By convention, climate is usually defined as the average of meteorological parameters over a period of 30 years. How can we use the available temperature data, intended for weather monitoring and forecasting, to characterize climate? The approach currently used is to calculate the arithmetic mean for an arbitrary base period, and subtract modern temperatures (either individual temperatures or averages) to determine what is called an anomaly. However, just what does it mean to collect all the temperature data and calculate the mean?
There is as yet no observational evidence that climate sensitivity increases with time in the real climate system – although this cannot be ruled out – nor is it fully understood why it increases in most AOGCMs. In any event, even if real-world climate sensitivity does increase with time, in the longer run other factors that are not reflected in ECS, such as melting ice sheets, are probably more important. Therefore, while time-varying climate sensitivity is of considerable interest from a theoretical point of view, for practical purposes its influence is likely to be very modest.
The Arctic is the most sensitive place to man-made emissions on Earth, which is why it has barely warmed since 1944? Well, it makes sense if CO2 is largely irrelevant. Humans have made 90% of all their CO2 in the last 70 years and nothing much happened in the place where it was supposed to hurt the most.
Looking at data objectively, it is pretty clear that there is little relationship between weather/climate and the rising CO2 concentrations in the atmosphere, as the global warming pause between 1997-2016 shows –
by Judith Curry, March 29, 2017, Professor, School of Earth and Atmospheric Sciences Georgia Institute of Technology Atlanta
Prior to 2010, I felt that supporting the IPCC consensus on human-caused climate change was the responsible thing to do. That all changed for me in November 2009, following the leaked Climategate emails, that illustrated the sausage making and even bullying that went into building the consensus.. (also, see .pdf)
Anyone who has studied the history of science knows that scientists are not immune to the non-rational dynamics of the herd.
This week’s March for Science is odd. Marches are usually held to defend something that’s in peril. Does anyone really think big science is in danger? The mere fact that the March was scheduled for Earth Day betrays what the event is really about: politics.
by By Julio Slingo, published in the Financial Times, 13 April 2017, Julia Slingo is the former chief scientist of the Met Office,
in WUWT, Anthony Watts
Last December, I retired after nearly eight years as Met Office chief scientist. It was a pleasure and privilege to lead one of the best environmental research organisations in the world at a time when, more than ever, we depend on skilful, comprehensive predictions of the weather, climate and the broader environment.
In summary, there are numerous data handling practices, which climatologists generally ignore, that seriously compromise the veracity of the claims of record average-temperatures, and are reflective of poor science. The statistical significance of temperature differences with 3 or even 2 significant figures to the right of the decimal point is highly questionable. One is not justified in using the approach of calculating the Standard Error of the Mean to improve precision, by removing random errors, because there is no fixed, single value that random errors cluster about. The global average is a hypothetical construct that doesn’t exist in Nature. Instead, temperatures are changing, creating variable, systematic-like errors. Real scientists are concerned about the magnitude and origin of the inevitable errors in their measurements.
The climate impact of all Paris INDC promises is minuscule: if we measure the impact of every nation fulfilling every promise by 2030, the total temperature reduction will be 0.048°C (0.086°F) by 2100.
Even if we assume that these promises would be extended for another 70 years, there is still little impact: if every nation fulfills every promise by 2030, and continues to fulfill these promises faithfully until the end of the century, and there is no ‘CO₂ leakage’ to non-committed nations, the entirety of the Paris promises will reduce temperature rises by just 0.17°C (0.306°F) by 2100.
Critical German climate site wobleibtdieererwaermung.de (WBDE) reports that the earth’s surface is cooling, and presents the latest chart from NCEP. As of April 11, the measured global values continue to decline (black curve) as do the computed values for April 18.
The time-delayed post El Niño cooling is now showing up in the UAH and RSS satellite data.
During the first decade of the twenty-first century, the Earth’s surface warmed more slowly than climate models simulated1. This surface-warming hiatus is attributed by some studies to model errors in external forcing2, 3, 4, while others point to heat rearrangements in the ocean5, 6, 7, 8, 9, 10 caused by internal variability, the timing of which cannot be predicted by the models1. However, observational analyses disagree about which ocean region is responsible11, 12, 13, 14, 15, 16
In light of all the above, the evidence is clearly mounting against those who point to warming on the Antarctic Peninsula as proof of CO2-induced global warming. For in the most incredible manner, warming trends that were once among the highest recorded on earth have slowed and even reversed to show cooling.
in Science of the Total Environment 580: 210-223, 2017 , Recent regional climate cooling on the Antarctic Peninsula and associated impacts on the cryosphere.
According to a new paper, the Bølling Warming event 14,700 years ago raised the surface temperature for the entire Northern Hemisphere by 4 to 5°C within a few decades. This is a hemispheric warming rate of approximately 2.0°C per decade, which is 40 times faster than the 0.05 °C per decade global warming rate since 1850 (and 1998).
We also discuss the challenges and opportunities in applying so-called objective methods in climate model tuning. We discuss how tuning methodologies may affect fundamental results of climate models, such as climate sensitivity. The article concludes with a series of recommendations to make the process of climate model tuning more transparent.
Carbon dioxide (CO2) and other greenhouse gases in the atmosphere can be reduce in two ways–by cutting our emissions, or by removing it from the atmosphere, for example through plants, the ocean, and soil.
The historic Paris Agreement set a target of limiting future global average temperature increase to well below 2°C and pursue efforts to even further limit the average increase to 1.5°C above pre-industrial levels. Yet the timing and details of these efforts were left to individual countries.
So it appears that the increase is due to improved/expanded reporting, not because there are in fact more tornadoes. This is essentially uncontroversial: NOAA gives a similar explanation on its website, though they get around the observation bias with a different method.
Le groupe français Total a signé le 7 avril un protocole de partenariat avec le Technology Centre de Mongstad (TCM), l’une des plus grandes installations au monde de tests en matière de captage de CO2.
For the first time, model calculations show a plausible way that fluctuations in solar activity could have a tangible impact on the climate. Studies funded by the Swiss National Science Foundation expect human-induced global warming to tail off slightly over the next few decades. A weaker sun could reduce temperatures by half a degree.
Continued weakening of the upper-ocean overturning is likely to strengthen the CO2 sink in the near future by trapping natural CO2 in the deep ocean, but ultimately may limit oceanic uptake of anthropogenic CO2.
Its also a stretch to assume perfect correlation of the real values, especially since its claimed that CO2 levels have increased due to human emissions and the latter have been at a steady rate for the last three years. There is also the question of why such a good correlation with SH sea-surface temperatures and not NH, and why should the correlation be so perfect when things like changes in ocean currents should have a large effect on how much is sequestered into the depths of the oceans.
The recent El Nino is cooling down as shown clearly in both sea surface temperatures and lower troposphere air temperatures. The two relevant data sets are UAH v.6 and HadSSTv3.1 now provide averages for the month of March 2017.
La géologie, une science plus que passionnante … et diverse
