Worldwide IT spending is set to hit $3.6 trillion by the end of 2012, $100 billion more than last year, according to the most recent projections from the Gartner IT consultancy.

“While the challenges facing global economic growth persist — the eurozone crisis, weaker U.S. recovery, a slowdown in China — the outlook has at least stabilized,” said Richard Gordon, research vice president of Gartner, in a statement “There has been little change in either business confidence or consumer sentiment in the past quarter, so the short-term outlook is for continued caution in IT spending.”

Although significant growth hasn’t occurred in the last year, Gartner projects a major increase in enterprise spending on public cloud services — a jump from $91 billion worldwide last year to $109 billion by the end of 2012. By 2016, Gartner expects enterprise public cloud services spending to hit $207 billion annually.

“Business process as a service (BPaaS) still accounts for the vast majority of cloud spending by enterprises, but other areas such as platform as a service (PaaS), software as a service (SaaS) and infrastructure as a service (IaaS) are growing faster,” Gordon said.

Global spending on IT services is expected to reach $864 billion by the end of this year — up 2.3 percent from last year. Demand for consulting services is expected to remain high because Gartner analysts said “consulting itself is becoming increasingly technology-based with the rise of analytics and big data, having deep implications on the future of consulting services.”

Conversation starter: How do you think money is being spent on IT worldwide? Have spending trends changed from 2011?