It's a phrase I always grew up with: you throw rubbish and trash "away" and take what you don't need to "the dump" or "the tip." However, a comment in a nature documentary made me reevaluate:

"You can't throw anything away. There is no 'away'."

Unless we're throwing a leaf or some grass cuttings back on the lawn, it matters where what we've used ends up. It doesn't go away—it goes somewhere, and eventually, that somewhere will catch up with us.

This is why I think "the garbage dump" is better as "the Recycling centre." And we should try to only buy things that we make good use of. And we should try and repair when we can and, if possible, find another home for what we no longer need rather than "dump" it. And why we try to buy recycled products to give a market for those making them.

It can be hard work. It's easier and more fun to bring new, shiny things into my life than to find homes for older, less shiny things. But there is no "away." The effort will pay us back in the long run.

(I don't mean to get preachy about it, it's just the comment has stuck with me from the moment I heard it)

There is no "away"

Mangroves are many species of tree adapted to living in salty water along coastlines and tidal rivers not far from the equator. They are remarkable in many ways and confer a host of benefits to their habitats. Here are some significant ones.

Mangroves and mangrove habitats play a major role in protecting coastal settlements from storm surges and waves. Mangroves significantly reduce the energy of waves, lowering wave height inland, including from tsunamis, and reduce surges from tropical storms. We took a boat through the mangroves in Southern Vietnam once, and it was an eye-opening maze of channels and islands. I could see how they act like a natural breakwater.

Mangroves help stabilise land from erosion. This helps plants and fauna inland make their homes. Mangrove root systems also trap sediment brought downriver or from the sea, building their environment and creating peaty soil when they decay.

Their incredible prop root network creates a wonderful sheltered space for marine wildlife to grow and develop. The nooks and crannies help protect young from predators until they are older and can better fend for themselves. This protective environment increases populations and helps local fishers and communities. The calm and sheltered waters inside mangrove habitats also provide sanctuary for birds and a host of other non-marine wildlife.

Mangroves are an excellent carbon sink. They capture carbon as they grow, and the low-oxygen sediments deposited beneath them help lock carbon away.

I've contributed to plant trees through Eden Projects with a portion of any monthly or one-off support I receive. I wanted to explain Mangroves partly because, as of July 2023, together, we've passed 26,000 trees planted, most in mangrove restoration projects in Madagascar, and provided over 350 work days for locals.

"Madagascar is one of the world's top biodiversity conservation priorities because of its endemic species and severe habitat loss rates. Restoration in Madagascar is important because the destruction of the mangrove estuaries along the coastline has caused mudflats to wash into the ocean, destroying once-productive fisheries and increasing the vulnerability of coastal communities to hurricanes, tsunamis, and floods. In the dry deciduous forests, deforestation threatens one of the world's rarest and most diverse forest systems."

Mangroves make a real difference. To everyone who's helped make this happen, thank you!

Mangroves

The siphon, or syphon, is a simple device that uses only a tube to seemingly pump water from a higher spot to a lower one. It's ingenious because once you start the siphon by filling the pipe to below the height of the upper reservoir level, it will continue draining the water, pulling it over the hump and towards the collection below without further help.

Most of us use siphons several times daily, as there are often two at work in the standard toilet. Sometimes there's one in the flush mechanism—one push of the handle to start the siphon drains the water from the reservoir until it runs out. And you can flush a toilet using the second siphon by pouring enough water directly into the bowl to push the water over the bend in the pipe to start it— think how the water drains by itself almost completely before filling up to the level of the bend once again. It's a clever way to power a toilet flush with just the press of a button or turn of a handle. They also minimise leaks and control the flow by running the water uphill.

We set up a greywater siphon to drain water from the bath and showers to a water butt in the garden. To get it started, we connected the end of the hose in the garden to a tap and ran water back up the hose until it shot out the top. Then, dipping it in the water, turning off the tap, and putting the end in the water butt, like magic, the siphon pulls water out of the bath until it's empty.

Surprisingly, a few effects are at work in a siphon, and its mechanism is debated. They can be made to work in a vacuum and even spray liquid upwards with the right setup.

I read that it is from the ancient Greek siphōn meaning a tube or pipe, often for drawing wine from a cask—that would be a decent situation to start the siphon by sucking on the end.

Siphon

With well-insulated houses and central heating as standard, I always grew up with heating the space as how you stay warm in the winter. A colleague once shared with me that where he'd lived, they thought of it as heating people, not spaces when looking to stay warm.

The heating people approach means rather than heating the air in the room, you focus on heating the person: warm clothes, hot drinks, baths, cosy furniture with high backs and sides that traps heat in, or furniture that is itself heated like the kotatsu or aga, and generally local heating where a small room or even part of a room may be warm while the rest may be cool — dividing screens are sometimes used.

This approach was common until relatively recently and also still is in countries where it was difficult to stay cool in the summer and houses weren't typically built to keep heat in.

Thanks to Peter Wyatt-Brandenburg for sharing with me many years ago.

Heating people, heating spaces

A rather clever way of capturing energy as vehicles slow down is to store the energy you'd use in braking as gravitational energy. This way of storing energy is used on a number of central London underground stations by constructing the stations at the top of a small hill in the track. Once built, the hump-back-station design has the handy effect of naturally slowing trains down as they approach a station and naturally accelerating them as they leave a station. Apparently, on London's Victoria line this saves 5% in energy and helps the trains run 9% faster.

You're not always going to be able to put a slope just where you need to slow down, unfortunately. However, it makes a ton of sense for pedestrian crossings where raising the crossing to the level of the payment means pedestrians don't have kerbs to negotiate and cars are naturally encouraged to slow down.

Victoria line data from Sustainable Energy without the Hot Air, by the late David JC MacKay

Hump-back stations

I've been there. I'm holding some packaging that kind of looks like it ought to be recyclable but isn't one of the standard products that are asked for. I could put it in the bin and then it'll head straight to landfill, or I could put it in the recycling and then it has a chance of being recycled, right? So it often seems better to recycle it in the hope that it might be recovered rather than consign it to certain landfill. This is known as wishcycling.

Sadly, from all that I've read about wishcycling it's not the best approach. When we put in non-recyclables into a recycling bin it contaminates the high quality recyclable materials and several things can happen:

A lot of dry recycling is still manually sorted in Materials Recovery Facilities (MRFs). When the quality of the input goes down it can require more people to sort it. It's not a pretty job if it also contains items that are contaminated with food waste

Non-recyclable items that processing machines aren't designed for can damage them and mean costly maintenance

Items like batteries that make it into regular recycling can start fires in paper bales which is dangerous and expensive

Non-recyclables mixed in can mean a lower quality end product to use to turn into new products. This can reduce what it can be used for and make it harder to sell

Paying more pickers and sorters and servicing machines costs money, and selling lower quality products brings less in, both of which reduce the profitability and potential viability of recycling operations

So the advice I have learned to take on board is:

Counterintuitively, if we want to recycle more, it seems at the moment we have to recycle less.

And even better is to reduce and reuse where possible in the first place.

Wishcycling

An average car, sat idling, can produce exhaust emissions to fill 150 balloons. That's a lot of balloons to imagine puffing away out of the cars idling outside a school for a pickup, say. Other tests have found (pdf) that for any time over 10s fuel use and emissions are always greater when idling than turning off the engine and restarting. Spread the word.

Of course, if you have an electric car this won't apply.

I did draw 150 balloons, but a few of them didn't fit on the page.

Idling

Life on a nuclear submarine is life under some pretty intense constraints. For one, there’s not naturally any fresh water and any time you use it the waste water builds up in the tanks and then has to be expelled, and when you expel it that makes noise, and because nuclear subs don’t want to give away their location they do their best to minimise the number of times they have to do that. That means taking care of all fresh water.

The other reason to take care of fresh water usage is that they have to make it the whole time — any fresh water for cooking, cleaning or drinking has to be made from sea water. If you drink a glass of water on a nuclear submarine you’re probably drinking the most expensive glass of water you’ll ever drink because it’s been desalinated by a nuclear submarine.

Hence the submarine shower with a total of 20 seconds of water: 10s with the water on, turn it off while you soap and scrub and finish with 10s of rinsing. That’s it. For me it’s a nice reframe in how much you actually need when you take a shower, and it still works. So if you fancy saving water and energy you could give it a try.

Submariner Tom Lewis even wrote a song about showers on submarines.

Submarine shower

Perhaps the most important curve of our times, Charles Keeling’s  curve shows the change in concentration of CO2 in the air with measurements taken every year for over 60 years. Taken at the top of Mauna Loa volcano in Hawaii because of its high altitude and relative isolation in the Pacific, Charles Keeling’s measurements show that the monthly average CO2 concentration in the air has risen from around 310 ppm (parts per million) to around 410 ppm in 2020. As a greenhouse gas this change in CO2 concentration is one of the critical causes of climate change.

The concentration varies seasonally as plants bloom in Spring and Summer reducing the concentration from its high around May as the CO2 has built up over the Norhern Hemisphere Winter.

The Scripps CO2 program is now overseen by Charles’ son Ralph Keeling.

The Keeling curve

If you lived on Easter Island, would you really cut down the last mighty tree knowing that would be it? It seems either foolhardy or desperate to knowingly cut down the last of a kind and your last source of timber. So how could it happen?

Jared Diamond, in his book Collapse and article Easter’s End, explains how this situation could happen through a gradual, hardly noticeable decline over many years. Those who remembered the great trees that they used to make rafts, canoes, and ships were old or had long since died. Today's trees may be nothing like the forests and towering trunks of tens or hundreds of years ago.

"Gradually trees became fewer, smaller, and less important. By the time the last fruit-bearing adult palm tree was cut, palms had long since ceased to be of economic significance. That left only smaller and smaller palm saplings to clear each year, along with other bushes and treelets. No one would have noticed the felling of the last small palm."

More recently, I read Rutger Bregman's story of Easter Island in his book Human Kind: A Hopeful History. In the chapter "The Mystery of Easter Island," he digs into the reconstruction provided by Diamond and others and questions whether the Easter Islanders really were reduced, after losing their trees, to infighting and destitution.

Bregman found evidence to suggest that rather than driving themselves to the brink of extinction, the Easter Islanders were likely still thriving when Peruvian slave traders arrived in 1862, and sixteen slave ships carried off a third of the island's population, 1,407 people.

Yet the worst for them was still to come a year later when the government was pressured to return the islanders home. A smallpox outbreak carried by the returning islanders wreaked devastation during the voyage, with hundreds dying at sea. The 15 islanders who made it home carried the virus with them, and it spread to the inhabitants who remained. He cites that the population was reduced to just 110 inhabitants in 1877 when the epidemic finally subsided.

Until the arrival of the slave ships, the population, despite their trials, was still thriving. Bregman suggests that it was, in fact, contact with the rest of the world that destroyed Easter Island.

For another thought-provoking perspective, Seth Godin asks who cut down the second-to-last-tree?

Who cut down the last tree?

The overview effect is the ultimate example of "seeing the forest for the trees." It’s the realisation that we live on a fragile planet, that we are all connected, and that this is all we’ve got—our one and only home.

Coined by author Frank White, this phenomenon is most vividly experienced by astronauts, who return to Earth profoundly changed by seeing our planet from space. Their reflections highlight the emotional and philosophical impact of this shift in perspective:

“You develop an instant global consciousness, a people orientation, an intense dissatisfaction with the state of the world, and a compulsion to do something about it. From out there on the moon, international politics look so petty.”
— Edgar Mitchell, Apollo 14 astronaut

“When we look down at the earth from space, we see this amazing, indescribably beautiful planet. It looks like a living, breathing organism. But it also, at the same time, looks extremely fragile … Anybody else who’s ever gone to space says the same thing because it really is striking and it’s really sobering to see this paper-thin layer and to realize that that little paper-thin layer is all that protects every living thing on Earth from death, basically. From the harshness of space.”
— Ron Garan, Shuttle/ISS astronaut

This sketch is inspired by the iconic photograph of Earth taken from the moon during the Apollo 11 mission. The image captures the striking beauty and fragility of our planet and perfectly embodies the spirit of the Overview Effect.

This sketch appears in my book Big Ideas Little Pictures

The Overview Effect A Profound Shift in Perspective

Jevon's Paradox is the counterintuitive idea that improvements in fuel efficiency tend to increase, rather than decrease, overall fuel use.

In 1865, William Stanley Jevons, a British economist, observed that despite significant improvements in coal efficiency in steam engines, total coal consumption actually rose. Rather than saving fuel, efficiency made coal-powered energy more economical, driving increased industrial use. This observation became known as Jevon's Paradox.

Though first identified towards the end of the Industrial Revolution, Jevon's Paradox is still highly relevant today, particularly in discussions around energy efficiency, sustainability, and technology.

Fuel-efficient cars – When vehicles become more fuel-efficient, the cost per mile driven decreases. As a result, people tend to drive more, offsetting the efficiency gains.

AI and computing power – Advances in AI and computing efficiency reduce the cost of processing power, leading to increased overall usage of AI models and cloud computing.

Battery technology – More efficient batteries lead to the proliferation of battery-powered devices rather than reducing energy consumption.

Water-saving devices – Low-flow showerheads and toilets may save water per use, but in some cases, they lead to longer showers or more frequent flushing.

Lighting — Though LED lights are vastly more efficient than their predecessors, we are continually finding new ways to use our low-wattage lights that we had never dreamed of before.

Household appliances – In her book More Work for Mother, Ruth Cowan addresses the ironies of household appliances, such as washing machines and vacuum cleaners, and how improvements in efficiency often led to more work through more frequent washing, not less.

This tendency is sometimes referred to as the rebound effect, where changes in behaviour partially or fully cancel out expected energy or resource savings.

With the rise of AI and automation, Jevon's Paradox is playing out again in new ways:

Computational efficiency – Though AI models are becoming more efficient—DeepSeek a case in point—the demand for AI-generated content, large language models, and deep learning applications is growing rapidly.

Automated processes – Instead of reducing overall workloads, automation often leads to more tasks being completed rather than fewer tasks needing to be done.

Cloud computing – More efficient data centres have not reduced overall energy use because the demand for cloud services and machine learning applications continues to skyrocket.

Understanding Jevon's Paradox can help in designing better policies and strategies to ensure efficiency gains lead to real reductions in resource consumption. Some approaches include:

Carbon pricing and regulation – Ensuring that energy efficiency is paired with policies that discourage excessive consumption. (see Goodhart's Law)

Shifting behaviors – Encouraging individuals and businesses to actively reduce energy use, rather than simply taking advantage of efficiency improvements.

Technology with constraints – Implementing smart grid systems, time-based energy pricing, and consumption limits to prevent unchecked increases in demand.

Jevon's Paradox reminds us that efficiency alone is not a guaranteed solution for reducing resource consumption. Instead, it often requires complementary policies, incentives, and behavior changes to make efficiency gains truly effective.

The Automation Paradox – The better the machines get, the more we struggle when they fail

Wishcycling — Hoping something can be recycled

Save some landfill with reusable diapers/nappies

Jevon’s Paradox

UPDATE: Since releasing this sketch, which is a fair summary of Kamal Meattle's TED talk, it's been made clear that, though plants do improve air quality, the improvement doesn't compare with a simple change like opening the window.

NASA conducted the original "Plants Improve Air Quality" study in an environment wholly unlike having a few plants in your living room. Listen to James Wong explain the situation in the Sketchplanations botany podcast.

In his 4-minute TED talk, Kamal Meattle explains how to grow your own fresh air inside with just three common house plants. The areca palm works hard during the day, the mother-in-law’s tongue during the night, and the money plant cleans out volatile chemicals. He transformed the air inside a New Delhi office park by filling it with these three plants with seemingly some wonderful health and productivity benefits.

Though plants are undoubtedly lovely to add to your office and home, see the update above for the caution around their potential to freshen your air.

How to grow your own fresh air

The fifth fuel is energy efficiency—the cheapest of all.

The Fifth Fuel: energy efficiency

From Michael Braungart and William McDonough’s groundbreaking book Cradle to Cradle (you should buy it just to feel the book itself). Production and use need not be a straight line. It has to be a loop. Known often as the circular economy.

Think cradle to cradle

If a baby wore 2 reusable nappies per day, that’s nearly 1500 nappies saved from landfill by the time a child is 2 years old. If every baby born in the UK did this, that’s 2.5 Big Ben’s worth saved from landfill.

Save some landfill with reusable nappies/diapers

Learned from Joe Smith’s short entertaining TED talk: How to use a paper towel.

Sustainability sketches