Tangled

Tangled


9: Walter Jehne – Rebuilding the Earth’s Soil Sponge

March 06, 2019

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Walter Jehne is an Australian soil microbiologist, with decades of experience teaching and advising governments, farmers, students and communities. Walter is the director of Healthy Soils Australia, and is also part of NGOs including Global Cooling Earth and Regenerate Earth.

I only came across Walter’s work recently, when I saw some of his lectures on YouTube (see here: one, two, three). And within the hour or two that it took me to watch those, he had managed to completely change the way I think about climate change.

Walter’s main message is that we need to regenerate what he calls the soil sponge.

Why is building soil so important?

It’s because so many of the problems we’re facing: extreme weather events from climate change, desertification, loss of biodiversity, water shortages, food shortages, reduced food nutrition and many others, can all be minimised – if not entirely eliminated – if we can re-build the living skin of the earth: the soil.

A particular point that Walter makes that shocked me was that carbon dioxide is only responsible for 4% of global heat dynamics. While the hydrological cycle (meaning, the way water moves between the atmosphere the ocean and the land) controls 95% of the heating or cooling of the planet. So even if we stopped burning fossil fuels completely tomorrow, it would barely make a dent in the overall temperature dynamics on earth. The only way we can really get the planet back to a stable climate is by building soil and letting the natural cooling processes that have been going on for billions of years, keep doing their work.

This episode is timely, because just a few days ago the United Nations announced that the years 2021 to 2030 will be named the Decade on Ecosystem Restoration. So clearly, Walter’s message has been reaching a lot of people, and now can hopefully reach even more.

As always, if you enjoy listening, please subscribe in whichever podcast app you use. And share the episode with anyone you know who might also like it.

SHOW NOTES

03:07 Walter’s early career as a microbiologist

04:37 The origins of climate change science and the shift to focus on carbon dioxide at the expense of the water cycle.

07:02 Stockholm 1972, World Environment Summit: All elements that play a role in global heat dynamics were discussed. But scientists in the mid 80s said there were too many variables to model easily. And that it was necessary to simplify the message for politics and the public. This led to the focus on CO2, which governs only 4% of global heat dynamics. A very simplistic analysis of the big picture.

* This was continued on through to the IPCC. So we’ve trapped ourselves in a tunnel of only looking at CO2* We can’t solve the problem with the climate wit...