In some of the analytical work.... There is actually very interesting literature around pathways. This tool is being used by developed countries and developing countries such as Mexico, which has articulated a long-term emissions reduction pathway.
I think there are a variety of very practical considerations. You have to look at the sources of emissions and you have to address each of those. To use one example, a very large percentage of global greenhouse gas emissions arises from the generation of electricity, the power sector. It's about 60% of total emissions. In many countries the most cost-effective thing you can do is to promote fuel switching in your power sector. So you switch from coal, which is broadly used globally, to either less carbon-intensive fossil fuels or, even better, to hydro, nuclear, wind, and other renewable sources of energy.
In Canada, about 75% of our electricity is produced without emitting greenhouse gases. About 60% is large hydro, about 14% comes from nuclear, and 1% is from other renewables. The government has made a policy commitment to increase that to 90% by 2020.
When you think about that in relation to a pathway, you then have to address what that means. In Canada's case that will mean the retirement of a number of coal-fired power plants, as is being planned here in Ontario, as well as identifying the other options for fuel switching, whether it is to bring new hydro online, promote the growth of renewables or other such measures, as well as demand management.
I think one of the critical issues going forward globally is to ensure that in developing countries, as they are building their energy systems to respond to growing demand from growing economies and growing populations, we do not lock in highly greenhouse-gas-intensive infrastructure, because that infrastructure would likely still be with us in 2050.
So that's one example of how thinking of pathways can help to inform policy decisions.