The year 2005 may have been the warmest year in a century, according to NASA scientists studying temperature data from around the world.
Climatologists at NASA’s Goddard Institute for Space Studies (GISS) in New York City noted that the highest global annual average surface temperature in more than a century was recorded in their analysis for the 2005 calendar year.
Some other research groups that study climate change rank 2005 as the second warmest year, based on comparisons through November. The primary difference among the analyses, according to the NASA scientists, is the inclusion of the Arctic in the NASA analysis. Although there are few weather stations in the Arctic, the available data indicate that 2005 was unusually warm in the Arctic.
In order to figure out whether the Earth is cooling or warming, the scientists use temperature data from weather stations on land, satellite measurements of sea surface temperature since 1982, and data from ships for earlier years.
Previously, the warmest year of the century was 1998, when a strong El Nino, a warm water event in the eastern Pacific Ocean, added warmth to global temperatures. However, what’s significant, regardless of whether 2005 is first or second warmest, is that global warmth has returned to about the level of 1998 without the help of an El Nino.
The result indicates that a strong underlying warming trend is continuing. Global warming since the middle 1970s is now about 0.6 degrees Celsius (C) or about 1 degree Fahrenheit (F). Total warming in the past century is about 0.8° C or about 1.4° F.
“The five warmest years over the last century occurred in the last eight years,” said James Hansen, director of NASA GISS. They stack up as follows: the warmest was 2005, then 1998, 2002, 2003 and 2004.
Over the past 30 years, the Earth has warmed by 0.6° C or 1.08° F. Over the past 100 years, it has warmed by 0.8° C or 1.44° F.
Current warmth seems to be occurring nearly everywhere at the same time and is largest at high latitudes in the Northern Hemisphere. Over the last 50 years, the largest annual and seasonal warmings have occurred in Alaska, Siberia and the Antarctic Peninsula. Most ocean areas have warmed. Because these areas are remote and far away from major cities, it is clear to climatologists that the warming is not due to the influence of pollution from urban areas.
From NASA
As it so happens Alaska has been getting warmer — see satellite data (http://www.ghcc.msfc.nasa.gov/temperature/), but as you can also see from the satellite data what applies to Alaska does not apply to the rest of the world. Alaska must be getting unusually warm for other reasons, ocean currents changes etc.
It would be nice if we could start thinking about energy and energy densities rather than temperature. Averaging temperatures doesn’t make mathematical sense (you can’t average the temperature of a liter of water with a liter of air — for example, not first without switching to energy representation). Temperature is proportional to the kinetic energy density (roughly — ignoring entropy). In order for global warming to occur more energy must be being trapped. So measure the energy (maybe?)
I’m suprised that NASA as a scientific entity is not more conservative with it’s statistics. This seems like a bold claim in light of the flawed statistical data gathering. I wish instead of making difficult to prove claims that they would instead spend energy on continuing to improve the data collection around this measurement. Helping to refine the results as more data is gathered.
i agree. an example that would demonstrate the problem is this,
there are 2 weather stations across the street from each other, they will record the same temp, if the mean average is taken for global temprature (temp recorded at each station added together / # of stations) then the station i mentioned is counted twice.
in this case, some areas are overrepresented, while others are unrepresented.
that being said i do think the earth is getting warmer, i live in alaska, in the last 20 years (im told, i moved here ~5 yrs ago) there were only 5 or so thunder and lightning storms, but in the last 2 yrs there have been over 10 thunder storms (total, not per year in both cases). asside from second hand info, there was also a newspaper article run that had data to back up these claims. the worlds weather is changing, whether this is just a natural fluctuation or ‘global warming’ i cant really say.
The technique for averaging global temperatures has not been standardized for 100 years. Not only that, but many of the measuring stations in use 100 years ago were lost over the past 40 years. They are comparing apples and oranges and ending up with prunes.