When it comes to the massive challenge of cutting carbon emissions, we usually hear about big offenders like fossil fuel intensive industries and dirty coal-fired power stations.

But what about your office or home computer and daily necessities like the "cloud" where so much data is stored these days?

A report from the Institute for Sustainable Futures at UTS Sydney and US tech company Pure Storage says data centres that are now critical to the global economy also create a growing share of emissions.