Land-based greenhouse gas emissions and removals

National land-based greenhouse gas emissions and removals

Key results

• In 2020,
  • natural disturbances (such as wildfires and insect infestations) accounted for emissions of about 8.8 megatonnes of carbon dioxide equivalent (Mt CO₂ eq)
  • human activities (such as timber harvesting and agricultural activities) accounted for removals of 6.3 Mt CO₂ eq
• Between 1990 to 2001, estimates of land-based GHG were net removals in all years with the exception of 1995 (emissions of 130 Mt CO₂ eq) and 1998 (emissions of 110 Mt CO₂ eq)
• Since 2002, the net exchange has consistently resulted in emissions, ranging between 2.5 Mt CO₂ eq (2020) and 260 Mt CO₂ eq (2015) 

National land-based greenhouse gas emissions and removals, Canada, 1990 to 2020

How this indicator was calculated

Note: Natural disturbances refer to emissions and removals related to wildfires and large forest insect infestations. Human activities refer to emissions and removals from managed lands (such as settlements, forested lands, agricultural land and wetlands) as well as emissions from harvested wood products. For more information, see the section on emissions and removals from human activities.
Source: Environment and Climate Change Canada (2022) National Inventory Report 1990-2020: Greenhouse gas sources and sinks in Canada.

Natural disturbances such as forest fires and large insect infestations have occurred in Canada's forests for thousands of years. These disturbances are part of the natural life cycle of the forest and generally help the forest renew itself. However, there is evidence that climate change is driving an increase in natural disturbances. These disturbances can contribute to the release of large amounts of GHGs into the atmosphere through the burning and decay of dead trees, as well as significant removals as the forest regenerates over time.^{Footnote 1} For the past 20 years, the total net GHG exchange (that is, the land-based GHG emissions minus removals) has been significantly impacted by these natural disturbances.

There was a shift in the net exchange in 2002 where it shifted from removals in prior years to emissions. This, in part, is due to an increase in emissions from natural disturbances, and a decline in removals from human activities.

In managed forests, emissions and removals due to natural disturbances such as forest fires or insect infestations are associated with human activities under specific circumstances. These circumstances are described in the methods section.

Land-based GHG emissions and removals from human activities

Land-based GHG emissions and removals from human activities are commonly referred to as land use, land-use change and forestry (LULUCF) according to international standards.

Key results

• In 2020,
  • Wetlands and settlements emitted 2.9 and 2.3 megatonnes of carbon dioxide equivalent (Mt CO₂ eq), respectively
  • Agricultural land and forested land removed 10 and 2.0 Mt CO₂ eq, respectively
• Between 1990 and 2020, human activities on managed land resulted in net removals. It has declined over time, from 63 Mt CO₂ eq in 1990 to 6.3 Mt CO₂ eq in 2020
• Prior to 2003, the activity sector that contributed the most to GHG removals was the forest sector. After 2003, this shifted to the agricultural sector

Land-based greenhouse gas emissions and removals from human activities by activity sector, Canada, 1990 to 2020

How this indicator was calculated

Note: Greenhouse gas exchange from the forest sector considers emissions and removals from managed forests and all harvested wood products. Harvested wood products originate from forest trees, urban trees and agricultural land. As such, the reported forest sector emissions may differ from the National Inventory Report. For more information, see Chapter 6.4 of the National Inventory Report.
Source: Environment and Climate Change Canada (2022) National Inventory Report 1990-2020: Greenhouse Gas Sources and Sinks in Canada.

Forest sector

In 2020, removals from the atmosphere through forests, and emissions to the atmosphere from harvested wood products were close to equal, having an estimated net removal of 2.0 Mt CO₂ eq.

GHG contributions from the forest sector have varied over the period from 1990 to 2020, ranging from removals of 74 Mt CO₂ eq (1991) to emissions of 14 Mt CO₂ eq (2005). This change is related to reduced carbon sequestration in forests due to natural disturbances (such as forest fires and insect infestations) and changes in harvest rates over time, in particular in the Mountain and Boreal regions. Natural disturbances increase GHG emissions through the decomposition of affected trees, and reduce the areas of mature growing trees that are removing carbon. Like harvesting, they can also cause a shift in forest age to younger forests that are either emitting carbon or removing less carbon than the mature forests that were harvested.

The forest sector category refers to emissions and removals from forest management activities such as timber harvesting, thinning and replanting, and ecological processes such as tree growth and decomposition. It also includes emissions from harvested wood products, which are the wood materials removed from the harvested site and turned into consumer products, such as timber for construction, furniture or paper products. Harvested wood products are not limited to wood harvested from forests, and include those harvested from agricultural land and land conversion. The carbon removed from the atmosphere by trees is stored in the harvested wood products and tracked over the lifespan of the consumer products. The carbon is emitted back into the atmosphere at the end of the products' useful life.

Agricultural land

Agricultural land has typically contributed to GHG removals, and has consistently done so since 2004. Removals by agricultural land has ranged between 2.6 Mt CO₂ eq (1992) to 43 Mt CO₂ eq (2014). This is due to changes in agricultural practices, such as the adoption of conservation tillage,^{Footnote 2} increases in crop yield, and the reduced use of summerfallow. However, the removal rate from agricultural land has been decreasing in recent years due to a decline in the adoption rate of conservation tillage and in the area of land used to grow perennial crops, and increases in the conversion of forested land and grassland to agricultural land.

The agricultural land category reports emissions and removals from annual and perennial cropland, as well as from forest lands and grassland converted to cropland. Cropland includes lands in annual crops, summerfallow and perennial crops. Managed agricultural grassland refers to rangeland that is used only for grazing domestic livestock.

Wetlands

Trends in this category are mainly driven by the creation of large reservoirs before 1990, resulting in higher emissions over the 1990 to 1993 period. Emissions from reservoirs have declined from 1990 to 2020, while emissions from drained and excavated wetlands for peat extraction have increased. Overall, total emissions has declined during this time period from 5.5 Mt CO₂ eq (1993) to 2.9 Mt CO₂ eq (2020).

The wetlands category includes activities such as peat extraction for use in horticulture and land flooding to develop reservoirs for hydropower development.

Settlements

Total emissions for settlements fluctuated between 1.2 Mt CO₂ eq (1997) and 2.7 Mt CO₂ eq (2016). Emissions were mainly driven by rates of forested land converted to settlements, and are offset by the storage of carbon in urban trees (annual removals of about 4.3 Mt CO₂ eq).

The settlements category refers to emissions and removals occurring on developed lands (such as urban environments, transport infrastructure, oil and gas infrastructure and mining) and from land conversion of forests and agricultural land to settlements.

Regional land-based emissions and removals from human activities

Key results

From 1990 to 2020,

• The Boreal region and the Prairies contribute to GHG removals
  • Removals in the Boreal region decreased from 87 megatonnes of carbon dioxide equivalent (Mt CO₂ eq) to 21 Mt CO₂ eq
  • Removals in the Prairies increased from 7.0 Mt CO₂ eq to 14 Mt CO₂ eq
• The West Coast, Mountain and Southeastern regions contribute to GHG emissions
  • Emissions from the West Coast and the Southeastern regions decreased from 18 Mt CO₂ eq to 7.6 Mt CO₂ eq, and from 7.6 Mt CO₂ eq to 0.69 Mt CO₂ eq respectively
  • The Mountain region, which is important for forestry, went from removals of 47 Mt CO₂ eq to emissions of about 10 Mt CO₂ eq. This region has been contributing to emissions since 2005

Regional land-based greenhouse gas emissions and removals from human activities, Canada, 1990 to 2020

How this indicator was calculated

Note: Regions are based on the location of the human activities across the country. Forest sector regional estimates provided do not include the long-term impact of emissions from forest harvest or deforestation prior to 1990.
Source: Environment and Climate Change Canada (2022) National Inventory Report 1990-2020: Greenhouse Gas Sources and Sinks in Canada.

The overall increase in removals of GHGs on the Prairies can be attributed to changes in agricultural land management practices, such as the adoption of conservation tillage, the proportion of annual and perennial crops, and the reduced use of summerfallow. These changes in land management decrease soil disturbance and thereby lower releases of carbon from the soil. However, due to a decrease in the proportion of perennial crops in the crop mixture and in the adoption rate of conservation tillage, and an increase in crop residue, there has been a decline in the rate of GHG removals in recent years.

In the West Coast and Southeastern regions, forestry management practices (changes in harvest rates and forest regeneration) contributed to the reduction in emissions. However, in recent years, net GHG emissions have been increasing in the Southeastern region. Similar to the Prairies, this increase is in part due to shifts in agricultural land management practices.

The decrease in GHG removals in the Boreal region and the shift from removals to emissions in the Mountain region are related to increased forest harvesting (in part in an effort to salvage timber from trees killed by the Mountain Pine Beetle) as well as a reduction in net carbon removals from forests. The latter is due to insect infestations and fires in managed forests. The disturbances reduce the area of mature growing trees, and increase decomposition and salvage logging (the harvest of dead or dying standing trees). For more information, see the Forest sector in Land-based emissions and removals from human activities.

Land-based emissions and removals from natural disturbances

Forests remove carbon from the atmosphere as they grow and release it along with other GHGs when they decay after dying or burn in forest fires.

Key results

• In 2020,
  • Emissions from wildfires contributed 16 megatonnes of carbon dioxide equivalent (Mt CO₂ eq)
  • Emissions caused by insect infestations were 20 Mt CO₂ eq
  • Removals due to forest regrowth post wildfire were 27 Mt CO₂ eq
• Since 2002, wildfires had the largest influence on land-based emissions and removals from natural disturbances

Land-based greenhouse gas emissions and removals from natural disturbances in managed areas, Canada, 1990 to 2020

How this indicator was calculated

Note: Wildfire emissions and removals are divided in 2 categories, (1) wildfire – immediate and (2) post wildfire. Wildfire – immediate includes emissions from trees and soils from the burning of wildfires. Post wildfire includes emissions released by the decay of dead trees and soil organic matter and removals related to forest regeneration. Insect disturbances include emissions from the decay of organic matter and removals from natural regeneration.
Source: Environment and Climate Change Canada (2022) National Inventory Report 1990-2020: Greenhouse Gas Sources and Sinks in Canada.

Natural disturbances are an important factor in determining whether forests remove or release GHGs each year. These disturbances contribute to immediate emissions (for example, from the burning of trees), as well as post-disturbance emissions and removals. Post-disturbance emissions are from the gradual decay of dead organic matter. Post-disturbance removals are related to the natural regeneration and regrowth of forests.

The variability in emissions and releases from natural disturbances can vary greatly from year to year. For example, emissions from managed lands were lower in 2016 than in adjacent years because of the smaller area burned.^{Footnote 3} However, since the mid-2000s, emissions from wildfires and insect disturbances have generally been increasing. Severe insect infestations in the early 2000s are having an effect on today's net GHG exchange and are expected to influence GHG emissions over the next few decades.

About the indicator

What the indicator measures

The Land-based greenhouse gas emissions and removals indicator tracks exchanges of greenhouse gas (GHG) emissions and removals between the atmosphere and Canada's managed lands. Reported GHG emissions and removals are annual totals from:

• Land use and land-use change activities
  • Forest sector (managed forested land and harvested wood products)
  • Agricultural land (cropland and agricultural grassland)
  • Wetlands (peat extraction and reservoirs for hydropower)
  • Settlements (developed land and land conversion to settlement)
• Natural disturbances (insect infestations and wildfires)

The indicator does not report emissions from Canadian economic sectors: oil and gas, transport, buildings, electricity, heavy industry, agriculture (such as fuel use, and crop and animal production) and waste. For information on anthropogenic (human-made) GHG emissions, refer to the Greenhouse gas emissions indicator.

Why this indicator is important

GHG emissions and their increasing concentrations in the atmosphere are having significant impacts on the environment, human health and the economy. Tracking the trends in Canada’s land-based GHG emissions and removals provides a useful context for understanding how different management activities could reduce emissions and increase removals over time. This indicator could also help identify opportunities for mitigating the impacts of climate change and the potential for enhancing carbon sequestration.

The distinction between emissions and removals from human activities versus natural disturbances allows for a better understanding of emissions that could be directly managed in the near to medium term. The National Inventory Report has made this distinction since 2017 in the 2015 National Inventory Report.

Related indicators

The Greenhouse gas emissions indicators report trends in total anthropogenic (human-made) GHG emissions at the national level, per person and per unit gross domestic product, by province and territory and by economic sector.

The Global greenhouse gas emissions indicator provides a global perspective on Canada's share of global GHG emissions.

The Carbon dioxide emissions from a consumption perspective indicator shows the impact of Canada's consumption of goods and services, regardless of where they are produced, on the levels of carbon dioxide released into the atmosphere.

The Greenhouse gas emissions projections indicator provides an overview of Canada's projected GHG emissions up to 2030.

The Greenhouse gas emissions from large facilities indicator reports GHG emissions from the largest GHG emitters in Canada (industrial and other types of facilities).

The Greenhouse gas concentrations indicators present atmospheric concentrations as measured from sites in Canada and at a global scale for 2 greenhouse gases: carbon dioxide and methane.

Data sources and methods

Data sources

This indicator is developed using data from Canada's National Inventory Report and includes emissions and removals associated with natural disturbances and with land use, land-use change and forestry (LULUCF) activity on managed lands. Managed lands are defined by the Intergovernmental Panel on Climate Change (IPCC) as "land where human interventions and practices have been applied to perform production, ecological or social functions."^{Footnote 4} Information on the land category definition and representation of managed lands is available in Chapter 6 of the National Inventory Report.

Land-based greenhouse gas (GHG) emissions and removals include emissions and removals of carbon dioxide (CO₂). It also includes emissions of methane (CH₄), nitrous oxide (N₂O), and indirect CO₂ from the atmospheric oxidation of carbon monoxide (CO) due to controlled biomass burning; CH₄ and N₂O emissions from wetland drainage and rewetting due to peat extraction; and N₂O released following land conversion to cropland.

Methods

Land-based GHG emissions and removals are quantified using methods that are consistent with an internationally agreed methodological framework set out in the 2006 IPCC Guidelines for National Greenhouse Gas Inventories. The methodologies used to estimate emissions and removals are reviewed, updated and improved on a periodic basis. Collaborative work with sector experts from within and outside Environment and Climate Change Canada is undertaken to incorporate available expertise and the latest advancements in scientific knowledge. Further information on these methods is available through Environment and Climate Change Canada's National Inventory Report.

Recent changes

Improvements were made to the methods used to calculate the emissions and removals from agricultural land and as such, reported emissions this year may vary from past publications. For example, the changes now track carbon inputs from crop residues and the use of manure. Refer to Table 6-3 of the National Inventory Report for more information.

Caveats and limitations

The methodologies for compiling land-based GHG emissions and removals improve over time. As a result, the land-based emissions and removals data reported in the indicator may be different from previously published estimates.

Harvested wood products are not limited to those that originate from forests and include those from urban trees and agricultural land. As such, the reported emissions from the forest sector may differ from the National Inventory Report. For more information, see Chapter 6.4 of the National Inventory Report.

Canada is a vast country with heterogeneous landscapes and climates. Factors such as geographic location, climatic conditions, plant species and age, and management activities all play a role in influencing the net amount of GHG that is removed or released back to the atmosphere from each location in Canada. The land-based emissions and removals data provide a simplified representation of the complex reality and may not account for all relevant ecological processes.

Current reporting of land-based emissions and removals does not account for climate feedback other than what is captured through natural disturbances such as wildfires and insect infestations. Climate feedback mechanisms can either amplify (positive feedback) or diminish (negative feedback) the effects of a changing climate. For example, as rising concentrations of GHGs warm Earth's climate, permafrost begins to melt. This melting releases the organic carbon stored, contributing to GHG releases that cause more warming, which causes more melting, and so on, in a self reinforcing cycle.

For a complete discussion of the caveats and limitations with respect to land-based GHG emissions and removals data, refer to the methodological issues sections in Chapter 6 of Canada's National Inventory Report.

The latest year reported (2020) coincides with the 1^st year of the COVID-19 pandemic. As the total impact of the pandemic is difficult to quantity, especially for the forest sector, long-term trends presented in the indicator must be interpreted with caution.

Resources

References

Environment and Climate Change Canada (2022) Canada's official greenhouse gas inventory. Retrieved May 13, 2022.

Environment and Climate Change Canada (2022) National Inventory Report 1990-2020: Greenhouse gas sources and sinks in Canada. Retrieved on May 13, 2022.

Intergovernmental Panel on Climate Change (2003) Good Practice Guidance for Land Use, Land-use Change and Forestry. Retrieved on May 13, 2022.

Intergovernmental Panel on Climate Change (2006) 2006 IPCC Guidelines for National Greenhouse Gas Inventories, Vol. 4: Agriculture, Forestry and Other Land Use. Retrieved on May 13, 2022.

Kurz WA, Hayne S, Fellows M, MacDonald JD, Metsaranta JM, Hafer M and Blain D (2018) Quantifying the impacts of human activities on reported greenhouse gas emissions and removals in Canada’s managed forest: conceptual framework and implementation. Canadian Journal of Forest Research 48: 1-14. Retrieved on May 13, 2022.

Warren FJ and Lemmen DS, editors (2014) Canada in a Changing Climate: Sector Perspectives on Impacts and Adaptation. Government of Canada, Ottawa, ON, 286p. Retrieved May 13, 2022.

Related information

Canada's Action on Climate Change

Climate Change

Greenhouse gas emissions: drivers and impacts

Land-based greenhouse gas emissions and removals infographic