Category Archives: Attribution

Atlantic vs Pacific vs AGW

Posted on August 28, 2014 by | 390 comments

by Judith Curry

I hope this will lead to a broader discussion about the contribution of natural variability to local climate trends and to the statistics of extreme events. – John Michael Wallace

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390 Comments

Posted in Attribution

The 50-50 argument

Posted on August 24, 2014 by | 833 comments

by Judith Curry

Pick one:

a)  Warming since 1950 is predominantly (more than 50%)  caused by humans.

b)  Warming since 1950 is predominantly caused by natural processes.

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833 Comments

Posted in Attribution, Uncategorized

Cause of hiatus found deep in the Atlantic Ocean

Posted on August 21, 2014 by | 421 comments

by Judith Curry

Rapid warming in the last three decades of the 20th century, they found, was roughly half due to global warming and half to the natural Atlantic Ocean cycle that kept more heat near the surface. When observations show the ocean cycle flipped, the current began to draw heat deeper into the ocean, working to counteract human-driven warming. – Chen and Tung

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421 Comments

Posted in Attribution

Role of Atlantic warming(?) in recent climate shifts

Posted on August 5, 2014 by | 180 comments

by Judith Curry

Record breaking trade winds may have led to hiatus in global surface average temperatures.

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180 Comments

Posted in Attribution

Disentangling forced from intrinsic climate variability

Posted on July 9, 2014 by | 323 comments

by Marcia Wyatt

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

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323 Comments

Posted in Attribution

Explaining(?) abrupt climate change

Posted on June 4, 2014 by | 152 comments

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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152 Comments

Posted in Attribution, Polar regions

Curry versus Trenberth

Posted on April 11, 2014 by | 431 comments

by Judith Curry

At the Conference for World Affairs, in Boulder Colorado.

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431 Comments

Posted in Attribution, Data and observations

Evidence of absence versus absence of evidence

Posted on April 1, 2014 by | 479 comments

By Judith Curry

Does global warming make extreme weather events worse?

 

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479 Comments

Posted in Attribution, Scientific method

Causes and implications of the pause

Posted on March 4, 2014 by | 432 comments

by Judith A. Curry

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

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432 Comments

Posted in Attribution

The Big Question

Posted on January 29, 2014 by | 556 comments

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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556 Comments

Posted in Attribution

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

Posted on January 23, 2014 by | 600 comments

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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600 Comments

Posted in Attribution

The case of the missing heat

Posted on January 20, 2014 by | 793 comments

by Judith Curry

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

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793 Comments

Posted in Attribution

Is global warming causing the polar vortex?

Posted on January 7, 2014 by | 332 comments

by Judith Curry

In a word, no.

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332 Comments

Posted in Attribution

Blame game

Posted on January 2, 2014 by | 282 comments

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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282 Comments

Posted in Attribution, Policy

Interpretation of UK temperatures since 1956

Posted on November 15, 2013 by | 432 comments

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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432 Comments

Posted in Attribution, Data and observations

Words of wisdom from Ed Lorenz

Posted on October 13, 2013 by | 314 comments

by Judith Curry

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

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314 Comments

Posted in Attribution

Spinning the climate model-observations comparison. Part III

Posted on October 13, 2013 by | 223 comments

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

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223 Comments

Posted in Attribution

The stadium wave

Posted on October 10, 2013 by | 1,198 comments

by Judith Curry

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

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1,198 Comments

Posted in Attribution

Understanding multi-decadal climate changes

Posted on October 8, 2013 by | 390 comments

by Judith Curry

Natural internal climate variability is getting some welcome attention.

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390 Comments

Posted in Attribution

IPCC’s pause ‘logic’

Posted on September 30, 2013 by | 426 comments

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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426 Comments

Posted in Attribution, IPCC

95% (?)

Posted on September 27, 2013 by | 524 comments

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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524 Comments

Posted in Attribution, IPCC

Natural internal variability: sensitivity and attribution

Posted on September 3, 2013 by | 568 comments

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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568 Comments

Posted in Attribution

Pause politics

Posted on August 30, 2013 by | 250 comments

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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250 Comments

Posted in Attribution, IPCC, Politics

What is internal variability?

Posted on August 29, 2013 by | 379 comments

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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379 Comments

Posted in Attribution

Pause tied to equatorial Pacific surface cooling

Posted on August 28, 2013 by | 492 comments

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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492 Comments

Posted in Attribution, climate models