CO2 emissions from fossil fuels such as oil, gas and coal contribute directly to climate change and global warming.
The more greenhouse gases that are in the atmosphere, the more
heat gets trapped, and as the temperature rises, the result is
climate change. Scientists predict that as the climate changes,
the spread of diseases will increase, agricultural production will
decline, and extreme weather such as floods and tornadoes will
become common.
Carbon dioxide is one of the most problematic greenhouse gases
as far as climate change goes. The amount of carbon in the
atmosphere increases as fossil fuels are burned, so the use of
coal, oil, and gas for heat and transportation means that carbon
dioxide is released into the atmosphere in excessive amounts, at
very fast rates, and the Earth does not have the capacity to absorb
it. The effects on the climate are now becoming obvious. The
northern hemisphere is warmer than it has been at any point in the
past 1000 years, natural disasters including hurricanes and floods
are increasing, and changes in lake and river levels mean that food
supplies are threatened.
In order to stall or turn back global warming, we need to
dramatically reduce the amount of fossil fuels we emit, and ensure
that carbon sinks are protected. Unfortunately, by developing the
Alberta tar sands, oil companies are doing precisely the
opposite.
Tar sands development is the single largest contributor to the
increase in climate change in Canada, as it accounts for 40 million
tonnes of CO2 emissions per year, and means that thousands of
hectares of ancient Boreal Forest are clearcut and destroyed.
These numbers are increasing: by 2011 it is expected that the tar
sands will emit 80 million tonnes of CO2 emissions. Please note
that these numbers only take into account the production of oil
from the tar sands. Once tar sands oil is burned as fuel, it does
create further "end-use" emissions.
Canada made an international commitment to meeting GHG emissions
reduction targets outlined in the Kyoto Protocol - the goal was to
reduce emissions to six per cent below 1990 levels by 2010.
Unfortunately, Canada has been unsuccessful at achieving even this
small number so far. As of 2004 emissions levels had significantly
increased. In order to meet the targets, emissions must go down by
280 million tonnes per year. If the tar sands continue to operate
as predicted, there is no hope of accomplishing this.
Why do the tar sands cause so many emissions?
The oil that is being sought from the tar sands is literally
stuck in tar and it is very difficult to separate them. Huge
industrial machines are needed to dig the mineable tar sands out of
the earth, and these burn a lot of fuel. As two tonnes of tar
sands must be moved in order to create a single barrel of oil, this
means that 35 kg of CO2 equivalent is emitted, making oil from the
tar sands the most energy intensive type of oil available.
If the tar sands are located deeper than 100 metres from the
Earth's surface, and cannot be mined, they are extracted by a
process called steam-assisted gravity drainage (SAGD), which
creates even more emissions than mining: 55 kg of CO2 per single
barrel of oil. In SAGD operations, steam is injected into the tar
sands to make it flow, and then it is pumped to the surface.
Heating the water for the steam greatly increases the amount of
fossil fuels that are burned.
As mentioned above, bitumen is the heaviest and worst quality
oil available. It has to be processed and refined heavily to be
turned into synthetic crude oil, which involves further use of
steam and energy.