CO2 and Climate Change
Posted May 23, 2008on:
We know that carbon dioxide (CO2) is increasing in the atmosphere from human activities such as burning of fossil fuels and deforestation. This increase is one of the major factors in global warming. There is no longer any scientific debate about this. The most recent report by the Intergovernmental Panel on Climate Change has confirmed this.
In 2007 the concentration of CO2 in the atmosphere is approximately 380 parts per million (ppm). Every year human activities add to that. Some scientists and economists in the climate science world such as David Stern and James Hansen have identified a concentration of 450 ppm as a maximum goal for CO2 that may avoid the most significant damage to the Earth’s ecosystems and economies. There is a great deal of uncertainty about the severity of the effects associated with this or any other target level for CO2. We have chosen to use it for this simulation, but we could have set it higher or lower. As you play with the simulation consider how the three scenarios would play out if the bathtub overflowed at a level other than 450 ppm.
Already there is much more CO2 in the atmosphere than at any time in the past 425,000 years. Follow the green line to the right edge of this graph. This is where we are today.