Mathematics show climate model wrong

For discussion of life's issues: current events, social trends and personal opinions.

Moderators: Tunnelcat, Jeff250

Post Reply
User avatar
woodchip
DBB Benefactor
DBB Benefactor
Posts: 17674
Joined: Tue Jul 06, 1999 2:01 am

Mathematics show climate model wrong

Post by woodchip »

Seems there is a Australian scientist who has found errors in how data is applied to the climate models:

A MATHEMATICAL discovery by Perth-based electrical engineer Dr David Evans may change everything about the climate debate, on the eve of the UN climate change conference in Paris next month.

A former climate modeller for the Government’s Australian Greenhouse Office, with six degrees in applied mathematics, Dr Evans has unpacked the architecture of the basic climate model which underpins all climate science.

He has found that, while the underlying physics of the model is correct, it had been applied incorrectly.

He has fixed two errors and the new corrected model finds the climate’s sensitivity to carbon dioxide (CO2) is much lower than was thought.

It turns out the UN’s Intergovernmental Panel on Climate Change has over-estimated future global warming by as much as 10 times, he says.

“Yes, CO2 has an effect, but it’s about a fifth or tenth of what the IPCC says it is. CO2 is not driving the climate; it caused less than 20 per cent of the global warming in the last few decades”.


Read more: http://therightscoop.com/australian-sci ... z3oGjfPnMl

So all this talk about "consensus science" was all based on incorrectly applied physics. Galileo anyone?
Liberal speak: "Convenience for you means control for him, free and the price is astronomical, you're the product for sale". Neil Oliver

Leftist are Evil, and Liberals keep voting for them. Dennis Prager
User avatar
sigma
DBB Fleet Admiral
DBB Fleet Admiral
Posts: 2840
Joined: Fri Dec 07, 2012 6:24 am
Location: Moscow

Re: Mathematics show climate model wrong

Post by sigma »

Scientists can adjust how much they like climate models, but the fact remains - a dramatic global warming began with the development of the industry in the early 20th century and the warming continues to increase steadily in comparison with the pre-industrial era weather statistics.
User avatar
Ferno
DBB Commie Anarchist Thug
DBB Commie Anarchist Thug
Posts: 15016
Joined: Fri Nov 20, 1998 3:01 am

Re: Mathematics show climate model wrong

Post by Ferno »

Warmest summer on record, ever.
User avatar
woodchip
DBB Benefactor
DBB Benefactor
Posts: 17674
Joined: Tue Jul 06, 1999 2:01 am

Re: Mathematics show climate model wrong

Post by woodchip »

Since neither of you is competent to reply I'll not bother to comment. I would value Lothar or Drakona's thoughts.
Liberal speak: "Convenience for you means control for him, free and the price is astronomical, you're the product for sale". Neil Oliver

Leftist are Evil, and Liberals keep voting for them. Dennis Prager
User avatar
sigma
DBB Fleet Admiral
DBB Fleet Admiral
Posts: 2840
Joined: Fri Dec 07, 2012 6:24 am
Location: Moscow

Re: Mathematics show climate model wrong

Post by sigma »

woodchip wrote:Since neither of you is competent to reply I'll not bother to comment. I would value Lothar or Drakona's thoughts.
If you think that only opinions of Lothar and Drakona are competent for you, then you need to specify at the beginning of a new topic that the discussion of your topics is addressed only to them.
User avatar
Ferno
DBB Commie Anarchist Thug
DBB Commie Anarchist Thug
Posts: 15016
Joined: Fri Nov 20, 1998 3:01 am

Re: Mathematics show climate model wrong

Post by Ferno »

woodchip wrote:Since neither of you is competent to reply I'll not bother to comment. I would value Lothar or Drakona's thoughts.
yes because denialism in the face of overwhelming evidence is so in vogue these days.
User avatar
Tunnelcat
DBB Grand Master
DBB Grand Master
Posts: 13320
Joined: Sat Mar 24, 2007 12:32 pm
Location: Pacific Northwest, U.S.A.

Re: Mathematics show climate model wrong

Post by Tunnelcat »

2 very dry and hot summers and snowless winters in a row here. With another strong El Nino, it looks like we're headed into a third dry winter, in the normally very wet Pacific NW. Our mountains are bare and the permanent glaciers have receded dramatically. I've also personally noticed that the trees in our locale, and apparently the same in happening in Vermont and the NE, are waiting a lot later into the fall to turn color and drop their leaves. Many trees have moved their leaf color change and drop from October into November or December. I never saw that happen when I was a kid.

http://modernfarmer.com/2014/09/will-le ... ed-planet/

If you don't think this has an economic impact on anyone, think again.

http://www.livescience.com/39820-climat ... eaves.html
Cat (n.) A bipolar creature which would as soon gouge your eyes out as it would cuddle.
User avatar
vision
DBB Material Defender
DBB Material Defender
Posts: 4337
Joined: Thu Feb 18, 2010 1:54 pm
Location: Mars

Re: Mathematics show climate model wrong

Post by vision »

Here are some problems, tracing back from your post. The link points to an article on a right-wing website where many of the headlines contain multiple exclamation points, excessive use of capital letters, and actual LOLs, including the title of this article:
  • "Australian scientist discovers ERRORS in Global Warming models that COMPLETELY undermine climate theory!!!"
Other headlines include:
  • "LOL! Democrat Chair can’t bring herself to say that socialist Bernie would beat any Republican"
    "New POLL has Hillary COLLAPSING by DOUBLE DIGITS in just FIVE DAYS!!"
    "Katie Pavlich OBLITERATES FIVE liberal myths on gun violence and gun control!"
The article you provided ends with the partisan jab:
  • "And you can bet that Obama will stay on track to destroy the ingenuity of American industry for the sake of a discredited hoax…"
Anyone who is a true skeptic would immediately see this as politicizing climate change, which is exactly what the deniers (those poor, persecuted victims) claim out pro-climate change system does. (Of course, if we really did have a pro-climate change system then there would be a hell of a lot more done to combat it.)

But let's move on, shall we?

There is no link to the original source, that is, Dr Evans own words. A quick search for Dr David Evans reveals he is a known climate denier. But of course, being a denier doesn't mean you automatically are discredited, but his new "theory" isn't a finding published in a scientific journal — it is from a series of blog posts on an Australian climate denier website, which naturally is littered with advertisements for anti-climate change books. (And they talk about pro-climate change being about making money? Ha!)

That said, we can get right to Dr Evans theory, which starts out by reiterating the long discredited idea "it's the sun" and then goes on and on about CO2 as if it is the only greenhouse gas, which it isn't. The crux of his argument is that current models treat radiative forcing as if the Earth was a true blackbody at infrared, which may or may not make a difference. Then he goes on the apply a different radiative forcing model, but then seems to arbitrarily fit his model into past data so it matches the also discredited "warming pause."

What to make of this? An interesting theory that might be useful to create better models, but he doesn't seem to be viewing the whole picture. I'll wait until he publishes some work that is reviewed by climate scientists before I take this seriously.
User avatar
Top Gun
DBB Master
DBB Master
Posts: 8021
Joined: Wed Nov 13, 2002 3:01 am

Re: Mathematics show climate model wrong

Post by Top Gun »

It looks like vision already beat me to trying to follow this back to the source. I don't necessarily mind the initial link coming from an obviously-biased site, but as always you need to follow the bread crumbs backwards. It does appear that Dr. Evans has an academic background, and I won't deny his qualifications in his fields, but even he himself states that he is not a climate-modeling expert. The biggest red flag for me is that all he really offers are posts on a private blog, without a single peer-reviewed scientific publication on the topic to his name. In the scientific arena, if you want to put up or shut up, that's how you do it, and at least so far he hasn't put up anything. What's more, a quick bit of searching (aided by the "criticisms" section on Evans's own site, ironically enough) turned up that the central foundation of his argument is essentially flat-out wrong. There doesn't seem to be anything of substance here.

Also I really wish the whole "global warming has plateaued" myth would die already, because it's been completely discredited by this point. Hell, even a look at popular media reports would show that the warmest seasons (and indeed whole years) on record have come within just the past few, well within the timeframe of this supposed pause.
User avatar
sigma
DBB Fleet Admiral
DBB Fleet Admiral
Posts: 2840
Joined: Fri Dec 07, 2012 6:24 am
Location: Moscow

Re: Mathematics show climate model wrong

Post by sigma »

tunnelcat, what are you talking about? What kind of trees you can say if in Northern Siberia is melting at an alarming rate relict permafrost?


Image

Deputy Director for Research of the Institute of Oil and Gas Problems, corresponding member of the Russian Academy of Sciences, doctor of technical sciences Vasiliy Epiphany notes that most of tundra lakes rounded shape on the Yamal Peninsula are thermogas origin as "Yamal funnel." The process takes place in areas where there permafrost Paleolithic period and underground ice. In connection with global warming in these territories formed craters.

"These hills, reaching a diameter of up to two kilometers and a height of dozens of meters and look quite exotic in the tundra plains. Gradually these objects at high temperatures break down and form a crater. However, a year ago in connection with the formation of the Yamal funnel, we learned that they could still explode. "
User avatar
Tunnelcat
DBB Grand Master
DBB Grand Master
Posts: 13320
Joined: Sat Mar 24, 2007 12:32 pm
Location: Pacific Northwest, U.S.A.

Re: Mathematics show climate model wrong

Post by Tunnelcat »

There's that too. Same in Alaska. But tree growth habit changes are akin to the canary in the mine. When they show signs of stress, we're probably environmentally in trouble. :wink:
Cat (n.) A bipolar creature which would as soon gouge your eyes out as it would cuddle.
User avatar
sigma
DBB Fleet Admiral
DBB Fleet Admiral
Posts: 2840
Joined: Fri Dec 07, 2012 6:24 am
Location: Moscow

Re: Mathematics show climate model wrong

Post by sigma »

I do not know, maybe Lothar or Drakona will explain this with the help of mathematics :)
User avatar
Ferno
DBB Commie Anarchist Thug
DBB Commie Anarchist Thug
Posts: 15016
Joined: Fri Nov 20, 1998 3:01 am

Re: Mathematics show climate model wrong

Post by Ferno »

Yay, I get to post this again.

[youtube]q71cMRGXx9o[/youtube]

pay attention this time, because the next time I see 'global warming is fake' from woody, you guys are going to see ten times as many.
User avatar
woodchip
DBB Benefactor
DBB Benefactor
Posts: 17674
Joined: Tue Jul 06, 1999 2:01 am

Re: Mathematics show climate model wrong

Post by woodchip »

Ferno wrote:Warmest summer on record, ever.
Temp. increase is insignificant statistically...still flat-lined:
The rate of global warming has been less since 2000 than in the prior 30 years (Fig. 6). Whether there has been a significant change in the long-term warming rate must await additional data, but the apparent slowdown has led to numerous assertions that “global warming has stopped.” Fig. 6 confirms that there has been little increase of the 60-month (5-year) and 132-month (11-year) running means in the past decade
http://csas.ei.columbia.edu/2015/01/16/ ... -and-2015/
Liberal speak: "Convenience for you means control for him, free and the price is astronomical, you're the product for sale". Neil Oliver

Leftist are Evil, and Liberals keep voting for them. Dennis Prager
User avatar
woodchip
DBB Benefactor
DBB Benefactor
Posts: 17674
Joined: Tue Jul 06, 1999 2:01 am

Re: Mathematics show climate model wrong

Post by woodchip »

vision wrote:Here are some problems, tracing back from your post. The link points to an article on a right-wing website where many of the headlines contain multiple exclamation points, excessive use of capital letters, and actual LOLs, including the title of this article:
  • "Australian scientist discovers ERRORS in Global Warming models that COMPLETELY undermine climate theory!!!"
Other headlines include:
  • "LOL! Democrat Chair can’t bring herself to say that socialist Bernie would beat any Republican"
    "New POLL has Hillary COLLAPSING by DOUBLE DIGITS in just FIVE DAYS!!"
    "Katie Pavlich OBLITERATES FIVE liberal myths on gun violence and gun control!"
The article you provided ends with the partisan jab:
  • "And you can bet that Obama will stay on track to destroy the ingenuity of American industry for the sake of a discredited hoax…"
Anyone who is a true skeptic would immediately see this as politicizing climate change, which is exactly what the deniers (those poor, persecuted victims) claim out pro-climate change system does. (Of course, if we really did have a pro-climate change system then there would be a hell of a lot more done to combat it.)

But let's move on, shall we?

There is no link to the original source, that is, Dr Evans own words. A quick search for Dr David Evans reveals he is a known climate denier. But of course, being a denier doesn't mean you automatically are discredited, but his new "theory" isn't a finding published in a scientific journal — it is from a series of blog posts on an Australian climate denier website, which naturally is littered with advertisements for anti-climate change books. (And they talk about pro-climate change being about making money? Ha!)

That said, we can get right to Dr Evans theory, which starts out by reiterating the long discredited idea "it's the sun" and then goes on and on about CO2 as if it is the only greenhouse gas, which it isn't. The crux of his argument is that current models treat radiative forcing as if the Earth was a true blackbody at infrared, which may or may not make a difference. Then he goes on the apply a different radiative forcing model, but then seems to arbitrarily fit his model into past data so it matches the also discredited "warming pause."

What to make of this? An interesting theory that might be useful to create better models, but he doesn't seem to be viewing the whole picture. I'll wait until he publishes some work that is reviewed by climate scientists before I take this seriously.
This is why I hold no regard for your views. You take all that space to talk about denier websites and how sentences are constructed (kinda like you would do with Wills posts) as though that disproves his work. Meanwhile Dr Evans has more degrees than you have brain cells and you want to ridicule him. Also lets get off the idea that all scientists are in agreement about global man made climate change.
Liberal speak: "Convenience for you means control for him, free and the price is astronomical, you're the product for sale". Neil Oliver

Leftist are Evil, and Liberals keep voting for them. Dennis Prager
User avatar
sigma
DBB Fleet Admiral
DBB Fleet Admiral
Posts: 2840
Joined: Fri Dec 07, 2012 6:24 am
Location: Moscow

Re: Mathematics show climate model wrong

Post by sigma »

Perhaps David Evans believes he has more degrees than I have brain cells, but at least it is strange that he complains about a number of political obstacles and at the same time he is looking for the support of those same politicians from the United Nations, instead than to seek recognition of its assumptions about the serious errors in the UN climate models, using proofs of his rightness among scientists.
P.S. I suppose that now Evans just tends to get another degree adding to formulas of Navier–Stokes equations the political coefficient :)
User avatar
woodchip
DBB Benefactor
DBB Benefactor
Posts: 17674
Joined: Tue Jul 06, 1999 2:01 am

Re: Mathematics show climate model wrong

Post by woodchip »

Did you not put on your reading glasses? Sigma did you see who I was quoting?
Liberal speak: "Convenience for you means control for him, free and the price is astronomical, you're the product for sale". Neil Oliver

Leftist are Evil, and Liberals keep voting for them. Dennis Prager
User avatar
Top Gun
DBB Master
DBB Master
Posts: 8021
Joined: Wed Nov 13, 2002 3:01 am

Re: Mathematics show climate model wrong

Post by Top Gun »

woodchip wrote:
Ferno wrote:Warmest summer on record, ever.
Temp. increase is insignificant statistically...still flat-lined:
The rate of global warming has been less since 2000 than in the prior 30 years (Fig. 6). Whether there has been a significant change in the long-term warming rate must await additional data, but the apparent slowdown has led to numerous assertions that “global warming has stopped.” Fig. 6 confirms that there has been little increase of the 60-month (5-year) and 132-month (11-year) running means in the past decade
http://csas.ei.columbia.edu/2015/01/16/ ... -and-2015/
You are SEVERELY cherry-picking that quote. The article does note that increase has been more gradual over the past decade, but also notes just a bit earlier that the 15 warmest years on record have occurred since 1998, and also that 2014 was the warmest year on record despite the lack of a strong El Nino (which is normally what drives particularly-warm years). They also describe the decreased warming rate as still potentially within short-term variations, and suggest a potential cause in the form of decreased Pacific surface temperatures. Finally, they note that even a recently-decreased rate of warming is still warming, and the conditions causing it to be so have certainly not abated.

And once again, while you cite Dr. Evans's degrees, he states himself that he is not experienced with climate modeling, and as I noted above, he has yet to publish anything backing up his claims.

I've asked you this same question before in other threads, but really, what are you hoping to accomplish with this? Literally every international scientific body even remotely connected to studying Earth's climate has stated in no uncertain terms that anthropogenic global warming is a legitimate issue, and yet you're scrambling for every single shred of a chance to convince yourself that it's not happening. Why? What's so important to you about all of those people being wrong? Is it just simple insecurity, or something more?
User avatar
Foil
DBB Material Defender
DBB Material Defender
Posts: 4900
Joined: Tue Nov 23, 2004 3:31 pm
Location: Denver, Colorado, USA
Contact:

Re: Mathematics show climate model wrong

Post by Foil »

woodchip wrote:I would value Lothar or Drakona's thoughts.
Hey now, they're not the only mathematicians around. My graduate work was in mathematics, as well. 8)

Back on topic, I'd like to take a look at what this Dr. Evans is claiming. But I can't find anything other than second/third/fourth-hand quotes in pop-media articles. If you can find a solid citation, please post it.
User avatar
sigma
DBB Fleet Admiral
DBB Fleet Admiral
Posts: 2840
Joined: Fri Dec 07, 2012 6:24 am
Location: Moscow

Re: Mathematics show climate model wrong

Post by sigma »

woodchip wrote: Sigma did you see who I was quoting?
I see what Evans is trying to prove that under the brand of "green energy" is hiding mafia parasitic activities on pumping subsidies from the national budgets of the developed countries. This is an amazing discovery, yes.
User avatar
vision
DBB Material Defender
DBB Material Defender
Posts: 4337
Joined: Thu Feb 18, 2010 1:54 pm
Location: Mars

Re: Mathematics show climate model wrong

Post by vision »

woodchip wrote:This is why I hold no regard for your views. You take all that space to talk about denier websites and how sentences are constructed ... as though that disproves his work.
I do it to point out your severe lack of critical thinking skills. You have shown time and time again that you will believe anything from anyone as long as it doesn't challenge your worldview. His work isn't disproven because it isn't published and seems to be based on ideas that are already disproven.
woodchip wrote:Meanwhile Dr Evans has more degrees than you have brain cells and you want to ridicule him.
Aaaand you are wrong about ridiculing him. I only presented the facts. He's a known denier and his work is not published. I also guarantee I'm an expert in areas he is not, though admittedly it's not mathematics, haha.
woodchip wrote:Also lets get off the idea that all scientists are in agreement about global man made climate change.
It was a scientist, a teacher of mine, who first explained to me that global warming was a fraud, decades ago. I believed her until I studied it myself and realized she was dead wrong. It took many years to change my mind, so there is still hope for you and that is why I post replies to these threads. Climate change is the biggest problem in the world, larger than guns, abortion, wealth inequality, civil rights, and everything else combined.
User avatar
snoopy
DBB Benefactor
DBB Benefactor
Posts: 4435
Joined: Thu Sep 02, 1999 2:01 am

Re: Mathematics show climate model wrong

Post by snoopy »

Ferno wrote:yes because denialism in the face of overwhelming evidence is so in vogue these days.
The irony is that this exact phenomena could apply to either side in this particular debate, for this particular OP. Time will tell which scientists making models which fit their agendas got closer to the mark... Still, the real questions is: so what should we do about it?
Arch Linux x86-64, Openbox
"We'll just set a new course for that empty region over there, near that blackish, holeish thing. " Zapp Brannigan
User avatar
Lothar
DBB Ghost Admin
DBB Ghost Admin
Posts: 12133
Joined: Thu Nov 05, 1998 12:01 pm
Location: I'm so glad to be home
Contact:

Re: Mathematics show climate model wrong

Post by Lothar »

I'm not sure how I'm supposed to analyze this guy's math, since I can't find it.
Izchak says: 'slow down. Think clearly.'
April Fools Day is the one day of the year that people critically evaluate news articles before accepting them as true.
User avatar
snoopy
DBB Benefactor
DBB Benefactor
Posts: 4435
Joined: Thu Sep 02, 1999 2:01 am

Re: Mathematics show climate model wrong

Post by snoopy »

Lothar wrote:I'm not sure how I'm supposed to analyze this guy's math, since I can't find it.
I don't know if you and Drak have made any models in your days... I've worked in test & evaluation basically my whole career & have developed a relatively heavy dose of scepticism for just about any type of "model" that attempts to extrapolate data. My experience is that you develop it for one test case (for which you know the extrapolated data) - and then for the very next test case it diverges much more than you'd like it to. My bet that the argument is akin to "no, the weighting factor for CO2 should be 0.00184, not 0.00381."

Maybe I'm just getting cynical in my old age.
Arch Linux x86-64, Openbox
"We'll just set a new course for that empty region over there, near that blackish, holeish thing. " Zapp Brannigan
User avatar
Lothar
DBB Ghost Admin
DBB Ghost Admin
Posts: 12133
Joined: Thu Nov 05, 1998 12:01 pm
Location: I'm so glad to be home
Contact:

Re: Mathematics show climate model wrong

Post by Lothar »

snoopy wrote:I don't know if you and Drak have made any models in your days... I've worked in test & evaluation basically my whole career & have developed a relatively heavy dose of scepticism for just about any type of "model" that attempts to extrapolate data. My experience is that you develop it for one test case (for which you know the extrapolated data) - and then for the very next test case it diverges much more than you'd like it to. My bet that the argument is akin to "no, the weighting factor for CO2 should be 0.00184, not 0.00381."
I'm tempted to just take a photo of the relevant part of my bookshelf ;) I spent 2 years of undergrad and 3 years of grad school doing mathematical modeling / numerical modeling. I collaborated with Drak to solve a problem she'd run into when she was a core systems integrator on pilot training sims for Boeing, that had to do with numerical integration of a particular physics model. I'm pretty familiar with what you can and can't do with giant physics models.

So if we had some actual math, even if I didn't dissect it entirely, I could at least give a brief overview of whether it was totally off the wall or potentially legit. But we don't, so I can't.
Izchak says: 'slow down. Think clearly.'
April Fools Day is the one day of the year that people critically evaluate news articles before accepting them as true.
User avatar
Top Gun
DBB Master
DBB Master
Posts: 8021
Joined: Wed Nov 13, 2002 3:01 am

Re: Mathematics show climate model wrong

Post by Top Gun »

Yeah, and that's the ★■◆● of it. In the (admittedly unlikely) event that the guy has worked out a valid issue with the models used, he's not putting out any of his actual work on it, which any self-respecting researcher would absolutely want to make a priority.
User avatar
Ferno
DBB Commie Anarchist Thug
DBB Commie Anarchist Thug
Posts: 15016
Joined: Fri Nov 20, 1998 3:01 am

Re: Mathematics show climate model wrong

Post by Ferno »

woodchip wrote:Temp. increase is insignificant statistically...still flat-lined:
goodie, another 'flat-lined' line.

[youtube]OWXoRSIxyIU[/youtube]
[youtube]oJAbATJCugs[/youtube]

snoopy wrote:so what should we do about it?
The answer is simple. Take the waste products and figure out how to utilize them. It's chemistry after all.
User avatar
sigma
DBB Fleet Admiral
DBB Fleet Admiral
Posts: 2840
Joined: Fri Dec 07, 2012 6:24 am
Location: Moscow

Re: Mathematics show climate model wrong

Post by sigma »

tunnelcat wrote:Same in Alaska :wink:
By the way, I found that in Alaska as well as in Siberia from the permafrost thawed mammoth bones!
In the last 30 years with the gradual thawing of the permafrost in Siberia, are increasingly found the remains of mammoths - their mining business in the region is becoming a popular and profitable. The reason for such interest in the mammoth was a ban on the production of ivory - annually in Siberia dig more than 50 tons of valuable remains of mammoths. Basically the bones and tusks are sold over the Internet: the most good samples taken by collectors and museums, and also mostly Chinese artisans.
This would be for my good finds! Unfortunately, there have too far to go from Moscow...

Image
Image
Image
User avatar
woodchip
DBB Benefactor
DBB Benefactor
Posts: 17674
Joined: Tue Jul 06, 1999 2:01 am

Re: Mathematics show climate model wrong

Post by woodchip »

Foil wrote:
woodchip wrote:I would value Lothar or Drakona's thoughts.
Hey now, they're not the only mathematicians around. My graduate work was in mathematics, as well. 8)

Back on topic, I'd like to take a look at what this Dr. Evans is claiming. But I can't find anything other than second/third/fourth-hand quotes in pop-media articles. If you can find a solid citation, please post it.
Good to know that you are into math along with Lothar and Drakona. What I was hoping was you guys were privy to trade journals or something where there was more info on what Evans was doing.
Liberal speak: "Convenience for you means control for him, free and the price is astronomical, you're the product for sale". Neil Oliver

Leftist are Evil, and Liberals keep voting for them. Dennis Prager
Post Reply