Deep time walk resumed

Last weekend (Sunday 31 May) Arthur (my husband) and I resumed the Deep Time Walk we started back in February. The weather was very warm but we were prepared with light clothing and hats so we were reasonably comfortable. We joined the walk where we left off before at ‘Crofters’ on Lammas land with a snack for lunch. 

Celebrating the last universal common ancestor (4.2 billion years ago).

For the Deep Time Walk 1 metre represents 1 million years. 

The idea behind the Deep Time Walk  is a walk through time with each metre representing a million years, so Earth’s history (4.6 billion years) is represented by 4.6 km. We stop at ‘earth stations’ where (when) there were significant events, either geological or biological such as ‘the great dying’ or the first plants. It is more usual to consider history compressed in time. E.g. the history of the universe (13.8 billion years) compressed into a year as in Carl Sagan’s Cosmic Calendar ) Home sapiens appeared only about 300,000 years ago so this is either about 11 minutes or 6.5 cm. Personally I find the 6.5 cm [300000 /4.6e9) * 1000 (to metres) * 100 ( to cm)] more relatable and the walk with other people is fun because you can get other viewpoints on related issues such as climate change, net zero and how we can adapt. It feels more like a community project and less like a personal problem. Amongst other things we talked about the impact of doing things as a community rather than as an individual.

The Boring Billion 

I learned that there is a period in the Earth’s history called the ‘Boring Billion’ which is about 1 billion years when there were no major climate events, tectonic plate movements or extinctions. However the walk was by no means boring. 

Human impacts positive and negative 

One thing we learn from history is that our behaviour can have huge impacts. The invention of agriculture was massively influential – not only enabling population increase but also modifying climate by removing trees. This has had serious consequences – mostly bad, but we now have examples of practical regeneration projects at community scale where water is captured, and land rehabilitated from desert to agriculture as shown in this video. 

Nature can evolve resilience, given time. 

Life is extraordinarily resilient. For example, our use of fossil fuels has polluted the air with CO2 and acidified the oceans which makes life very difficult for sea creatures with shells as the carbonates that make their shells strong dissolve in acid. However, with selective breeding over time, oysters and other shellfish have evolved protection from the acid (see https://www.stir.ac.uk/news/2019/09/farmed-oysters-able-to-protect-themselves-from-acidification/). The big problem with human induced climate change is that it happens far too fast – even when adaptation is possible.  Slowing it down to the point where nature can adapt fast enough would help enormously. (see https://theconversation.com/cop29-how-fast-is-earth-warming-244093).

Deep Time Walk preview

Yesterday, my husband Arthur (who has been doing a heroic job looking after me through the last year while I have been unwell) and I had a private preview of the Deep Time Walk which is scheduled for 1st March, organised and led by Clara Todd from Water Sensitive Cambridge. We did this partly for Clara to test it out and partly because I was not sure if I could keep up with everyone for the whole walk on the day. In fact we only did half of it – starting with the formation of the Earth (Parker’s Piece) and ending with oxygen-breathing life on Earth, albeit single cell (Lammas Land), in total about 2.3 billion years. That was enough for me, I’m afraid. The framework of the Deep Time walk comes from a team at Schumacher College.

I am writing this to recommend it to you. Perhaps you know it all anyway– but doing it with friends and the opportunity to chat and ask questions (Clara is pleased to take questions and if she does not have the answer maybe someone else will) was fun. Besides which, it is a good excuse for a leisurely walk through our beautiful city.

The walk was designed with 1 metre for 1 million years and we paused at interesting times along the way (Earth Stations) so that Clara could explain what was going on. For example we stopped for

1. Formation of the Earth (4567 million years ago)
2. Formation of the Moon (4450 mya)
3. Ocean Earth (4100 mya)
4. Origin of Life on Earth (3800 mya)
5. First Continents (3100 mya)
6. Oxygenic Photosynthesis (2900 mya)
7. The Great Oxygenation/Snowball Earth (2300 mya) 

Clara has some pictures which are obviously artist’s impressions and not photographs. These and her short explanations are very engaging. 

We took some photos on the day. The weather was fairly dry but it has been very wet recently. We avoided the puddles on Parker's Piece. 

Parker's Piece with Gulls - The weather has been very wet though on the day it was mostly dry; the way was muddy in places but the worst was avoidable. Hopefully by March it will be dryer.

View of the Cam from near Hodson's Folly. It was a grey day but mostly dry.

 I am still not well but Arthur lends me a helping hand when needed.

I thoroughly recommend this walk to you so do sign up for 1st March. 

Why I volunteer for ECCG

I went to an event at Empty Common Community Garden recently and met a lady called Isobelle who has been volunteering there for some weeks. She kindly agreed to answer some questions about her experiences - this is what she said. I hope that if you were thinking about volunteering but not sure, then this will convince you.

When did you first come to the gardens?  My first session in the garden was in late August (24th) this year and I've been every Sunday since. I first came across the garden on a walk last winter, but didn't realise it was a community project in which anyone could join in. I went to a community event by Cambridge Zero earlier in the summer and saw a flyer about the garden there, and then saw the Sunday sessions on the events page on the Transition Cambridge website. 

Reducing the mountain of e-waste

The UK produces about 6 million tonnes of e-waste annually, of which households are responsible for about 400,000 tonnes each year. That's not just phones, laptops, and computers - an ever increasing number of products and appliances now incorporate some electronics, and anything with a plug or battery qualifies as e-waste.

Working with Contractors - update

Depending on what you want to do, retrofitting your house could involve for example changing your heating system or installing solar power. This can be simple or quite complicated, possibly including hiring several contractors, and maybe a project manager too. You may be taking a ‘big bang’ approach or doing it in phases. Selecting competent, reliable contractors that you can trust and maintain a good relationship with is very important. This page is not a step-by-step approach to your retrofit but general advice about how to choose and work with contractors. Much of the advice on this page came from pooled experiences from the Energy Group members and friends.

Improvements in energy efficiency in buildings since 2000

This post is largely based on the article Advances Toward a Net-Zero Global Building Sector in Annual Review of Environment and Resources 2020 [1]. The article is open access so anyone can read it for free. It explores why energy efficiency is important for net zero emissions and charts improvements since 2000 in different regions of the world. It briefly compares the Passivhaus standard with other standards widely used for low energy buildings. The focus is on the UK although much of the evidence comes from elsewhere, primarily Europe.

The Environmental Cost of AI

With the UK Government's recent announcement about investing heavily in AI, it's appropriate to ask: what is the environmental footprint of all the computing infrastructure that this AI requires?

The answer is simple: it's massive. While there are huge uncertainties, some of the projections have the AI boom causing data centres to generate more carbon emissions than Africa and South America combined. 

The recently announced plans for AI expansion lead to huge increases in resource requirements, and on relatively short timescales. The power needed by AI might exceed that used in all the world's current data centres within 3 years.

That's going to need a lot more electricity, which is likely to increase carbon emissions in the short term, before renewable generation ramps up – and that’s not to mention the carbon footprint of putting up such massive buildings to house the servers and manufacturing the servers that go into them. 

For the longer term, some of the tech giants are starting to look at small modular reactors (SMR, i.e. small nuclear reactors) to power their data centres. Microsoft is trying to bring one of the reactors at Three Mile Island back online. Even if you can generate the electricity, generally there isn't enough grid capacity to get it to the right place, which is one reason why there's such interest in putting the generator, such as an SMR, right next to a data centre.

It's not just drawing electrical power that's a problem. Gargantuan amounts of water, already a scarce resource, are needed for cooling, as all this electricity gets converted into heat.

All this environmental damage leaves open another question: will the benefits from AI outweigh the environmental damage it causes?

For a good overview of the issues about AI and sustainability, this report from the Green Web Foundation is a good read, and this article from UNEP closes with five recommendations to “rein in the environmental fallout of AI”. A great book on the topic is the “Atlas of AI: Power, Politics, and the Planetary Costs of Artificial Intelligence” by Kate Crawford.

To find out how to turn off AI in your search engine or on your device, just search the phrase “how to turn off AI on…” and instructions often come up.

Blog post by Peter Tribble. Peter also has a personal website: https://ptribble.blogspot.com/