Best scientific assessment, without man-made impact earth would be gradually cooling now.

[pampango]

Global warming is not just 100% caused by humans. It is 110% man-made.



http://thinkprogress.org/climate/2015/05/28/3662017/jeb-scientists-warming-humans-caused/

How could 110 percent of the warming since 1950 be due to human activity? As Schmidt explained way back in 2009, “Over the last 40 or so years, natural drivers would have caused cooling.”

These cooling natural drivers include:

In recent decades, volcanoes have released particles that partially block the sun and cool the planet slightly.
Only recently have we come off “the deepest solar minimum in nearly a century,” which also cooled the planet slightly.
The underlying long-term trend — driven largely by orbital changes — had been cooling (see Human-caused Arctic warming overtakes 2,000 years of natural cooling, “seminal” study finds).

In short, “human factors are most likely responsible for all the warming we’ve seen and then some (110%),” as environmental scientist Dana Nuccitelli put it in the UK Guardian

[DirkGently]

1. Imagine if we were actually in a "natural warming trend"

as climate science deniers like to claim.

We'd be having this conversation at the bottom of the ocean.