by Kenneth Richard, November 9, 2017 in NoTricksZone
Though advocates of the dangerous anthropogenic global warming (AGW) narrative may not welcome the news, evidence that modern day global warming has largely been driven by natural factors – especially solar activity – continues to pile up.
Much of the debate about the Sun’s role in climate change is centered around reconstructions of solar activity that span the last 400 years, which now include satellite data from the late 1970s to present.
by Clive Best, October 3, 2017
It started as a nice simple idea: There is a finite amount of Carbon that humanity can burn before the planet warms above 2C. This idea was based on AR5 Earth Systems Models (ESMs) ‘showing’ that the relationship between global temperatures and cumulative emissions was linear. At last the IPCC had something easy for world leaders to understand! This was all nicely summarised in Figure SPM-10, shown below. The Paris accord is essentially derived from this one figure.
The problem though is that it wasn’t really true.
by Paul Homewood, October 30, 2017 in NotLofPeopleKnowThat
(…) There is nothing unusual at all about this increase in CO2. It is a result of a perfectly natural event, El Nino (…)
by Anthony Watts, October 20, 2017 in WUWT
The annual assessment of global greenhouse gas (GHG) emissions by the JRC and the Netherlands Environmental Assessment Agency (PBL) confirms that CO2 emissions have stalled for the third year in a row.
The report provides updated results on the continuous monitoring of the three main greenhouse gases: carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O).
See also here
by P. Gosselin, October 2017 in NoTricksZone
(…) It appears that the much larger changes predicted by other models arise from additional water vapor evaporated into the atmosphere and not from the CO2 itself (…)
(…) Assuming a doubling of CO2 by the late 21st century (assuming no positive water vapor feedback), we should likely expect to see no more than about 0.3-0.5°C global surface warming and certainly not the 2-5°C warming that has been projected by the GCMs [global circulation models (…)
by Hermann Harde, March 30, 2017 in Inter.J.Atm.Sciences
Including solar and cloud effects as well as all relevant feedback processes our simulations give an equilibrium climate sensitivity of = 0.7°C (temperature increase at doubled CO2) and a solar sensitivity of = 0.17°C (at 0.1% increase of the total solar irradiance). Then CO2 contributes 40% and the Sun 60% to global warming over the last century.
by Kenneth Richard, October 16, 2017 in NoTricksZone
A recently highlighted paper published by atmospheric scientists Scafetta et al., (2017) featured a graph (above) documenting post-2000 trends in the published estimates of the Earth’s climate sensitivity to a doubling of CO2 concentrations (from 280 parts per million to 560 ppm).
by Uzbek, 29 septembre 2017, in Climato-Réalistes
Dans quelle mesure les émissions anthropiques qui s’élèvent à 9 Giga Tonnes par an (dont 1,5 dues au changement d’utilisation des sols) perturbent le cycle du carbone contribuant à l’augmentation de la concentration de CO2 dans l’atmosphère?
by Connaissance des Energies, 13 octobre 2017
Les émissions américaines de CO2 liées à l’énergie ont baissé de 1,7% en 2016. Elles ont toutefois encore atteint près de 5,2 milliards de tonnes l’an dernier, ce qui fait toujours des États-Unis le 2e émetteur mondial après la Chine.
by Nicole Jacobs, October 3, 2017 in ClimateChangeDispatch
The report, which bases its CO2 emissions estimates off International Energy Agency (IEA) and BP data through 2016, found the global CO2 levels essentially remained flat in 2015 and 2016. As BP noted earlier this year, the global trend is “well below the 10-year average growth of 1.6% and a third consecutive year of below-average growth” and that “during 2014-16, average emissions growth has been the lowest over any three-year period since 1981-83.”
by Ross McKitrick, September 26, 2017 in ClimateEtc.
A number of authors, including the IPCC, have argued that climate models have systematically overstated the rate of global warming in recent decades. A recent paper by Millar et al. (2017) presented the same finding in a diagram of temperature change versus cumulative carbon emissions since 1870.
by University of California, September 12, 2017 in WUWT
A trend toward greater discrimination under higher CO2 levels is broadly consistent with tree ring studies over the past century, with field and chamber experiments, and with geological records of C3 plants at times of altered atmospheric CO2, but increasing discrimination has not previously been included in studies of long-term atmospheric 13C/12C measurements. We further show that the inferred discrimination increase of 0.014 ± 0.007‰ ppm−1 is largely explained by photorespiratory and mesophyll effects.
by Arthur Viterio, 2016, in J Earth Science Climate Change
Earth’s climate is a remarkably “noisy” system, driven by scores of oscillators, feedback mechanisms, and radiative forcings. Amidst all this noise, identifying a solitary input to the system (i.e., HGFA MAG4/6 seismic activity as a proxy for geothermal heat flux) that explains 62% of the variation in the earth’s surface temperature is a significant finding.
See also here
by André Bijkerk, September 17, 2017
Considering the likelihood of future presentations and discussions, an update of paleoclimatological information was overdue. I was amazed to bump into a full overview of the atmospheric CO2 content of the last 420 million years published much earlier this year. An important milestone in the history of climate on Earth
by F. Pretis and M. Roser, June 2017, Energy, Elsevier
The wide range of socio-economic scenarios in climate projections results in high uncertainty about climate change.
We compare socio-economic scenario projections to observations over 1990–2010.
Global CO2 emission intensity increased despite all major scenarios projecting a decline.
Under-projection of emission intensity raises concerns about achieving emission targets.