Related Experiment Video
Updated: May 1, 2026
08:39
Simulating Temperature in a Soil Incubation Experiment
Published on: October 28, 2022
5.1K
Temperature trends over the past five centuries reconstructed from borehole temperatures
1Department of Geological Sciences, The University of Michigan, Ann Arbor 48109-1063, USA.
Nature
|February 29, 2000
Summary
Subsurface temperature data from 616 boreholes reveal that Earth has warmed approximately 1 K over the past 500 years. This borehole data provides a crucial long-term climate perspective, complementing traditional temperature proxies and instrumental records.
Area of Science:
- Paleoclimatology
- Earth Science
- Climate Change Research
Background:
- Accurate assessment of Earth's climate variability and anthropogenic influence requires long-term temperature reconstructions.
- Instrumental records are limited to the past 150 years, necessitating reliance on climate proxy records.
- Traditional climate proxies have inherent strengths and limitations in capturing climatic variability.
Purpose of the Study:
- To reconstruct century-long temperature trends over the past 500 years using subsurface temperature data.
- To provide an independent archive of past surface temperature changes complementary to instrumental and proxy records.
- To assess global, hemispheric, and continental temperature changes over the last five centuries.
Main Methods:
- Analysis of present-day subsurface temperatures from 616 boreholes across all continents except Antarctica.
- Reconstruction of past temperature trends based on heat conduction into the Earth.
- Comparison of borehole-derived trends with instrumental records and conventional climate proxies.
Main Results:
- Confirmed the significant warming observed in the twentieth century through instrumental records.
- Estimated a cumulative temperature increase of approximately 1 K over the past 500 years.
- Indicated that borehole-derived cumulative warming exceeds recent estimates from conventional climate proxies.
Conclusions:
- Subsurface temperature data from boreholes offer a valuable method for detecting long-term climate trends.
- Borehole data provide a complementary perspective to conventional climate proxies and instrumental records.
- Further investigation is needed to reconcile differences between borehole data and other climate reconstruction approaches for a comprehensive understanding of past warming.
Related Concept Videos
01:50Global Climate Change
24.4K
Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global temperatures is well outside of the Earth’s cyclic norms, and evidence for human-caused global climate change is compelling. Paleoclimatology, the study of ancient climate conditions, provides ample evidence for human-caused global climate change by comparing recent conditions with those in the past.
24.4K
01:14Temperature Measurement Sites
4.3K
A thermometer measures body temperature. The common sites for measuring body temperature are the oral cavity, axillary region, temporal artery, and skin surface, such as the forehead, abdomen, and axilla. True core body temperature is assessed in the rectum, tympanic membrane, pulmonary artery, esophagus, and urinary bladder.
Oral: When assessing oral temperature, the thermometer tip should be placed under the tongue in the posterior sublingual pocket. It offers accurate readings and can be...
Oral: When assessing oral temperature, the thermometer tip should be placed under the tongue in the posterior sublingual pocket. It offers accurate readings and can be...
4.3K
01:27Assessing Body Temperature - Rectal
16.5K
Rectal temperature measurement is considered the most precise method for assessing core body temperature and typically registers higher than oral temperature. For adults, the rectal thermometer should be inserted 1 to 1.5 inches into the rectum to obtain the most accurate reading.
Follow these steps for rectal temperature assessment:
Step 1: Perform hand hygiene and don clean gloves to prevent cross-infection.
Step 2: Position the patient in a side-lying position to better visualize the rectal...
Follow these steps for rectal temperature assessment:
Step 1: Perform hand hygiene and don clean gloves to prevent cross-infection.
Step 2: Position the patient in a side-lying position to better visualize the rectal...
16.5K
01:19Assessing Body Temperature - Temporal Artery
1.6K
Here is a stepwise guide to assessing the body temperature at the temporal artery using a temporal artery thermometer
Step 1: Perform hand hygiene and don a fresh pair of gloves to prevent cross-infection and ensure patient safety.
Step 2: Explain the procedure to the patient to establish trust. Clear communication establishes trust with the patient, ensures they understand what to expect, promotes cooperation, and enhances comfort during the procedure.
Step 3: Assess the patient's...
Step 1: Perform hand hygiene and don a fresh pair of gloves to prevent cross-infection and ensure patient safety.
Step 2: Explain the procedure to the patient to establish trust. Clear communication establishes trust with the patient, ensures they understand what to expect, promotes cooperation, and enhances comfort during the procedure.
Step 3: Assess the patient's...
1.6K
01:22Thermometers and Temperature Scales
6.1K
Any physical property that depends consistently and reproducibly on temperature can be used as the basis of a thermometer. For example, volume increases with temperature for most substances. This property is the basis for the common alcohol thermometer and the original mercury thermometers. Other properties used to measure temperature include electrical resistance, color, and the emission of infrared radiation.
As many physical properties depend on temperature, the variety of thermometers is...
As many physical properties depend on temperature, the variety of thermometers is...
6.1K
01:21Hyperthermophilic Bacteria
792
Domain Bacteria includes some unique hyperthermophilic species. They exhibit remarkable adaptations that enable survival in extreme environments.Thermotoga species are rod-shaped, gram-negative, non-sporulating hyperthermophiles that form a sheath-like envelope called a toga. They ferment sugars or starch, producing lactate, acetate, CO₂, and H₂, and can also grow via anaerobic respiration using H₂ and ferric iron. Found in hot springs and hydrothermal vents, over 20% of their...
792