Archives de catégorie : climate-debate

Impact of the ~ 2400 yr solar cycle on climate and human societies

by  Javier, September 20, 2016


The role of solar variability on climate change, despite having a very long scientific tradition, is currently downplayed as a climatic factor within the most popular hypothesis for climate change.

As the root of this neglect lie two fundamental problems. Solar variability is quite small (about 0.1% of total irradiation), and there is no generally accepted mechanism by which the solar variability signal could be amplified by the climate system

The Meaning and Utility of Averages as it Applies to Climate

by Clyde Spencer, April 23, 2017


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?

How inconstant are climate feedbacks – and does it matter?

by Nic Lewis, April 18, 2017


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.

House Science Committee Hearing

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)

Politics Disguised as Science: When to Doubt a Scientific ‘Consensus’

by Jay Richards, April 19, 2017


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.

Slingo Speaks: ‘…no extreme weather or climate event can be attributed solely to climate change”

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.

 

Are Claimed Global Record-Temperatures Valid?

by Clyde Spencer, April 12, 2017


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.

Also : Perspective Needed; Time to Identify Variations in Natural Climate Data that Exceed the Claimed Human CO2 Warming Effect

Paris climate promises will reduce temperatures by just 0.05°C in 2100 (Press release)

by Bjorn Lomborg, April 2017


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.