A proxy climate indicator is a local record that is interpreted using physical or biophysical principles to represent some combination of climate-related variations back in time.
What are the four types of proxy climate indicators?
There are four main types of proxy climate indicator, for example, which are historical (oral or written records), biological (records of faunal and floral growth and distribution), geological (terrestrial deposits and features, and marine ocean sediment cores), and glaciological (ice cores). Subjects: Science and technology — Environmental Science
What is a proxy indicator?
An indicator that is used to provide proxy data. There are four main types of proxy climate indicator, for example, which are historical (oral or written records), biological (records of faunal and floral growth and distribution), geological (terrestrial deposits and features, and marine ocean sediment cores), and glaciological (ice cores).
What is a climate proxy?
What is a climate proxy? The Earth's climate has changed greatly through geologic time, and even in recent centuries. The study of past climates is called paleoclimatology ("paleo-" means "early" or "past"). Something that represents something else indirectly is called a proxy. In some elections, a voter can choose another person to cast the vote.
How important is understanding the environment when interpreting proxy data?
On a local scale, for example, “the relationship between proxies and their environments may differ in different systems, so understanding the system you are working in is critical to accurately interpreting proxy data”, she says.
What are some examples of proxy indicators?
There are four main types of proxy climate indicator, for example, which are historical (oral or written records), biological (records of faunal and floral growth and distribution), geological (terrestrial deposits and features, and marine ocean sediment cores), and glaciological (ice cores).
What can proxy indicators tell us about?
Proxy data can provide insights on a range of climate-relevant changes. These include sudden events – such as volcanic eruptions or floods – and gradual, long-term trends – such as warming and cooling, drought, changing sea levels, cyclone patterns, monsoon seasons, fluctuating atmospheric CO2 or thinning ice sheets.
Why are proxy indicators important to the study of climate?
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.
Which of the following is an example of a proxy indicator of climate change?
Which of the following is an example of a proxy indicator of climate change? A chemical signatures from ancient marine biota or ice used to estimate temperatures for the past 800,000 years.
Are climate proxies accurate?
Since reliable modern records of climate only began in the 1880s, proxies provide a means for scientists to determine climatic patterns before record-keeping began, though it appears that the the distribution of proxy records for global average temperatures, just like the instrumental record, is strongly non-uniform, ...
What is the most important indicator of climate change?
One widely used indicator in climate science is the change in the global average temperature of the lower atmosphere.
What is the greatest indicator of climate?
1. Air temperatures over land are increasing. It's clear that weather stations on land show average air temperatures are rising, and as a result, the frequency and severity of droughts and heat waves are increasing.
Is pollen a climate proxy?
Pollen was one of the first climate proxies used by scientists for climate reconstructions. Vegetation produces pollen every year. Each plant genus produces pollen with a distinct shape, size, and surface texture. The pollen travels through the surrounding area and may be washed or blown into lakes and bogs.
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 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?
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.
How do paleoclimatologists use leaf teeth?
Paleoclimatologists often use leaf teeth to reconstruct mean annual temperature in past climates, and they use leaf size as a proxy for mean annual precipitation. In the case of mean annual precipitation reconstructions, some researchers believe taphonomic processes cause smaller leaves to be overrepresented in the fossil record, which can bias reconstructions. However, recent research suggests that the leaf fossil record may not be significantly biased toward small leaves. New approaches retrieve data such as CO#N#2 content of past atmospheres from fossil leaf stomata and isotope composition, measuring cellular CO 2 concentrations. A 2014 study was able to use the carbon-13 isotope ratios to estimate the CO 2 amounts of the past 400 million years, the findings hint at a higher climate sensitivity to CO 2 concentrations.
What are some examples of 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 ...
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 is a glycerol dialkyl glycerol tetraether?
A novel climate proxy obtained from peat ( lignites, ancient peat) and soils , membrane lipids known as glycerol dialkyl glycerol tetraether (GDGT) is helping to study paleo environmental factors, which control relative distribution of differently branched GDGT isomers. The study authors note, "These branched membrane lipids are produced by an as yet unknown group of anaerobic soil bacteria." As of 2018#N#[update]#N#, there is a decade of research demonstrating that in mineral soils the degree of methylation of bacteria (brGDGTs), helps to calculate mean annual air temperatures. This proxy method was used to study the climate of the early Palaeogene, at the Cretaceous–Paleogene boundary, and researchers found that annual air temperatures, over land and at mid-latitude, averaged about 23–29 °C (± 4.7 °C), which is 5–10 °C higher than most previous findings.
What is tree ring?
Tree rings seen in a cross section of a trunk of a tree. Main article: Dendroclimatology. 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.
What are the gases in ice?
Air bubbles in the ice, which contain trapped greenhouse gases such as carbon dioxide and methane, are also helpful in determining past climate changes. From 1989 to 1992, the European Greenland Ice Core Drilling Project drilled in central Greenland at coordinates 72° 35' N, 37° 38' W.
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 is proxy data?
Proxy data, therefore, is information that is a substitute for direct observations of the Earth’s climate.
What are some examples of physical proxy?
Physical. Finally, for the last of the three categories, an example of a physical proxy is marine and lake sediments. Each year, billions of tonnes of sediment are washed into lakes and seas around the world. These sediments build up over time, adding layer upon layer with each year that passes.
How have proxy records helped scientists?
For example, proxy records of both greenhouse concentrations and temperatures over the past 800,000 years have helped scientists understand the drivers of ice age cycles – including the critical role of CO2 in the process.
How are fossilised remains used to infer climate?
The fossilised remains of insects can be used to infer past climate. Grains of pollen from flowering plants are preserved in lake sediments, and can be used to infer changes in both vegetation and climate. The amount of charcoal in lake sediments can be used to infer changes in fire frequency and intensity.
What is the baseline for anomalies plotted with respect to a 1880-1899 baseline?
Anomalies plotted with respect to a 1880-1899 baseline to show warming since the preindustrial period. This means that scientists have a robust account of how global temperatures have changed over the past century and a half, or so. But, of course, the Earth is much older than that.
Where is proxy data found?
From the ice sheets of Antarctica and the seabed of the Atlantic, to the boreal forests of Europe and corals of southeast Asia, proxy data is found across the Earth’s land and ocean. NOAA holds an archive of more than 10,000 proxy datasets covering more than a dozen categories.
Where are the clues to past climate scattered?
These clues to past climate are scattered across the Earth, from the layers of vast ice sheets and sediments at the bottom of lakes to rings of tree growth and towering stalagmites in caves. (See later section for more on the different sources of proxy data.) Stalagmites in Han-sur-Lesse caverns, Belgium.
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 analysis of 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’.
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 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.
What instrument is used to collect wood cores from living trees?
Scientists use an instrument called an increment borer to collect thin cores of wood from living trees, and this causes no harm to the tree. Researcher collecting tree core in Smith Woods. Photo: Carol Griggs. Dig deeper into climate change and energy on the Learn More page of this exhibit.
How to tell if a tree is old?
You can tell the age of a tree by counting its rings. Tree rings also record the climate during the time when the tree grew. When the climate is warm and wet, trees tend to grow more rapidly, and the spacing between rings is wider than during cold, dry years.
What do the arrows on fossil leaves mean?
The arrows point to annual growth bands. Photo: Linda Ivany. Fossil leaf edges tell us about temperature. In warmer climates, a higher proportion of leaves tend to have smooth edges. Conversely, in cooler climates, most leaves have toothed edges. We can use the relative proportions to estimate ancient temperatures.
Where is the rock core located?
The 3D image below is of a rock core from the Lockport Dolostone near Buffalo, New York. It is from the Middle Silurian Period, about 430 million years ago. Click on the image and move your pointer around to view the rock core from different perspectives. Scroll to zoom in and out.
Where does the climate information in the cores come from?
Most of the climate information within the cores comes from the shells of single-celled plankton called foraminifera that sank to the ocean bottom after death. The ratio of two varieties (isotopes) of oxygen atoms in their shells is controlled by water temperature.
Where does glacial ice form?
Glacial ice forms from layer upon layer of seasonal snow. Ice cores are long cylinders of ice that have been drilled in the Antarctic and Greenland ice sheets, as well as some mountain glaciers. Ice cores hold records of past temperatures and atmospheric CO₂, which scientists can extract from chemical analysis of the ice itself, ...
Do clam shells preserve the climate?
Clam shells preserve the climate. Clam shells have annual growth bands, and the spacing between the bands depends on the environment during the time when the growth bands formed. Chemical analysis of clam shells can reveal the water temperature during the winters and summers when ...
Historical Data
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, and proxies provide the only means for scientists to deter…
Corals
Pollen
Ice Cores
Tree Rings
Caves
Pack Rat Middens
- 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…
Ocean and Lake Sediments
- 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…