You probably saw the headlines a few weeks ago on the latest UN IPCC Climate Report. It was dire. It stated that we are unequivocally on pace to reach and exceed 1.5 degrees Celsius of warming in the next twenty years. This new reality will affect every single resident of planet Earth as sea levels rise, lands flood and droughts persist.  We are already seeing the devastating effects of climate change, just this summer. But together, landowners, landscape designers and land stewards can harness the power of plants and soil to reverse our path of reckless emissions, before our planet is altered forever. Every landscape has the potential to sequester and store the greenhouse gas carbon dioxide. By maximizing these potentials AND reducing emissions, we might just stand a chance at reversing global climate change. This blog post is a call to action: design landscapes as carbon sinks!

This is Part One of a two-part series. Read Part Two – Landscape Design to Halt Climate Change: Designing Carbon Sinks!

Image courtesy of UN IPCC Sixth Assessment Climate Report.
Image courtesy of UN IPCC Sixth Assessment Climate Report.

About the IPCC Report 

First, a little background. The IPCC report is groundbreaking because for the first time, it undoubtedly linked human-generated emissions to a quantifiable amount of warming – we are on-pace to reach 1.5 degrees C or more in the next two decades. This proverbial line in the sand was drawn by climate scientists, a line that when crossed would initiate “several regional changes in climate.” We are already seeing these regional impacts. The report directly connects the extreme weather we’ve seen this year to human-initiated climate change, from the historic drought / heat wave / wildfires in the western US, to destructive flooding in Europe, hurricanes on the gulf coast, and massive earthquakes in Haiti.When we reach 1.5 degrees of warming, many natural climate regulating systems may tip out of balance, threatening exponential warming. 

Image courtesy of UN IPCC Sixth Assessment Climate Report.

2 degrees Celsius is another line, one with catastrophic implications, which we are on-pace to hit in our current gas economy. At 2 degrees of warming, scientists warn we could see icebergs collapse, and 1.5 to 4 meters of sea level rise by 2,300. Our habitable land would be altered beyond recognition. Not to mention the predicted water wars, loss of arable land, and abundance of extreme weather events that come with a rapidly warming planet. This is the path we are currently on.

Image courtesy of UN IPCC Sixth Assessment Climate Report.
Image courtesy of UN IPCC Sixth Assessment Climate Report.

Designing a Landscape Solution to Climate Change: Carbon Sinks

So, as stewards of the land, designers and caretakers, what can we do to address climate change head on, with measurable, immediate impact? We make each landscape a carbon sink, harnessing the power of photosynthesis, and soil microbe ecology to sequester carbon dioxide from the atmosphere into a stable sink: soil and biomass – the very earth beneath us.

Image courtesy of IPCC Sixth Assessment Report.

In this blog we’ll address the revolutionary idea of carbon farming, designing carbon sinks, and generating a carbon net-positive landscape. But first, a lesson in the magic of photosynthesis and plant-microbe partnerships. 

What is a Carbon Sink?

Simply put, a carbon sink is stably stored carbon. We often think of forests as carbon sinks – the Amazon rainforest is described as the lungs of the planet because of its massive ability to sequester carbon and release oxygen through photosynthesis. Photosynthesis converts sunlight, CO2, and water into glucose (a form of carbon) for the plant, while emitting oxygen as a byproduct. Trees can store carbon in their woody biomass, which is a very stable application…until a forest fire burns the area and releases all the carbon back into the atmosphere. Between forests and prairies just in the U.S., we have the potential to sequester and store 1000 pounds of C02 per acre per year!!   

Image courtesy of Research Gate.

Other plants like grasses and perennials also sequester carbon dioxide and release oxygen, but the carbon is stored in the soil, through the process of (the creation of topsoil!). This magnificent process occurs from a partnership between the plant and soil microbes, called mycorrhizae. A diverse community of microbes attach themselves to plant roots; the plant relinquishes a small amount of sugars and water in exchange for the mycorrhizaes’ breakdown of nutrients (N,P,K and micronutrients) from the soil into a plant-accessible form. Ah, the barter system! 

The microbes then excrete the sugars into a gluey substance called glomalin, which is a stable form of carbon (glomalin is 40% carbon!). Glomalin helps aggregate soil particles into clumps, a via humusification. Humus is up to sixty percent carbon!

Image courtesy of Parkways Seattle

Deeply rooted plants, like prairie grasses, are able to store carbon at deeper soil strata, increasing the stability of the sink. In general, the more diverse a planting, the more variety of root depth and soil microbe partnerships, the more potential for carbon sequestration and storage.

Image courtesy of flattenthecarboncurve.org

Scientists estimate that baseline soil carbon content is 1-2% per acre, but with proper management and plantings, soil can store 5-8% carbon per acre, meaning 25-60 tons of stored carbon per acre. By some estimates, if we implemented carbon-smart land management across all landscapes and agricultural land, we could reduce atmospheric carbon by 30%! Carbon sinks are a real and tangible climate solution.

Action Items for Climate-Smart Landscape Designers

In part 2 of this blog post, we’ll dive into best practices for landscape designers and land stewards interested in converting their landscape to a carbon sink, with net zero emissions.

Read Part Two – Landscape Design to Halt Climate Change: Designing Carbon Sinks!

Green Jay Landscaping

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