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Reducing emissions, reducing energy usage: which actions have the biggest impact?

YAS’ Zero Carbon by 2045 Grand Challenge Team

Amidst a whole range of potential emissions-reducing and energy-saving actions, reducing energy usage in the home and changing our travel and consumption patterns are likely to have the biggest impact on our emissions. However, there is an urgent need for support to ensure that the measures which provide the greatest energy and cost savings are accessible to the households that need them most.

Energy prices and carbon emissions have been in the news a lot recently. We’ve known for months that significant price rises will disproportionately impact the least well-off and least empowered households. Sanctions on Russia following Vladimir Putin’s invasion of Ukraine have caused further instability in oil and gas prices, and led to calls for us to reduce and eventually eliminate completely our reliance on fossil fuels provided by authoritarian regimes. All of this comes against the ongoing issue of COP26 and our commitments in Scotland and the UK to reduce our emissions and decarbonise our energy systems. The launch of the Intergovernmental Panel on Climate Change’s latest assessment report on mitigation of climate change has brought into sharp focus the urgency with which new technologies and societal changes are required, if we are to avoid the most harmful climate change impacts.

Against this backdrop, there has been significant discussion in the media about the different actions we can take to promote energy efficiency in our daily lives – both in terms of saving money and reducing our carbon dioxide emissions. But what is the evidence base underpinning each of these actions, and how effective might they be in helping us meet our climate obligations? In this post, we’ll look at some of the different energy-saving actions across different areas of daily life, and assess what the evidence says about their emissions-reducing potential as well as the cost implications.

Long distance, high-speed train in station.
Long-distance trains provide an efficient and low-carbon alternative to flying, especially in Europe

Commuting and transportation

Take fewer flights

The BBC reports that “a return flight from London to San Francisco emits around 5.5 tonnes of CO2 equivalent (CO2e) per person – more than twice the emissions produced by a family car in a year, and about half of the average carbon footprint of someone living in Britain. Even a return flight from London to Berlin emits around 0.6 tonnes CO2e – three times the emissions saved from a year of recycling.” CO2 equivalent is a measure of how all gases associated with an activity, and not only carbon dioxide, contribute to global warming. Lund University similarly ranks avoiding air travel as one of the top four actions you can take to reduce your carbon footprint.

Taking the train instead of a short-haul flight could reduce emissions by over 90%, while the travel time from city centre to city centre is comparable for distances up to 400 km. Clearly this depends on the power source for the railway, but a case study from Finland suggested the emissions reduction from travelling by train instead of short-haul flight could reduce emissions by up to 95%. Travel blog The Man in Seat 61 reports similar figures.

However, certainly within the UK and also for some travel to continental Europe from the UK, it is still the case that rail travel can be notably more expensive than flying. If you are travelling for business, you can make the case to your employer for supporting you to travel by land rather than by air, in line with the principles we outline in the YAS Sustainable Business Travel Pledge.

Reduce car journeys

Lund University rank living car-free as another of their top four lifestyle actions that can reduce your carbon footprint, noting that living car-free for a year saves 2.4 tonnes of carbon dioxide.

Buy an electric car

Climate change policy experts Carbon Brief calculated that emissions over the whole lifespan are around three times lower than a conventional car. Note, however, that this also depends on the type and size of electric car, and how it is driven and used! It should also be noted that there can be a significant up-front cost to buying an electric car, which can be prohibitive for lower-income households who may have less access to cash or may be less able or willing to access credit.

Meet online more

Recent research in Germany suggests working two additional days from home per week would save 20.9 billion passenger kilometres and 3.2 million tonnes of CO2 equivalent annually, corresponding to an 11 percent emissions savings from commuter travel and 2 percent from total passenger travel. It is true, though, that online meetings produce emissions too. Research published in 2021 calculated that a one-day virtual conference (on Zoom) with about 200 participants resulted in 1,324 kg of CO2 emissions – still much less than the emissions associated with meeting face-to-face, though!

Food and drink 

Eat less meat and dairy

Switching to a plant-based diet was another of the actions that Lund University assessed as having a big carbon impact, noting that eating a plant-based diet saves about 0.8 tonnes CO2 equivalents per year. This saves about 4 times more greenhouse gas emissions per year than recycling. The Lund study noted that their calculation “includes emissions from fertilizers, methane production by livestock and transport of food to retail centers.” Research published in The Lancet in 2021 found that in higher-income countries, healthy and sustainable dietary patterns cost, depending on the pattern, up to 22–34% less than meat-based. However, the study authors acknowledge that there may be a need for support for low-income households, as well as measures to ensure availability and accessibility of healthy plant-based food.

Eat locally and seasonally

Food production contributes around a fifth of CO2e emissions from wealthy nations. Locally grown food reduces this, by reducing transport, packaging and processing. The 52 Climate Actions Partnership explains that for the UK on average, 12% of food emissions come from transportation; 7% from packaging; 12% from processing; 45% from growing; and 23% from home cooking, catering, and retail. The partnership notes that food may be especially damaging to the climate if it is air-freighted, explaining that “the CO2e emissions of transporting one tonne of food for one mile is roughly: 25g by train, 48g by boat, 297g by lorry and 1527g by plane.”

Waste less food

The World Wildlife Fund claims that about 6%-8% of all human-caused greenhouse gas emissions could be reduced if we stop wasting food

Donside hydro in Aberdeen, Scotland
Community energy schemes, such as the Donside Hydro run by Aberdeen Community Energy, provide alternative models of producing net-zero energy

Heating and power

Insulate your home

According to the House of Lords Library and researchers from Heriot-Watt University, about 15% of the UK’s total carbon emissions – 68 million tonnes – comes directly from homes, mostly from boilers burning gas for hot water and space heating. The majority of energy used in homes, 63%, is for space heating. Insulation reduces the amount of heat lost through walls, roofs and floors, meaning that less energy is required to heat a building. In the face of rapidly rising energy prices, and a drive to keep down gas usage to reduce revenue flows to Russia, six actions you can take to reduce home heating demand are:

  1. Reduce room temperature by 1 degree Celsius. This reduces heat energy demand by 5 to 10%;
  2. Reduce temperature at night and in unused/seldom used rooms, e.g. stairwells;
  3. Get an engineer to hydraulic balance your heating system;
  4. For customers with a night storage heater: learn how to control the charge and discharge settings, and adjust them based on the weather forecast;
  5. Lots of heat is lost through leaky windows, so draught-proofing can have a huge effect;
  6. When you are airing your house, open the windows as wide as possible so that the air is exchanged quickly. This allows the airing process to happen faster, and means you can close the windows sooner so that the walls, furniture, etc. don’t cool down.

Install a heat pump

According to the BBC, a heat pump produces anything from 50% to 75%+ less CO2 emissions than a conventional gas boiler. These numbers depend on how much CO2 is emitted to produce the electricity in the first place. In Scotland we are often close to 100% renewable electricity. For example, South Scotland is at 17gCO2/kWh at the moment, which would give ~6g CO2 for 1 kWh with a heat pump compared to around 200g CO2 for a gas boiler. There can be long lead-in times and notable upfront costs for installing heat pumps (although grants may be available), which again means this option can be challenging for those with limited access to finance or in rented accommodation.

Switch to a green energy tariff

Third sector organisation Carbon Independent calculates that the best ‘green’ energy tariffs in the UK will at present correspond to a reduction of 25% in CO2 emissions. Depending on where you live, there may be opportunities to get involved with community energy initiatives such as Glasgow Community Energy or to invest in larger cooperative energy ventures such as Ripple Energy, which can give you part-ownership in a project or a cooperative.

Be more energy efficient

Around 20% of our energy use comes from home, according to the International Energy Agency. The IEA explains that behaviour changes (in addition to changing technologies, heating, insulation etc as above) can lower energy consumption overall by about 5%. As above, these behaviour and lifestyle changes can include reducing temperatures, using storage heaters more efficiently, and adopting insulation and airing practices that help to retain heat. Energy provider OVO Energy also has a helpful explainer showing the costs of leaving different home appliances on standby.

Home Energy Scotland can provide advice, and free recommendations on suitable changes to your house following a home visit by one of their specialists.  They also have lots of info on green options.

The Green Homes Network also allows you to view case studies of various energy efficiency measures and visit the properties to view these and speak to the homeowners.

Keep electronics longer

The benefits of keeping electronics longer are not so clear cut. The European Environment Agency explains a trade-off needs to be made between newer models (which are more energy efficient) versus the waste that is generated disposing of older equipment.

Shopping

Buy clothes that last

The fashion industry is responsible for 10 % of annual global carbon emissions, more than all international flights and maritime shipping combined. That’s according to information from the World Bank, who also say that at this pace, the fashion industry’s greenhouse gas emissions will surge more than 50 % by 2030. Making a pair of jeans equates to the emission of around 33.4 kilograms of carbon equivalent.

Reduce next day deliveries

Researchers from Technological University Dublin, writing for Irish national broadcaster RTE, say that the carbon emissions we create from buying a garment online can be four times higher than buying it in a physical store, with 0.81 kg vs 0.24 kg in terms of carbon dioxide equivalent emissions emitted respectively.

Buy British-made goods

The issue is not with the country that goods are made in per se, rather with goods that are delivered by air. So goods delivered from overseas by rail/truck/ship will carry less emissions than those delivered by air (see the relative emissions associated with different forms of food transport above). Environmental news team GreenBiz state that air cargo, which is necessary in many cases for rushed delivery — particularly when long distances are involved — produces more than eight times the CO2 per kilometer of transportation than trucks.

woman watering plants in urban community garden
Community green spaces and gardens may not soak up a lot of carbon dioxide, but they can bring many other sustainability benefits such as health, wellbeing and food production.

Gardening

Plant a tree

NASA report that a typical tree can absorb 21 kgs of CO2 per year. We would therefore need a massive level of tree planting to offset CO2 emissions both in Scotland and globally. However, tree-planting, if done sensitively and in collaboration with local communities, can bring many other benefits such as health, wellbeing, and adapting to climate change impacts (heat/rainfall) if planted and looked after appropriately.

Keep your lawn

Having a natural lawn rather than artificial grass or tarmac does not itself have a significant effect on CO2 emissions, according to researchers from Auckland University of Technology. But lawns bring many other benefits such as reducing runoff in rainfall (and thus reducing flood risk), and protecting biodiversity.

Get involved with community green space

Again, this in itself is unlikely to significantly contribute to reducing or offsetting CO2 emissions – but depending on what you are doing, the UK Government’s forestry research institute Forest Research find that greenspace brings lots of other benefits like social interaction, health and wellbeing, reducing the risks of heat islands or floods, and even food provision!

Add green space at home

This is again not likely to make a big different to CO2 emissions in the UK climate. However, on larger buildings (such as office buildings) and also in warmer areas, the US Environmental Protection Agency explains green walls and roofs can keep buildings cool in summer, reducing the need for electricity and thus the emissions produced to make the electricity.