NASA says global climate change likely to be 'on hotter side of projections' (al.com)

[eppur_se_muova]

By Lee Roop | [email protected] The Huntsville Times
on November 09, 2012 at 10:08 AM, updated November 09, 2012 at 10:10 AM

BOULDER, Colorado -- In what NASA says could be "a breakthrough in the longstanding quest to narrow the range of global warming expected in the coming decades," scientists in a new analysis say they have found the most accurate climate models. Those models, unfortunately, show temperature increases in the coming century on the high side of the range now considered most likely.

Current climate models predict temperature increases in this century, if current carbon dioxide emission levels continue unchanged, at between 3 and 8 degrees Fahrenheit, compared to 19th century temperatures. The average prediction is 5 degrees. If this new study proves accurate, that would mean temperature increases on the upper end of the 3-to-8 degree range if nothing changes. The greater the temperature rise, the greater the effect on sea level rise, heat waves, droughts and other effects, the scientists say.

The new data analysis, published today in the journal Science, was funded by NASA and conducted by the National Center for Atmospheric Research in Boulder. NASA also released the findings on its website today. Scientists led by John Fasullo and Kevin Trenberth compared how well 16 leading climate models reproduced relative humidity recorded in the tropics and subtropics. They used NASA satellites and a NASA data analysis.

"There is a striking relationship between how well climate models simulate relative humidity in key areas and how much warming they show in response to increasing carbon dioxide," said Fasullo. "Given how fundamental these processes are to clouds and the overall global climate, our findings indicate that warming is likely to be on the high side of current projections."

NASA said the analysis is possible because satellite measurements of global relative humidity have become more reliable in recent years. They focused on the dry subtropics because seasonal drying and cloud decreases serve as a good analog of patterns projected by climate models.
***
more: http://blog.al.com/breaking/2012/11/global_warming_breakthrough_sa.html#incart_river_default

NASA Web post: http://www.nasa.gov/topics/earth/features/earth20121108.html

The UCAR post: https://www2.ucar.edu/atmosnews/news/8264/future-warming-likely-be-high-side-climate-projections-analysis-finds

Would post a link to the Science article, but it is behind a paywall.

[AverageJoe90]

1. If we keep up with business-as-usual, then yeah, that very well could happen.

The worst case scenario, btw, is actually higher than 8*F....it's about 6*C by 2100(and possibly a few more degrees after that), if we do nothing and if most or all plausible feedback theories play out as much as they can(that is, far worse than many would expect).

[joshcryer]

3. What do you fucking mean "if"?

We are. There's no if, ands, or buts, about it. We are. Rio+20 was the last attempt. There won't be another for a decade. BAU is the route we're on.

[AverageJoe90]

4. We don't really know for sure. And we shouldn't be assuming that it's inevitable either.

And frankly, if we keep telling everybody that it's inevitable no matter what, then guess what? If anything it'll only cause more people to stick their heads in the sand.(In fact, it kinda already has to a point)

TBH, success in all the various fields I can think of, from Civil Rights to labor protections, and many others, didn't come because people assumed that total failure was a given, that it was inevitable. No, it came because people dedicated themselves to the cause no matter whether or not they leaned towards pessimism or optimism.

[joshcryer]

5. What next big climate summit is planned for the next decade?

There ain't one. Yes, there are regular summits that happen every 6 months or so, but they're largely attended by NGOs. There won't be another United Nations Conference on Sustainable Development for 20 years. There is simply no evidence we plan to do squat about climate change.

[AverageJoe90]

6. Do the summits really necessarily matter?

They can be helpful, yes. But they're not necessarily needed for individual countries to take action. Just look at Obama's CAFE mandate for example. That's a pretty damn decent start.

There may not be much evidence out there to suggest drastic action on climate change, but there isn't much to suggest that we're really stuck on the BAU course, either. Let's do our part to nudge the needle towards the former, eh?

[joshcryer]

7. CAFE equals a 2% reduction, starting in 2016. Rio+20 will easily offset that.

The new CAFE standard was designed to bring down US oil dependence, not affect climate change.

There is no indication whatsoever that we're going off the BAU course. We're headlong in that direction.

[AverageJoe90]

8. We may be heading in that direction. but again,

it can still be turned around at some point.....though, TBH, I think that you and I can at least agree that it's better sooner than later.

[joshcryer]

9. I don't disagree.

It can be "turned around at any point."

We can spend 10 trillion a year to build out renewables.

We can spend 1 trillion a year to build a moon base with automated factories that build space based solar factories.

That doesn't mean that we will. We most certainly won't.

[AverageJoe90]

10. "That doesn't mean that we will. We most certainly won't."

We may not get around to building a moon base or whatever this century, but contrary to some people's beliefs, mitigation isn't nearly as expensive as some people might think it would be.

http://www.skepticalscience.com/solving-global-warming-not-easy-but-not-too-hard.html

One of the things what we need to do is keep educating people.

[joshcryer]

11. We need to spend 10% of global GDP every single year, at the minimum.

100+ trillion dollars. It's inconceivable how badly we're dealing with it. Anyone can do a pen and paper solution and come up with nonsense that won't be politically possible. The "wedges" solution is one of them. There is simply no political will to do it. As Rio+20 proves.

[AverageJoe90]

13. The "wedges" solution isn't nonsense.

Just because there may be political hurdles to overcome, doesn't mean it's nonsense. Hell, it looks like one of them may have already been achieved: CAFE is now requiring automakers to have an average mileage of 54 MPG or better by no later than 2025.

Remember this?

"Improved fuel economy: One wedge would be achieved if, instead of averaging 30 milesper gallon (mpg) on conventional fuel, cars in 2054 averaged 60 mpg, with fuel type and distance traveled unchanged. Given recent advances in hybrid and electric vehicle technology, this is a very plausible wedge."

[joshcryer]

15. The possiblity that the "wedges solution" is adopted is near zero.

As I said, a 2% reduction in light of Rio+20 is nothing, it's a joke. And since it doesn't come into effect until Obama is gone, there's no guarantee it will be implemented. The general solution is to create lighter, less safe, vehicles, that have a "smaller footprint" than those currently on the road. Consumers will be against the changes.

[AverageJoe90]

16. " The possiblity that the "wedges solution" is adopted is near zero." I wouldn't be so sure.........

Could it fail? Yes, perhaps. But could it succeed? Yes. Do we know what will happen yet? No.

[joshcryer]

17. Point me to one single piece of legislation that has the wedges solution.

You can't because it doesn't exist. It's not the legislative trajectory we or the world are on. Fact. Rio+20. Go back to it. Read about it. Complete failure. Nothing is going to fucking change.

[AverageJoe90]

18. Josh, we don't know that.

Just because we've had some failures in the past, doesn't automatically doom us to continue in that direction. We could, but it's really not inevitable, even some people may think otherwise for whatever reason.

[joshcryer]

2. One of the authors should post it to this page soon:

If you scroll down you can see that the author posts all of their work: http://www.cgd.ucar.edu/cas/Staff/Fasullo/index.html

In the meantime you can read the supplementals here: http://www.sciencemag.org/content/338/6108/792/suppl/DC1

If the author doesn't post the Science Mag article to his page in the next week or so I'll shoot him an email to give him a polite reminder. I'm sure he'll post it.

This is a dramatic, disgusting, incredible result that we really need to look at hard, because it means exactly the opposite for the climate that we would've expected. Less clouds is more warming, less precipitation, more dryness, it's a damn travesty.

[OKIsItJustMe]

12. A Less Cloudy Future: The Role of Subtropical Subsidence in Climate Sensitivity

The primary thrust of the paper is a method for “reducing the uncertainty in future projections.”

[font face=Serif][font size=5]A Less Cloudy Future: The Role of Subtropical Subsidence in Climate Sensitivity[/font]

John T. Fasullo* and Kevin E. Trenberth

[font size=4]An observable constraint on climate sensitivity, based on variations in mid-tropospheric relative humidity (RH) and their impact on clouds, is proposed. We show that the tropics and subtropics are linked by teleconnections that induce seasonal RH variations that relate strongly to albedo (via clouds), and that this covariability is mimicked in a warming climate. A present-day analog for future trends is thus identified whereby the intensity of subtropical dry zones in models associated with the boreal monsoon is strongly linked to projected cloud trends, reflected solar radiation, and model sensitivity. Many models, particularly those with low climate sensitivity, fail to adequately resolve these teleconnections and hence are identifiably biased. Improving model fidelity in matching observed variations provides a viable path forward for better predicting future climate.[/font]

[font size=3]Estimates of how much Earth’s global surface temperature would increase if the concentration of atmospheric carbon dioxide were double its pre-industrial concentration vary across climate models by a factor of about 2 (1). This metric, termed equilibrium climate sensitivity (ECS), serves as a canonical measure of climate model sensitivity to external changes. Differences across models cause considerable uncertainty in projected future climate. Despite substantial model improvements, the simulated range of ECS has changed little over the past several decades (2). This study therefore addresses the questions of what physical processes govern the spread of ECS among models, and whether model development efforts can be better directed at the goal of reducing this uncertainty.

Changes in clouds exert a primary influence on Earth’s energy budget and ECS. Clouds apparently act as a modest net positive feedback (3, 4), thereby amplifying changes due to anthropogenic influences, and most models capture this behavior (5–7). Constraining simulated clouds is a challenge, however, as clouds are complex and difficult to observe. The historical record is plagued by errors associated with the drift and failure of satellites, inconsistencies in the detection of clouds, and instrument biases (8). Moreover, clouds can vary not just in their bulk characteristics but also in their microphysical properties, for which global observations are lacking generally, and considerable uncertainty persists regarding the feedbacks of various cloud types that may occur in a changing climate (9). Hence, owing to the wide range of scales involved, cloud processes in models are often not represented explicitly but instead are parameterized and tuned. Although there is some anticipation that new satellite programs may begin to address observational issues, and model resolution is improving, it is likely to be several decades before observations provide an adequate constraint on models.

We propose an approach for circumventing many of these issues that emphasizes constraints on the environment in which clouds occur, rather than on the clouds themselves. Doing so provides a robust and physically based framework for reducing uncertainty about future climate through the use of readily available observations. Variations in clouds and relative humidity (RH) are inherently linked in nature, and the approach here is motivated by the fact that models generally use RH to parameterize clouds (e.g., fig. S1). Tropospheric RH is proposed as a particularly useful diagnostic because it also is strongly linked to the dynamics of the overturning circulation, for which observable constraints are weak (9). Although it is known that biases exist in the simulated mean state of RH and that a modest relationship exists between its biases and model sensitivity (10), the reasons for the simulated variability of RH remain poorly understood, and constraints linking present-day variations to future climate have not yet been thoroughly explored. Whereas some model fields, such as clouds and the planetary energy budget, are generally tuned (11) to observations, the vertical structure of the troposphere is not. However, observations of RH through the full depth of the troposphere are readily available, including those from microwave observations from operational NOAA satellites and the AIRS (Atmospheric Infrared Sounder) instrument aboard NASA’s Aqua satellite since July 2002. Along with balloon-borne measurements, they provide a solid baseline of both the mean state and variability across a range of time scales.

…[/font][/font]

[Kablooie]

14. Today is a good day to die.