Issue Summary
From Lauraibm
Contents |
Carbon Neutral
Carbon neutrality refers to the practice of balancing carbon dioxide released into the atmosphere from burning fossil fuels, with renewable energy that creates a similar amount of useful energy, so that the net carbon emissions are zero, or alternatively using only renewable energy.
For an organisation to become carbon neutral it needs to achieve a combination of; limiting energy usage and emissions from transportation, getting electricity from a renewable source and finally offsetting the remaining emissions that can not be avoided or generated.
Increasingly corporations are becoming carbon neutral as it is seen as good corporate social responsibility.
Carbon Offset
Carbon offsetting is the act of mitigating ("offsetting") greenhouse gas emissions. A well-known example is the planting of trees to compensate for the greenhouse gas emissions from personal air travel. The benefit of this is that trees absorb carbon dioxide through photosynthesis, so a growing forest will reduce atmospheric CO2 levels. An advantage of tree-planting is that it has low costs in relation relative to other options—$90 will plant 900 trees.
Alternatively a company can offset emissions via renewable energy or via methane collection and combustion.
Some people disagree with the principle of carbon offsets. Companies which use offsetting without reducing their emissions will increasingly be accused of using carbon neutrality as a public relations exercise.
Climate Change
Climate change refers to the variation in the Earth’s global climate, these changes can occur as a result of processes internal to the earth, external forces (e.g. variations in sunlight intensity)or human activity.
Variations that occur within the earth’s climate include the percentage of advancing glaciers (this is one of the most sensitive indicators of climate change) and ocean variability.
The non-climate factors that drive climate change include greenhouse gases (studies have found this to be the primary source of global warming), plate tectonics, solar variation, orbital variation and finally volcanism.
The largest anthropogenic factor contributing to climate change is the increase in CO2 levels due to emissions from fossil fuel combustion; it is known that CO2 levels are substantially higher now than they have been at any point in the last 800 years; this along with rising methane levels is anticipated to cause an increase of 1.4 – 5.6 degrees centigrade between 1990 and 2100. Other human influences include aerosols, cement manufacture and land use.
A number of techniques are used which provide evidence for climate change, for example pollen analysis, beetles, glacial geology and historical methods.
Global Warming
Global warming is the increase in the average temperature of the Earth’s near-surface air and oceans in recent decades and its projected continuation. It is thought that most of the observed increase in globally averaged temperatures since the mid 20th century is likely to be due to the increase in anthropogenic greenhouse gas concentrations. Most national governments have now signed and ratified the Kyoto Protocol, aimed at combating greenhouse gas emissions.
It is hard to give detail of causes of recent warming as this is an area under research; however, the scientific consensus identifies increased levels of greenhouse gases due to human activity as the main influence.
The greenhouse effect is the process by which absorption and emission of infrared radiation by atmospheric gases warms a planet’s atmosphere and surface, without the greenhouse effect the mean temperature of the earth would be an estimated 30 degrees C lower, hence the earth would be uninhabitable. On Earth the major natural greenhouse gases are water vapour, carbon dioxide, methane and ozone. It is expected that within the future CO2 levels will rise due to the ongoing burning of fossil fuels and land use change.
It is thought that variations in solar output, possibly amplified by cloud feedbacks, may have contributed to recent warming.
Peak Oil
Peak oil is a theory devised by M. King Hubbert, concerning the long-term rate of conventional oil depletion. In 1974, he predicted that peak oil would happen in 1995 "if current trends continue".
The theory predicts that the world's oil production will reach a peak and then rapidly decline. Some people believe that we have already reached the peak—i.e. that the world will never again be able to pump as much oil as we are pumping today. Some optimists still believe the peak will not come until 2020.
Demand for crude oil demand has been growing, especially in the developing countries, particularly in India and China, with most of it used for transportation.
Most of the easy-to-extract oil has already been found. However the development of the Canadian tar sands and the success of America's enhanced oil recovery technqiues give some grounds for hope.
But the world is approaching the end of the age of oil, whether the peak is here already or is 12 years away.
Solar Energy
Solar energy from the sun is a source of renewable energy and is in widespread use around the world. It has many benefits, as solar electric generation has the highest power density among all the renewable energy sources. It is also pollution-free, so it doesn't harm the Earth's atmosphere and environment. Also, after the initial set-up costs, the operating costs are very low. However, solar electricity is for the consumer expensive to buy, compared to normal grid electricity.
However, it could be considered expensive compared to the normal grid electricity and the main down-side is that it is obviously unavailiable at night and in poor weather conditions. As well as the poor weather, recently there has been a concern about global dimming, an effect of pollution allowing less sunlight to reach the Earth's surface, which will result in lowering the power density that could be achieved from solar energy.
