Dear Umbra,

I read your column on how best to spend six hours of time a week on environmental issues, but how about the best way to spend limited financial resources on environmental issues? Obviously, giving a gift to Grist would help, but what can I do with my limited pocketbook to make the most difference on a daily basis?

Kent, Wash.

Dearest Chris,

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Save up your money and use it to replace an inefficient but necessary object. We use many large, energy-sucking objects virtually every day (the fridge, the car, the heater, the air conditioning), and the power they consume accounts for a big lump of our individual environmental impact. Moreover, our home and transport are (usually) directly under our control. Improving those items is a great use of your money; upgrading an inefficient, important doohickey will make a difference every day.

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Spend wisely.

Replace a major appliance: the water heater, the refrigerator, and the furnace are the top candidates. Alternatively, you can save up your money a little longer and replace the entire energy system of your home with photovoltaic solar, and/or install an on-demand hot-water heater. Replace your windows with double-paned new ones or insulate your house.

Mayhap you rent. In that case, you might not want to invest heavily in your own home, but you can donate money to a local group that builds energy-efficient low-income houses, or you can put your money into Green Tags — green energy credits — per my last column. Also: Buy sustainably grown foods as often as you can afford.

If you have a car (and truly need it), prioritize getting a better one. Eighty to 90 percent of the impact of vehicle ownership comes from driving (as opposed to manufacturing impacts and the like), so it’s worth changing over to a more efficient model: a hybrid, a low-emission vehicle, or a zero-emission vehicle. Or convert your current car to biodiesel. Of course, if you can, you should jettison the car and join a car-sharing service. That might actually save you money, so you’ll have all the more to put toward organic cauliflower and a better fridge to store it in.

In fact, with many of these investments you may eventually recoup your costs and fill out your pocketbook even more. Then you’ll have to write me again and ask how best to spend your newfound loot.