Archives de catégorie : climate-debate

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.

Satellite Data: Post El Niño Global Surface Cooling Continues… Pause Extends To 20 Years

by P. Gosselin, April 12, 2017


Critical German climate site wobleibtdieererwaermung.de (WBDE) reports that the earth’s surface is cooling, and presents the latest chart from NCEP. As of April 11, the measured global values continue to decline (black curve) as do the computed values for April 18.

The time-delayed post El Niño cooling is now showing up in the UAH and RSS satellite data.

The subtle origins of surface-warming hiatuses

 by Christopher Hedemann et al., March 17, 2017, Nature

During the first decade of the twenty-first century, the Earth’s surface warmed more slowly than climate models simulated1. This surface-warming hiatus is attributed by some studies to model errors in external forcing2, 3, 4, while others point to heat rearrangements in the ocean5, 6, 7, 8, 9, 10 caused by internal variability, the timing of which cannot be predicted by the models1. However, observational analyses disagree about which ocean region is responsible11, 12, 13, 14, 15, 16


See also  Anthony Watts, April 17, 2017

The Antarctic Peninsula: No Longer the Canary in the Coal Mine for Climate Alarmists

by M. Oliva et al., 2017


In light of all the above, the evidence is clearly mounting against those who point to warming on the Antarctic Peninsula as proof of CO2-induced global warming. For in the most incredible manner, warming trends that were once among the highest recorded on earth have slowed and even reversed to show cooling.

in Science of the Total Environment 580: 210-223, 2017 , Recent regional climate cooling on the Antarctic Peninsula and associated impacts on the cryosphere.

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.

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.