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| The Climate Change Connection |
| | Climate change affects and is affected by forests in a number of significant ways. Through a brief overview of four important considerations, the link between credible carbon management and forest conservation becomes clear.
Impacts of Climate Change
Although no-one can accurately predict the exact impacts of climate change on any particular forest, much is known in a general sense of the types of impacts that can be expected. These include:
changes in climatic zones, with much of the boreal forest zone reclassified as having a climate better suited to temperate forests;
increased forest growth, due to warmer temperatures, longer growing seasons and the ‘fertilization’ effects of enhanced levels of atmospheric CO2;
increased outbreaks of insects and diseases, which can migrate quickly into new areas where the climate has become more conducive to them;
increased frequency and severity of fires, especially in regions that see reduced precipitation; and
increased damage due to extreme weather events, such as freak windstorms and the like.
All in all, these changes are largely negative and they are caused by all greenhouse gas emissions equally, whether they come about as a result of deforestation or from burning fossil fuels. Solutions must come not just from the forestry sector but must include intense efforts to reduce emissions through energy efficiency, demand reduction and conversion to appropriate renewable energy sources.
Adapting to a Changing Climate
We have already seen a global temperature rise of about 0.5° C, and all future scenarios project sharp additional increases, even if we were to halt all emissions of greenhouse gases tomorrow. Over the long term, effective adaptation to climate change will require plant and animal species to migrate and relocate to areas better suited to them. Industrial developments and forest fragmentation tend to restrict this migration, however. Therefore it will be especially important to establish large intact protected areas in the boreal forest that must offer opportunities for migration, not simply narrow ‘corridors’. North–south alignment will be crucial because much of the migration will be northwards. But hilly areas are also important, as many species will adapt to the climate change by migrating ‘up-slope’ to offset the effects of rising temperature.
How Forests Affect Climate Change
Forests store significant amounts of carbon in living biomass, dead organic matter and in soil organic carbon, including peatlands. This pool of carbon is steadily added to by new growth, at the same time as it is reduced by fire, decay, logging and deforestation. If removals are less than new growth the forest is considered to be a carbon sink. If removals exceed new growth the forest is a net source of carbon.
When considered over a large area and a long time span, natural forests will tend to be net carbon sinks, largely because of the slow build-up of soil carbon. Forests that are newly established on previously non-forested land will also be carbon sinks, at least until the stands reach maturity. On the other hand deforestation results in significant losses of carbon to the atmosphere.
In general, the conversion of primary forests to managed secondary forests, a practice currently widespread in the boreal forests of Canada and Russia, results in a loss of carbon. This happens for three main reasons. Firstly, there is significant deforestation from the creation of a new network of roads. Secondly, secondary forests are usually managed to a rotation age that is significantly shorter than the natural disturbance interval, meaning that the average age (and volume) of the forest is reduced. Thirdly, even where the rotation age is similar to the natural disturbance interval (such is in a fire-dominated region) there is still a loss of carbon, because logging preferentially removes high-volume stands whereas fire acts more randomly, leaving significant pockets of high-volume old-growth forests intact.
Forest Carbon Credits and the Kyoto Protocol
The Kyoto Protocol includes several provisions to account for changes in forest carbon. Industrialised countries that sign and ratify the Protocol may claim credit for carbon sequestered in newly established forests, and must account for all carbon losses due to deforestation. Countries can claim credit for reforestation and afforestation projects in developing countries, as part of the Clean Development Mechanism. And countries can choose to account for the net changes of carbon due to forest management.
The inclusion of credit for sinks in the Kyoto Protocol has been opposed by NGOs for many reasons, including concerns about additionality, uncertainty, impermanence and the social and environmental impacts of plantations. However, it is also true that with proper safeguards in place the easy credits that some forest industry apologists have been promoting will not materialise. Industry spokespeople, for instance, are quick to point out that young trees sequester carbon more rapidly than old trees (so-called ‘overmature’). This is true, but what they overlook is that older forests store more carbon than younger forests. And if older forests get converted to younger forests this results in a significant release of carbon due to logging, which will have to be accounted for if the industry hopes to get the credit for the forest regrowth.
So, what conclusions can be drawn? First of all, it is important to remember some incontrovertible facts, namely that industrial infrastructure development results in deforestation, that old forests store more carbon than young forests and that converting primary forests to secondary forests usually results in a loss of on-site carbon. In other words, there is a positive link between credible carbon management and good forest conservation. This link is valid regardless of what is eventually recognised under the Kyoto Protocol. So while there is much to be wary about regarding forest sinks credits, there are at the same time numerous opportunities to generate the public pressure and political will needed to support good forest conservation measures.
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| | Contact
Martin von Mirbach, Sierra Club of Canada |
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