Author Archives: kathyprokhovnik

What is the carbon footprint of an email?

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This is what I was wondering today as I deleted old emails from my bulging inbox folders. Working from a vague sense of data centres that use a lot of CO2-emitting energy, I felt the halo glowing above my head. But was that halo deserved?

I have found a number of sources that quote the figure of 4 g of CO2 emitted for a simple email, up to 50 g for one with an attachment. The emissions come from the electricity used by the devices (such as your laptop and wifi) you use to send it, plus the energy use of the data centres the email goes through. However, these figures are over 10 years old, and according to the BBC’s Smart Guide to Climate Change, may have increased.

Data centres store and process data in large quantities. They are ‘the cloud’. And not only is ‘the cloud’ here on land, but transmission between countries takes place via cables laid on the ocean floors. The Conversation tracked down the physical location of some Sydney data centres in Alexandria, making their existence even more earth-bound.

Data centres use an enormous amount of energy to process and store data and for temperature control. In 2013 they consumed 7.3TWh (26.3 PJ) of electricity in Australia (3.9% of national consumption). More recent figures for worldwide use show data centres consumed at least 1% of global electricity. If a data centre uses green energy, this is a lot less polluting than fossil-fuel energy, but how can I know where my email is going, or what sort of energy it is being transmitted by? Once it leaves my house (powered by green energy) the answer is, I don’t know. Search as I might, burning about 0.2 g of CO2 with each search, I can find lists of Australian and NZ data centres, and information about Telstra’s data centre ownership, but what does that mean for me? My internet is provided by Telstra so presumably my emails and internet searches go through them, but are my photos stored there too, or in an Apple data centre? Following these assumptions, I can find no information about their power sources.

Of course a lot of internet use is creating efficiencies, letting us email rather than send a letter, or Zoom rather than travel, but at a time when we have to look at reducing our CO2 emissions, and quickly, every reduction counts.

So, did I deserve my halo? Yes! Deleting emails means they’re not stored in the data centre, requiring processing and cooling to survive. Better still though, would be to have fewer emails in the first place. I need to go through the emails I subscribe to and unsubscribe from the ones that I don’t read. Even those aspirational ones that someone I admire recommended but which I never seem to have the time for. And in the future, please don’t think me rude if I don’t send a ‘Thanks’ by email. I might send it by text instead, and just use 0.014 g of CO2.

I know I know! There are 1 million grams in a tonne, so you’d need to send 250,000 simple emails to generate 1 tonne of CO2. Trimming your inbox isn’t going to save the world, but it does remind you to do so.

PS If you’re willing to use an extra 0.2 g of CO2 (maybe you can economise elsewhere) here’s a good infographic to take you through the figures for all types of internet use.

A day at the salvia pot

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At 8.30 am the air is still a little crisp, but the pot of salvia is in full sun. There are a few blue-banded bees (Amegilla murrayensis) on the pink-tipped Hot Lips flowers, some sucking from the sides but most delving deep into the flower, its petals swallowing all but their quivering round stripy bottoms. I’m reminded of that description, ‘nectar robbers’, that I discovered in researching my previous blog (here) and its inherent judgement of bad behaviour. Today I’m noticing that the bees go to the sides of the thinner flowers, and plunge into the ones that are more open. Maybe they only ‘rob’ when they can’t get into the flower by other means, and if their behaviour is to be judged, it should be seen as pragmatic rather than illicit.

At 11 am the flowers are surrounded by a haze of tiny Tetragonula carbonaria, doing more hovering than harvesting. Once they do select a flower and land on it they spend some busy time there, collecting. A blue-banded bee hurries in, tongue already out, ready for action. This one hurtles into the centre of a flower and stays there until I move, and it moves. A couple of honey bees glide around. One is repelled by a tetragonula in one flower even though the honey bee is many times larger. A hover fly darts in for a look, slips sideways from one flower to another then flies off again.

At midday the miasma of tetragonula is still there, searching. A honey bee flies in, targeting the flowers that look dead, brown and limp. Some fall off as it lights on them, but most produce what it wants, and a packet of yellow pollen develops on one back leg as it digs and scrapes.

At 1 pm the honey bees are favouring the shadier undergrowth of blue salvia, leaving the wilder reaches of Hot Lips to the tetragonulas.

At 1.30 pm a blue-banded bee hovers in the middle of a wire basket, little wings beating, apparently at frequencies of up to 350 Hz. There is nothing in the wire basket but the bee, and I wonder if it’s performing some sort of arcane mating ritual with its own shadow. If it would just sit still I could see if it has 4 bands (female) or 5 bands (male). A honey bee is still pursuing the dead flowers, now checking out the last little wispy bits of flower that have dropped to the ground. More than a memory, it calls up the sensation of walking with trepidation in bare feet on a path covered in jacaranda flowers – followed by exasperation at my own stupidity when the inevitable happens and the sole of my foot is stung by a bee hidden inside those wilting purple trumpets.

The afternoon clouds over. When the sun re-emerges it appears as a ball of brightness behind the trees. With each moment it falls, its gleams shifting as they hit trunks and branches.

At 4.15 pm, one lone blue-banded bee buzzes its noisy buzz in the pot of salvia.

Nectar robbers

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A year ago, after the bushfires, when everything that wasn’t burnt was scorched or looking like it had heat stroke, I planted a big pot of salvia for a quick burst of flowers for whatever insects had survived. It became a gathering point for native bees and honey bees alike, and every time I looked at it I felt I’d done something good. This summer it reflowered, and it continues to flower: an enormous coronet of ‘Hot Lips’ salvia with its circus flowers of pink and white; smaller, more compact, deep purple salvia beneath. Earlier this morning there was a dragonfly on its stalks, and just now two blue-banded bees (Amegilla cingulata), with their familiar buzz, careering around, dipping in and out. One is carrying a big yellow bundle of pollen on one of its back legs.

Not for the first time I wondered about nectar and pollen. Does the flower just keep exuding nectar, or does it run out? Why do the bees choose one flower over another? Why do they sometimes pop into one then pop out again immediately? And why are the blue-banded bees sometimes in the flower and sometimes under the flower, below the base of the petals?

Many hours later I have some answers. But first, I had to get some definitions.

Nectar.

Nectar is a sweet, nutritious secretion produced by a flower’s nectaries. It is mainly sugars (fructose, glucose and sucrose), but may contain traces of other elements, such as amino acids, salts and essential oils. Its composition varies enormously, depending on the plant species, soil and air conditions. Fascinatingly, the connection between a plant and its pollinator may be built in to the nectar:

All these substances often impart a particular taste and odour that may be essential for maintaining certain pollinator groups.[1]

Nectar is secreted from the nectaries in a distinctive pattern for each species, maybe in response to or just in tune with the different pollinators’ needs. The sugar levels may change as nectar is taken, or not. One study of nectar production in salvia showed varying levels of nectar production through the day, depending on the type of salvia, with average production ranging from lows of less than 0.5 µl to highs of 1.75 µl per flower between 9 am and 2 pm. The researchers found that most of the flowers stopped producing nectar after 2 pm. Removal of nectar, either by the researchers or by bees, did not stop the flower from producing nectar.

Nectaries.

The position of the nectaries is not fixed within the flower.

To ensure that ideally only legitimate pollinators can access the reward (and in that way successfully transfer pollen), flowers are often “built” around the nectary or the nectar.[3]

However, nectaries are usually found at the base of the stamens, so the pollinator comes into contact with the pollen as it goes into the flower.

Pollen, and other parts of the flower.

At this point I had to go back to flower terminology. Pollen grains contain the male gametes of plants. They are found on the anther, which is at the top of the stamen. When pollen is transferred to the stigma, it (hopefully) germinates. A pollen tube grows from the stigma down the style to fuse with the female nucleus in the ovary. The style and stamen are those fine upright parts of a flower, typically visible in the middle of the petals. So the importance of attracting pollinators lies in the fact that pollen may be being produced in one flower at a time when its stigmas are not receptive. The pollen carried by the pollinator to another plant’s flowers may find a more receptive stigma, leading to germination.

Putting it all together.

So nectar attracts bees (and other pollinators) in the hope that they will pick up some pollen and carry it around, leading to the survival of the species. Nectar is often exuded in small amounts to attract many different pollinators throughout the day, improving the chances of spreading the pollen around.

And those blue-banded bees sucking at the base of the flower?

Some insects, known generally as nectar robbers, bypass the sexual organs of the flowers to obtain nectar, often by penetrating the outside of the flower rather than entering it. In this way, nectar robbers ‘steal’ the nectar reward without facilitating pollination.[4]

Ooh. Nectar robbers!

[1] https://academic.oup.com/aob/article/94/2/269/174092

[2] http://sixseven.org/NectarMonitoring.pdf

[3] https://www.botany.one/2018/07/on-nectaries-and-floral-architecture/

[4] https://www.britannica.com/science/nectar

People = male Part 1

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In 2019 my story, ‘Still Life’, was published by Margaret River Press in their anthology, We’ll stand in that place and other stories, and in 2020 MRP invited me to be one of their guest bloggers. For a long time I’ve wanted to do some research on how using the male pronoun as a general pronoun affects our perception. This was my chance to explore. I had four posts to do it in.

This is the first post.

Fifty words for one day

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9 October 2020

Miss you already, my fifty word habit. One last kiss as I say goodbye to you, slumped on the couch in your tight party clothes before being hustled out the door by the designated driver, poured onto the back seat and driven deep into the night on dark, rain-soaked streets.

Fifty words for two days

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8 October 2020

The seeds we germinated, the trees we planted are no longer ours. They flourish – I hope – in that garden we built from a paddock of kikuyu. The garden beds are tended by other people now – I hear – and they live in the house that we built. It shelters others now.