One recent posting on Holthaus' Quartz feed says -
The world’s best scientists agree: On our current path, global warming is irreversible—and getting worse (September 27).
I have mixed emotions about this set of twitter feeds. Holthaus (as far as I can find on the net) went to the Saint Louis University and then to the Columbia University MA in Climate (at Jeffery Sachs Earth Institute) - The Saint Louis program (at least according to some sources is unranked. The Columbia program is well regarded but is criticized for being ideologically biased. This is not an area I have worked in so I can't evaluate how well trained this guy actually is. On his linked in page he has some tie to the University of Arizona which is ranked among the top 30 programs in the county. At one point he has been a weather reporter for places like the WSJ (he did some of their coverage on the storm Sandy. He is also on one climate advisory board for the Sierra Club. All that background says two things. First, based on experience and education, he has some expertise although, second, a good deal of his experience/expertise is ideologically biased. He is far from what one could reliably call a climate scientist. The term scientist should be reserved for those few who can start from a position of inquiry - his seems to be based on reinforcing conclusions. His thesis title at Columbia ("The social justice of weather: hurricane risk management for development in Latin America and the Caribbean") seems a bit odd. I've always had a problem with putting modifiers on terms like Justice but I wonder how weather and justice can be conflated.
While I admit to chuckling at his twitter feeds on September 27 I am more concerned with the comment in his Quartz feed - is something is irreversible—and getting worse why bother to quit flying? A lot of the commentary from the right has been that this latest climate report has a hard time explaining the seeming contradiction (that being that for a while - all the perils of Global Warming including temperature change in increased volatility seemingly have been less extant than in earlier times) between the data and the hype.
I will admit that I have been interested in some of the economics literature about the trend line declines in economic growth (See Tyler Cowen's The Great Stagnation and or Naill Ferguson's The Great Degeneration - both authors make a powerful case about risks facing society; the US in particular). But as I read Holthaus' twitter feeds I was reminded about writers from Thomas Malthus to Paul Ehrlich who have for at least the last several hundred years projected apocalyptic results from seeming trends only to be shown as fools by advances in thinking or technology. It must be very hard, as Julian Simon wrote in several books to think life can only follow one path. Being burdened with an idea that life's patterns are irreversible—and getting worse must be an awful burden to carry.