chubbs

Yes it is a step in the right direction but will need follow-up to be meaningful. Main reason it is voluntary is US and our strong political opposition to action.

CO2 emissions show recent evidence of stabilizing with a small 0.6% increase in 2014 and a 0.6% decrease projected for 2015. Main factors are a big slowdown in the growth of coal use in China and a general trend to less coal and more renewable energy elsewhere. While the future path is uncertain, it looks like following the unmitigated RCP8.5 pathway is becoming less likely. http://www.globalcarbonproject.org/carbonbudget/

2) The article you posted above states that the earth is even more sensitive to carbon dioxide than originally thought. Why then, since carbon emissions have been rising almost exponentially for decades with the rapid development of BRIC nations, has temperature maintained a more or less linear rate of increase? (Some might say there’s been a pause). Shouldn’t such sensitivity and strong correlation suggest we should have observed rapid temperature increase for some time? A couple of points: 1) GHG forcing is proportional to the log of CO2 in the atmosphere. So an exponential or constant percentage increase in CO2 in the atmosphere results in a linear increase in temperature. If atmospheric CO2 doubles it will take twice as much CO2 to have the same effect. 2) The yearly percentage increase in atmospheric CO2 depends on: man-made CO2 emissions, natural carbon sinks and the amount of CO2 already in the atmosphere. Recently atmospheric CO2 has been increasing by about 0.5% per year. This percentage rate has increased slowly and unevenly from roughly 0.3% per year in the 1960s. 3) The rate of increase in non-CO2 man-made GHGs, like methane and refrigerants, has slowed down since the 1980s. When you add the impact of non-CO2 GHG to CO2, the resulting equivalent CO2 concentration has been increasing by roughly 0.6% per year recently. 4) The rate of increase in man-made aerosals, which have a cooling effect, has slowed considerably since roughly 1970. When you put it all together man-made forcing increased slowly up to roughly 1970 and then began to increase faster in a roughly linear manner. The long-term global temperature trend fits the man-made forcing trend well. Note that man-made forcing increases slowly from year-to-year, so short-term pauses or spikes in temperatures from natural causes are to be expected.

Here is a recent video from Alley on CO2's role in past climates. This "minor" gas has kept the earth's climate well suited for life. http://climatestate.com/2015/07/31/richard-alley-4-6-billion-years-of-earths-climate-history-the-role-of-co2/

Yes we will have to adapt. We are inching to a global solution. The physics will push us there eventually.

Climate change is a global problem and will require a global solution. A carbon tax applied equally across the globe is the best solution. This would allow market economics to reduce emissions in the most cost-effective manner. Driving the best long-term energy technologies and regional emission strategies. It may or may not be cheaper to reduce emissions in China vs the US or other countries. Note that our current system is sub-optimal and has resulted in over-investment in fossil fuels, particularly coal. We are generating huge future liabilities to replace fossil energy infrastructure and pay for climate damages.

US public acceptance of AGW has rebounded to near previous peak - following the warming phase of the enso cycle? http://closup.umich.edu/issues-in-energy-and-environmental-policy/25/acceptance-of-global-warming-among-americans-reaches-highest-level-since-2008/

According to Citicorp reducing GHG is the low cost option. Clicking through to the underlying report provides a wealth of information on energy and climate economics. http://www.theguardian.com/environment/climate-consensus-97-per-cent/2015/aug/31/citi-report-slowing-global-warming-would-save-tens-of-trillions-of-dollars

April 2015 snowpack in the Sierra Nevada was 5% of normal - unprecedented in snowpack record and 500 year tree-ring proxy. http://www.nature.com/articles/nclimate2809.epdf?referrer_access_token=8U88K0Q

That is why they grid the radiosonde data. The radiosonde data lines up very well with the re-analysis data even over short time periods. You wouldn't get such close agreement if the radiosondes were missing important regional temperature trends.

Here is a chart from Christy's upper-air section in the 2014 BAMS state-of-the-climate. He uses RATPAC data and shows that it agrees very well with other upper-air datasets. http://www.ncdc.noaa.gov/bams-state-of-the-climate/

Nevins blog corrected their initial estimate to 12.5km2 down an order of magnitude from the original. Still a very significant event. With the calving, the glacier has retreated roughly 600m since last years max retreat (max retreat is usually in September) indicating that net mass losses continue in the glacier drainage.

2012 - 2019/20, 2013 - not in our lifetime - but I would have taken 2016-2020 if it was offered. Just eyeballing the trend line, looks like 2013 is more likely to occur than 2012 up until roughly 2018.

See the interviewers summary of the discussion below. It was a very informal discussion. I don't sense a desire to mislead or exaggerate on Hanson's part. We have had posts alleging that Hanson was to blame for climate denial by overstating climate impacts. After a little investigation we haven't found too many examples of exaggeration - just some bad reporting perhaps. On the other hand Anthony Watts plays fast and loose with the truth about Hanson and this becomes an internet myth. This gets repeated over and over again in the denier blogosphere. Our posters pick it up and there you are. Bob Reiss reports the conversation as follows: "When I interviewe­­d James Hansen I asked him to speculate on what the view outside his office window could look like in 40 years with doubled CO2. I'd been trying to think of a way to discuss the greenhouse effect in a way that would make sense to average readers. I wasn't asking for hard scientific studies. It wasn't an academic interview. It was a discussion with a kind and thoughtful man who answered the question. You can find the descriptio­­n in two of my books, most recently The Coming Storm."

According to skeptical science this is an internet myth that has been propagated by Anthony Watts. Hanson's original statement needs to be placed in the proper context. He was asked to speculate in a 1988 interview what the view from his office might look like in 40 years if CO2 doubled. The interviewer published Hanson's response in a book 10 years later, but in a subsequent interview for Salon the interviewer left out the doubled CO2 and shortened the time to 20 years. A key learning over the past few days - don't believe what you read on the internet about climate scientists. http://www.skepticalscience.com/Examining-Hansens-prediction-about-the-West-Side-Highway.html

Yes its silly to blame scientists for their communication limitations - that is what politicians and PR experts are for. Climate change happens over very long time frames and there is large uncertainty. Scientists who have a little clearer vision into the future have a huge communication challenge that they are not prepared for. The potential WAIS collapse is a good example.The impact is so large that it is difficult for most to fathom and our current science cannot provide any timing estimate. So messaging is difficult. No matter what is said most people find it too alarming to contemplate or far enough in the future to ignore. The flip side is effective communication by deniers/skeptics. Their job is much easier since they mainly aim to confuse and discredit. The key components are a few simple talking points repeated in a consistent and reinforcing manner combined with villains that many can identify with (liberals, lying scientists, big government etc).

I can see where it would be misleading if snippets were taken out of context. These posts stimulated me to read portions of his 1981 paper. While portions are dated and missed the mark, many of his 1981 predictions are very accurate. His discussion of WAIS could have been written today but was way ahead of his time. It would be the height of irony if his warning of a WAIS collapse turns out to be correct - and yet leads to inaction per the theory outlined above

I wasn't familiar with Hanson's testimony so I googled and came up with the document linked below based on his 2007 testimony. Its not nearly as bad as you suggest. Its very scientific in tone - unlikely to cause a reaction in anyone except those already of a skeptical bent. His temperature projections are close to consensus. Some of his effect projections are high end but I wouldn't call them outlandish. He says SLR could be 2 meters in 100 years due to mainly to WAIS.. At the time this was quite aggressive.Since then however much more has been published on ice sheet instability and WAIS in particular. His projection is still high end but it is moving into the range of possible outcomes. Blaming Hanson for climate denial/skepticism is a big exaggeration. I discuss climate with many skeptics. They mainly stick close to the denier talking points:: the data is fudged, the scientists are in cahoots to get grant money, temperatures haven't increased in 18 years, climate has always varied etc.. No one ever mentions Jim Hanson. For the most part people believe the story lines that fit in with their preconceived views. http://arxiv.org/abs/0706.3720

That is a ridiculous assertion. These predictions made by Hanson in a 1981 paper before global warming was even an issue have proven to be quite accurate. Unfortunately we didn't make much use of them. Hansen, J., D. Johnson, A. Lacis, S. Lebedeff, P. Lee, D. Rind, and G. Russell, 1981: Climate impact of increasing atmospheric carbon dioxide. Science, 213, 957-966, doi:10.1126/science.213.4511.957. The global temperature rose 0.2°C between the middle 1960s and 1980, yielding a warming of 0.4°C in the past century. This temperature increase is consistent with the calculated effect due to measured increases of atmospheric carbon dioxide. Variations of volcanic aerosols and possibly solar luminosity appear to be primary causes of observed fluctuations about the mean trend of increasing temperature. It is shown that the anthropogenic carbon dioxide warming should emerge from the noise level of natural climate variability by the end of the century, and there is a high probability of warming in the 1980s. Potential effects on climate in the 21st century include the creation of drought-prone regions in North America and central Asia as part of a shifting of climatic zones, erosion of the West Antarctic ice sheet with a consequent worldwide rise in sea level, and opening of the fabled Northwest Passage.

That's the rub though no one can identify a natural factor that fits the long-term pattern of warming as well as AGW.

I looked at the abstracts and didn't see anything that makes me want to read further. Why should I go to the trouble of reading and critiquing obscure papers. Would be much easier if you summarized the key science in the papers that supports low sensitivity.

The final report summarizing the recent Ringberg ECS workshop has been posted. The report is not earthshaking. The main recommendation is to focus research on the science needed to justify ECS below 2C and above 4C. The unstated implication is that ECS between 2 and 4C are reasonable in the absence of new science.. http://www.mpimet.mpg.de/en/science/the-atmosphere-in-the-earth-system/ringberg-workshop/ringberg-2014.html

Sure I just used 1979 because the NASA GHG forcing series starts then on the website. However we've been locked into a relatively steady T increase since around 1970. The rate of temperature increase per unit of forcing was lower before 1970 and particularly before 1900. That is one reason the energy balance ECS estimates that go back that far are lower.

Yes.I do not advocate estimating ECS or even TCR this way. It is just useful in producing mileposts to check progress. If temperature trends diverge from recent history then there is evidence for a change in behavior.

Sure it could be off, but the longer we maintain a relatively steady warming the more likely the the middle estimates are correct.