hardest one to calculate, and it wouldn’t surprise me if this isn’t that accurate, simply because the data has too many assumptions in it to be that accurate.

Compared to the average UK resident I just don’t buy much new stuff.  A lot of what constitutes my footprint is the typical non-durable purchases of normal life, or materials for DIY projects.

I buy second hand goods were possible, upcycle what I can and generally aren’t that bothered with a lot of products, as I think too much stuff can crowd out more important things in life. If anything I’m actively trying to purge the number of possessions I have, though this is a slow process.  You can check out some recent upcycles below.

3 Pallet Projects

My Services Footprint

Services are by far the least carbon intensive way to spend money.  In most cases I actively encourage others to spend more on services if that reduces their spending else where.  My main reason for cutting down on service spending is to try to save money. Our service budget is pretty minimal, and includes boring but necessary stuff like banking, telephone, internet, car as well as the odd bit of  holiday accommodation.

The graph below showing the average carbon intensity of spending in the US gives you an idea of why cutting your service footprint should be your last priority.  Moreover, many services like education and health aren’t exactly discretionary.

paytheman

My footprint in context

Although I am passionate about helping people take steps to reduce their carbon footprints, I don’t think such actions are the biggest climate levers we have.  In fact when you get serious about your footprint you’ll quickly realize how important things like carbon pricing, innovation policy and efficiency legislation are to helping you improve your own footprint.

This much said, individual action is still important.

Almost 70% of global greenhouse gas emissions are paid for private consumption.  This means that people the world over, and the wealthy in particular, have enormous potential to cut emissions simply by changing the way they spend.  Diverting a little money to improving insulation, getting an efficient vehicle and insulating your house can reap very large emissions reductions. Moreover, I find that the process of understanding and tackling one’s own footprint can serve as a bridge to help everyday people gain an interest in broader action that is generally intangible for them.

Getting into the nitty-gritty of your own emissions also provides tremendous context as to the scale of the challenges we face. I am perpetually amused by people who think a ‘single solution’ like renewables, or nuclear, or efficiency, or CCS, or innovation, or carbon pricing, is going to be sufficient to stabilize the climate.  You can’t possibly think that if you’ve had a proper look at the data.  We have many different levers we need to use, and we could really do with some more too.

I’ll show you what I mean by putting my personal footprint of 4.7 t CO2e into the context of a 2C global carbon budget.

In the graph below I show how the average personal carbon budget globally will need to decline over coming decades in order to have a chance at staying inside 2C of warming by 2100.  This is based on the UNEP emissions gap budgets and global population forecasts from the UN.  The grey section is our business as usual scenario (BAU) trajectory.

Carbon Budget

My personal footprint of 4.7 t CO2e in 2012 is just a little below the global average from 2010 of 5t.

This figure compares well to a North American’s at around 20 t, or a European at 10 t (you can see some examples here), but is much higher than in poorer Asian, African or South American nations.  In fact half the world’s population have personal footprints of 2 t or less, largely due to the fact they have limited access to energy.

In order to limit warming to 2C above pre-industrial temperatures the global average would need to drop to below 2t by 2050.

How would I get my emissions from 4.7 down to 1.5 over the coming decades without greatly reducing my standard of living?

Let’s look at it by sector:

  • Housing: improve insulation, switch all heat, water and electricity to low carbon electricity.
  • Transport: use bikes, eBikes, public transport and electric cars, all powered by low carbon electricity.  No flying.
  • Food: further shift to low carbon foods, minimize food waste, improved food production inputs
  • Stuff: better materials and manufacturing, greater recycling rates, improve product life, less stuff
  • Services:  reduced emissions from power supply, buildings and manufacturing

In each sector the answer is to squeeze more life out of less carbon.

In the long term that means electrifying everything possible and switching totally to low carbon electricity supply (a gargantuan task). This means no natural gas for heating, no gasoline or diesel for fuel as well as buying goods with fewer and fewer fossil fuel inputs.

My emissions would then result solely from the processes of making and moving stuff.  Some of these areas will be not decabonize any time soon, things like steel, shipping and other materials.  Viable carbon capture and storage would help a lot in improving industrial emissions.  Flying will remain a problem.

If you are prepared to live a very low energy life, then having a low carbon footprint is not hard.  But this is not what the vast majority of people, myself included, actually want.

The real challenge is to create a low carbon lifestyle that people are actually happy with.  That doesn’t mean having a mansion and a private jet, but it does mean a comfortable place to live, some decent transport, a healthy diet, decent stuff and good access to services.

So that is my footprint and some global context.  If you made it this far congratulations ;-) For some simple ideas to shrink your own footprint check out our free eBook Emit This: 13 Strategies for Squeezing More Life Out of Less Carbon.
Source: Shrink That Footprint. Reproduced with permission.

Comments

10 responses to “How I shrank my carbon footprint”

  1. Joshua Marriage Avatar

    Awesome article! Such a great level of detail and a joy to read! Really inspires me to do more!

    1. suthnsun Avatar
      suthnsun

      I second that, fantastic!
      Lindsay, I hope to get some time to study your methodology and reconcile it with my own shorthand method, hoping to use your far more detailed approach to validate and calibrate my approach, if you don’t mind I might come back with some questions?

      My shorthand approach entails a 250kg target CO2 for residential energy and transport, fairly easily measured, then scale up by a factor (of 4) to impute total attributable emissions (the factor is dependent on specific country/city circumstances)
      I’m nearly there according to my calculation but validation with the help of your far more exhaustive approach would be great.

  2. biroses Avatar
    biroses

    Great effort Lindsay.
    I’d be interested to see what result you get using my Australian calculator http://www.ghgenergycalc.com.au. It doesn’t have electricity factors for the UK but as you don’t use much, you can select the green energy options or select a low emissions state like NT, which has natural gas fired electricity. The emission factors for other fuels and consumption categories won’t be significantly different for UK.

    Ben Rose

  3. Motorshack Avatar
    Motorshack

    I note that the author still has a “struggle” to keep hot water emissions under control, but solar hot water heating can be up to 80% efficient, has a built in storage component that is dirt cheap, and can easily be done on a DIY basis. For most people hot water chews up as much energy as driving a car, so it is well worth looking at solar water heating.

    For a wealth of ideas, plans, and experimental data see http://www.builditsolar.com/. The guy running the site is a retired engineer who does very well documented experiments that will show you exactly how to to solar hot water (and space heating, too) as cheaply and reliably as possible. He also lives in Montana, so he is not able to take advantage of a mild climate.

    Also, given the popularity of rooftop PV in Australia, I am very surprised not to read more about solar hot water. Again, it would cut out a great deal of the load on the grid, and there is built in storage, so there is none of the political argument about feed-in tariffs and all that. You can use all the energy you gather, at your own convenience.

    And you can cut your use of electricity (no matter where it is produced) by about a third if you get rid on an electric water heater. So, for those lusting to kick the power company in the knees, it ought to be extremely attractive.

    1. suthnsun Avatar
      suthnsun

      Yes , agree about the hot water. Hot water was the second thing I did (first was go around and see where all that 36kWh/day was going and stop losing it everywhere – from memory that process saved around 4-5). After installation of ET hot water and sorting out where I was losing from that, it now needs minimal backup and only in winter, probably .5kWh/day year round average compared to the old direct element setup which was around 12. (didn’t do DIY , not sure that would be legal here?)
      Builditsolar is a great site, I got some tips on how to build solar air heater , built one mainly from scraps I already had, it’s working great and a bigger model is on the to-do list.
      There is quite a bit of solar hot water in OZ, more-so in northern climes, for years they were telling us that it was not very effective at higher latitude than say Perth. I think they weren’t trying very hard. The more recent problem has been the high cost compared to PV and the generally lower tariffs charged for hot water, specifically off peak and heating tariffs. I still think it’s the most responsible emission reduction ‘production’ method overall, I don’t rate the hot water production embodied energy as a charge in my shorthand system, whereas I do for PV. .

      1. Motorshack Avatar
        Motorshack

        I think people assume that solar thermal collectors can’t work well in higher latitudes because the air tends to be colder, but, of course, that is not true. You are collecting energy in the form of radiation, not by conduction or convection, so the temperature of the air through which the radiation passes is entirely irrelevant. As long as the collector is pointed straight at the sun, and the sky is clear, a square meter of collector will gather the same amount of energy anywhere on the planet.

        As for the legality of DIY, I have no idea what the law is like in Australia. However, here in the U.S. homeowners have a near-sacred right to work on their own dwellings, so long as they get a proper building permit, and have the finished work properly inspected by the building department. Basically no one much cares how the work gets done, so long as qualified, independent inspectors say it has been done right.

        It is different for commercial buildings, presumably because the general public is much more exposed to any risks from badly done work. Also insurance companies are very sticky about such risks in commercial buildings, and they often do their own inspections, independent of the city building department.

        I’m intrigued to hear that you like your solar air heater. I’ve read good things about them, but have yet to build one myself. It also strikes me that it might be worth combining an air heater with a big heat sink, from which heat can be drawn over a much longer period. The idea would be like a Russian masonry stove, but with hot air as the source of the heat, instead of a wood fire. It seems as though it ought to work quite nicely, but, again, I have yet to do the actual experiment.

        Finally, people seem to sneer at the idea of putting on extra clothing or using extra blankets at night, but it is the very cheapest and easiest way to stay comfortable in cold temperatures. In half a century of regular camping, I have probably spent something like 1,500 nights sleeping in unheated tents, trailers, and vans, in freezing weather, and yet I have almost never been uncomfortable.

        The average homeowner in my neighborhood now spends about $4,000 each winter on heating oil, but several times in recent years I have gone an entire winter without paying a penny. No carbon footprint either. The bedding in which I slept had a total cost of about $100, and would have lasted at least a decade, if not much longer.

        In short, your body heat is all you really need, if you are just careful about conserving it properly. Thus, I can hardly believe the way that most people insist adamantly that they absolutely “have to” burn tons of fossil fuel every year to be comfortable in cold weather.

        Talk about laughing all the way to the bank.

        1. suthnsun Avatar
          suthnsun

          Precisely about the heat sink/solar thermal collector. When I read David MacKay’s Sustainable Energy without the hot air, it alerted me to the possibility of seasonal heat store also (further to masonry stove). If a thermal mass (being dirt/rock etc.) receives a heat spike greater than 6 metres from perimeter it takes around 6 months to conduct. Hence I’ve arranged my heat to go under floor around 6 metres from external foundations and insulated the foundations. Provided I don’t overheat in summer and require cooling (not happening yet) I am slowly raising the temperature of the underfloor thermal mass (which used to be quite cool to cold). Hence space heating demand is vastly reduced, I estimate average 5kWh/day year round average so far. If I build a bigger heater will I get to near zero heating demand without requiring cooling?
          My 60 yo house has high thermal walls also which helps the whole process.

          1. Motorshack Avatar
            Motorshack

            Check out John Hait’s book on Passive Annual Heat Storage, if you have not run across it yet. You can find it on Amazon, and probably other places as well.

            He’s been doing this sort of thing for over thirty years. His website, http://earthshelters.com/, seems to be in maintenance mode just this minute, so I can’t say what all you will find on it now, but a couple of years ago it had all sorts of stuff on moving summer heat into the ground, and then pulling it back in winter.

            Again, I have not been in a position to build any houses since I first started reading about this sort of notion, almost ten years ago, but Hait claims that his houses maintain their temperatures within a few degrees of 70F completely passively all year round, once the ground around the house reaches thermal equilibrium, which takes about three years.

            Note in particular, the energy is free, and no additional energy is required to move it around actively. Everything is driven by natural convection as the temperatures in different parts of the system change their relationships over the course of the year. It’s not perpetual motion, since it requires the input of solar energy to drive the system, but it is the next best thing.

            As an engineer I can only admire the elegance of the concept. No moving parts, no controls, rock steady performance, and made from some of the cheapest materials around. It’s brilliant stuff, and hardly anyone has ever heard of it.

            (Probably because the HVAC industry spends millions on propaganda every year to convince everyone that they are actually selling useful products.)

            In contrast, everyone is all excited about electric cars, which have all the design elegance of used dog crap. Overpriced, over-engineered, and solving a “problem” (i.e. commuting to a pointless job) that only exists in the delusions of people who willingly indenture themselves to heartless corporations.

            In fact, the comparison is grossly unfair to dog crap, which is actually valuable fertilizer.

            Anyway, my pet rant aside, you should definitely keep on with your trial of seasonal heat storage. It is far and away the best idea I have seen for completely dumping your heating and cooling bill forever.

            And, of course, there is a nearly zero carbon footprint. Just the embodied energy of a few hundred pounds of plastic, which has a service life that probably runs to several centuries.

            That is to say, instead of plugging up landfills with plastic junk that persists for a thousand years, we could use that very persistence to our advantage. So, yet another reason that Hait’s concept wins first prize for elegance.

            Anyway, have fun getting rid of your heating and cooling bill.

    2. Lindsay Wilson Avatar
      Lindsay Wilson

      Thanks for the link to builditsolar.com. There is some wonderful stuff on there, full on inspiration

  4. Diego Matter Avatar
    Diego Matter

    Hi Lindsay.

    Thanks for the great post which told me some facts and connections I never thought about until now.

    But I have a small objection: I guess you will fly at least every three years on average. Wouldn’t it be therefore more honest to say that your footprint averaged over the three years is 7.9 tonnes of CO2 per year?

    Just sayin…

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