It's difficult to find global data for the last few years, but there are several studies suggesting about 5% for data centers. Given that networking is the major source of consumption with 40+% of IT consumption, this would indicate more than 10% today.
Edit: A few years ago, when Google still wasn't evil, they published an article on why Mercator projection was chosen for Google Maps. The estimated savings regarding all the global views per year were impressive!
First of all, Electricity consumption != Energy consumption
So although very important, Electricity is around 35-40% of the global emissions. https://www.vox.com/2015/3/31/8319859/electricity-vs-energy
Second, the best number right now for all the ICT sector is around 5% in electricity, which is equivalent to 2% in emissions. One single guy in a super fatalistic scenario is projecting a worst case situation for 2020 of 20% of electricity which it we assume the same distribution as today it would be equivalent to 8% of the world emissions, a 4X growth in 10 years. Even that is not going to happen.
https://www.nature.com/articles/d41586-018-06610-y
> Data centres contribute around 0.3% to overall carbon emissions, whereas the information and communications technology (ICT) ecosystem as a whole — under a sweeping definition that encompasses personal digital devices, mobile-phone networks and televisions — accounts for more than 2% of global emissions. That puts ICT’s carbon footprint on a par with the aviation industry’s emissions from fuel. What could happen in the future is hard to forecast. But one of the most worrying models predicts that electricity use by ICT could exceed 20% of the global total by the time a child born today reaches her teens, with data centres using more than one-third of that (see ‘Energy forecast’)1. If the computationally intensive cryptocurrency Bitcoin continues to grow, a sharp rise in energy demand could come sooner rather than later
There's very different data, as well, e.g., from a SIA/SRC report:
> For this benchmark energy per bit, computing will not be sustainable by 2040, when the energy required for computing will exceed the estimated world’s energy production. Thus, radical improvement in the energy efficiency of computing is needed.
https://www.semiconductors.org/wp-content/uploads/2018/06/RI...
One way to tackle this is reducing the number of bits moved.
I would like to request a serious citation on that, it is an absurdly high number and 2030 is 10 years away.