Key Questions

Comparing an average world temperature today to one from a year, decade—or even century ago—requires an agreed, accepted, consistent protocol on determining that data point.

A carefully-designed scientific protocol, involving a methodology agreed to by those who might make some substantive use of the resulting readings—one tested (and adjusted) over a considerable period of time, correcting for long-term historical trends in global temperature and solar activity—might have some indicative, directional value in determining world temperature trends that might be cause for alarm.

The World . .

1. Comprises immense land, sea, and air areas of varying shapes and depths—each zone retaining, dissipating, and affecting temperature and weather differently.
2. Possesses highly diverse geological features that affect temperature and weather.
3. Experiences measureless weather events and activity during any given period.
4. Supports other living creatures, that outnumber humans, who can have their own effect on temperature readings. 

And regional and global climate is always, and has always been, changing.

Human beings . .

1. Affect temperature readings by their presence and activities—e.g., building locations and design, roads and pavement, etc.
2. Populate, depopulate, and repopulate diverse regions of the World at different times historically.
3. Measure temperature differently depending on prevailing technology and procedures.

Temperature readings used to make determinations of climate change—that might drive social, political, or economic policy—must consider and account for these aspects and dimensions of global human experience.

Reported differences in average world temperature . .

• "According to an ongoing temperature analysis conducted by scientists at NASA’s Goddard Institute for Space Studies (GISS) and shown in this series of maps, the average global temperature on Earth has increased by about 0.8°Celsius (1.4°Fahrenheit) since 1880."¹
• "Averaged over all land and ocean surfaces, temperatures warmed roughly 1.53°F (0.85ºC) from 1880 to 2012, according to the Intergovernmental Panel on Climate Change . ."²
• "The average temperature of the Earth's surface increased by about 1.4 °F (0.8 °C) over the past 100 years, with about 1.0 °F (0.6 °C) of this warming occurring over just the past three decades."³

In 1880 and 2000s: What was the technology and procedure used to determine an average global temperature in the atmosphere; oceans, lakes, and rivers; and earth? Where were measuring devices placed geographically, and at what height? When were measurements taken? Over what daily time period were they averaged? How were measurements recorded? What areas were populated? What was the impact of human development on temperature readings?

How does this difference in average temperature over time compare to what's expected historically and in terms of solar activity and carbon dioxide in the atmosphere? How do we measure carbon dioxide then and now?

How much of any difference in temperature year-to-year might be attributed to variations over time in any of the above areas? to a lack of any agreed protocol on how to determine an average global temperature?

KEY QUESTIONS:

1. Is there any real way to have a generally accepted average world temperature, or trend in global temperature, without a scientific protocol agreed to by groups concerned?
2. Has there ever been a scientific protocol agreed to by groups concerned about determining an average world temperature at any given point in time?
3. How might one be developed?

RELATED: Discuss amongst yourselves . .

---

1. The Earth Observatory, part of EOS Project Science Office, NASA Goddard Space Flight Center.

2. The University Corporation for Atmospheric Research.
3. The National Academies.