In Kurt Vonnegut’s 1969 masterpiece Slaughterhouse-Five, one of the most memorable passages occurs when the novel’s protagonist Billy Pilgrim watches a film about US bombers in the Second World War in reverse. The fires on the ground are doused as the bombs are lifted back up into the bellies of the planes. The bombers fly backwards to their airfields, the bombs are returned to the US where factories “were operating night and day, dismantling the cylinders, separating the dangerous contents into minerals. Touchingly, it was mainly women who did this work. The minerals were then shipped to specialists in remote areas. It was their business to put them into the ground, to hide them cleverly so they would never hurt anybody ever again.”

Barely two weeks into 2020, Microsoft made a bold pledge to become carbon negative by 2030. In a blog post on 16 January, company president Brad Smith outlined a number of measures Microsoft intended to take to achieve its goal. He also revealed that the software giant had set a target of 2050 to “remove from the environment all the carbon the company has emitted either directly or by electrical consumption since it was founded in 1975.”

But there’s something about that statement which brings to mind the reversing bombers and their deadly payload returned to the earth from which they had been mined. While removing the carbon directly emitted or through electrical consumption by Microsoft sounds impressive, it doesn’t truly reflect the carbon emissions which Microsoft has enabled through the use of its technology. In uncharitable terms, it’s a bit like accepting responsibility for mining the minerals that formed the bombs but washing your hands of everything that people did with them afterwards.

Microsoft software drives much of the computer industry. Hardware manufacturers build systems with more powerful processors, graphics cards and bigger hard drives to run that software. Businesses, organisations and people are often forced to replace their computers and devices if they want to run the company’s latest operating systems and applications. Often, there comes a point where they have no choice because Microsoft stops supporting its older software. And while it’s true that the new systems may offer power and energy saving improvements on their predecessors, what about the environmental costs associated with the development, manufacture and delivery of those new systems?

Which just goes to show that sweeping statements about sustainability might sound very impressive but they often overlook the fact that so much of what a manufacturer, supplier, business or person might do is just one part of the overall environmental cost of a product or service. Trying to put them all together so that we can comprehend and appreciate there are so many links in the chain and we are responsible for all of them is much more difficult. But if we don't, then, to continue with the Slaughterhouse Five analogy, the bombers will still fly and the bombs will still fall.