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).