Missing News: that climate sensitivity thing again

ABC have ignored the work of Nic Lewis and Judy Curry, their new paper may change this! The results provide further evidence that human impacts on climate will be minor.

The implications for climate sensitivity of AR5 forcing and heat uptake estimates

• Nicholas Lewis,
• Judith A. Curry

Abstract

Energy budget estimates of equilibrium climate sensitivity (ECS) and transient climate response (TCR) are derived using the comprehensive 1750–2011 time series and the uncertainty ranges for forcing components provided in the Intergovernmental Panel on Climate Change Fifth Assessment Working Group I Report, along with its estimates of heat accumulation in the climate system. The resulting estimates are less dependent on global climate models and allow more realistically for forcing uncertainties than similar estimates based on forcings diagnosed from simulations by such models. Base and final periods are selected that have well matched volcanic activity and influence from internal variability. Using 1859–1882 for the base period and 1995–2011 for the final period, thus avoiding major volcanic activity, median estimates are derived for ECS of 1.64 K and for TCR of 1.33 K. ECS 17–83 and 5–95 % uncertainty ranges are 1.25–2.45 and 1.05–4.05 K; the corresponding TCR ranges are 1.05–1.80 and 0.90–2.50 K. Results using alternative well-matched base and final periods provide similar best estimates but give wider uncertainty ranges, principally reflecting smaller changes in average forcing. Uncertainty in aerosol forcing is the dominant contribution to the ECS and TCR uncertainty ranges.

Missing News: Climate sensitivity

A new GWPF report on climate sensitivity by Nic Lewis and Marcel Crok with introduction by Judy Curry.

Take home message:
"Only in recent years has it become possible to make good empirical estimates of climate sensitivity from observational data such as temperature and ocean heat records. These estimates, published in leading scientific journals, point to climate sensitivity per doubling most likely being under 2◦C for long-term warming, and under 1.5◦C over a seventy-year period. This strongly suggests that climate models display too much sensitivity to carbon dioxide concentrations and in almost all cases exaggerate the likely path of global warming."

"The new information on climate sensitivity suggests that even with relatively high emissions the government’s two-degree limit for global warming is likely to be reached only towards the end of the century."
Once again the tumbleweeds roll around ABC's news room as yet another good news story fails to breach its walls of groupthink.

More on climate sensitivity

Since starting the blog we have run a few articles covering ABC's reluctance to cover any stories that run against the CAGW meme. The C being for Catastrophic. The notion of "Luke"warming just as distasteful to ABC's activist ashen cloth reporters as the notion of no warming or even cooling. It's a weird form of doomsday syndrome funded by the Australia taxpayer.

Judy Curry, a climate expert that the ABC has so far avoided speaking with, provides a link and commentary to a series of submissions to the UK Parliament's review of the IPCC 5th assessment report. Amongst the submissions and definitely newsworthy is a piece by Nic Lewis.

On this Curry states:
A number of submissions make scientific arguments that they believe refute the IPCC’s conclusions.  Of these, Nic Lewis‘ submission is a tour de force.  Not surprisingly, his submission is on the topic of climate sensitivity. This is the clearest explanation I’ve seen of the problems with the IPCC’s arguments regarding climate sensitivity.


The intro and summary to Lewis'submission reads as follows:
Introduction and summary
1. The terms of reference for this inquiry ask various questions. I address the following 
questions; my related conclusions are italicised.

•  How robust are the conclusions in the AR5 Physical Science Basis report (AR5-WG1)? 

In the central area of climate sensitivity, they are misleading. The substantial divergence 
between sensitivity estimates from, on the one hand, satisfactory studies based on 
instrumental observations over an extended period and, on the other hand, from flawed 
studies and from computer models was not brought out.

• Does the AR5 address the reliability of climate models? 

Not adequately. Shorter-term warming projections by climate models have been scaled 
down by 40% in AR5, recognising that they are unrealistically high. But, inconsistently, no 
reduction has been made in longer term projections.

• Do the AR5 Physical Science Basis report’s conclusions strengthen or weaken the economic case for action to prevent dangerous climate change? 

Although the conclusions fail to say so, the evidence in AR5-WG1 weakens the case since it 
indicates the climate system is less sensitive to greenhouse gases than previously thought.

Missing News: That climate sensitivity thing again

ABC take any and every chance to jump on news that supports an alarmist take global warming, however when the news fits a different picture, only crickets to be heard in those drab Ultimo corridors.

Heat going out of global temperature rises

GLOBAL temperature increases as a result of increased carbon dioxide levels in the Earth's atmosphere are likely to be lower than previously thought, an international research team has found.

The Oxford University-led study found that a predicted doubling of CO2 concentrations, expected to occur later this century, is likely to raise global temperatures in the short term by between 1.3C and 2C.

Update: ABC play catch up but fail to see the internal contradictions in their reporting. On the one the headline reads...New reports suggests global warming could be slower than first thought yet somehow this supports the notion that the "Longer-term warming trend will not change". Seems a few reporters forgot to pack their brains before heading off to Palais Ultimo this morning!

As for natural cycles being responsible, this has been the case of sceptical scientists for sometime, but you wouldn't have read about it on the ABC, because it doesn't fit their alarmist message.

Missing News: lower climate sensitivity

WUWT reports on a paper reportedly "in press*" in the journal Science that finds climate sensitivity to increased CO2 is less than previously thought. Seems those predictions about extreme events our climate commission is so fond of may require some re-thinking. Let's see how long it takes for the ABC to cover this important result.

Schmittner, A., et al., 2011. Climate sensitivity estimated from temperature reconstructions of the Last Glacial Maximum, Science, in press*,http://www.princeton.edu/~nurban/pubs/lgm-cs-uvic.pdf

ABSTRACT
Assessing impacts of  future  anthropogenic carbon emissions is currently  impeded by uncertainties in our  knowledge  of  equilibrium  climate sensitivity to  atmospheric  carbon dioxide doubling. Previous studies suggest 3 K as best estimate, 2–4.5 K as the 66% probability range,  and non-zero probabilities  for much higher values, the latter implying  a small but significant chance  of  high-impact climate changes that would be difficult to avoid.  Here, combining extensive sea and land surface temperature reconstructions from the Last Glacial Maximum with climate model simulations we estimate a lower median (2.3 K) and reduced uncertainty (1.7–2.6 K 66% probability).  Assuming paleoclimatic constraints apply to  the future as predicted by our model, these results imply lower probability of imminent extreme climatic change than previously thought.


*According to the authors