Polar Bears

The information available for download is from IUCN/SSC Polar Bear Specialist Group web site ( last updated in 2014. They demonstrate that for many sub-populations the information is insufficient to make a reliable estimate of numbers or to assess changes in the population. Where the data are sufficient they show that “removals” have a significant effect on the status of the population.

Sea Ice

The data for sea ice for the period 1978 to 2011 was downloaded from (Reference: Fetterer, F., K. Knowles, W. Meier, and M. Savoie. 2002, updated 2009. Sea Ice Index, Boulder, Colorado USA: National Snow and Ice Data Center.)

Data for the period 1870 to 2008 was downloaded from: (Reference: William Chapman, University of Illinois Sea Ice Dataset, Northern Hemisphere : 1870 – 2008).

For Sea ice thickness, the data sources were taken from:

  • Hibler, W.D. III and K. Bryan. 1987. A diagnostic ice ocean model. 1. Phys. Oceanogr., 1 7(7), 987-1015.
  • Hogan T.F. and Rosmond T.E. The description of the Navy Operational Global Atmospheric Prediction System’s spectral forecast model. Mon. Weather. Rev. 119 , 1786 to 1815, 1991
For more information see:

Sea Level

The data for two independently calculated sea level series based on tide gauges were downloaded from: (References: Jevrejeva, S., A. Grinsted, J. C. Moore, and S. Holgate (2006), "Nonlinear trends and multiyear cycles in sea level records", J. Geophys. Res., 111 and Church, J. A., and N. J. White (2006), A 20th century acceleration in global sea-level rise", Geophys. Res. Lett., 33)

The data for the satellite based level series were downloaded from: (Reference : Leuliette, E. W, R. S. Nerem, and G. T. Mitchum, 2004. Calibration of TOPEX/Poseidon and Jason altimeter data to construct a continuous record of mean sea level change. Marine Geodesy, 27(1-2)). The data were downloaded in August 2009 and include data up to October 2011.They were adjusted using an “inverted barometer” which compensates for the effect of atmospheric pressure on sea level. The satellite data were also adjusted to give the same average level as the tide gauges for their period of overlap.

The tide gauge data for the Maldives were extracted from the file “prints.rlr” downloaded from: The satellite data were downloaded from:

Pacific islands
Data for the 12 South-West Pacific were extracted from: The file was downloaded in November 2011 and has data up to October 2011.

The data for the Rabual were extracted from the file “prints.rlr” downloaded from

Tropical Cyclones

The csv files, ACEAtlantic.csv and ACEPacific.csv, were based on hurricane data downloaded from: The file has three types of data:

  • Type A: A brief summary including the data, number, name, whether the hurricane made landfall and its SSS index
  • Type B: Details of storm movement every 6 hours
  • Type C: Details of maximum intensity and where it made landfall
The csv file, atlantic_hurricanes.csv, is based on the file tracks_atl downloaded from: A program was written to read the original file and extract the details of type A. Only events where land-fall was made and the storm was classed as a hurricane were included. The attached csv file (storms.csv - see downloads) has the year number and five columns. Each column shows the number of events in a given year which attained or exceeded a values of the SSS. For example if in a single year there were two hurricanes, one of an SSS of 2 and one of 4, then columns 1 and 2 would have the value 2, columns 3 and 4 would have the value one and column 5 would have the value 0.