Global adspend will rise by 4.5% this year, and 4.2% next year, according to the report.
It said: "With the exception of newspapers and magazines, all major media channels are expected to record adspend growth this year and next.
"However, the two largest, TV (+1.1%) and internet (+13.0%) are forecast to see their growth rate ease during 2017. The same is true for mobile, though it is still set to be the fastest-growing ad channel over the period."
Mobile adspend is expected to grow by 47.1% this year, and 34.2% next year.
For magazines and newspapers, the decline is predicted to ease next year. According to the report adspend will be -5.9% this year, and -4.5% in 2017 for magazines. Newspapers will see a decline of 8% this year and a 6.1% drop next year.
The report pulls together adspend predictions from a number of sources including Carat, eMarketer, GroupM, Magna Global, Nikkei Advertising Research Institute, Pitch-Madison, Pivotal Research Group and Zenith.
James McDonald, senior research analyst at Warc, said: "We have identified a common trend among more mature markets whereby increasing investment in internet - particularly mobile - ad formats is driving headline growth.
"Applying consensus trends to Warc's adspend data shows that mobile will grow to be the world's third-largest ad channel by the end of 2016."