Scientists tell us we need to reduce our greenhouse gas emissions by 80% or more. What does an 80% reduction look like? How hard will it be? While we work towards comprehensive policy solutions, we can begin reducing global warming pollution now. It's especially important that our large purchases (such as houses and cars) are made with care, since they have a large impact and last a long time.

You can see from the chart of greenhouse emissions, that electricity, transportation, and heat and hot water are the big three items (in the U.S., and in most industrialized nations). But you can also see that residential emissions are only a fraction of the total. To take into account the whole economy, we add consumption and workplace to the equation:

This one's easy: for a few dollars a month, you can reduce your electicity emissions nearly to zero. Buy clean electric power. Do it, now! You can offset the expense by reducing your electric usage through choosing super-efficient appliances and lighting. Net reductions: 100%.

You can instantly reduce your transportation emissions by driving a greener car. For example, if you replace your Subaru Outback (21 mpg) with a Toyota Prius (44 mpg), you reduce your auto emissions by more than 50%. Replacing your Dodge Durango (12 mpg) cuts emissions by 73%, and even replacing a Honda Civic (31 mpg) cuts emissions by 30%. You can trim another 20% or more by driving less and driving smarter. Net reductions: 50-90%.

The average U.S. home has single-pane windows, uninsulated ducts, and no insulation on the water heater. Depending on your home, sealing the building shell can reduce emissions by two-thirds or more. A combination of insulation and conservation measures produces similar savings for water heating. (We need info here about more advanced techniques such as heat pumps and solar water heaters.) Net reductions: 70%.

Everything we buy has a climate impact according to how it is produced. To cut emissions: reduce, reuse, recycle, buy smart. For example, buying 100% post-consumer waste recycled paper cuts emissions by 40%. If in addition you print double-sided instead of single, that adds up to a 70% cut in emissions. Food is very high impact, and it's easy to do a lot better: buy local, buy organic, and eat less meat. Net reductions: 10-90%.

Most workplaces have the same basic issues as individuals (electricity, transportation, and heat & water). Because of their larger energy use, the opportunities for emission reductions and cost savings are even larger. Chemical giant DuPont reduced their emissions by 72% below 1990 levels, and saved $3 billion. Aluminum giant Alcan met a target of 25% below 1990 levels by 2002, and saved millions. Regardless of whether you are the top decision-maker, you can have a personal influence at your workplace. Net reductions: Up to you.