Beyond mean climate change: Using paleoclimate archives to better constrain climate variability
In order to adapt to the changing climate, not only changes in the mean
climate state but also the magnitude and change of climate variability
have to be known.
Whereas variations on weather to interannual time-scales in the climate
system are well documented and current climate models are generally able
to simulate them realistically, much less is known about the amplitude
and the mechanisms of natural climate variability on longer time-scales,
e.g. between decades and centuries. Estimating that variability is the
basis for the detection and attribution of the anthropogenic component,
determines the range of plausible future climate changes and also
provides information about the time-scales of the earth system components.
Paleo-climate archives (‘proxies’) such as ice-core and marine sediment
records can provide long records of the past climate evolution and thus
provide the needed information about climate variability. However, they
are sparse, inherently noisy and at times provide contradictory evidence.
This hampered quantitative reconstructions off climate variability and
systematic testing of the variability simulated from climate models.
In the last years, several advances have been made to better extract
climate variability estimates from climate archives. These include a
better understanding how climate archives record the climate signal
based on lab and field studies, proxy system models simulating this
recording process as well as novel statistical techniques tailored to
separate climate from noise components.
Based on these advances we were able to improve our understanding of the
present climate variability as well as to provide first estimates how
climate variability responds to a changing climate.
In this presentation, I will discuss recent advances in the toolbox of
teasing out climate variability from marine, lake and ice-core based
climate archives and show recent results quantifying interannual to
millenial temperature variability on the ocean and on land.