From The Encyclopedia of Earth
(Redirected from Proxy methods)
Proxy measures are measurements of physical, chemical, or biological processes that depend on the weather, and therefore provide an indication of past climates.
Researcher works with a drill that extracts ice cores from glaciers during the 2003 Antarctic Megadunes expedition.
Ted Scambos & Rob Bauer, NSIDC
you will find further resources on this topic in the CAMEL Collection
- Featured Article The Past Million Years
Climate researchers have reliable temperature records from weather stations dating back to about 1850. To study variations in climate that pre-date the advent of weather... More »
- Featured Article Antarctic Ice: An 800,000 Year Record of...
Antarctic Ice: An 800,000 Year Record of Climate Change provides an extraordinary opportunity for scientists to reconstruct climate events of the past. Scientists have recently... More »
Coral bleaching (Proxy Methods) Last Updated on 2014-05-12 12:51:51 Coral bleaching is the reduction of intracellular endosymbionts in living coral reefs either via loss or expulsion of algal pigmentation. The symbiotic relationship between coral and zooxanthellae is directly related to coral bleaching. When this relationship fails, and the zooxanthellae do not receive required inputs from the coral or vice-versa, the zooxanthellae will pale and turn white or be expelled into the water. The resultant decline in coral health from bleaching is deleterious to the coral ecosystem. Chief drivers for coral bleaching are freshwater dilution, change in pH, marine water pollution, increase in sunlight or alteration of seawater temperature. Particularly widespread water pollution is in the form of marine sedimentation from excessive runoff and discharge of untreated sewage. In addition to these abiotic causes of coral bleaching, the phenomenon of overfishing... More » Module: Recent Climate Change Last Updated on 2011-08-04 00:00:00 Summary This is a data-driven module designed to address key questions about the stability of the Earth’s climate in the past and the factors that drive climate change. This information is essential for students who want to study current climate change using NASA data, and interprets this in a correct historical context Goals · Students will investigate how land surface and ocean surface temperatures have changed since 1840. · This exercise asks students to consider two contrasting interpretations of climate change over the last 2,000 years. · Both interpretations use a range of proxy data, but the Loehle data specifically excludes tree ring data. Investigate how the level of CO2 level in the... More » The Past Million Years Last Updated on 2010-12-19 00:00:00 Climate researchers have reliable temperature records from weather stations dating back to about 1850. To study variations in climate that pre-date the advent of weather stations, climatologists rely on reconstructions based on a variety of proxy and direct measurements. Reconstruction of global temperature changes based on 695 boreholes in the Northern Hemisphere. Blue-shaded area indicates the range of values for various reconstructions. After Pollack and Smerdon 2004. The historical temperature record based on ice core proxy measures indicates that Earth’s climate during the past million years has been punctuated with about 8 cycles of relatively long, colder periods (glacials) interrupted by relatively short, warmer periods (interglacials). Each of nine interglacial periods correlates with higher concentrations of the greenhouse gases CH4,... More » Climate Change Research Since World War II Last Updated on 2010-11-09 00:00:00 With the dawn of the nuclear age at the end of World War II, atmospheric and oceanic scientists became preoccupied with other products of human ingenuity, namely radioactive wastes. Anxiety was escalating. Would radioactive carbon dioxide (14CO2), which was generated in the atmosphere during nuclear explosions, dissolve in the oceans and widely contaminate sea life and seafood? Roger Revelle (1909–1991) and Hans Suess (1909–1993) of the Scripps Institution of Oceanography in San Diego, California, analyzed the exchange of 14CO2 between the atmosphere and the oceans. They published a seminal work in 1957 showing that only a thin, upper layer of seawater rapidly exchanged materials with the atmosphere.  These results had broad implications. On the positive side, contamination of sea life from nuclear testing would be highly localized; but on the negative side, the... More » Lecture: Stephen Schneider Climate Change Mitigation and Adaptation Video Last Updated on 2010-10-07 00:00:00 This video is of a lecture that Stephen Schneider presented a number of times. It covers climate change from a risk perspective, discussing the underlying science, uncertainties, and implications of different possible decisions. Here is it captured with many (although not all) of his graphics. It is a well organized, evenly presented lecture that carefully differentiates questions of "what we know" from "what we should do." It presents data and modelling at a level appropriate for undergraduates. More »