Accelerating Climate Change?

It's common to hear suggestion that climate change is occuring much faster than originally anticipated by scientists. The Intergovernmental Panel on Climate Change (IPCC), for example, had originally suggested that an ice-free Arctic was anticipated in the 2070-2080 timeframe. Today, it's common to hear it suggested that it could occur during the next decade. Mercer Consulting, in its 2011 assessment of the business materiality of climate change, suggested that the physical impacts of climate change were still decades away (and not material). By 2015 another Mercer report concluded exactly the opposite.

But is climate change actually accelerating? That's a different question, and it can be evaluated in all kinds of ways given the wide range of variables that make up the climate change fingerprint.

Scientists James Hansen is one source of information on this question. His most recent communication is summarized in the graphic below:

The graphic indicates that average global temperature has now diverged from the linear trend suggested by 1970-2015 temperature records.