Studies
of past climate changes suggest the land and oceans start releasing more CO2 than they absorb as the planet warms.
By investigating the regional - scale patterns
of past climate variability, the study helps to understand and quantify the processes that cause climate to change.
Warming can be the result of a number of factors, so that the
cause of past climate change is not necessarily implicated in current climate change.
, gather
indicators of past climate conditions, and use biochemical markers to determine the gender and health of the animals that left them behind.
The real concern lies with increase of both carbon dioxide emissions and temperature that can not be predicted using the
models of past climate fluctuations and patterns.
Thus, an estimate of climate sensitivity from past data requires an estimate of the
magnitude of the past climate changes and of the radiative forcings causing the changes.
This provides a transfer function that enables the proxies to be used as predictors
of past climate where proxy data are available in the absence of direct temperature measurements.
Before that, we have scattered, sparse records using instruments of questionable accuracy and «stories»
of past climate warming and cooling periods.
Like marine sediment cores, an ice core provides a vertical
timeline of past climates stored in ice sheets and mountain glaciers.
Ice sheets contain a record of hundreds of thousands of
years of past climate, trapped in the ancient snow.
Confidence in the understanding
of past climate change and changes in orbital forcing is strengthened by the improved ability of current models to simulate past climate conditions.
«USING PALAEO - SCIENCE TO UNDERSTAND ClIMATE CHANGE IN AUSTRALIA... As the geographic coverage, time resolution and detail of palaeo - climate records have improved, it has become possible to identify the
effects of past climate variations on high impact events such as fire....
So in that way, the streaks might serve as indicators of whether ice may have been present at the time of an impact, which could lend insight into reconstructions
of past climate on Mars.
Scientific
analysis of past climates shows that greenhouse gasses, principally CO2, have controlled most ancient climate changes.
Maybe the simpler explanation would have been easier to parse, but the more complex interpretation also points towards the potential for a richer understanding
of past climate dynamics in a range of boundary conditions.
Around the 13th minute in the recording, we shift to discussing how studies
of past climate help build understanding of human - driven climate change and the built - in variability in the climate system that can occasionally produce extraordinarily potent droughts and floods.
«deficiencies in a match of models vs. observations (whether a forecast, or a simulation
of a past climate event) may not be entirely due to problems inherent within the model, but a problem in the experimental setup, or at least a difference in what the modeler was trying to answer.»
«The reconstruction
of past climate reveals that recent warming in the Arctic and in the Northern Hemisphere is highly inconsistent with natural climate variability over the last 2000 years.»
Thomas Crowley (now in Edinburgh) has sent me a note essentially challenging you to develop your own time series [
of past climate patterns](kind of a «put up or shut up» challenge).