China Met Office Confirms Global Warming Hiatus

The annual warming trends were statistically significant at the 5% confidence level for all periods except 1998–2014… It is also clear from our analysis that the recent “warming hiatus” was characterized by the more slowly warming or even cooling trends in the low to mid-latitude zones of the two hemispheres, with the noticeable cooling occurring in North America, East and Central Asia, northern Australia and southern Africa. –Xiubao Sun et al., Science Bulletin, 62(4) 2017

The China Meteorological Administration (CMA) has recently developed a new global monthly land-surface air temperature data set called CMA GLSAT. Using it researchers from the administration reanalysed the change in global annual mean land-surface air temperature during three time periods (1901–2014, 1979–2014 and 1998–2014) to see if there was any evidence of a hiatus or pause in recent surface global warming.

In preparing the new database Xiubao Sun and colleagues from the CMA say they addressed a number of problems with other surface temperature databases, in particular the relatively poor coverage of stations across Antarctica, Africa, South America, and Asia. The researchers find very clear evidence for the recent warming hiatus. Their results show linear trends of 0.104 °C per decade, 0.247 °C per decade and 0.098°C per decade for the three periods, respectively. The trends were statistically significant except for the period 1998–2014, the period that is also known as the ‘warming hiatus’. –David Whitehouse, GWPF Observatory, 4 July 2017

The China Meteorological Administration (CMA) has recently developed a new global monthly homogenized land-surface air temperature data set. Based on this data set, we reanalyzed the change in global annual mean land-surface air temperature (LSAT) during three time periods (1901–2014, 1979–2014 and 1998–2014). The results show that the linear trends of global annual mean LSAT were 0.104 °C/decade, 0.247 °C/decade and 0.098 °C/decade for the three periods, respectively. The trends were statistically significant except for the period 1998–2014, the period that is also known as the “warming hiatus”. –Xiubao Sun et al., Science Bulletin, 62(4) 2017

With preparations under way for the Intergovernmental Panel on Climate Change’s next report, a key challenge for scientists remains to explain properly the 20- year slowdown in surface temperature rises and the failure of models to predict it. The so-called pause has been a totemic issue for sceptics, who have earned derision from much of the climate science community since bringing it to global attention. The slowdown or hiatus was mentioned, however, in the IPCC fifth assessment report, and ­behind the vitriol there has been a lot of work done to provide some answers for the sixth assessment report to be published next year…. It is why many sceptics advocate a more robust contest of climate science alongside the peer-reviewed process. The immediate dispute is over whether the spike in global temperatures during the most recent El Nino represented an end to the pause. The latest evidence is that temperatures are returning quickly to pre-El Nino levels. —The Australian, 1 July 2017

U.S. EPA Administrator Scott Pruitt is leading a formal initiative to challenge mainstream climate science using a “back-and-forth critique” by government-recruited experts, according to a senior administration official. The program will use “red team, blue team” exercises to conduct an “at-length evaluation of U.S. climate science,” the official said, referring to a concept developed by the military to identify vulnerabilities in field operations. “The administrator believes that we will be able to recruit the best in the fields which study climate and will organize a specific process in which these individuals … provide back-and-forth critique of specific new reports on climate science,” the source said. –Emily Holden, E & E News, 30 June 2017

Last week, Scott Pruitt, EPA Administrator, stated he intended to form a ‘red team’ to debate climate science.  What exactly is ‘red teaming’, and how can this be implemented in a way that is useful for climate science and for policy makers? There are many pitfalls in  establishing and conducting a successful and useful red team exercise. To avoid these pitfalls, the relevant policy makers, potential scientist participants, and journalists should have an open discussion on the objectives and guidelines. And not to mention actually learn something from experts on red teaming. –Judith Curry, Climate Etc. 3 July 2017

I can understand when pop-scientists like Bill Nye spout scientific silliness. But complete nonsense coming from Stephen Hawking? Really? In a video, Stephen Hawking claims that Trump withdrawing the U.S. from the Paris Accord could lead to the Earth being pushed past a tipping point, with Venus-like 250 deg. C temperatures and sulfuric acid rain. The trouble with this statement is that no reputable climate scientist would claim such a thing. The reason is that Venus has about 220,000 times as much carbon dioxide in its atmosphere as does Earth. Venus is a very different planet. Venus has 93x as much atmosphere as Earth, and it is almost 100% CO2. The CO2 concentration in our comparatively thin atmosphere is only 0.04%. I have no idea where Hawking ever got such a wild idea. Apparently, he had his audience in tears with his dire predictions. Roy Spencer, 3 July 2017

Students are now so powerful that university professors are afraid to teach controversial subjects for fear of being sacked, an academic conference was told on Thursday. Professor Dennis Hayes, a co-founder of “Academics for Academic Freedom” said that universities were now ruled by a “culture of censorious quietude” where academics were not able to discuss “anything difficult.” Speaking at the University of Buckingham yesterday, Prof Hayes added: “There’s an interesting turn today, it’s not that people are abusive, it’s just that they don’t say anything at all in universities. There’s so many things that could be discussed that you dare not say. And the consequences of arguing anything difficult is potentially that you could be sacked.” –Harry Yorke, The Daily Telegraph, 30 June 2017