The annual global mean temperature anomaly is an important and highly publicized index of climate change. Changes in the global mean temperature are a result of an energy imbalance in the Earth system. Over the past 150 years, human emission of greenhouse gases has led to increased global temperatures with the last seven years being the seven warmest years on record. This increased global mean temperature results in regional climate changes in temperature and precipitation that impact life on Earth. While the global mean temperature is important, it is not straightforward to calculate, particularly 100+ years ago. In this session, we will explore the history of global mean temperature calculations, discuss how scientists currently calculate changes in the temperature of the Earth, show how confident these calculations of global temperature are, and discuss the various sources of data used to calculate and verify the temperature record over the past 150+ years.
INTRODUCTORY SLIDE SHOW (pptx) (pdf)
Nathan Lennsen’s slide show (pdf)
GISS Surface Temperature Analysis
https://data.giss.nasa.gov/gistemp
Additional Resources
Global Energy Balance, Greenhouse Effect, and Climate Change
Information about NASA GISTEMP
Sea Surface Temperature– NASA description on how sea surface temperature is and has been measured
4th National Climate assessment https://nca2018.globalchange.gov/
6th IPCC AR6 Climate Change 2021:
The Physical Science Basis https://www.ipcc.ch/report/ar6/wg1/