By JR on Tuesday, October 20, 2015
Is NASA actually unserious about global warming?
Considering their unwavering support of it, that would be a surprising conclusion. But we find surprising carelessness about it in a place -- their home page -- where they should be very careful about it. One gets the impression that they are just going through the motions without any real commitment to the claim or interest in it. The following email was sent to the senior science editor for the NASA site about the matter. Whoever wrote the NASA piece concerned is either very dumb or very careless:
Re: Scientific consensus: Earth's climate is warming
Hi Senior Science Editor: Laura Tenenbaum,
At the top of the above referenced web page, it is stated:
"Multiple studies published in peer-reviewed scientific journals show that 97 percent or more of actively publishing climate scientists agree: Climate-warming trends over the past century are very likely due to human activities. In addition, most of the leading scientific organizations worldwide have issued public statements endorsing this position. The following is a partial list of these organizations, along with links to their published statements and a selection of related resources".
I question the use of the time frame, "trends over the past century."
Generally speaking, I believe you will find the consensus (IPCC summary included) to be that it is not until around the middle of the 20th Century - 1950 is often referenced (several, many decades later) - that AGW comes into play. It is not widely believed that until this time CO2 had not yet risen to a level where their might be any potentially observational evidence of a human foot (from anthropogenic greenhouse gases) to be present on global temperature.
In fact - among the various scientific orgs listed on your web site (several referenced in the footnotes), I find very consistent views on this issue:
" . . on the global climate change observed over the past 50 years." [ 2013-50 ='s 1963]
" . .that human activities (mainly greenhouse‐gas emissions) account for most of the warming since the middle 1900s."
" It is likely that most of the warming in recent decades can be attributed to human activities ."
"The global warming of the past 50 years is due primarily to human-induced . ."
"Most of the observed increase in global average temperatures since the mid-20th century . ."
"Human activities (mainly greenhouse-gas emissions) are the dominant cause of the rapid warming since the middle 1900s (IPCC, 2013)" - GSA
"It is likely that most of the warming in recent decades can be attributed to human activities (IPCC 2001)." Joint Science Academies Statement.
"The global warming observed over the past 50 years is due primarily to human-induced emissions of heat-trapping gases." From Executive Summary "Global Climate Change Impacts in the United States (2009) - U.S. Global Change Research Program.
"Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations. This is an advance since the TAR’s conclusion that “most of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations” IPCC Fourth Assessment Report: Climate Change 2007
I'd suggest that at a minimum the summary regarding consensus on the "birth of AGW," be changed to match your own expert witnesses, i.e., 'somewhere between the middle of the 20th Century to the late 1970's.'
Lest us not forget the graphic on the top of your page shows a clear global cooling cycle from about the 1940's through the late 1970's. It's a bit awkward to sell the view that man's footprint on GW occurred just as the Earth was getting serious - for several decades - about global cooling.