The World Resources Institute has produced an excellent flowchart showing the activities that generate greenhouse gas emissions and the magnitude of those flows in terms of CO2 equivalence.
The data is from 2000, but I would expect the relative magnitudes to be reasonably similar now. This graphic provides a powerful and intuitive view into where the problem lies, and suggests areas where the greatest improvements could be made.
Author: Milan
In the spring of 2005, I graduated from the University of British Columbia with a degree in International Relations and a general focus in the area of environmental politics. In the fall of 2005, I began reading for an M.Phil in IR at Wadham College, Oxford.
Outside school, I am very interested in photography, writing, and the outdoors. I am writing this blog to keep in touch with friends and family around the world, provide a more personal view of graduate student life in Oxford, and pass on some lessons I've learned here.
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A nice graphic, indeed. It looks very biological.
Two things about this graph surprised me: one was the massive effect of deforestation. Clearly this should be one of the most immediate and major concerns. The second is agriculture. I was completely unaware of the scale of outgassing of nitrous oxide from soils. I also seriously overestimated the carbon emissions of industrial agriculture. Given the large share of emissions that transportation is responsible for, I wonder what share of that is used transporting food.
Climate forcing from the transport sectors
Although the transport sector is responsible for a large and growing share of global emissions affecting climate, its overall contribution has not been quantified. We provide a comprehensive analysis of radiative forcing from the road transport, shipping, aviation, and rail subsectors, using both past- and forward-looking perspectives. We find that, since preindustrial times, transport has contributed {approx}15% and 31% of the total man-made CO2 and O3 forcing, respectively. A forward-looking perspective shows that the current emissions from transport are responsible for {approx}16% of the integrated net forcing over 100 years from all current man-made emissions. The dominating contributor to positive forcing (warming) is CO2, followed by tropospheric O3. By subsector, road transport is the largest contributor to warming. The transport sector also exerts cooling through reduced methane lifetime and atmospheric aerosol effects. Shipping causes net cooling, except on future time scales of several centuries. Much of the forcing from transport comes from emissions not covered by the Kyoto Protocol.