The Benefits of Long Term Data

In studying climate change, long-term data sets help us understand how our environment is changing. Many prehistoric societies observed and tracked changes in plant and animal communities to monitor food resources. By the 1700s, compiling written records on insect, tree and bird distributions had become common practice in many human societies [1]. Avid naturalists often started these long-term data sets, and few likely thought their work would be continued hundred of years into the future. Nevertheless, it is these pieces of information that are now helping us understand how abrupt climate change may be affecting the planet's ecosystems.

Long-term studies allow us to keep an eye on how our planet is changing. Some changes may be so dramatic that we immediately notice them, but many are subtle and not as obvious. The data sets that span long time periods help us put the information that we collect today into a larger context. How do we know if a trend or pattern is emerging if we do not know what has happened previously?

In 1917, Joseph Grinnell specifically looked at how climate determined the geographical ranges of bird species in the US [1]. Today, thanks to the efforts of Grinnell and other pioneering field biologists, scientists can make comparisons between different centuries and put together meaningful insights about the climatic factors that influence plants and animals today.

Here is a short list of the long-term data sets that are currently helping scientists assess the impacts of abrupt climate change:

• Bird and insect distributions in Europe have been tracked since the mid 1700s [1]
• Ship logs have provided information on marine mammal populations dating back to the 1700s [2]
• Cherry tree blossom times and the onset of spring have been monitored in Japan since around 1400 [1]
• Atmospheric CO₂ concentrations at Mauna Loa Observatory, Hawaii have been recorded since 1958 [3]

The Mauna Loa Observatory site in Hawaii. A) shows the Mauna Loa Observatory when it was founded in the 1950s B) the Mauna Loa Observatory in 2005. Used with permission from the Mauna Loa Observatory.

• Data on the range of the Chesapeake Bay oyster parasite were first collected in 1949 on North America's east coast [1]
• Long-term data sets for plankton in the Atlantic Ocean go back to 1931 [4]
• Global surface temperature records have been collected since 1880 [5, 6]
• Tropical storm data from China span the last 900 years [7]
• Intertidal study sites at Hopkins Marine Station in California were first started in 1931 [8]
• The Audubon Society has been conducting annual Christmas Bird Counts across North America since 1900 [9]
• Scientists in the Antarctic have been monitoring two penguin species, the Adelie penguin and the Emperor penguin, and their distribution since the 1950s [10]

The continuing collection of work done in these areas, as well as others will allow us and future generations of scientists better understand the world we live in, and how it is constantly changing.

Long Term Data lesson plan

1. Parmesan, C., Ecological and Evolutionary responses to recent climate change. Review of Ecological and Evolution Systems, 2006. 37 : p. 637-669.

2. Webb, R.L., On the Northwest: commercial whaling in the Pacific Northwest . 1988, Vancouver: University of British Columbia Press.

3. NOAA In Situ Carbon Dioxide (CO₂) Measurements. 2007, NOAA.

4. Dybas, C.L., On a collision course: oceans plankton and climate change. BioScience, 2006. 56 (8).

5. Bratcher, A.J. and B.S. Giese, Tropical decadal variability and global warming. Geophysical Research Letters, 2002. 29 (19): p. 24-1 to 24-4.

6. Zwiers, F.W. and A.J. Weaver, The Causes of 20th Century Warming. Science, 2000. 290 (5499): p. 2081-2083.

7. Overpeck, J.T. and J.E. Cole, Abrupt change in Earth's climate system. Annual Review of Environmental Resources, 2006. 31 : p. 1-31.

8. Harley, C.D. and L. Rogers-Bennett, The potential synergistic effects of climate change and fishing pressure on exploited invertebrates on rocky intertidal shores. CalCOFI Rep, 2004. 45 : p. 98-110.

9. LeBaron, G.S., The 106th Christmas Bird Count , in American Birds. 2007.

10. Ainley, D., et al., Decedal-scale changes in the climate and biota of the Pacific sector of the Southern Oceans, 1950s to the 1990s. Antarctic Science, 2005. 17(2): p. 171-182.