What are three types of proxy indicators?
List three types of proxy indicators. Ice cores, ancient sediments, tree rings.
What is an example of a proxy indicator of climate change?
Examples of proxies include stable isotope measurements from ice cores, growth rates in tree rings, species composition of sub-fossil pollen in lake sediment or foraminifera in ocean sediments, temperature profiles of boreholes, and stable isotopes and mineralogy of corals and carbonate speleothems.
What is a proxy indicator?
PROXY INDICATOR Definition & Legal Meaning Also known as an indirect indicator. It is an indirect sign or measure that can approximate or can be representative of a phenomenon without the presence of a direct sign or measure.
What are examples of proxy data?
What Are Proxy Data?Historical Data. Historical documents, which are one type of proxy data, can contain a wealth of information about past climates. ... Corals. ... Pollen. ... Ice Cores. ... Tree Rings. ... Caves. ... Pack Rat Middens. ... Ocean and Lake Sediments.
Which of the following is an example of something used as climate proxy data quizlet?
Which of the following is an example of a proxy data source that can be used by paleoclimatologists? Ice cores, seafloor sediment, and tree rings are all sources of proxy data. Which of the following provides data on changing air temperatures?
What are 2 climate proxies for CO2?
Ice core records provide a high-resolution proxy record of past atmospheres and climates. Scientists combine many types of proxy records to reconstruct environmental conditions from thousands to many millions of years ago. Other examples of proxy evidence include sediments in lakes and oceans, and micro fossils.
Which of the following are proxy indicators that scientists use to determine the Earth's climate history?
Other proxies include ice cores, tree rings, and sediment cores. Chemical proxy records include isotope ratios, elemental analyses, biomarkers, and biogenic silica. Taken together, these proxies extend our knowledge of past climate back hundreds of millions of years into the past.
Which is a proxy indicator of climate change that tells us what tropical oceans were like in the past?
Tree rings are now invaluable proxy indicators, because of their continuity and remarkable precision. In a similar vein, though more recently, the study of annual rings in massive corals is now yielding information regarding marine climates.
What is proxy data?
Paleoclimatologists gather proxy data from natural recorders of climate variability In paleoclimatology, or the study of past climates, scientists use what is known as proxy data to reconstruct past climate conditions. These proxy data are preserved physical characteristics of the environment that can stand in for direct measurements.
What are the underground chambers of Earth's climate?
Caves. Caves and the unique rock formations inside them also serve as proxy data. These underground chambers contain the secrets of Earth’s climate in speleothems— also known as stalactites, stalagmites, and other formations. Speleothems grow over time as water drips down from a cave’s ceiling or pools in its floor and mineral deposits build up in ...
What do ice cores tell us?
Ice cores can tell scientists about temperature, precipitation, atmospheric composition, volcanic activity, and even wind patterns.
What is a climate proxy?
In the study of past climates (" paleoclimatology "), climate proxies are preserved physical characteristics of the past that stand in for direct meteorological measurements and enable scientists to reconstruct the climatic conditions over a longer fraction of the Earth's history . Reliable global records of climate only began in the 1880s, ...
What are some examples of climate proxies?
Examples of proxies include stable isotope measurements from ice cores, growth rates in tree rings, species composition of sub-fossil pollen in lake sediment or foraminifera in ocean sediments, temperature profiles of boreholes, and stable isotopes and mineralogy of corals and carbonate speleothems. In each case, the proxy indicator has been influenced by a particular seasonal climate parameter (e.g., summer temperature or monsoon intensity) at the time in which they were laid down or grew. Interpretation of climate proxies requires a range of ancillary studies, including calibration of the sensitivity of the proxy to climate and cross-verification among proxy indicators.
How do boreholes affect weather?
Boreholes have a great advantage over many other proxies in that no calibration is required: they are actual temperatures. However, they record surface temperature not the near-surface temperature (1.5 meter) used for most "surface" weather observations. These can differ substantially under extreme conditions or when there is surface snow. In practice the effect on borehole temperature is believed to be generally small. A second source of error is contamination of the well by groundwater may affect the temperatures, since the water "carries" more modern temperatures with it. This effect is believed to be generally small, and more applicable at very humid sites. It does not apply in ice cores where the site remains frozen all year.
How are borehole temperatures used?
Borehole temperatures are used as temperature proxies. Since heat transfer through the ground is slow, temperature measurements at a series of different depths down the borehole, adjusted for the effect of rising heat from inside the Earth, can be " inverted " (a mathematical formula to solve matrix equations) to produce a non-unique series of surface temperature values. The solution is "non-unique" because there are multiple possible surface temperature reconstructions that can produce the same borehole temperature profile. In addition, due to physical limitations, the reconstructions are inevitably "smeared", and become more smeared further back in time. When reconstructing temperatures around 1500 AD, boreholes have a temporal resolution of a few centuries. At the start of the 20th Century, their resolution is a few decades; hence they do not provide a useful check on the instrumental temperature record. However, they are broadly comparable. These confirmations have given paleoclimatologists the confidence that they can measure the temperature of 500 years ago. This is concluded by a depth scale of about 492 feet (150 meters) to measure the temperatures from 100 years ago and 1,640 feet (500 meters) to measure the temperatures from 1,000 years ago.
What is the science of determining past climates from trees?
Dendroclimatology is the science of determining past climates from trees, primarily from properties of the annual tree rings. Tree rings are wider when conditions favor growth, narrower when times are difficult. Other properties of the annual rings, such as maximum latewood density (MXD) have been shown to be better proxies than simple ring width. Using tree rings, scientists have estimated many local climates for hundreds to thousands of years previous. By combining multiple tree-ring studies (sometimes with other climate proxy records), scientists have estimated past regional and global climates (see Temperature record of the past 1000 years ).
Why are proxy records used?
Proxies can be combined to produce temperature reconstructions longer than the instrumental temperature record and can inform discussions of global warming and climate history. The geographic distribution of proxy records, just like the instrumental record, is not at all uniform, with more records in the northern hemisphere.
What is the technique used to combine proxy records into an overall hemispheric temperature reconstruction?
The skill of algorithms used to combine proxy records into an overall hemispheric temperature reconstruction may be tested using a technique known as " pseudoproxies ". In this method, output from a climate model is sampled at locations corresponding to the known proxy network, and the temperature record produced is compared to the (known) overall temperature of the model.
What is proxy temperature?
The proxy is in fact something giving an indirect measurement of temperature, via the ecological limits of a plant or animal or a chemical reaction that works differently in different temperatures. But this is also true of the direct measurement.
Is temperature a proxy?
All measurements of temperature are proxies. And whatever you were thinking about some scale of believability or applicability across different kinds of proxies may very well be incorrect.
What are proxy indicators?
These six indicators of community vitality are presented in the following sections using a series of ten images , a technique known as petcha kucha. They are intended firstly to convey the nature of the indicator and secondly to stimulate discussion on that indicator and its meaning for community vitality. But what is an indicator and why are they important? oOften what is measured doesn't count, and what doesn't count is often measured (Einstein).
What is an indicator of sustainability?
The International Institute of Sustainable Development (IISD) in their paper Creating Indicators of Sustainability (2007), provides defines an indicator as: "anything that gives an indication to its reader of a key feature or state of a human or environmental system.
What is critical about the Vitality Project?
A critical point about the analysis of the Vitality Project (and other such decision-support methods) is that, on their own, they do not provide a clear ‘answer’ to questions about ‘which options are best’, or ‘is a project acceptable’. At root, such questions involve value judgements, and no method can provide a clear answer without being based on subjective values. Instead, these methods are best thought of as a framework for ordering preferences and judgements in a consistent and clear way.
Is there a set of indicators that are universally accepted?
Despite the considerable and growing body of work around sustainable development indicators, there is no set of indicators that is universally accepted, nor has influenced the dominant measure, gross domestic product, GDP.
Is the selection of indicators subjective?
the selection of indicators is ultimately subjective. As a result different value judgements and assumptions can lead similar studies to radically different results (Stirling, 1999), yet this subjectivity is not acknowledged; and.
Is an indicator reductionist?
indicators are reductionist and fail to capture the emergent results of the inter-dependency and relationships between characteristic s being measured and as a result there is a loss of complexity (Munda, in-press);
What are climate indicators?
Climate change indicators are used to track and communicate changes in the Earth’s climate. The indicators represent the trend or state of certain societal and environmental conditions in a given area and over a given period. For example, measurements of temperature in the long-term can be used as an indicator to track and allow scientists and ...
What is the emission gap report?
An emission gap report recently released by the UN revealed that humankind was not doing enough to keep the Earth's temperatures from rising to near catastrophic levels. Commitments made by various nations to mitigate the climate crisis are not enough to stave off record-high temperatures. The report calls on all countries across the world to strengthen the commitments made in the Paris Agreement. Scientists have warned that the measures that are currently adopted will not limit global temperature within a safe level. The G20 nations, which emit 78% of the world’s greenhouse gases, need to do more to limit their emissions.
How can glaciers be examined?
It can also be examined through the average change in thickness across the surface of a glacier. The advancing or receding and growing or shrinking of a glacier provides evidence of changes in precipitation and temperature. Scientists have determined that glaciers have been losing their mass since the 1940s.
How does precipitation affect the ecosystem?
The indicator is particularly crucial since precipitation can have wide-ranging effects on the ecosystem and human well being. Snowfall, rainfall , and timing of precipitation can affect the amount of groundwater and surface water available for irrigation, drinking, and industry.
Historical Data
Corals
- Another type of proxy data, coralsbuild their hard skeletons from calcium carbonate—a mineral extracted from seawater. The density of these calcium carbonate skeletons changes as the water temperature, light, and nutrient conditions change, giving coral skeletons formed in the summer a different density than those formed in the winter. The carbonate also contains isotopes of oxyge…
Pollen
- All flowering plants produce pollen grains, which are another type of proxy data. Scientists can use the distinctive shapes of pollen grains to identify the type of plant from which they came. Since pollen grains are well preserved in the sediment layers in the bottom of a pond, lake, or ocean, an analysis of the pollen grains in each layer tells scientists what kinds of plants were gr…
Ice Cores
- Located high in the mountains and near the poles, ice—another type of proxy data—has accumulated from snowfall over many millennia. Scientists drill through the deep ice to collect ice cores, which often have distinct layers in them. These layers contain dust, air bubbles, or isotopes of oxygen, differing from year to year based on the surrounding environment, that can be used t…
Tree Rings
- Trees and their unique ringsalso serve as proxy data. Because climate conditions influence tree growth, patterns in tree-ring widths, density, and isotopic composition reflect variations in climate. In temperate regions where there is a distinct growing season, trees generally produce one ring a year, recording the climate conditions each year. If ...
Caves
- Cavesand the unique rock formations inside them also serve as proxy data. These underground chambers contain the secrets of Earth’s climate in speleothems—also known as stalactites, stalagmites, and other formations. Speleothems grow over time as water drips down from a cave’s ceiling or pools in its floor and mineral deposits build up in thin, shiny layers. Because the …
Pack Rat Middens
- Plant-rich deposits called pack rat middensare another type of proxy data. To produce these middens, pack rats gather plant materials at close range and accumulate them in dry caves and crevices. There, those plant materials and other debris are cemented by large masses of crystallized urine and can be preserved for tens of thousands of years. After collecting, cleaning…
Ocean and Lake Sediments
- Another type of proxy data can be found on the floors of Earth’s oceans and lakes. Billions of tons of sediment accumulate in ocean and lake basins each year, providing a vast amount of information about the environment. Scientists drill cores of the sediments from the basin floors and examine their contents, which include tiny fossils and chemicals, to interpret past climates. …