Environment & Energy
Related: About this forumGood news on Climate Change front
Several peer reviewed papers say we probably have more time to act on climate change than was originally thought. All of the urgency to lower CO2 emissions stem from computer model projections that say the 2C target might be exceeded as soon as 2040 if economic and population growth continue as they have. However, observed temperature changes over the last 15-20 years now make that prediction seem extremely unlikely. Moreover, new evidence suggests that those climate models are using climate sensitivity figures that are twice the actual figure, meaning we have more time than we originally thought to avoid a 2 degree increase in global temperatures.
http://link.springer.com/article/10.1007%2Fs00382-014-2342-y#page-1
http://www.researchgate.net/publication/260740743_Bayesian_estimation_of_climate_sensitivity_based_on_a_simple_climate_model_fitted_to_observations_of_hemispheric_temperatures_and_global_ocean_heat_content
http://www.iac.ethz.ch/people/knuttir/papers/otto13nat.pdf
http://www.earth-syst-dynam.net/5/139/2014/esd-5-139-2014.html
edgineered
(2,101 posts)Cheap_Trick
(3,918 posts)caraher
(6,279 posts)I think not. The 2C target is pretty arbitrary, nobody really knows the impacts of lesser changes, even half the rate of increase promises risk of enormous problems.
I would agree that knowing more about the actual rate of increase is important in making policy decisions. And I would agree that lower-than-previously-believed climate sensitivity would indeed be good news.
But all these estimates have huge uncertainties. RealClimate has two commentaries on some of the research you present. Michael Mann's remarks conclude
In a similar vein, Oxford's Richard Millar concludes his commentary on the Lewis and Curry paper by pointing out
It would appear that we're working with the boundary between "doomers are right" and "we can maybe just manage this problem with urgent action," rather than the boundary between the latter and taking our sweet time to figure out what to do...
RiverLover
(7,830 posts)Monday 1 September 2014 07.34 EDT
Scientists reveal Greenland and Antarctica losing 500 cubic kms of ice annually, reports Climate News Network
"German researchers have established the height of the Greenland and Antarctic ice caps with greater precision than ever before. The new maps they have produced show that the ice is melting at an unprecedented rate.
...Overall, the southern continent ? 98% of which is covered with ice and snow ? is losing 125 cubic km a year. These are the highest rates observed since researchers started making satellite observations 20 years ago."
http://www.theguardian.com/environment/2014/sep/01/new-satellite-maps-show-polar-ice-caps-melting-at-unprecedented-rate
Also, must see~~
http://www.upworthy.com/they-took-a-camera-to-a-remote-area-in-greenland-and-what-they-recorded-is-simply-terrifying?c=upw1
LouisvilleDem
(303 posts)Ironically, studies have shown that an open northwest passage for shipping will actually reduce CO2 emissions significantly.
truebrit71
(20,805 posts)Thanks!
LouisvilleDem
(303 posts)Just to be clear, when I said "reduce CO2 emissions significantly", I did not mean to imply that global CO2 emissions would actually decline as a result.
NickB79
(19,258 posts)Your post about reducing CO2 via the Northwest Passage is like telling a chemotherapy patient "Hey, but think of all the money you'll save on haircuts and mousse now that all your hair fell out!"
Nihil
(13,508 posts)Sigh.
Viking12
(6,012 posts)According to your source, "Using a trans-polar route may reduce global CO2 emissions from ships by roughly 0.1 % in 2030 and 0.15 % in 2030 and 2050, respectively" (p.19).
and...what about this? "Based on certain assumptions about hydrocarbon reserves in the Arctic and their development and an oil price of $80/boe, CO2 emissions from shipping related to oil and gas production (tankers and service vessels) in the Arctic was estimated to be 40 % higher than the CO2 emissions from Arctic transit traffic in 2030 and about twice that from transit traffic in 2050" (p.19).
In other words, the tiny reduction in emissions via shipping will be overwhelmed by the emissions from increased carbon production in the Arctic.
Fail.
LouisvilleDem
(303 posts)...is a wonderful thing.
Viking12
(6,012 posts)Quit trying to dodge the question.
LouisvilleDem
(303 posts)I think you missed something--or deliberately decided to ignore it.
Viking12
(6,012 posts)If, as you now admit, the arctic route won't reduce shipping emissions significantly, what exactly are you referring to when you say it will significantly reduce emissions?
Viking12
(6,012 posts)I am so glad 4 cherry-picked papers can so easily upset the balance of evidence.
http://scholar.google.com/scholar?hl=en&q=climate+sensitivity&btnG=&as_sdt=1%2C50&as_sdtp=
http://www.realclimate.org/index.php/archives/2014/10/climate-response-estimates-from-lewis-curry/
http://blog.ucsusa.org/wall-street-journal-offers-a-skewed-climate-perspective-from-judith-curry-681
LouisvilleDem
(303 posts)And no, a link to a Google Scholar search result does not count. I believe it would be interesting to find out just how many papers in the last four years place climate sensitivity below the 2.5 C figure that climate models tend to use.
Viking12
(6,012 posts)Why isn't the list of papers provided via google scholar useful? Because the majority of them contradict your pollyanish view?
LouisvilleDem
(303 posts)Your link was to the results of a Google Scholar search on the words "climate sensitivity". It is not useful because it simply returns a list of any papers published with the words "climate sensitivity" in it, regardless of when it was published, or whether it supports your view or mine. In sum, it proves absolutely nothing.
caraher
(6,279 posts)It's worth remembering that peer-reviewed literature is never the last word, with results that are mostly not obviously wrong. The current literature in any field of active research ought to contain some contradictions and disagreements. But since you asked for different views from the peer-reviewed literature, here are a few, followed by the end of a paper in preparation by an economist asking what the policy conclusion should be based on recent reassessments of climate sensitivity (hint: it's not using papers suggesting the low end of the range and concluding we need not take swift action)
A Nature abstract
Despite important advances in other areas of climate science, we have discovered new uncertainties that make us even less confident about the range of equilibrium climate sensitivity than we were before the publication of the latest IPCC report. Given the increasing marginal costs of global warming, greater uncertainty, other factors equal, has an unambiguous implication for policy. It raises the return for taking action to curb greenhouse emissions.
Abstract of Nature: Climate Change paper concluding that the lowest end of sensitivity estimates is unlikely:
Another abstract, this from Geophysical Research Letters. What's interesting here is that they assess how much data would be needed to really nail down climate sensitivity, and by this analysis we're 15 years' worth short of being able to make with confidence the distinction between the lower values in the papers touted in the OP and 3 degrees.
This is from a non yet peer-reviewed draft paper from an economist, but speaks to what we ought to conclude concerning policy from revised estimates. The conclusion:
Despite important advances in other areas of climate science, we have discovered new uncertainties that make us even less confident about the range of equilibrium climate sensitivity than we were before the publication of the latest IPCC report. Given the increasing marginal costs of global warming, greater uncertainty, other factors equal, has an unambiguous implication for policy. It raises the return for taking action to curb greenhouse emissions.
LouisvilleDem
(303 posts)However, only the first paper in your list that actually supports the idea that climate sensitivity is more than 3 degrees. The second merely says a number below 1.3 is very unlikely, the third describes how much time would have to pass before we can accurately determine what climate sensitivity is, and as far as I can tell, the last one says absolutely nothing about what climate sensitivity is, but rather discusses the impact of increasing uncertainty in the measurement.
OKIsItJustMe
(19,938 posts)[font size=5]Judith Curry is Back Advocating Climate Inaction in the Wall Street Journal[/font]
This is a guest post by Climate Nexus.
[font size=3]Judith Currys latest op-ed in the Wall Street Journal touts her new study co-authored with Nic Lewis. The takeaway of the piece - that the need for emissions reductions is less urgent than policymakers assume is not even supported by her own study, much less the scientific mainstream.
Curry provides a highly biased and skewed overview of climate sensitivity studies, which makes sense for publication in the Wall Street Journal. In reality, the IPCC sensitivity estimate remains the most reliable and comprehensive expression of the state of knowledge on the topic, and scientists agree that this sensitivity range implies an urgent need for climate action.
- Currys study doesnt reveal new information that would affect IPCC estimates.
- She examines only a small group of studies that agree with her conclusion, while the IPCC took many additional methods and factors into account.
- Even low climate sensitivities still carry an urgent need to reduce greenhouse gas pollution.
- Curry has growing ties to denier groups and her consulting business serves fossil fuel companies.
NickB79
(19,258 posts)The Arctic ice shelves in mass retreat, species rapidly migrating north, the Antarctic ice sheets in a now-unstoppable slide into the ocean, ocean acification already damaging fisheries and reefs, etc.
It's abundantly clear that "only" 2C of warming is not safe in any sense of the word.