"A letter from former administrators, astronauts, and engineers at NASA expressing climate change scepticism does not deserve parity with the agency's peer-reviewed climate scientists."
"We have seen many examples of climate denialists producing long lists of fake experts, for example the Oregon Petition and the Wall Street Journal 16. Now we have yet another of these lists of fake experts. 49 former National Aeronautics and Space Administration (NASA) employees (led by Harrison Schmitt, who was also one of the Wall Street Journal 16) have registered their objection to mainstream climate science through the most popular medium of expressing climate contrarianism - a letter. As is usually the case in these climate contrarian letters, this one has no scientific content, and is written by individuals with not an ounce of climate science expertise, but who nevertheless have the audacity to tell climate scientists what they should think about climate science.
It's worth noting that when the signatories Meet The Denominator, as is also always the case, their numbers are revealed as quite unimpressive. For example, over 18,000 people currently work for NASA. Without even considering the pool of retired NASA employees (all signatories of this list are former NASA employees), just as with the Oregon Petition, the list accounts for a fraction of a percent of the available pool of people.
This letter, as these letters always do, has gone viral in the climate denial blogosphere, and even in the climate denial mainstream media (Fox News). But why exactly is this letter being treated as major news? That is something of a mystery. Or it would be, if the behavior of the climate denial community weren't so predictable."
"Global Climate Change: Vital Signs of the Planet" (NASA) 
"Are 49 Former NASA Astronauts, Scientists and Engineers Climate Change Deniers?" (Reason) 
"The 5 Characteristics of Scientific Denialism" (Skeptical Science) 
"Carl Sagan's Baloney Detection Kit" (The Demon Haunted World; Science as a Candle in the Dark) 
"NASA Video Debunks Climate Deniers in 26 Seconds" (350 or Bust)
45 Former NASA Space Program Employees Send a Letter Disputing Climate Change (Business Insider)
"NASA Global Warming Stance Blasted By 49 Astronauts, Scientists Who Once Worked At Agency" (Huffington Post)