EMPIRICAL CLIMATE SENSITIVITY IN THE MAUNA LOA ERA: 1959-2017 (original) (raw)

VALIDITY AND RELIABILITY OF THE CHARNEY CLIMATE SENSITIVITY FUNCTION

Monthly means of Mauna Loa atmospheric CO2 concentrations are used in conjunction with surface temperature data from two different sources for the sample period 1979-2017 to test the validity and reliability of the empirical Charney climate sensitivity function. Detrended correlation analysis of temperature in five global regions from two different sources did not show that surface temperature is responsive to changes in the logarithm of atmospheric CO2 at an annual time scale. Correlations observed in source data are thus shown to be spurious. We conclude that the empirical Charney Climate Sensitivity function is specious because it is based on a spurious correlation.

Sensitivity of inter-annual variation of CO2 seasonal cycle at Mauna Loa to atmospheric transport

Tellus Series B-chemical and Physical Meteorology, 2003

Origins of the inter-annual variations of the Mauna Loa atmospheric CO2 seasonal cycle related to atmospheric transport were examined using a global atmospheric transport model with prescribed land biota CO2 source functions at 11 land sections. On average, the seasonal variation of atmospheric CO2 at Mauna Loa is influenced mostly by the Siberian CO2 flux, followed by temperate Asia and North America. The inter-annual variability of the seasonal cycle is caused mainly by the inter-annual variation in the transport of the Siberian signal to Mauna Loa. The characteristics of the simulated seasonal cycle and its inter-annual variability at Mauna Loa are found to be sensitive to the quality of the wind data used to drive the transport model. Implication of this result is that for studying a long-term variations of atmospheric transport a meteorological data set for driving an atmospheric transport model should be obtained from the same production procedure.

Lessons on Climate Sensitivity From Past Climate Changes

2016

Authors: von der Heydt A. S., Dijkstra H. A., van de Wal R. S. W., Caballero R., Crucifix M., Foster G. L., Huber M., Kohler P., Rohling E., Valdes P. J., Ashwin P., Bathiany S., Berends T., van Bree L. G. J., Ditlevsen P., Ghil M., Haywood A., Katzav J., Lohmann G., Lohmann J., Lucarini V., Marzocchi A., Palike H., Ruvalcaba Baroni I., Simon D., Sluijs A., Stap L. B., Tantet A., Viebahn J., Ziegler M. Over the last decade, our understanding of climate sensitivity has improved considerably. The climate system shows variability on many timescales, is subject to non-stationary forcing and it is most likely out of equilibrium with the changes in the radiative forcing. Slow and fast feedbacks complicate the interpretation of geological records as feedback strengths vary over time. In the geological past, the forcing timescales were different than at present, suggesting that the response may have behaved differently. Do these insights constrain the climate sensitivity relevant for the present day? In this paper, we review the progress made in theoretical understanding of climate sensitivity and on the estimation of climate sensitivity from proxy records. Particular focus lies on the background state dependence of feedback processes and on the impact of tipping points on the climate system. We suggest how to further use palaeo data to advance our understanding of the currently ongoing climate change.