Sentences with phrase «shows past ice ages»

The paleoclimate record combined with global models shows past ice ages as well as periods even warmer than today.

Not exact matches

Mike's work, like that of previous award winners, is diverse, and includes pioneering and highly cited work in time series analysis (an elegant use of Thomson's multitaper spectral analysis approach to detect spatiotemporal oscillations in the climate record and methods for smoothing temporal data), decadal climate variability (the term «Atlantic Multidecadal Oscillation» or «AMO» was coined by Mike in an interview with Science's Richard Kerr about a paper he had published with Tom Delworth of GFDL showing evidence in both climate model simulations and observational data for a 50 - 70 year oscillation in the climate system; significantly Mike also published work with Kerry Emanuel in 2006 showing that the AMO concept has been overstated as regards its role in 20th century tropical Atlantic SST changes, a finding recently reaffirmed by a study published in Nature), in showing how changes in radiative forcing from volcanoes can affect ENSO, in examining the role of solar variations in explaining the pattern of the Medieval Climate Anomaly and Little Ice Age, the relationship between the climate changes of past centuries and phenomena such as Atlantic tropical cyclones and global sea level, and even a bit of work in atmospheric chemistry (an analysis of beryllium - 7 measurements).

Climate estimates compiled by geochemists from past periods with large changes (e.g. ice ages) show that the climate is a highly non-linear system, with thresholds and sudden dramatic changes.

See e.g. this review paper (Schmidt et al, 2004), where the response of a climate model to estimated past changes in natural forcing due to solar irradiance variations and explosive volcanic eruptions, is shown to match the spatial pattern of reconstructed temperature changes during the «Little Ice Age» (which includes enhanced cooling in certain regions such as Europe).

Seafloor sediments show that during past ice ages, more iron - rich dust blew from chilly, barren landmasses into the oceans, apparently producing more algae in these areas and, presumably, a natural cooling effect.

In the past 400, maybe, but then that means Mann's data only shows that things are warmer then they were during the Little Ice Age.

Their two main results are a confirmation that current global surface temperatures are hotter than at any time in the past 1,400 years (the general «hockey stick» shape, as shown in Figure 1), and that while the Medieval Warm Period (MWP) and Little Ice Age (LIA) are clearly visible events in their reconstruction, they were not globally synchronized events.

64) Michael Mann of Penn State University has actually shown that the Medieval Warm Period and the Little Ice Age did in fact exist, which contrasts with his earlier work which produced the «hockey stick graph» which showed a constant temperature over the past thousand years or so followed by a recent dramatic upturn.

The hockey stick pattern also shows up in the following papers: «Medieval Warm Period, Little Ice Age and 20th century temperature variability from Chesapeake Bay» «Inter-hemispheric temperature variability over the past millennium»

This scenario is actually more in line with recent — past 100,000 years — geological history, which has mostly been Ice Age, and planetary observations, which show the surface temperatures of Mars and Venus have recently risen at about the same rate as Earth's.

Scientific records over the past million years show that as periodic ice ages ended, global average temperatures rose a total of 4 - 7 degrees Celsius over the course of about 5,000 years.

It is also in line with past temperatures showing recovery from cold periods such as the Little Ice Age that we are still recoveing from and we are still not as warm as Roman Warm Period and perhaps approaching the temperatures of the Medieval Warm Period.