# Is there any natural phenomenon that can account for the 100 fold faster $CO_2$ rate increase?

"Based on the best historical data that we have available CO2 is probably increasing at a rate at of least 100 times faster than at any time in the last 800,000 years." Pieter Tans lead scientist of NOAA's Global Greenhouse Gas Reference Network.

Peter Tans approved the above verbatim quote to be directly attributed to him. I contacted him by email today on the basis of this material:

“The rate of CO2 growth over the last decade is 100 to 200 times faster than what the Earth experienced during the transition from the last Ice Age,” Pieter Tans, lead scientist of NOAA’s Global Greenhouse Gas Reference Network, said in a statement. “This is a real shock to the atmosphere.”

The annual rate of increase in atmospheric carbon dioxide over the past 60 years is about 100 times faster than previous natural increases, such as those that occurred at the end of the last ice age 11,000-17,000 years ago.

## 1 Answer

Extremely unlikely.

IPCC 5th assessment report: "It is extremely likely that human influence has been the dominant cause of observed warming since 1950, with the level of confidence having increased since the fourth report." (as summarized by Wikipedia)

• I am thinking that none of climate science (or any other science) currently has any even implausible scenarios that could possibly account for this. My view is merely an educated guess on the basis of the two orders of magnitude above the norm. – polcott Oct 8 '19 at 5:31
• And it is absolutely certain that fossil fuel use is the cause of the increase in atmospheric CO$_2$ levels. – Pieter Oct 8 '19 at 6:48
• There is global scientific near-consensus on this issue: Human civilization is causing the $\text{CO}_2$ spike. Any “natural” explanation is a fringe view. – G. Smith Oct 8 '19 at 16:10