According to this study (2.15mb PDF), produced by the Commission for Environmental Cooperation, sustainable construction could be a fast, cheap path to cutting global carbon emissions. The study evaluated the impact of North American buildings on the environment, and came up with the following:

In Canada, buildings are responsible for:

• 33 % of all energy used;
• 50 % of natural resources consumed;
• 12 % of non-industrial water used;
• 25 % of landfill waste generated;
• 10 % of airborne particulates produced; and
• 35 % of greenhouse gases emitted.

In Mexico, buildings are responsible for:

• 17 % of all energy used;
• 25 % of all electricity used;
• 20 % of all carbon dioxide emissions;
• 5 % of potable water consumption; and
• 20 % of the waste generated.

In the United States, buildings account for:

• 40 % of total energy use;
• 12 % of the total water consumption;
• 68 % of total electricity consumption;
• 38 % of total carbon dioxide emissions; and
• 60 % of total non-industrial waste generation.

According to this study, and studies by Vattenfall, insulation, water heating, and lighting system improvement in buildings are three of the top five solutions to abate CO2 at marginal cost. The study shows that a wholesale change in the building industry could reduce North American CO2 emissions to pre-1990 levels.

What’s the bottom line? Simple energy improvements in new and existing buildings could reduce carbon emissions by as much as the entire transportation emissions in the United States in 2000.

So, why is it that building buildings to at least Energy Star levels isn’t mandatory building code – everywhere?

Someone, please tell me why.

I’m going to take a guess until you respond, though – that these improvements aren’t a reality because, also according to the CEC study:

“A survey released in August 2007 by the World Business Council on Sustainable Development found that key players in the real estate industry overstated the cost of green building by an average of 300 percent, estimating the cost to be 17 percent above conventional construction, more than triple the cost estimated by the study’s authors of 5 percent.” -- cec.org, 2.15mb PDF (emphasis added)