To order the activities from greatest to least impact in terms of reducing fossil fuel consumption, we should consider which options use the least amount of fossil fuels.
- Walk to work - This has the greatest impact as it involves no fossil fuel consumption.
- Carpool to work - This reduces the number of vehicles on the road, lowering total fossil fuel usage.
- Drive an electric car to work - While electric cars generally have a lower environmental impact than gasoline vehicles, they still require energy that may come from fossil fuels, depending on the power source.
- Drive alone to work - This has the least impact as it consumes the most fossil fuels compared to the other options.
Therefore, the order from greatest to least impact to reduce fossil fuel consumption is:
Walk to work, carpool to work, drive an electric car to work, drive alone to work.