The Climate System with Human Actors – A Time Scale Perspective

The IPCC now assess the global mean temperature increase since the latter part of the nineteenth century to be entirely anthropogenically in its origin. Along this development, decision-makers engaged with mitigating climate change are looking closely to the findings by the IPCC to achieve the goals of the Paris Agreement. This close encounter between decision-makers and the scientific community give rise to both scientific and public discussions that take their point of departure in the perception of the findings or lack thereof by the IPCC. Related to this, certain time scales emerge that reflect scientific progress as well as the frequency of IPCC updates. Here I report on these processes and how it implies intrinsic time scales to this interaction between the scientific and decision-making communities, emerging to be about 6 and 30 years.