Any climate sceptic who takes on a debate in Australia encounters the GBR argument: even if the climate isn’t warming we are going to lose The Reef! This study finds a far more nuanced situation, with no catastrophe in progress.
In conclusion, precise estimates of coral cover from a dedicated monitoring program revealed that system-wide coral cover changed very little on the GBR between 1995 and 2009. Although coral cover averaged 29% across the whole GBR, previous studies indicate that coral cover was higher prior to when our surveys began. Nonetheless, there appears to be no evidence of continued system-wide decline since 1995. During this 16 year period, storms and A. planci predation had the largest impact on coral cover, especially at subregional scales (10–100 km), in terms of reefs affected, summed coral lost at all reefs, and amount of decline at individual reefs. The impact of bleaching and coral disease, to date, was not severe on our sites. There are a number of factors however, that suggest that the current disturbance regime may not be sustainable. One inshore reef, for example, had a phase shift from hard coral to macroalgae, similar to that which has occurred at much larger scales in the Carribbean . Corals with less capacity for growth and recruitment than Acroporidae had widespread negative trends. However, the abundance of Acroporidae species and relatively low anthropogenic agents of disturbance appears to place the GBR in a healthier state than the global average.
Roy Spencer provides more “Evidence that Global Warming is a False Alarm: A Model Simulation of the last 40 Years of Deep Ocean Warming.”
Yes, in Hansen’s worldview he thinks he KNOWS with certainty what the climate sensitivity is, and that it is pretty high. In that case, for a given amount of warming, you can figure out the net forcing.
The trouble is that there has not been as much warming as expected for high climate sensitivity and the forcing from increasing CO2, so Hansen has to find some COOLING influence that he presumes in canceling out much of the CO2 warming.
His latest thing is claiming we are experiencing a delayed rebound effect from Pinatubo cooling. I find this very unconvincing.
These folks will go through all kinds of contortions to preserve their belief in high climate sensitivity, because without that, there is no global warming problem.
Cox and Stockwell reported on the same point here …
But Hansen does not question the magnitude of warming from CO2 despite recent measurements showing CO2 heating may be saturated. Indeed, the need to increase the cooling of aerosols comes about because the large positive forcing from CO2 is held constant.
… and another view here from Geoff Davies, e.g.:
It claims Hansen merely assumed the warming effect of greenhouse gases is known, when in fact Hansen has clearly spelt out the independent evidence for this.
While this post was previously removed for publication purposes, the publication guidelines do allow discussion of papers under review on private blogs. The also allow submission of manuscripts to archives. The full text of an early version of the accumulation theory can be read here.