If you go a-googling for information on the relative environmental footprints of laptop vs. desktop computers, by far the most common opinion is that laptops are the superior choice. This is based primarily on the indisputable fact that they consume considerably less power than desktop computers, and a little less convincingly on the premise that since they are smaller, they must be better.

On the latter point, a typical summary:

Purchasing a laptop is a smart environmental decision when compared with purchasing a desktop PC. The main reason being that a notebook is smaller than a desktop so there is less of an environmental impact at the time of disposal. The slim size of the flat laptop means that there are smaller and less hazardous parts to be disposed of, such as hard drives, CD/DVD drives, flash card readers, USB ports, etc. The manufacturing of smaller and smaller laptop computers also has an indirect effect, in that the processing plants produce less harmful emissions into the environment.

I am unconvinced, if only on an anecdotal basis. In the last five years, I have gone through three laptops at work, while staying with the same basic desktop at home (although I must confess that my home machine is on its last legs). Laptops are hard to fix, hard to upgrade, and fragile. In comparison to desktops, they are disposable computers, and frequent disposability is not necessarily a sustainable attribute.

Eco PC Review offers some reasons why laptops might not be the environmentally more friendly computing choice.

• Laptops are smaller and lighter... but most of the cost is in manufacturing and most of the manufacturing cost is in the chips and these are similar for laptops and desktops so there may not be much difference.
• Laptops have shorter lives (more fragile, parts more costly and harder to find, uneconomic to replace batteries, impractical to upgrade).
• Laptops have batteries (particularly toxic, waste energy in charge/discharge cycle, waste energy when degraded).
• Laptop components are hard to re-use at end of computer life
• Wherever possible we can buy for longer life and lower power to encourage the industry to change. That's more of an option when buying desktops and desktop components than when buying laptops.

Laptops appear to be well on their way to displacing desktops as the platform of choice for most computer users, so the comparison may well be moot. And perhaps the power savings conferred by laptops outweigh all other considerations. Even so, until laptops are designed so they are easier to fix and easier to reconfigure into new and more powerful machines, that archaic lumbering desktop dinosaur might still boast some environmental selling points.