A recent Florida Time-Union editorial quoted a National Academy of Sciences committee statement. in a report on climate change claiming that temperature increases in the 20th century were "very likely caused primarily by the emission of greenhouse gases from human activities."
In my opinion, and the opinion of hundreds of scientists and meteorologists, this statement was based on faulty science.
Pro: Editorial right to blame humans for climate change
It has been said that this decade was the warmest on record. But the "record" referred to the 150 years or so of actual temperature measurements taken at various locations around the world.
This period, beginning in about 1850, just happens to coincide with the end of the Little Ice Age.
We would expect a gradual increase in surface temperature during this period.
National Oceanic and Atmospheric Administration records indicate that the average temperature has only risen about 0.7 degrees Celsius over this 150 plus year period, whereas the peak temperature during the Little Ice Age was about 2 degrees C lower and the Medieval Warm Period was about 2 degrees C warmer than current temperatures.
It is important for each of us to understand the history of climate change, particularly for the last 10,000 years or so.
A book by Ian Plimer titled "Heaven and Earth, Global Warming — the Missing Science" is a good reference work.
Simplified, the studies tell us that there have been a number of previous ice ages and warming periods, beginning with the aforementioned Medieval Warm Period, the Roman Warm period, the Minoan Warm Period and more with their corresponding ice ages.
These occurred over periods of 1,000 to 1,500 years with mini cycles of warm and cold periods of about 25 to 40 years in length.
Temperatures during these warming periods have been as high as 5 to 7 degrees C higher than the current temperatures.
The latest warming period, the Medieval Warm Period, occurred from about 900 to 1300. This was followed with the Little Ice Age period ending in about 1850.
Written records document these warming and cooling periods with the prosperous living conditions described during the warm period and difficult living conditions likewise described during the Ice Age.
A warming trend generally occurred from 1850 until 1940, with a mini cold cycle from the late 1880s into about 1910 and a warming cycle in the 1920s and 1930s.
From 1940 until 1975, we experienced a mini cold cycle during which some current global warming proponents worried that we were going into a new ice age.
We again experienced a warming trend from 1976 until 1999 and have experienced a cooling trend for the last decade.
We are continually exposed to highly publicized misrepresentations followed by corrections hardly covered by the press.
One example was a statement by NASA in 2009 that nine of the 10 hottest years were in the last decade.
When called on this gross misrepresentation, NASA quietly recanted.
In fact, only one year in this decade, 2006, was in the top 10, the years being in the 1920s and 1930s and two in the 1950s.
Marvin Wicker is a retired environmental engineer from Orange Park.


Editorial selections for journalism
Period 3;  Phil-voting rights
                  Dynesha- facebook
                  Summer-contraception
                   Khamphasong- contraception
                   Jaida- beards in prison
                   Morgan- voting rights
                  Nicole- facebook
                  Tahmir-beards in prison / religious freedom
                   Nick-contraception
                   Concetta- beards in prison
                   Elaine-voting rights
                    Hannah-affirmative action
                    Katherine-affirmative action
                    Sidney- voting rights
                   Angelica- beards in prison / religious rights
                   Nadine-voting rights
                   Miricle-contraception
                  Diamond- facebook
                  Mazarita- beards in prison / religious
Period 5
         Duncan- abortion
         Shelby- voting rights
         Deon’e –abortion
         Jackson- beards in prison/ religious freedom
         Heidi- Facebook
         Nathaniel- beards in prison
         Jacob- contraception
         Lillian-affirmative action
         Deja-voting rights
          Samyra- voting rights
          Betty-affirmative action
          Nathan-beards in prison
          Simon- contraception
          Quinn-affirmative action
          Lauryl-affirmative action
         Jasmyn-voting rights
        Michael-  affirmative action
         Phalyn- abortion
          Enuma-beards in prison/ religious freedom
          Julia- contraception
           Veronica- contraception
          Ethan- voting rights
         Alexis –contraception
          Rachel- facebook
          Molly-facebook
          Mystique –voting rights
         Tessa- contraception
Period 9
Alice –voting rights
Shantia- Facebook
Laura- contraception
Chloe-Facebook
Jerimiah –Beards in Prison
Sevyion-beards in prison
Shakeiya—beards in prison
Joyce-Facebook
Maya-contraception
Taylor-beards in prison
Elizabeth-affirmative action
Gina-voting rights
Adi-abortion
Aleigha-facebook
Claire-contraception
Darren-abortion
Clarissa-voting rights
Zach-contraception
Abram-affirmative action
Brittany-Abortion
Emma-abortion
Alison-affirmative action