Drawdown: The Most Comprehensive Plan Ever Proposed to Reverse Global Warming by Paul Hawken

Author:Paul Hawken [Hawken, Paul]
Language: eng
Format: azw3
Publisher: Penguin Publishing Group
Published: 2017-04-17T16:00:00+00:00

This diagram shows some of the plants that have adapted to peatlands. They include sedges, mosses, the carnivorous sundews, orchids, bog myrtle, and many others that thrive in a waterlogged environment where nutrients are scarce.

For peatlands to stockpile carbon effectively, they must have plants to absorb and store it through photosynthesis, and water to create anaerobic conditions that keep carbon from escaping back into the atmosphere. Eighty-five percent of the world’s peatlands have the water retention that is crucial. As intact ancient ecosystems they can effectively collect carbon, while absorbing and purifying water, protecting against floods, and supporting biodiversity from foxes to orangutans. Safe-guarding them, through land preservation and fire prevention, is a prime opportunity to manage global greenhouse gases, and a cost-effective one by comparison. (While unspoiled peatlands do emit some methane, the carbon they sequester vastly outweighs the methane they release.)

The ability to siphon and hold carbon has a flip side, of course. Holding up to ten times more carbon per acre than other ecosystems, these wetlands can become powerful greenhouse chimneys if disrupted. Fifteen percent already have been. When peat is exposed to the air, the carbon it contains gets oxidized into carbon dioxide. It can take thousands of years to build up peat, but a matter of only a few to release its greenhouse cache once it is degraded. Drained peatlands make up 0.3 percent of the world’s land area, yet they produce 5 percent of all carbon dioxide emissions caused by human beings.

The causes of peatland degradation are varied. These boggy ecosystems are found predominantly in temperate-cold climates across the northern hemisphere, covering large swaths of North America, Northern Europe, and Russia, as well as in tropical-subtropical climates, such as Indonesia and Malaysia. In Southeast Asia, forest fires and clearing for palm oil and pulpwood plantations are major drivers of peatland damage—and on the increase. Indeed, it is why Indonesia’s greenhouse gas emissions are so high. When emissions from land-use change and forestry are included in country totals, Indonesia consistently ranks in the top five emitters in the world, in tandem with India and Russia. As global warming grows, so does the risk of peatland fires. In more temperate parts of the world, mining peat for fuel, extracting peat moss as a horticultural commodity, and draining peatlands for timber production and grazing are the main culprits.

Though not as effective as halting degradation before it starts, restoring drained and damaged peatlands is an essential strategy. Rewetting is the chief priority—an aptly named process that aims to saturate an expanse of peat by retaining water and raising the water table. In other words, stop water from escaping and reflood the soils. Once the peatland is wet again, oxidation and carbon release are curbed. Paludiculture, from the Latin palus for “marsh” and cultura for “growing,” can build on the success of rewetting by cultivating biomass to protect and regenerate peat. It is the artful creation of vegetation decay that can renew peat layers over time, and can accommodate certain crops such as oranges and tea trees.

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