This award is made under the auspices of the EArly-concept Grants for Exploratory Research (EAGER) program, to develop an independent record of the last 100 years based on paleoclimate proxies. This is a database compilation and analysis effort.
The researchers will compile hundreds of time series, many produced as the result of NSF-funded research, to composite the individual temperature sensitive time series into a global average and produce regional and thematic subsets suitable for addressing climate research questions.
Preliminary research by the researchers, using a database without tree-rings data, produced a global paleo trend index from 110 temperature-sensitive proxy records. From 1880 to 1995, the index trends significantly upward, similar to the global surface temperature (GST), supporting the fidelity of the GST, and confirming the global extent of the warming trend of the past century.
If successful, this approach could be applied to other climate indicators with short length (e.g., ocean pH) or sparse geographic coverage and extend the focus of the paleoclimate research community towards this short but critically important time period. In this manner, the research could have broad impact on the wider science community by catalyzing new scientific thinking using paleoclimate data.
The activities fit well into the potentially transformative, high risk, and exploratory nature of the EAGER programs. It also represents a strong collaboration between NSF and NOAA scientists and archivists at the NOAA-funded World Data Center (WDC) leveraging the resources of the NSF-funded science community and the professional archivists at the WDC.
The warming that the Earth has experienced in the past 100 years is recognized as a serious environmental challenge, however our understanding of this warming is based on thermometer records (from weather stations) that have been heavily criticized. The record is short (beginning in 1880), geographically biased, and the corrections needed to observe the trends are themselves uncertain. An independent record, longer and with better geographic coverage, would be a valuable contribution. We produced a new independent record of global warming during the past 130 years by analyzing temperature-sensitive Paleoclimate proxies including ice cores, cores, cave deposits, and ocean and lake sediments. The new record is significant because it supports the controversial record developed from thermometers (see figure). Both records reveal a warming trend that has been attributed partly to the effect of increased greenhouse gas concentrations in the atmosphere. In the second part of the study we extended this record back to 1730. The longer record shows that the warming began around 1800, prior to the start of recordkeeping. In future work our approach will be extended to other aspects of climate and environmental change where the existing record is even shorter. Our study is part of an emerging trend in science to synthesize and re-use existing data, to study compelling research questions. This approach is sometimes called data mining, or data intensive science, and it stands alongside field or laboratory approaches as a new way to test hypotheses and characterize the physical world. Data intensive science is particularly useful when the data are noisy and incomplete, or poorly sampled in time or space, and when uncertainties are large. All of these problems are present in the climate record of the past century.
