Climate change remains a hotly debated topic. But a scientific fact not up for dispute is the pronounced spike in the concentration of carbon dioxide in the Earth's atmosphere over the past two centuries.
There's a building urgency to find solutions that can manage/reverse that spike — a process known as carbon sequestration. But how to do that on a planetary scale? It's a massive predicament. And most of the 'solutions' being proposed are technologically unproven, prohibitively costly and/or completely impractical.
Enter carbon farming. It uses nature-based farming practices to park gigatons of carbon in the soil, rebuild soil health and complexity, and revitalize the nutrient density of the foods that we eat. It is quite likely the only practical — and best — way to sequester carbon at massive scale, as well as reap a multitude of by-product benefits.
In this week's podcast, field ecologist and agroforestry specialist Connor Stedman explains the science behind the carbon farming process:
For the last few million years of the Earth’s history, when there’s been this cycle of glaciers advancing and receding in the northern hemisphere, the concentration of carbon dioxide in the atmosphere has gone between about 180 parts per million and 280 parts per million. That is the band in which all of human history has happened, up until the last 200 or 300 years.
Now the concentration of carbon dioxide is about 407 parts per million, almost 50% higher than the upper end of that historical normal. Carbon dioxide is one of a number of greenhouse gases that hold heat in the Earth’s atmosphere, rather than it being fully reflected back out into space
To give you an image of the numbers involved here, to get down from 407 parts per million to 350 parts per million, we would have to remove at least 130 billion tons of carbon from the atmosphere and put it somewhere, plus zero net emissions beyond that. And because going to zero net emissions globally is not what’s going to happen, we’re going to have to take out quite a bit more than 130 billion tons. Most people are estimating between—even with rapid de-carbonization — between 200 and 250 billion tons of carbon are going to have to be stored somehow.
Often when you read in the news about carbon sequestration, the main way it’s talked about is through geoengineering schemes and technologies. These include things like seeding clouds to increase the Earth’s albedo, the Earth’s reflective effect, so that more heat is reflected back into space. Or seeding the oceans with iron so that more carbon is stored in sea water. Or inventing nanomachines that would pull carbon out of the atmosphere and turn it into plastics directly. Or sucking carbon out of the atmosphere and putting it in deep geologic structures. Or even more fanciful things like huge arrays of panels orbiting the Earth reflecting sunlight back out into space. It’s really wild, some of the things that are being talked about.
There are a few different problems with these geoengineering proposals. One of them is that they’re enormously expensive, in the many billions or even trillions of dollars. Another one is that most of them rely on totally unproven technology. I mean, this is like cold nuclear fusion category speculation in a lot of cases. And the third one is that they don’t address any other human problems. They’re a way for some of the people who have gotten very wealthy off of our current crisis to continue getting very wealthy off of the solution for it.
So, the big thought behind carbon farming is that we already have the technology needed to accomplish that level of sequestration. And it’s sequestration into ecosystems and land rather than into technological forms. And it’s sequestration using trees and wetlands and soil and living things that people have been working with for all of human history, rather than requiring a cutting-edge breakthrough.
And also, that carbon farming systems have the potential to address a lot of other human needs as well at the same time: needs around food security; needs around other forms of climate security, like resilience from flooding, resilience from drought and heat waves; and just a lot of other things that come with more biodiversity and more intensified and diverse food production.
Click the play button below to listen to Chris' interview with Connor Stedman (57m:00s).
by pauljam