Category Archives: Attribution

Disentangling forced from intrinsic climate variability

by Marcia Wyatt

Implications for the “stadium wave” and Northern Hemisphere climate variability.

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Explaining(?) abrupt climate change

by Judith Curry

 . . . suggesting that Dansgaard-Oeschger events resulted from a combination of the effects of sea ice and ice shelves—structures that help define the margins of ice sheets—to account for both the rapid and the slower parts of the cycle.

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Curry versus Trenberth

by Judith Curry

At the Conference for World Affairs, in Boulder Colorado.

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Evidence of absence versus absence of evidence

By Judith Curry

Does global warming make extreme weather events worse?

 

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Causes and implications of the pause

by Judith A. Curry

My invited talk at the American Physical Society Meeting in Denver.

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The Big Question

by Dagfinn Reiersøl

The Big Question in the climate change debate, as traditionally and conventionally posed, is: “is global warming caused by humans?”

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The logic(?) of the IPCC’s attribution statement

by Judith Curry

How can the IPCC increase their confidence in anthropogenic global warming at the same time their model projections are diverging farther and farther from reality? – John Nielsen-Gammon

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The case of the missing heat

by Judith Curry

Sixteen years into the mysterious ‘global-warming hiatus’, scientists are piecing together an explanation. – Jeff Tollefson

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Is global warming causing the polar vortex?

by Judith Curry

In a word, no.

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Blame game

by Judith Curry

 The scientific case is strengthening: developed countries are to blame for global warming – and there will soon be a legal reckoning.  - Chris Huhne

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Interpretation of UK temperatures since 1956

by Euan Mearns and Clive Best

In this post we present evidence that suggests 88% of temperature variance and one-third of net warming observed in the UK since 1956 can be explained by cyclical change in UK cloud cover.

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Words of wisdom from Ed Lorenz

by Judith Curry

Insights from Ed Lorenz, pioneer of chaos theory, on the detection of anthropogenic global warming.

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Spinning the climate model-observations comparison. Part III

Several new analyses of relevance to interpreting the comparison of climate models with observations.

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The stadium wave

by Judith Curry

This paper will change the way you think about natural internal variability.

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Understanding multi-decadal climate changes

by Judith Curry

Natural internal climate variability is getting some welcome attention.

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IPCC’s pause ‘logic’

by Judith Curry

Well here it is, the pause discussion is buried in Box 9.2 of the IPCC Working Group I Report.

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95% (?)

Ok, it is now official:

“The long-term climate model simulations show a trend in global-mean surface temperature from 1951 to 2012 that agrees with the observed trend (very high confidence). There are, however, differences between simulated and observed trends over periods as short as 10 to 15 years”

It is extremely likely that more than half of the observed increase in global average surface temperature from 1951 to 2010 was caused by the anthropogenic increase in greenhouse gas concentrations and other anthropogenic forcings together. The best estimate of the human induced contribution to warming is similar to the observed warming over this period.

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Natural internal variability: sensitivity and attribution

by Judith Curry

There is growing evidence to support the hypothesis that the pause cause is tied to a change in tropical Pacific Ocean circulations.  What are the implications of this for climate sensitivity and attribution of warming in the latter part of the 20th century?

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Pause politics

by Judith Curry

U.S. and European Union envoys are seeking more clarity from the United Nations on a slowdown in global warming that climate skeptics have cited as a reason not to “panic” about environmental changes, leaked documents show.

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What is internal variability?

by X Anonymous

According to the IPCC, “climate variability refers to variations in the mean state and other statistics (such as standard deviations, the occurrence of extremes, etc.) of the climate on all spatial and temporal scales beyond that of individual weather events. Variability may be due to natural internal processes within the climate system (internal variability), or to variations in natural or anthropogenic external forcing (external variability).”

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Pause tied to equatorial Pacific surface cooling

by Judith Curry

Update:  New comment from Xie

My mind has been blown by a new paper just published in Nature.

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Overestimated global warming over the past 20 years

by Judith Curry

Recent observed global warming is significantly less than that simulated by climate models. This difference might be explained by some combination of errors in external forcing, model response and internal climate variability.

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Climate model simulations of the AMO

by Judith Curry

What are the implications of climate model deficiencies in simulating multi-decadal natural internal variability  for IPCC’s climate change detection and attribution arguments?

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UK Met Office on the pause

by Judith Curry

The recent pause in global surface temperature rise does not, in itself, materially alter the risks  of substantial warming of the Earth by the end of this century. – UK Met Office

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Unforced variability and the global warming slow down

by Patrick Brown

How we interpret the current slow-down in the rate of global warming depends very much on the length of the ‘leash’ in the true climate system (i.e., how large internal variability is).

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