Newswise — Global average temperature trend since Nov. 16, 1978: +0.13 C per decade

January temperatures, preliminary:

Global composite temp.: +0.31 C (about 0.56 degrees Fahrenheit) above20-year average for January.

Northern Hemisphere: +0.45 C (about 0.81 degrees Fahrenheit) above 20-yearaverage for January.

Southern Hemisphere: +0.17 C (about 0.31 degrees Fahrenheit) above 20-yearaverage for January.

December temperatures (revised):

Global Composite: +0.18 C above 20-year average

Northern Hemisphere: +0.41 C above 20-year average

Southern Hemisphere: - 0.05 C below 20-year average

(All temperature variations are based on a 20-year average (1979-1998) forthe month reported.)

Notes on data released Feb. 11, 2009:

Color maps of local temperature anomalies may soon be available on-line at:

The processed temperature data is available on-line at:

As part of an ongoing joint project between The University of Alabama in Huntsville, NOAA and NASA, Dr. John Christy, director of UAHuntsville's Earth System Science Center (ESSC), and Dr. Roy Spencer, a principal research scientist in the ESSC, use data gathered by microwave sounding units on NOAA and NASA satellites to get accurate temperature readings for almost all regions of the Earth.

This includes remote desert, ocean and rain forest areas for which reliable climate data are not otherwise available.

The satellite-based instruments measure the temperature of the atmosphere from the surface up to an altitude of about eight kilometers above sea level. Once the monthly temperature data is collected and processed, it is placed in a "public" computer file for immediate access by atmospheric scientists in the U.S. and abroad.

Neither Spencer nor Christy receives any research support or funding from oil, coal or industrial companies or organizations, or from any private or special interest groups. All of their climate research funding comes from state and federal grants or contracts.