Professional Forestry's Position on Global Warming

Forestry's Assessment of Global Warming and Climate Change in North America

Pine Beetle Damage in British Columbia
Mountain Pine Beetle Attack. opentextbc.ca

Brief Review of Greenhouse Gasses

Our planet and every living thing on its surface depend on the energy of the sun. About half of the sun's light passes through Earth's atmosphere to reach the surface where it is absorbed then radiated back as infrared heat. This reflected heat is trapped by gasses in the lower atmosphere that causes a surface warming called the "greenhouse" effect. As these greenhouse gasses (GHG) increase in volume, they collect and store more heat in the atmosphere which increases the mean annual temperature at the Earth's surface.

Here are the major GHGs that collect atmospheric heat and are keeping most of it from escaping. They are long-lived gasses and are nearly permanently fixed in the atmosphere. The most important greenhouse gasses include water vapor (H2O), carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4).

Let's look at the most common greenhouse gasses:

  • Water vapor - H2O is the most abundant of the gasses and increases as the atmosphere warms. Although essential to life, it takes on heat from the other gasses that are "forcing" climate change due to the increase in average global temperatures.
  • Carbon dioxide - CO2 is an important GHG gas that we exhale with every breath. It is also released via human activity by burning fossil fuels, deforestation, and land use changes. It is the primary gas blamed for climate change.
  • Methane -  CH4 occurs from many natural processes and is less worrisome when compared to the more abundant CO2 gas. This GHG is produced from human activity via landfill and sewerage decomposition and poor livestock manure management.
  • Nitrous oxide - N2O is a powerful GHG that is produced by soil cultivation practices that use commercial and organic fertilizers, burn fossil fuels along with biomass burning.

Interestingly, of the actively publishing climate scientists 97 percent agree that climate-warming trends over the past century are most likely due to human activities.

These activities have increased the atmospheric gasses I mention above. 

I do not include the chlorofluorocarbons (CFCs) which are synthetic compounds entirely of industrial manufacturing and origin. This group of GHGs is heavily regulated by international agreement to prevent their release into the atmosphere. They have been linked to the destruction of the ozone layer and are considered greenhouse gasses.

Global Warming's Effect on North American Forests

Although now recognizing that climate change is certainly causing global warming, some forestry professionals have been slow to agree that it is man-made. The forest products industry does leave a carbon footprint as do many industrial product manufacturers. Still, there is an underlying fear of excessive regulation in both the tree planting and harvesting process and wood products manufacturing.

The top offenders of total global emissions come from the producers of electricity and heat, heavy industrial manufacturing processes, gasses given off from all forms of transportation and from agricultural food and fiber production. Forest management including planting and harvesting trees has only a very small part to play when considering total global emissions.

On the other hand, practicing foresters are seeing the negative changes in climate staring them in the face. In the Sierra and Rocky Mountains of the North American west, three threats to our forests are visibly troubling to the forest visitor and of major concern for timber managers and wildland firefighters.

  • Extreme Heat and Drought - The lack of water along with abnormally high temperatures has put trees under severe stress. Forest managers have observed a doubling in tree mortality in recent years, even in areas undisturbed by insects and wildfires.
  • Insect Infestation Increase - Pine bark beetles have taken advantage of the drought-stressed western conifers. Insect infestations have killed more trees at a faster pace over a longer period on more acreage becoming one of the worst tree die-offs over the last century.
  • Wildfires Increase in Size and Number of Starts - Because of droughty conditions and trees killed by insects, resulting wildfire has increased throughout the Mountain States. Wildfire seasonality is now uncertain and becoming much longer than it used to be.

This observable climate change, whether a short or long-term event, is affecting the economic, social, and biological systems in and around these North American forests. A concern for  species conservation is whether or not the rate of ongoing climate change will exceed the rate at which species can adapt or move to suitable environments. 

Forestry's Answer to Climate Change

The Society of American Foresters (SAF), an organization representing professional foresters, believes that climate change policies and actions should recognize the role that forests play in reducing greenhouse gas GHG emissions. Here are their priority issues in combating climate change:

  1. The substitution of wood products for non-renewable building materials -  the idea here is that lumber, wood panels, and other solid wood products locks up potential GHGs over time and use less fossil energy than steel, concrete, brick, or vinyl, whose manufacture is energy intensive and produces substantial emissions. 
  2. Forest biomass substitution for fossil fuel-based energy sources - the idea here is to substitute forest and mill wood residues as an energy source for the fossil-derived coal and gas.
  3. Reducing wildfire and other disturbance emissions - active forest and wildland fire management planning (including prescribed fire) will reduce fire intensity, restore forest health and "dramatically reduce GHG emissions".
  4. Avoiding land-use change - More carbon is stored in forests than in agricultural or developed land. Preventing land-use change from forests to nonforest uses will reduce GHGs. 

SAF also believes that sustainably managed forests can reduce GHG concentrations by sequestering atmospheric carbon in trees over time and by storing carbon in wood products made from the harvested trees.

Finally, climate change policies can invest in sustainable forest management to achieve these benefits, and respond to the challenges and opportunities that a changing climate poses for forests.

 

Sources:

NASA, Global Climate Change  http://climate.nasa.gov/scientific-consensus/

Society of American Foresters, Position on Climate Change

United States Forest Service, miscellaneous reports on western US fires and mountain pine beetle infestations