Wetlands are not just “nice to have” – they provide services that are of direct financial benefit to our communities. These services include soaking up and storing water to reduce flood risk, helping to keep water flowing during times of drought, filtering our drinking water and reducing extreme heat in urban areas. When we lose wetlands, we also lose all of these services. However, this loss is not transparent since the financial value of wetlands does not routinely figure on our balance sheets.
 
The good news, as outlined in the recent report Getting Nature on the Balance Sheet: Recognizing the Financial Value Provided by Natural Assets in a Changing Climate, is that over 90 local governments across Canada are working to identify and value services provided by natural assets, such as wetlands, including 27 local governments in Ontario. Work within these communities has focused on valuing services that local governments are responsible for, for example provision of clean drinking water and flood protection.

So what are wetlands “worth”?
 
Economic valuation studies outline examples of significant, “hidden” financial benefits of wetlands, focused on specific community services.
 
Water filtration
In Southern Ontario, University of Waterloo researchers, Tariq Aziz and Philippe Van Cappellen found that wetlands provide an estimated $4.2 billion worth of water filtration services each year. If these services are lost, communities would need to treat the water by building and maintaining costly grey infrastructure solutions.
 
Flood protection
The report Combating Canada’s Rising Flood Costs: Natural infrastructure is an underutilized option demonstrated the significant value of flood protection provided by wetlands drawing on examples from across Canada. For a rural case study in Ontario (in the Credit River watershed), flood damages were 29% ($3.5 million) higher when headwater wetlands were assumed lost to agriculture. In an urban case study (Uptown Waterloo in the Laurel Creek watershed) estimated flood damages were 38% ($51 million) higher without the wetlands. These estimates were also noted as conservative. If wetlands are lost to urban development rather than agriculture, the increased runoff from impervious (waterproof) urban surfaces (such as buildings, roads and parking lots) is likely to further increase flood damages. You can find more details of each case study in the report When the Big Storms Hit.
 
Carbon storage and sequestration
As communities implement plans to reduce greenhouse emissions and reach net-zero, wetlands are again on our side. According to the Geological Survey of Canada, Canada’s wetlands hold almost 60 per cent of all the carbon stored in soils across the country.  As an example at the local level, wetlands within the National Capital Region are estimated to provide climate regulation services to a value of $ 2.9 million per year.
 
A parting thought
Wetlands are essentially our front line allies in tackling climate change and biodiversity loss. Preserving these habitats is a cost-effective way to maintain services of financial value to our communities. It is more complex and costly to restore wetlands once they are lost, or to replace the essential services they provide with grey infrastructure.

In the face of the climate emergency, you’ve probably heard “save our rainforests” or “plant two billion trees”. We’re producing too much carbon dioxide (CO2) and causing climate change. Trees uptake CO2 and cutting them down releases it back to the atmosphere, so it seems like a no-brainer to protect and plant trees. But what other important ecosystems do we have? Maybe you know that the ocean absorbs a lot of CO2 (about 30% of what we release into the atmosphere). What you may not know about is the importance of wetlands. Like forests storing carbon in trees, wetlands hold carbon underground in soil, and in northern regions, they currently store over 30% of the soil carbon while only covering around 3% of the total land area!

Wetlands being wet means that decomposition is slow (think of how well “bog bodies” are preserved). Slowly decomposing plant litter and other organic materials hold onto their carbon and do not release much CO2 into the atmosphere. The CO2 that is slowly released is outbalanced by the living plants, including trees, actively sucking up CO2. With this imbalance, carbon is consistently stored in the decaying organic matter leading to carbon rich soil, often called peat. So, wetlands act like a bank account for carbon that is stored beneath our feet. But, this storage takes time, building up slowly over thousands of years.

Canadian wetlands cover about 13% of our land area and account for almost a quarter of global wetlands. Unfortunately, wetlands and their importance often fly under the radar when it comes to land use planning and are not given the protection they deserve. Across Southern Ontario, we have lost about 56% of our wetlands to human development - in some places as much as 90%! Just like cutting down the rainforest, draining or building over wetlands causes us to lose both the active uptake of carbon and a large amount of the stored carbon. Once wetlands are no longer wet, the organic matter in the soil starts to decompose more quickly and carbon is released. Our development in Southern Ontario has released wetland carbon stocks leading to a reduction in the carbon stored of 2 billion tonnes since the 1800s. This loss is equivalent to the average annual greenhouse gas emissions of over a billion gasoline cars!

While wetlands can be restored or even constructed, the long-term carbon stocks are not quickly recovered. The process of carbon storage in wetlands is slow and restored wetlands may not recover their natural ability to store carbon for many years or decades. Wetlands are significant carbon stocks and have a high potential to mitigate climate change if properly protected and managed. Avoiding wetland disturbance provides more climate benefit than restoring areas that have been disturbed.

With our large wetland area and their importance for climate action, we as Canadians have a responsibility to protect these forgotten ecosystems. Take the time to learn more about wetlands and what you can do to help.