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What are carbon credits and how do they
work?
Carbon credits are a key component of national and international
emissions trading schemes that have been implemented to mitigate global warming.
They provide a way to reduce greenhouse effect emissions on an industrial scale
by capping total annual emissions and letting the market assign a monetary value
to any shortfall through trading. Credits can be exchanged between businesses or
bought and sold in international markets at the prevailing market price. Credits
can be used to finance carbon reduction schemes between trading partners and
around the world.
There are also many companies that sell carbon credits to commercial and
individual customers who are interested in lowering their carbon footprint on a
voluntary basis. These carbon offsetters purchase the credits from an investment
fund or a carbon development company that has aggregated the credits from
individual projects. The quality of the credits is based in part on the
validation process and sophistication of the fund or development company that
acted as the sponsor to the carbon project. This is reflected in their price;
voluntary units typically have less value than the units sold through the
rigorously-validated Clean Development Mechanism.
A 'carbon credit', sometimes referred to as an offset, is a permit to
emit a specified amount of greenhouse gases, usually expressed in metric
tonnes of carbon dioxide equivalent (CO2e). 'Carbon credits' are named
after the most prominent greenhouse gas, carbon dioxide, but can
represent other warming gases.
Carbon dioxide equivalent (CO2e) is a metric used to compare the global
warming potential of various greenhouse gases. For example, the
contribution of methane to global warming is rated as 21 over 100 years.
This means that an emission of one metric tonne of methane is equal to
emissions of 21 tonnes of carbon dioxide.
Credits can be allocated by a government as part of a plan that sets a
limit on the total amount of CO2 that may be emitted in that
jurisdiction, in what generally referred to as a cap-and-trade system.
Companies may be awarded a number of permits, and must emit only as much
GHG for which they have permits. Carbon credits can be earned through
projects that reduce emissions, or by companies that cut their own
emissions and thereby free up credits they possess for trading. Carbon
markets exist wherein which companies may purchase and sell credits.
The World Bank has reported that worldwide trading of carbon credits was
valued at $21.5 billion during the first nine months of 2006, more than
double the value for all of 2005. The market suffers from volatility and
will require some reforms, but is showing promise of achieving its goal
of using financial incentives to curb emissions, says the bank.
As noted, the 'Cap-and-Trade' approach uses free market principles to
achieve a reduction in emissions of a particular greenhouse gas. A
government or regulatory body sets a limit on the total amount of
emissions that are allowed, and issues or auctions permits (carbon
credits) for that amount. Companies or organizations covered by the cap
must only emit according to the permits they possess.
If companies exceed their allowable limits of emissions, they must
obtain credits from other companies that have surplus credits, or by
investing in projects that offset their emissions (Offset Projects).
Thus, emissions are 'capped', and emitters can 'trade' credits until
their emissions match the amount of permits they possess.
Although it can be argued that purchasing carbon offsets amounts to
"buying one's way out," it is clear that companies can never eliminate
100% of their emissions. Purchasing carbon credits offer the opportunity
for companies to better manage their climate impact.
Also, creating an emissions inventory, which is a necessary first step
in determining how many offsets need to be purchased, is an important
first step for many companies that can lead to emission reductions
later.
Currently, the European Union possesses the only legally mandated carbon
trading system, the EU Emissions Trading Scheme, which works as a
cap-and-trade system. Other jurisdictions have made legislation in
preparation for future carbon trading markets, including California and
a group of seven Northeast U.S. states. Other carbon trading that does
not take place under Kyoto Protocol mechanisms is based on voluntary
schemes. These markets are discussed in the section "Where are other
carbon trading markets located?"
Offset Project is a term describing a venture that reduces greenhouse
gas emissions, such as a renewable energy development or energy
efficiency upgrade. An example would be a wind power installation in an
area that received most of its electricity from coal; total emissions
would be reduced because less coal would need to be consumed. A wind
farm in an area that uses hydroelectricity would not 'offset' any
emissions.
For many companies, an Offset Project is one that is undertaken outside
normal operations. For example, a company that owned a natural gas plant
could invest in the development of a methane capture project at a
landfill. While the natural gas plant would continue to produce carbon
dioxide, the company would 'offset' those emissions by capturing methane
at the landfill.
In this case, investors would hope to earn carbon credits that can then
be applied against their own emissions to help them meet their targets.
Another way that the natural gas plant operator could meet their
emissions targets would be to invest in pollution control technology.
While this could result in the same net reduction in emissions, the
company would not earn carbon credits. However, the upgrade could allow
the company to sell some credits it owns under a cap-and-trade scheme,
as its emissions would be lower than previously.
Carbon sequestration is another way of reducing emissions. It occurs
when carbon dioxide in the atmosphere is trapped in a sink. A Sink is
any natural reservoir that stores carbon. The most commonly thought-of
sinks are forests and vegetation. The world's oceans are also large
sinks. This concept is applied in the Kyoto Protocol, as the creation of
sinks can help countries earn carbon offsets through sequestration.
The Kyoto Protocol allows for carbon credits to be earned for
sequestration projects, such as the planting of trees. For example,
forestry companies that replant deforested areas could potentially earn
offset credits, as forests absorb carbon dioxide as they grow. A key
issue in this area is that the projects must represent an actual
reduction of emissions compared to 'business as usual'.
Many developing nations want the opportunity to earn credits by
preventing deforestation. Brazil has proposed the creation of a fund
that nations could tap into if they reduced deforestation to below 1990
levels, and this topic has been up for debate by the UNFCCC in the past
year.

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