Archives for March 11, 2008

According to an analysis by Scafetta and West published in the March edition of Physics Today (subscription required), the Sun ‘could account for as much as 69% of the increase in Earth’s average temperature.’

Article title: “Is climate sensitive to solar variability?” By Nicola Scafetta of Duke University Physics Department and Bruce J. West of the US Army Research Office, Research Triangle Park, North Carolina

Excerpt: “Thus the average global temperature record presents secular patterns of 22- and 11-year cycles and a short time-scale fluctuation signature (with apparent inverse power-law statistics), both of which appear to be induced by solar dynamics. The same patterns are poorly reproduced by present-day GCMs and are dismissively interpreted as internal variability (noise) of climate. The nonequilibrium thermodynamic models we used suggest that the Sun is influencing climate significantly more than the IPCC report claims. If climate is as sensitive to solar changes as the above phenomenological findings suggest, the current anthropogenic contribution to global warming is significantly overestimated. We estimate that the Sun could account for as much as 69% of the increase in Earth’s average temperature, depending on the TSI reconstruction used. Furthermore, if the Sun does cool off, as some solar forecasts predict will happen over the next few decades, that cooling could stabilize Earth’s climate and avoid the catastrophic consequences predicted in the IPCC report.”

This article is based on Scafetta and West’s previously published peer reviewed papers.

Yes, I know Real Climate are exceedingly rude about this work and RC are entitled to their politically motivated views, just as Scafetta and West are entitled to their’s.

Update: Full article now available here.

A new paper published in Science magazine suggests that ocean the floors are getting deeper and sea levels have fallen by about 170 meters (560 ft) since the Cretaceous period 80 million years ago, due to tectonic shifts. Previous estimates were between 40 to 250 meters. On this basis of this work, a fall of 120 metres is expected over the next 80 million years, which equates to just 0.015 centimetres per century. Not much when we we consider IPCC projections of sea level rise. That said, the IPCC seems to have abandoned decadal projections in their latest report and gone for a 90-year projection, following the accuracy failures of the 1990, 1995 and 2001 reports. See the January 15th post over at Prometheus: Verification of IPCC Sea Level Rise Forecasts 1990, 1995, 2001.

The research article is entitled: ‘Long-Term Sea-Level Fluctuations Driven by Ocean Basin Dynamics’

The first paragraph reads:

Earth’s long-term sea-level history is characterized by widespread continental flooding in the Cretaceous period (145 to 65 million years ago), followed by gradual regression of inland seas. However, published estimates of the Late Cretaceous sea-level high differ by half an order of magnitude, from 40 to 250 meters above the present level. The low estimate is based on the stratigraphy of the New Jersey margin. By assimilating marine geophysical data into reconstructions of ancient ocean basins, we model a Late Cretaceous sea level that is 170 (85 to 270) meters higher than it is today. We use a mantle convection model to suggest that New Jersey subsided by 105 to 180 meters in the past 70 million years because of North America’s westward passage over the subducted Farallon plate. This mechanism reconciles New Jersey margin–based sea-level estimates with ocean basin reconstructions.

The paper is also reported by Reuters, with their usual perspective on climate change.