Gavin A. Schmidt is a climatologist and climate modeler at the NASA Goddard Institute for Space Studies (GISS) in New York.
He works on the variability of the ocean circulation and climate, using general circulation models (GCMs).
He was educated at The Corsham School, earned a BA (Hons) in mathematics at Jesus College, Oxford, and a PhD in applied mathematics at University College London.(Wikipedia)
Luboš Motl (born December 5, 1973) is a Czech theoretical physicist who keeps a blog commenting on physics, global warming and politics.
He received his master degree from the Charles University in Prague, and his Doctor of Philosophy degree from Rutgers University and has been a Harvard Junior Fellow (2001–2004) and assistant professor (2004–2007) at Harvard University.
On Luboš' blog, the Reference Frame (link in title) he comments on Gavin's "fight against" the Galileo Movement's booklet - Science in a nutshell.
If Luboš is to be believed ( and TCS blog, for one believes and trusts him) then Gavin Schmidt is either a complete scientific buffoon or worse, a denier of the truth, trying to uphold the falsified AGW hypothesis.
Here is just one example. For an enlightening read go to the Reference Frame and read the whole post and don't miss the comments.
GM - Galileo Movement
GS - Gavin Schmidt
LM - Luboš Motl
GM: In every 85,000 molecules of air, just 33 are CO2. For every 33 molecules of CO2, 32 are from Nature and known to be essential to all life on Earth. How can one molecule of the same gas produced by humans be blamed for supposed imminent, irreversible, catastrophic global warming? It cannot.
GS: False.LM: The statement by the Galileo Movement is obviously right, totally accurate, and immensely important for this whole discussion.
Two hundred years ago, only 24 of those molecules would have been CO2. Today, 33 molecules are – a 40 percent rise of a key greenhouse gas.
The reference to "one molecule" is misleading: By talking ratios, the Galileo Movement obscures the staggering amount of carbon dioxide society has pumped into the air. In the last two centuries, society has dumped 220 billion tons of carbon dioxide into the atmosphere by burning fossil fuels. It added another 110 billion tons via deforestation and land-use changes.
The atmosphere weighs about 5 quadrillion tons, and carbon dioxide, despite our emissions, remains a small component of that. But it grows larger every year. The International Energy Agency expects annual global CO2 emissions from fossil fuels alone to top 40 billion tons a year by 2030.
The math gets complicated from here, but there is an enormous quantity of molecules in those 330 billon tons of CO2.
It just says that 33 molecules among 85,000 - not sure why this number was chosen (I guess that it was 100,000 to start with but they wanted the final small numbers to agree with something else) - are CO2 molecules and none of these CO2 molecules can individually be identified as "harmful". In fact, when you ask each molecule how they got into the atmosphere the last time they did, 32 of them will reply that they got to the atmosphere from natural sources.
This small percentage of the "fresh man-made molecules" boils down to something we discussed at the beginning - the man-made CO2 emissions are just a small portion of the annual CO2 budget. Schmidt is right that the total number would be close to 24 and not 33 or 32 molecules if there had been no industrial activity. But that doesn't mean that there's anything inaccurate about the statement by the Galileo Movement.
You may say that 24 molecules would be there regardless of the humans - you can't say which ones among the 33 molecules, of course. They're identical to each other. 1 molecule was added by humans during the last loop of the carbon cycle. And what about the remaining 33-25=8 molecules? They were added by Nature during the most recent cycle but Nature wouldn't be able to add them if men didn't previously get them to the circulation.
In this sense, you might call the recently emitted 1 molecule a "recent stimulus package" and the remaining 8 molecules are "results of Nature's activity that boils down to the historical stimulus packages in the past". At any rate, the main point is that the CO2 molecules that have been added to the system in the past have been recycled dozens of times and became a standard part of the cycle of Nature. That's what Nature does with any molecules, especially the totally inherent and like-like molecules such as CO2 that have been driving life for billions of years.
These 8 molecules are the same molecules - in principle, totally indistinguishable - as the 24 natural molecules. So you can't even say which one is which. There is no physical experiment that would distinguish the 24 "totally natural molecules" from the 8 "natural now but man-made in the past" molecules or 1 "recently man-made molecule". (There might be heavier isotopes and their percentage in different sources may differ but biochemical processes don't distinguish the isotopes and all of them are ultimately mixed with everyone else.) If you admit that the 24 molecules are very important and beneficial for the plant life, you must admit that we have increased the happiness of the plants on Earth by 40%, while causing no disadvantages for anyone else.
The alleged disadvantage that the climate fearmongers made up - the temperature - would actually also be an advantage. But more importantly, its magnitude is totally tiny. In the language of economists, it's an externality but its value is much smaller than the value of the "internalities" that are never talked about because they're inconvenient (even though they decide about 99+ percent of the key quantities).
Just try to imagine that you're a plant. And you are offered this deal: your food happiness may increase by 40% - because the amount of CO2 will grow by this figure - but you may dislike the temperature change that is connected with this deal with may be about 0.6 °C of warming (and I am generously assuming that all temperature change in the last 100 years is due to human activity). Will you accept the offer? You bet. Half a degree in either direction is totally irrelevant in comparison with a 40% increase of your food supply. (And I am generously overlooking that the warming would be good for almost any plant, too.)
As some children already know, plants are important even for those people who prefer meat because the meat comes from animals that either ate some plants :-) or they ate other animals that [....] and ultimately the final animals eat plants which is why everyone depends on CO2. Some children even call this insight "food chain".
The idea that there is something wrong about our addition of the CO2 molecules just doesn't add up. It's complete rubbish. What propagandistic articles such as Schmidt's tirade in SciAm want to achieve is something that can't really be achieved: they want all the people to abandon all of their common sense and 99% of their knowledge of science and mindlessly repeat some cherry-picked 1% of science factoids, add 100 times larger pile of myths to this scientific core, and convince themselves that these cherry-picked factoids as well as myths are important for their lives - or the life on Earth - even though they are demonstrably not important.
The Galileo Movement must be applauded for producing a booklet that actually and accurately explains many more key scientific points about the CO2 and temperature dynamics than all the movies ever shot by the climate alarmists combined.