Of butterflies and tsunamis…

Born on May 23, 1917, Edward Norton Lorenz was an American mathematician and meteorologist. He established the theoretical basis of weather and climate predictability, as well as the basis for computer-aided atmospheric physics and meteorology. As a rather quiet and shy man, he didn’t shout his findings from the rooftops, but one of his theories effectively challenged the classical understanding of nature. Isaac Newton’s laws, published in 1687,  which suggested a tidily predictable mechanical system (the “clockwork universe”), were now put under the spotlight. By the 1980s, many researchers recognized the challenge as valid, and a new way of interpreting the world was born. Edward died on April 16, 2008, at the ripe old age of 90, having changed the way we look at the world – forever!

So, what was this viewpoint and why is it important to us today? Well, the idea came to be known as the “butterfly effect”, and it posed the question: “Does the flap of a butterfly’s wings in Brazil set off a tornado in Texas?” The unexpected result of this question led Lorenz to a powerful insight about the way nature works – small changes can have large consequences. Also known as “sensitive dependence on initial conditions”, this reasoning also has a profound corollary: forecasting the future can be nearly impossible. His insight turned into the founding principle of chaos theory, and Daniel Rothman, a professor of geophysics at MIT, stated that “It became a wonderful instance of a seemingly esoteric piece of mathematics that had experimentally verifiable applications in the real world”. In his 1990 book, The Essence of Chaos, Lorenz went a step further, and made it clear that scientists cannot calculate the odds. Nature’s interdependent chains of cause and effect are usually too complex to disentangle. The true value of his question is the larger point it evokes – that nature is highly sensitive to tiny changes. And that is the real topic of this newsletter…

Let’s begin with an example that went viral a year or two ago…  Yellowstone National Park, one of the largest  National Parks in the world (8,992 square km), made the choice to introduce wolves back into the system. Putting these apex predators back into the system helped return the elk and deer numbers to manageable levels, whereas before, the grazers were overpopulating and overwhelming the ecosystem. The result? Species like willow and aspen are regrowing and stabilising the riverbanks, thus allowing the rivers to flow properly and carve out new routes. See the video detailing the whole scenario in the info box below.

The European beaver was hunted to extinction (in the UK) – for their fur and sweat glands. As such, they have been absent from UK wetlands since the end of the 16th century. This resulted in a loss of lakes, mires, tarns, and bogs – all of which are vital ecological staples for many other creatures. In 2009, beavers were re-released into the Scottish wilds – for the first time in 400 years. The results? Their building of dams and redistribution of vegetation helped alleviate flooding caused by climate change, which had created more frequent downpours. These created landsides and destruction, but the beavers are ‘ecosystem engineers’, acting as a natural water management system—improving the health and function of river catchments.

Every March/April, an estimated twenty million Mexican Free-tailed bats (tadarida brasiliensis) female bats who are expecting pups migrate about 1600 km from their winter home in Mexico to the Bracken Cave near San Antonio, Texas. These numbers make it the largest known concentration of mammals. Each mother gives birth to only one pup and they raise their young here. As many as 500 baby bats live crammed into one square foot of space (which is warm and cozy)!! So, surely pups get lost? Not at all – the mothers use their sense of smell to identify their youngster. Each night that the bats leave the cave, they are going to feed – on insects and mosquitos. It is said that this group eat the equivalent of the volume of two 747 aeroplanes – every night! Can you imagine what that saves the local farmers on pesticides? Can you imagine the knock-on effects should this colony be damaged?  (Watch the video in the info block). Not to mention how great it is that they are eating the mozzies as well. When they exit, they make a column so thick that it shows up on radar at the nearby airport, and it can take three hours for all of them to emerge!! In general, there is a sentiment that one has to choose between humans and nature. In reality there are many situations where they can live in harmony, contributing in significant ways to our wellbeing. 

Let’s move to a more localised examples and the difficult conversation of climate change. In Gauteng, the beautiful Jacaranda (Jacaradanra mimosifolia) trees lining our streets are now blooming as much as two months earlier than they did in the 1920s.

In a similar way, brown-veined white butterflies (Belenois aurora) have annually migrated through Johannesburg on their annual migration eastwards from the dry Kalahari to the moist coast of Mozambique. Apparently, a local newspaper published in 1934 noted that the butterflies’ presence once held up a cricket match! They are, however, arriving progressively earlier – an average rate of 2,9 days earlier per decade over the past century. So, over a period of 100 years, their due date has moved from mid-January to mid-December. In 2022, many were surprised when the butterflies appeared at the end of November – so much earlier than any other dates. There were so few butterflies that they didn’t even make any news headlines at all. The best guess at the reason? Climate change. Who knows what the knock-on effects are…

Humans tend to think of themselves as separate from the world of nature. I’m not sure why, because without the natural world we won’t survive. The web of life is delicate and completely interconnected, a world in which there is no place for violence and destruction. And yet, here we are… 

Steve Jobs said “You can’t connect the dots looking forward; you can only connect them looking backwards. So, you have to trust that the dots will somehow connect in your future.”  But what of a hummingbird beating its wings? Don’t we need to connect the dots going forward?

I’m going to suggest that we start by looking backwards, connecting the dots and then doing our best to connect them looking forward. Many times, actions of ours have a ripple effect much the same as one would get throwing a stone into a lake…

We need to see the damage done to the planet and use that information to re-engineer our efforts for the future. As we’ve seen from the above examples, minute changes can have completely unexpected consequences… Here’s hoping that they are all for the best!!

Jacqui Ikin & The Cross Country Team

A simple guide to chaos theory – BBC World Service:

How Wolves Change Rivers:

Beavers in Scotland:

How Beavers stop flooding and make rivers better:

Bracken Bat Cave: