In their seminal paper on the Vostok Ice Core, Petit et al (1999) [1] note that CO2 lags temperature during the onset of glaciations by several thousand years but offer no explanation. They also observe that CH4 and CO2 are not perfectly aligned with each other but offer no explanation. The significance of these observations are therefore ignored. At the onset of glaciations temperature drops to glacial values before CO2 begins to fall suggesting that CO2 has little influence on temperature modulation at these times.
Last week, I posted a global temperature reconstruction based mostly on Marcott, et al. 2013 proxies. The post can be found here. In the comments on the Wattsupwiththat post there was considerable discussion about the difference between my Northern Hemisphere mid-latitude (30°N to 60°N) and the GISP2 Richard Alley central Greenland temperature reconstruction (see here for the reference and data). See the comments by Dr. Don Easterbrook and Joachim Seifert (weltklima) here and here, as well as their earlier comments.
This paper presents the first coherent large-scale national analysis undertaken on historical flood chronologies in Britain, providing an unparalleled network of sites (Fig. 1), permitting analysis of the spatial and temporal distribution of high-magnitude flood patterns and the potential mechanisms driving periods of increased flooding at a national scale (Britain) since AD 1750.
L’atténuation du changement climatique grâce au secteur forestier doit être mesurée par une approche scientifique objective. Elle ne doit pas permettre aux États de masquer les impacts des politiques responsables de l’augmentation nette de leurs émissions.
Dr Joanna House est maitre de conférence en sciences et politique environnementales à l’Institut Cabot, à l’Université de Bristol. Elle co-signe cette tribune avec d’autres spécialistes de l’environnement.
On June 2, 2017, in a Letter regarding US withdrawal from Paris climate agreementaddressed to the MIT community, Professor Rafael Reif, president of MIT, criticized President Trump’s decision to exit the Paris Climate Accords. In this refutation, we propose to clarify the scientific understanding of the Earth’s climate and to dispel the expensively fostered popular delusion that man-made global warming will be dangerous and that, therefore, the Paris Agreement would be beneficial.
Global Warming More Moderate Than Worst-Case Models A new study based on 1,000 years of temperature records suggests global warming is not progressing as fast as it would under the most severe emissions scenarios outlined by the Intergovernmental Panel on Climate Change (IPCC).
The West Antarctic Ice Sheet, a landbound mass of ice larger than Mexico, experienced substantial surface melt through the austral summer of 2015-2016 during one of the largest El Niño events of the past 50 years, according to scientists who had been conducting the first comprehensive atmospheric measurements in the region since the 1960s.
Hundreds of built and proposed hydroelectric dams may significantly harm life in and around the Amazon by trapping the flow of rich nutrients and modifying the climate from Central America to the Gulf of Mexico. These findings, published in Nature, emerge from a multidisciplinary, international collaboration of researchers from 10 universities, led by scientists at The University of Texas at Austin.
To meet energy needs, economic developers in South America have proposed 428 hydroelectric dams, with 140 currently built or under construction, in the Amazon basin — the largest and most complex network of river channels in the world, which sustains the highest biodiversity on Earth.
“It is absolutely critical to recognize that I am NOT claiming that humans haven’t done great damage to marine and terrestrial [ecosystems], nor that many extinctions have not occurred and more will certainly occur in the near future. But I do think that as scientistswe have a responsibility to be accurate about such comparisons.”
Many popular science articles take this as a given, and indeed, there’s something emotionally satisfying about the idea that humans’ hubris and shortsightedness are so profound that we’re bringing down the whole planet with us.
As the reconstruction of the climate’s development in the past by proxy data shows, there’s a series of temperature cycles that appear to be unknown, or ignored by many climate scientists. Among these are the larger climate cycles of 150 million to 180 million years (see Part 1 and Part 2), but also the shorter and for us the more important following cycles:
1000 years (900-1100) Suess cycle with +/- 0.65°C
230 years (230-250) deVries cycle with +/- 0.30°C
65 years (60-65) Ocean cycles with +/- 0.25°C
This regrettably postpones the much-anticipated Hudson Bay System Study (BaySys) involving 40 scientists from five universities across Canada. Timing was key for this $17 million, four-year, University of Manitoba-led project.
Scientists at Michigan State University (MSU) show that examining the daily minutia of climate, not just temperature, but also sunshine, precipitation and soil moisture simultaneously all over a country gives a better understanding of how variable a land’s climate can be. That information is crucial when countries are setting policies aimed at growing food, protecting water supplies and the environment and stemming disease outbreaks. The findings were reported in this week’s Scientific Reports.
The reduction in global temperature after the recent El Nino continues though not as swiftly as some predicted. The next few months will be interesting to see if it returns to levels seen before the recent El Nino took place when global annual average temperatures changed little for at least 15 years.
La géologie, une science plus que passionnante … et diverse
