The 800 year lag in CO2 after temperature – graphed
Carbon dioxide follows temperature in the Vostok Ice Cores
In the 1990’s the classic Vostok ice core graph showed temperature and carbon in lock step moving at the same time. It made sense to worry that carbon dioxide did influence temperature. But by 2003 new data came in and it was clear that carbon lagged behind temperature. The link was back to front. Temperatures appear to control carbon, and while it’s possible that carbon also influences temperature these ice cores don’t show much evidence of that. After temperatures rise, on average it takes 800 years before carbon starts to move. The extraordinary thing is that the lag is well accepted by climatologists, yet virtually unknown outside these circles. The fact that temperature leads is not controversial. It’s relevance is debated.
It’s impossible to see a lag of centuries on a graph that covers half a million years so I have regraphed the data from the original sources, CO2 Data here and Temperature data here (Petit 1999), and scaled the graphs out so that the lag is visible to the naked eye. What follows is the complete set from 420,000 years to 5,000 years before the present.
NOTE 1: What really matters here are the turning points, not the absolute levels.
NOTE 2: The carbon data is unfortunately far less detailed than the temperature data.
Beware of making conclusions about turning points
or lags when only one single point may be involved.
NOTE 3: The graph which illustrates the lag the best, and also has the most carbon data
is 150,000-100,000 years ago.
https://joannenova.com.au/global-warming-2/ice-core-graph/
