Without doubt releasing billions of tonnes of stored fossil carbon into the atmosphere must change the ratio of gases present over time.
The biggest problem is acidification of the oceans - CO2 desolves in water forming carbonic acid. Up until now the sea has been a sink for fossil carbon emissions but it is possibly near the point of saturation.
We have had higher levels of atmospheric CO2 before but these were reached gradually, this time perhaps the increase is happening at a rate faster than adaptation can keep pace with ?
As we go up in altitude or south in latitude it is cooler so perhaps living at 500 mtrs asl or shifting to bluff is the answer ?
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