I was involved in the 80's in the Greenland Ice Core Temperature History Data. The Sargasso Sea temperature history data also supports the Greenland data. Both of these data sets show warming since the 1700's but it just appears to be normal cyclical data since the earth was warmer during the Medieval Warming Period around 1100 AD before cooling into what was known as the Little Ice Age in the 1700's. The earth was also substantially warmer during portions of the Roman era than it is today after coming out of the last Ice Age about 10,000 years ago. These data sets are objective as opposed to subjective tree ring data that has been averaged into many charts by proponents of man caused global warming. Averaging subjective data with objective data is questionable science. Both data sets should be presented separately. The question is: How much of current warming is caused by fossil fuels and how much is caused by natural cyclical changes?