Concentration of CO2 in the Atmosphere

Waters That Can Emit Greenhouse Gases or Draw Them Down

Growing peat bog. (Agnes Monkelbaan, CC-BY-SA 4.0,

George Harvey

Water is amazing. So are the things that live in it. In fact, some things we seldom think about and seem to have nearly no value, could turn out to be the things that save us. Consider peat bogs. At the website of the International Union for Conservation of Nature, we find this interesting statement: “Peatlands are the largest natural terrestrial carbon store; the area covered by near natural peatland worldwide (>3 million km2) sequesters 0.37 gigatons of carbon dioxide a year – storing more carbon than all other vegetation types in the world combined ().”

Unfortunately, while peatlands can be powerful allies for drawing down carbon dioxide (CO₂), they can also be serious greenhouse gas emitters. That can happen if they are damaged. So, restoring a peat bog to good health can be a powerful act to help with climate change. For those who are especially interested in peatland, we might suggest visiting the website of the International Peatland Society (

There are other wetlands, apart from peatlands. They may not all be as valuable as peatlands for drawing down CO₂, but they are similar in important ways: While they can draw down CO₂ if they are healthy, they can emit CO₂, methane, and nitrous oxide if they are not. These other wetlands can also be valuable ways that peatlands are not, for example as sources of food.

Recently, an article posted by the BBC went into the carbon value of healthy rivers versus the costs of those that are damaged. This article, “The Rivers that ‘Breathe’ Greenhouse Gases,” took an especially close look at the rivers in Hong Kong’s New Territories (). This region has a large population, but it includes rural areas with farm land.

The New Territories region has waterways running through it, which, if left in a natural state, would take in CO₂ and breathe out oxygen in a natural cycle of respiration. Instead, the waters are so overloaded with CO₂, nitrous oxide, and methane that the air above them does not need any other source of these chemicals to be badly polluted.

Part of the problem with the water is the farmland. The runoff from the farms includes waste from livestock, along with residues of any chemicals or organic materials that might have been used to fertilize the land. In addition, there are scores of thousands of people who live in buildings with no connection to any sewage system.

The result of the situation is that the microflora in the waterways are species that can live in such an environment. Operating on the food they find, they produce toxic by-products. Where one set of microbes, living in unpolluted waters, would act to maintain the purity of the water, and with it the air above it, with polluted water a different set of microbes makes the pollution worse.

Somehow, this seems very much like things that are going on closer to home. Whether it is the Connecticut River, Lake Champlain, the Hudson River, or any other body of water, allowing pollutants into the water can make that water even more polluted.

We have known, for example, that farm runoff going into Lake Champlain can feed cyanobacteria, causing “algae blooms.” This makes the water of the lake even more toxic and kills fish.

Clearly, part of the issue is simple. Treat the waters well, so the environment they provide is healthy, and we have a valuable friend in the fight against climate change. But treat the waters badly, and they become a powerful enemy.

Leave a Reply

You can use these HTML tags

<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>