Need to know????

[Michael Larson]

SOLAR MINIMUM VS. GLOBAL WARMING: From 2002 to 2008, decreasing solar irradiance has countered much anthropogenic warming of Earth's surface.

That's the conclusion of researchers Judith Lean (NRL) and David Rind (NASA/GISS), who have just published a new analysis of global temperatures in the Geophysical Research Letters.

Lean and Rind considered four drivers of climate change: solar activity, volcanic eruptions, ENSO (El Nino), and the accumulation of greenhouse gases. The following plot shows how much each has contributed to the changing temperature of Earth's surface since 1980:

Volcanic aerosols are a source of cooling; ENSO and greenhouse gases cause heating; the solar cycle can go either way. When added together, these factors can account for 76% of the variance in Earth's surface temperature over the past ~30 years, according to the analysis of Lean and Rind.

Several aspects of their model attract attention: "The warmest year on record, 1998, coincides with the 'super-El Nino' of 1997-98," points out Lean. "The ESNO is capable of producing significant spikes in the temperature record." Solar minimum has the opposite effect: "A 0.1% decrease in the sun's irradiance has counteracted some of the warming action of greenhouse gases from 2002 - 2008," she notes. "This is the reason for the well-known 'flat' temperature trend of recent years."

What's next? Ultimately, the authors say, temperatures will begin rising again as greenhouse gases accumulate and solar activity resumes with the coming of the next solar cycle. Of couse, the solar cycle could be out of whack; if solar minimum deepens and persists, no one is certain what will happen. Lean and Rind reveal their predictions for the future here.

Reference: Lean, J. L., and D. H. Rind (2009), How will Earth's surface temperature change in future decades?, Geophys. Res. Lett., 36, L15708

[Michael Larson]

Treemometers: A new scientific scandal

If a peer review fails in the woods...

By Andrew Orlowski • Get more from this author
Posted in Environment, 29th September 2009 16:03 GMT

A scientific scandal is casting a shadow over a number of recent peer-reviewed climate papers.

At least eight papers purporting to reconstruct the historical temperature record times may need to be revisited, with significant implications for contemporary climate studies, the basis of the IPCC's assessments. A number of these involve senior climatologists at the British climate research centre CRU at the University East Anglia. In every case, peer review failed to pick up the errors.

What went wrong?

The scandal has serious implications for public trust in science. The IPCC's mission is to reflect the science, not create it.

As the panel states, its duty is "assessing the scientific, technical and socioeconomic information relevant for the understanding of the risk of human-induced climate change. It does not carry out new research nor does it monitor climate-related data." But as lead author, Briffa was a key contributor in shaping (no pun intended) the assessment.

A small group was able to rewrite history.

When the IPCC was alerted to peer-reviewed research that refuted the idea, it declined to include it. This leads to the more general, and more serious issue: what happens when peer-review fails - as it did here?

The scandal has only come to light because of the dogged persistence of a Canadian mathematician who attempted to reproduce the results. Steve McIntyre has written dozens of letters requesting the data and methodology, and over 7,000 blog posts. Yet Yamal has remained elusive for almost a decade. ®

[George A. H. Luck]

Leave it to a bloody Canadain to upset the apple cart!!