Earlier this fall, a commentary in the Nature Communications, Earth & Environment journal argued for a change to implementing the Paris Agreement’s reporting mechanisms. The authors called for all countries to report carbon emissions and removals across their territories, not just within so-called “managed” lands (as is presently the case).
However, this poses a challenge here in Canada, as there is deep uncertainty about the total carbon flux (balance of emissions and captures) in Canada’s “unmanaged” land.
I echo calls for the Government of Canada to scale up and improve its greenhouse gas (GHG) monitoring and modelling across Canada’s entire territory and to report these findings more openly and transparently as part of its annual National GHG Inventory.
Differentiating between managed and unmanaged land
Under the UN Framework Convention on Climate Change, member countries are expected to report GHG emissions and removals resulting from human activities. However, within the LULUCF (or Land Use, Land-Use Change, and Forestry) sector, what constitutes an anthropogenic influence is not always clear.
The guidance provided by the Intergovernmental Panel on Climate Change (IPCC) has been to delineate between “managed” and “unmanaged” lands and to focus GHG reporting on the former since these are areas under substantive human influence. While a number of countries make use of this distinction, the unmanaged land in Canada is truly significant — equivalent to about 69 per cent of the country’s total land area.
Canada’s National GHG Inventory does contain information about the carbon flux within managed lands, or lands comprised mostly of managed forests. There are currently around 232 million hectares of managed forest in Canada. However, this leaves roughly 715 million hectares of land in Canada, which is technically unmanaged — all unaccounted for in the National GHG Inventory.
What’s more, while Canada does track emissions from natural disturbances (such as in a forest fire) occurring in managed areas, it does not report these disturbances to the UN as part of its LULUCF emissions, based on the claim that these are not anthropogenic.
While there is a logic to separating these out, there is a substantial difference in Canada’s total LULUCF emissions, depending on whether or not they are included. For instance, if natural disturbances are included in the tally, Canada’s managed land is typically a net carbon source. In contrast, if they are not included, Canada’s managed land is typically a net carbon sink.
The underlying problem, however, is the lack of clear and transparent information about GHG emissions and removals in Canada’s unmanaged lands.
Estimates vary widely
Earlier this summer, during Canada’s unprecedented wildfire season, I asked the Ministry of Energy and Natural Resources of Canada (NRCAN) for historical information about the net Carbon flux in unmanaged lands. I was surprised to learn that NRCAN does not yet have this data.
NRCAN has a very robust carbon budget modelling tool, and thanks to this, some preliminary (unverified) estimates of wildfire emissions in unmanaged forests are available.
Wildfire emissions estimates for unmanaged forests are a step in the right direction (as wildfires account for the bulk of emissions from natural disturbances). However, most unmanaged land remains unforested — including, for instance, vast peatlands, which are also subject to wildfires.
No GHG emissions occurring in unmanaged lands are currently being tracked or reported within the National GHG Inventory process.
Various efforts have been made to quantify these emissions, yet estimates vary considerably, with some data sets limited to forest lands and others looking at the entire national territory.
One recent estimate used 16 different “Dynamic Global Vegetation Models” and found that over the 20 years from 2000-2020, unmanaged forests sequestered, on average, about 189 megatons of CO2 per year.
However, the Global Carbon Project’s estimates of “atmospheric inversions” suggest there may be orders of magnitude more carbon removal in Canada’s unmanaged land.
The size of the discrepancy between these estimates is puzzling. While one obvious explanation comes down to the former model using intact forests as a proxy for unmanaged land and the latter model including all of Canada’s unmanaged land area, scientists believe there may be more to this discrepancy.
A need for further research and better reporting
It is unfortunate that Canada has no publicly stated estimate of the country’s total carbon flux. This is important information to help track whether Canada’s landmass is sequestering enough CO2 to offset natural disturbances or whether the latter outweighs the former.
It is essential that the Government of Canada enhance its current efforts in land-based carbon flux analysis, and that such data and analysis is reported to the public in a more precise and transparent way.
Ryan M. Katz-Rosene, Associate Professor, School of Political Studies, L’Université d’Ottawa/University of Ottawa
- This article is republished from The Conversation under a Creative Commons license. Read the original article.
