by J.P. Bardinet et al., 12 avril 2017
Pour répondre à quelques idées reçues sur l’énergie, à l’heure où cette question est primordiale aux yeux du monde.
Egalement, lien sur Mediapart
Archives de catégorie : climate-debate
New Paper: Northern Hemisphere Temperatures Rose 4–5°C Within ‘A Few Decades’ 14,700 Years Ago
By Kenneth Richard , April 2017
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).
The Art and Science of Climate Model Tuning
by Hourdin et al., March 2017,
Bulletin of the American Meteorological Society
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.
Claim: Next 10 years critical for achieving climate change goals
by Anthony Watts, April 13, 2007
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.
Michael Mann Adjusts the Climate “Turning Point” Out to 2020
by Eric Worall, April 9, 2017
Professor Michael Mann, inventor of the climate Hockey Stick, has just shamelessly shifted the dreaded climate tipping point to 2020.
Until recently Mann claimed 2016/17 was a climate tipping point.
Reporting bias and the “increase” in weather events in the US
by Alberto Comendador, April 11, 2017
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.
Captage du CO2 : Total investit à nouveau en Norvège
by Connaissances des Energies, 11 Avril 2017
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.
Sun’s impact on climate change quantified for first time
by W. Schmutz, March 27, 2017
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.
Recent increase in oceanic carbon uptake driven by weaker upper-ocean overturning
by Tim De Vries et al., Nature Feb 9, 2017
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.
Questions on the rate of global carbon dioxide increase
by Robert Balic, April 7, 2017
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.
GLOBAL TEMPERATURES DROP TO PRE-EL NINO LEVELS
by Ron Clutz, April 5, 2017
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.
The art of green deception . . . about those record temperatures in Antarctica
by Warren Blair, April 7, 2017
The unusually high Esperanza temperature is likely the result of a strong jet stream that brought a strong ridge of high pressure over the Antarctic Peninsula, allowing warm air from South America to push southwards over Antarctica. Antarctic sea ice was at record-highs in 2014 and again in 2015 when modern records were shattered.
Influence of high-latitude atmospheric circulation changes on summertime Arctic sea ice
by Q. Ding et al., March 13, 2017, Nature Climate Change
The Arctic has seen rapid sea-ice decline in the past three decades, whilst warming at about twice the global average rate. Yet the relationship between Arctic warming and sea-ice loss is not well understood. Here, we present evidence that trends in summertime atmospheric circulation may have contributed as much as 60% to the September sea-ice extent decline since 1979.
Egalement : Recul de la banquise arctique: 30% à 50% lié à la variabilité naturelle de l’atmosphère
Learning from the climate’s history: the Arctic heat waves of the 1930s and 40s
by Dr. Sebastian Lüning and Prof. Fritz Vahrenholt [German text translated/edited by P Gosselin] , April 1, 2017
Now let’s extend the time scale and look back 100 years. What a surprise: In the 1930s and 1940s there were two heat decades in the Arctic which were almost as warm as today (Fig. 2). This is just a small fact that went missing in the WMO press release and in the derwesten.de article.
Global Warming and Hurricanes – NOAA says no measurable effect yet
by Anthony Watts, April 5, 2017
From NOAA’s Geophysical Fluid Dynamics Laboratory, March 17, 2017
Two frequently asked questions on global warming and hurricanes are the following:
Have humans already caused a detectable increase in Atlantic hurricane activity or global tropical cyclone activity?
What changes in hurricane activity are expected for the late 21st century, given the pronounced global warming scenarios from current IPCC models?
Why Is Asia Returning to Coal?
by Grace Guo, February 17, 2017
Just a few short years ago, few would have dared to predict that coal could have a future in the energy policies of emerging and developed countries alike. Yet the fossil fuel is undergoing an unexpected renaissance in Asia, buoyed by technical breakthroughs and looming questions about squaring development with energy security.
Greenland was nearly ice-free for extended periods during the Pleistocene
by JM Schaefer et al., Nature, December8, 2016
Here we show that Greenland was deglaciated for extended periods during the Pleistocene epoch (from 2.6 million years ago to 11,700 years ago), based on new measurements of cosmic-ray-produced beryllium and aluminium isotopes (10Be and 26Al) in a bedrock core from beneath an ice core near the GIS summit.
On the Existence of a ‘Tropical Hot Spot’
by Dr JP Wallace III et al., August 2016
These analysis results would appear to leave very, very little doubt but that EPA’s claim of a Tropical Hot Spot (THS), caused by rising atmospheric CO2 levels, simply does not exist in the real world. Also critically important, even on an all-other-things- equal basis, this analysis failed to find that the steadily rising Atmospheric CO2 Concentrations have had a statistically significant impact on any of the 13 critically important temperature time series analyzed.
Methane emissions from trees
Tree trunks act as methane source in upland forests
by University of Delaware, March 30, 2017
Methane is about 25 times stronger than carbon dioxide, with some estimates as high as 33 times stronger due to its effects when it is in the atmosphere.
Because of methane’s global warming potential, identifying the sources and “sinks” or storehouses of this greenhouse gas is critical for measuring and understanding its implications across ecosystems.
Daniel L. Warner, Samuel Villarreal, Kelsey McWilliams, Shreeram Inamdar, Rodrigo Vargas. Carbon Dioxide and Methane Fluxes From Tree Stems, Coarse Woody Debris, and Soils in an Upland Temperate Forest. Ecosystems, 2017; DOI: 10.1007/s10021-016-0106-8
Absence of 21st century warming on Antarctic Peninsula consistent with natural variability
by J. Turner et al., Nature/July 2016
Here we use a stacked temperature record to show an absence of regional warming since the late 1990s. The annual mean temperature has decreased at a statistically significant rate, with the most rapid cooling during the Austral summer. Temperatures have decreased as a consequence of a greater frequency of cold, east-to-southeasterly winds, resulting from more cyclonic conditions in the northern Weddell Sea associated with a strengthening mid-latitude jet.
See also : 20+ Scientists: ‘No Continent-Scale Warming Of Antarctic Temperature Is Evident In The Last Century’
Recent Sea-Level Change at Major Cities
by Rich Taylor, March 29, 2017
Where the ground is stable, typical change appears to be a rise of 1- to 2-mm/y. Rates above 3 mm/y seem to have a substantial component of natural and/or anthropogenic subsidence. Rates above 10 mm/y appear to be a primarily a consequence of human activity, which implies they should be manageable to some degree.
All records in this review are from the website www.psmsl.org of the Permanent Service for Mean Sea Level.
Updated list of 66 excuses for the 18-26 year ‘pause’ in global warming
by The Hockey Schtick, November 19, 2014
An updated list of at least 29 32 36 38 39 41 51 52 63 64 65 66 excuses for the 18-26 year statistically significant ‘pause’ in global warming, including recent scientific papers, media quotes, blogs, and related debunkings.
Published measurements of climate sensitivity declining
by Laterite, June 20, 2015
The climate sensitivity due to CO2 is expressed as the temperature change in °C associated with a doubling of the concentration of carbon dioxide in Earth’s atmosphere. The equilibrium climate sensitivity (ECS) refers to the equilibrium change in global mean near-surface air temperature that would result from a sustained doubling of the atmospheric carbon dioxide concentration. The transient climate response (TCR) is defined as the average temperature response over a twenty-year period centered at CO2 doubling in a transient simulation with CO2 increasing at 1% per year. The transient response is lower than the equilibrium sensitivity, due to the “inertia” of ocean heat uptake.
Also, this post
“[T]here is growing evidence of much smaller climate sensitivity to CO2; and even if these drastic emissions reductions occurred, we see little impact on the climate in the 21st century (even if you believe the climate models).”
Effect of Atmospheric CO2 Concentrations on Early Human Societies
by Don Healy, March24, 2017
During the past 100,000 years, human societies have witnessed the vast change in climate that has occurred as we have transitioned from a glacial period that ended about 20,000 years ago, into the current interglacial period.
Alberta’s Proposed Climate Plan: A Burden with No Benefit
by Ken Gregory, July 2005
Energy Balance Climate Sensitivity
The most important parameter in determining the economic impact of climate change is the sensitivity of the climate to greenhouse gas emissions. Climatologist Nicholas Lewis used an energy balance method to calculate the Equilibrium Climate Sensitivity (ECS) best estimate at 1.45 °C. ECS is the global temperature change resulting from a doubling of CO2 in the atmosphere after allowing the oceans to reach temperature equilibrium, which takes about 3000 years in the models.
A more policy-relevant parameter is the Transient Climate Response (TCR) which is the global temperature change at the time of the CO2 doubling. A doubling of CO2 at the current growth rate would take 126 years. The analysis gives the TCR best estimate at 1.21 °C with a likely range [17 – 83% confidence] of 1.05 to 1.45 °C.