Archives par mot-clé : CO2

Most Modern Warming, Including For Recent Decades, Is Due To Solar Forcing, Not CO2

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.

Carbon Budgets

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.

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What crisis? Global CO2 emissions stalled for the third year in a row

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

65 Papers Find Extremely Low CO2 Climate Sensitivity

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 (…)

Radiation Transfer Calculations and Assessment of Global Warming by CO2

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.

Thanks to Shale, U.S. CO2 Emissions Continued to Decline in 2016

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.”

Study: plants are globally getting more efficient thanks to rising carbon dioxide

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.

The Correlation of Seismic Activity and Recent Global Warming

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.

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Carbon dioxide emission-intensity in climate projections: Comparing the observational record to socio-economic scenarios

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.