A few whoppers are missing. Steel, for example, is responsible for 8-10% of global emissions and is a hard nut to decarbonise (though green steel is a growing thing – and may emerge even more so after COP26). This is a small selection - from the big or tricky to the surprising.
Half the tiny particles that penetrate our lungs that are emitted by cars come not from the exhaust, but the tyres.– It’s a wheely big deal
The real party poopers though are the data centres - the biggest consume as much power as a city of a million people, mainly to keep them cool.– The (carbon intensive) IT Crowd
It takes 20,000 litres of water to make just 1kg of cotton. Growing the stuff led to the virtual disappearance of the fourth largest lake in the world, the Aral sea.– Strike a pose
When we break, speed up or turn a corner, minute microplastic particles fly off from the tyres into the air. NEE’s (non-exhaust emissions), as they’re known, are being increasingly talked about.
Research in 2019 by Emissions Analytics showed these particles can be 1,000 times worse than exhaust pollution, and a 2017 study estimated that 5-10% of microplastics that enter our oceans each year come from car tyres. A number of start-ups are looking at devices that can be fitted to cars that collect these particles - preventing them from getting into the air we breathe.
The energy we use to google, send emails and stream the latest episode of Squid Game is not insignificant (80% of internet traffic is now streaming). The real party poopers though are the data centres - the biggest consume as much power as a city of a million people, mainly to keep them cool. Many firms are now moving data centres to chilly places - a major one in Norway runs on hydropower and is cooled by freezing water from a fjord.
It adds more greenhouse gases to our atmosphere than all international flights and maritime shipping combined - approximately 10% of global emissions - and it looks to rise, as our addiction to fast fashion grows and more people rise out of poverty.
It’s not just pollution we have to fix - it’s also water use. It takes 20,000 litres of water to make just 1kg of cotton. Growing the stuff led to the virtual disappearance of the fourth largest lake in the world, the Aral sea, as two rivers that fed it were diverted from the 1950s to irrigate cotton fields. By 1998 it was just 10% of its original size. It's considered the greatest environmental disaster of the 20th century (and most people have probably never heard of it).
40% of the UK’s carbon footprint comes from the built environment - from how we build and use our homes, offices, shops etc. Many put emphasis on retrofitting, as it always has a lower carbon footprint than building new. Many of the above new New York’s will be in America, China and India. In the UK, 80% of all buildings that will be here in 2050 already exist. We have to crack how we renovate them and make that process more circular. A world-first sustainable office retrofit is currently being done at Cambridge University. It is turning a 1930’s telephone exchange into a low-carbon bastion of change - not just low energy and water, but reusing as much material from other buildings as possible, from wall panels to 300+ LED bulbs.
Between 2011-2013, China used more concrete than the US did in the entire 20th century. It is responsible for 8-10% of global emissions alone, but it’s also tricky and damaging in other ways. To make it, you need a lot of sand. And that sand can’t come from deserts - the sand particles are too rounded by wind, they don’t bind well with cement. We have to mine or dredge it - and it’s the most mined substance on the planet.
So much sand was pulled from the bed of the Yangtze River that, by the 1990s, bridges were undermined, shipping routes were reduced and whole lengths of riverbank collapsed. The water level continued to drop, as illegal mining efforts continued, jeopardising the water supply to a third of the Chinese population. (FYI, in case it crossed your mind, illegal mining is using fake permits, not massive sand dredging barges sneaking in under the cover of night...).
It’s also a clanger for biodiversity (85% of creatures at risk of extinction are on that list thanks to our food production). Deforestation is driven mainly by the need for four things: beef, soy, palm oil and wood. Not going near soy milk or tofu doesn’t mean you don’t play a part - most soy is used to feed chickens, pigs and other livestock.
But it’s the cows that really spell doom for the trees have to go; they need land, and beef cattle are responsible for more than double the deforestation of the other three combined. In 2019, it’s estimated the world lost 30 football pitches of rainforest every minute – a third of that being mature carbon-rich forest. Aside from the methane, it’s been estimated that if we ate less meat we could reduce agricultural land by 75% - that means relieving the pressure on virgin forests - particularly rainforest - and turning more land back to a natural or wild-ish state, to increase biodiversity and carbon syncs (things that suck in and store carbon).
Before you think that reducing how much you fly is impossible, consider that only 6% of the world population have ever stepped foot on a plane (one scientific paper says only 2-4% of the world population flew in 2018). It doesn’t automatically mean no long distance travel - we are likely to see superfast low carbon rail networks replacing transcontinental flights.
The UK has gone big on cracking the sustainable (and quieter) aviation nut, and launched it’s cutely named Jet Zero Council in 2020. It's plugged £500m into developing sustainable fuels (called SAF by the cool kids). SAF is made from things like waste, then mixed with normal aviation fuel to make it fit to drink by a plane. But it’s also about fuel efficiency and noise. Continuous descent (basically a descent that looks like a smooth steady curve rather than a staircase), for example, makes a huge difference to how much fuel a plane uses and how much noise it makes..
You can also now make more informed decisions: Google launched a tool in October 2021 that allows you to see the carbon footprint of your proposed flight - and filter flights by the level of C02 it spits out, just as you would do by price. That footprint is based on factors such as the route, altitude, type and age of plane and the number of seats filled.