What we can learn from potholes

In News4 MinutesBy NZ Trucking magazineMarch 18, 2021

Covid-19 has accustomed us to terms such as ‘exponential growth’ and ‘R-number’, but their meaning isn‘t always obvious. ‘Feedback loop‘ captures these ideas of self-reinforcing change. So, with Covid-19, an R-number of two means, on average, each case infects two more (the feedback), so one case soon becomes two, then four, eight, 16…

Such ‘exponential growth‘ can be graphed, like this Covid-19 “hockey stick”. But notice the time trap before we sense the escalation (arrow), tricking us into a false sense of security.

However, we‘ve been much less effective on climate, though we‘ve known about it for more than a century. In August 1912, The Rodney & Otamatea Times ran a story in its Science Notes and News section about how coal consumption affected climate change. 

And there are plenty of everyday examples. Take potholes. It‘s no coincidence that potholes start unnoticed, then suddenly become problematic. Their growth is accelerated by at least three feedback loops: increasing water getting into the subgrade (softening it), the deepening hole (vehicles drop further with greater force), and steepening angle of the lip (intensifying the impact). 

Pothole “A” hardly allows water in, dries quickly, wheels bump slightly. “B” catches more water, wheels drop further and strike the lip heavily. “C” soaks in even more water, dries slowest, drops furthest, and wheels hammer the lip. Message? Fix small potholes quickly: Go early and go hard.

NASA‘s global overheating graph illustrates the time trap (notice the steepening curve), and we‘ve known about it since at least 1912 (orange arrow).  

Scientists have warned of sea levels since 1962 (the graph shows different scenarios depending on how well we slash emissions).  

 And here‘s why delays can have such alarming consequences. A “normal” response here results in a problem escalating 100 times. 

Here are further examples of problematic feedback loops from global warming: 

  • It thaws the Arctic tundra, releasing locked-up methane, a greenhouse gas that then makes global warming even worse.

  • It reduces snow cover, meaning less solar heat reflected back to space, causing even more warming. 

  • It encourages more aircon systems, but refrigerants are among the worst greenhouse gases (some thousands of times worse than CO2).


But the news isn‘t all bad as good ideas can take off the same way. Check out this London School of Economics study, showing the spectacular uptake of sustainable transport systems. 

Decarbonising the trucking sector can take off the same way, so let‘s get cracking and go as early and as hard as we can manage – like great ideas to kickstart the sector‘s decarbonisation.

Click here to find out more about the Trucking Toward a Better Future competition and get your entries in: https://www.nztrucking.co.nz/trucking-toward-a-better-future-calling-all-truckers-and-trucking-people