Measuring our impact on the planet like a shoe size seems odd but “carbon footprints” are a useful way to bring the problem home. A carbon footprint sums up the total greenhouse-gas contribution made by an individual, item, company or country; it’s the stamp we leave on the planet.

In the 21st century, we all leave a trail. The average person in the UK is responsible for generating 10 tonnes of greenhouse gases every year, enough to fill 24 million balloons. The problem can feel bigger than us, the fault of big industry – not our business. Carbon and other greenhouses gases are belched forth from power stations plugged into the electricity grid, running diesel engines and woodlands burned to clear space for agriculture, trapping heat from the sun in the lower atmosphere. Yet every time you take a flight, shop for anything from half a world away or leave the lights on overnight, your own carbon deficit mounts.

Last year, the UN warned of dangers if global temperature increase isn’t tethered to between 1.5ºC and 2ºC in the next 12 years: sea level rises, mass extinction among insect and coral species, and a world that simply can’t support us. Here’s how to take baby steps in reducing your footprint and do your bit to help the planet.

Travel – and think – adventurously. Air travel must fall. Aviation is responsible for about seven per cent of the UK’s greenhouse gas emissions, largely from international flights (a round-trip transatlantic flight can easily gobble up a tonne of carbon dioxide per passenger). Not everyone is going to travel by cargo ship like hardcore eco-adventurers (newer ships average only three kilograms of CO2 for every kilometre, and charge around $100 a day for a cabin). But staycations, or travelling via Interrail, are light on the pocket and high on fun.

Electric vehicles are part of the solution when combined with electricity from a green supplier: the diesel Golf TDI produces 140g/km CO2 on average over its entire life cycle, while an electric e-Golf emits 119g/km on average. Taxis are a sticky point: both Uber and Lyft have made strides towards sustainability (the latter has been carbon neutral since 2018), but critics point out they increase traffic congestion in urban areas, contributing to greater exhaust emissions. When you can, choose to hike or cycle instead.

Use your property properly. Insulate your home to reduce wasted energy – or ask your landlord to do this for you. The Domestic Renewable Heat Incentive scheme allows property owners to apply for funding to set up systems including solar panels, biomass boilers and certain types of heat pump. Switch to a green-energy supplier, such as Ecotricity, Bulb or Tonik Energy. One million UK homes are now being at least partly supplied with “green gas” energy produced from biodegradable farm and food waste.

The human diet is choking the planet. Clearing forests for grazing livestock releases vast stores of carbon into the atmosphere; fossil fuel burnt while transporting food around the world adds up, too. As much as 20 per cent of global emissions come from food production, and 58 per cent of that total is from animal products. Carbon-footprint labels exist on some packaging, but just a fifth of shoppers recognise them. An estimated 22 million in the UK have committed to a flexitarian diet (reducing, but not totally refusing meat consumption). Now is the time to explore gateway meat substitutes: the plant-based Moving Mountains “hot dog” made from sunflower seeds, the jackfruit biryani at Dishoom, or virtually indistinguishable plant protein-based “meat” burgers from companies such as US firm Impossible Foods. It’s also good to know your imports: environmentalist Mr Mike Berners-Lee notes bananas keep well on long shipping journeys, averaging 80g of CO2e each, better than asparagus flown in from Peru. His book How Bad Are Bananas? explores carbon footprints of activities and items in greater detail.

Reuse and recycle. Storing and processing music in the cloud, for instance, depends on vast data centres that use a tremendous amount of resources and energy, so if you need another excuse to splash out on vinyl… Be a discerning connoisseur. If it’s not good enough, leave it on the shelf.

Put pressure on the government. “Individual action only takes us so far,” says Mr Paul Allen, a renewable energy technologies expert at The Centre for Alternative Technology. “Many of the changes needed to tackle climate change require policy and financial support from government and industry. This means that one of the most important things we can do as individuals is to use our voice to push for change.”