What’s the history of climate?

Scientists began measuring global temperatures in the 1880s.(1) Since then, researchers have developed increasingly advanced techniques to monitor temperature and carbon dioxide.2 With modern equipment, scientists can see trends from a million years ago and how today’s climatic changes compare to the past.(3),(4),(5),(6)

Nature’s climate trackers
Temperatures, carbon dioxide (CO2) levels, and many other climate conditions are recorded by natural organisms such as trees and coral. By analyzing the chemical composition of coral fossils, for example, scientists can calculate carbon dioxide levels at the time they were alive.(7),(8) Ancient ice near the North and South Pole can create similar records.9 Corals and ancient ice are just two of 173 natural climate trackers scientists use to estimate temperatures.(7),(8),(9),(10) Scientists are confident in these natural trackers because their recent predictions closely align with thermometer records since the 1800s.(11)


Natural Trackers and Scientific Instruments Show the Same Results
The two lines below compare temperatures measured with instruments and temperatures predicted using natural climate trackers, or “proxies”. Results show the accuracy of natural climate trackers.


Source: Geophysical Research Letters

*Natural trackers represent NOAA’s Paleo Index, an average of 173 paleoclimate proxies

VIDEO: Scientists use natural clues to track temperature before the time of people

Improving Technology has Enhanced Our Ability to Understand the Climate
From simply watching the clouds to launching satellites into space, the technology scientists use to calculate climate metrics has become significantly more advanced since 1880.

measuring-temp_ghgs-01Source: IPCC Working Group 1




  1. NOAA: State of the Climate
  2. NASA: News
  3. NOAA: Paleoclimatology
  4. Department of Energy
  5. NOAA: Mauna Loa Carbon Dioxide Level
  6. NOAA Global Climate Change Indicators
  7. NASA: Paleoclimate
  8. NASA: Coral
  9. NASA: Ice Core Record
  10. NASA: Sediment Cores
  11. NASA: Independent Evidence Confirms Global Warming in Instrument Record



  1. Paleo Index Graph – Geophysical Research Letters via University of South Carolina
  2. Methods & Instruments Used for Measuring Climate Metrics – Intergovernmental Panel on Climate Change