Less than 0.1C of Global Warming and much less than 1% of all climate changes.
The total energy generated by Hurricane Harvey's 6 days of fury had nothing to do with humans, but generated more energy than all humans did in all of last year. Nobody really understands how small of a footprint humans really make. The energy that already existed in our atmosphere before humans started using fossil fuels is unfathomable by most people. We've added next to nothing to our immensely energetic system.
If ALL humans (7.3 billion people) were packed like sardines in one spot on Earth, they would take up the space equal to 1/3rd of one cubic mile. 3 times the entire Global population (21.9 billion people) could ALL fit standing on Long Island, New York. Our footprint isn't as big as "Climate Clowns", extreme environmentalists, and BIG GOVERNMENT, Progressive, Liberal Democrats would have you believe. You should try riding in a Hot Air Balloon sometime.
HadSST3 (Global Average Sea Surface Temperature) dropped by an average of -0.17C across all ocean measuring stations (ARGO Floats + various measuring stations) from August 2017 to September 2017. Most of Northern Russia, Greenland, and most of Northern Canada are currently well below 0.
Ocean oscillations (El Nino's and La Nina's) have more to do with surface temperature changes and climate shifts than anything else. Ocean surface makes up 71% of the Earth's overall surface area. Ocean upwelling/down-welling of warm/cold ocean waters have an instantaneous affect on ALL Global surface temperatures including land.
CO2 changes are a very small player in surface temperature variations. VERY small!!!
If CO2 was such a strong greenhouse gas Global temperatures would never fall so fast in the Arctic Region.
It's very cold in much of the Arctic at this time. Some warming is left in the Atlantic and Pacific sides of the Arctic ocean waters, but those will also be overcome by COLD, ocean oscillations.