Climate change: February was hottest month on record as 'exceptional' Nasa shows

Your understanding of climate sensitivity is flawed. Since it can take centuries for the climate to equalize after doubling CO2, the 1.5 °C warming projected by 2100 is mostly due to the extra CO2 we've already added to the atmosphere. Add the 1 °C warming from the last century and you have 2.5 °C of the estimated 3.0 °C warming from doubling CO2.

Unless the economic cost of not taking action is worse than the cost of reducing CO2 emissions.

http://www.scientificamerican.com/article/top-economic-risk-of-2016-is-global-warming/

Here is a good explanation from NASA.

http://www.nasa.gov/topics/earth/features/climate_by_any_other_name.html

Are you seriously suggesting that tree ring proxies are more accurate than actual measurements for determining temperature trends during the late 20th century?

The current temperature spike has lasted much longer than one month.

First of all, your top chart is from Judith Curry, not the IPCC AR5. Here is the relevant figure from AR5:

As you can see, Jevrejeva et al. (2008 ) only briefly exceeds the current 2.9 mm/yr increase in sea level during the early 1950's, and their latest analysis in 2014 shows a linear trend of only 1.9 ± 0.3 mm/yr during the 20th century.

Richard Muller and some colleagues thought there was some merit to the whole "hiding the decline" trick that people claimed Mann used in 2008 to create the hockey stick graph, so they formed Berkeley Earth in 2010 with the specific intent of reanalyzing Earth’s surface temperature record, only to find " a global warming trend that is very similar to that previously reported by the other groups."

 

Duh, so has the El Nino. Guess where all that warmth put into the atmosphere ends up?

 

Then why did YOU call it a "one month spike"?

 

Simple, that is the headline.

 

Well, there's your problem. You should have kept reading.

 

El Nino is not a one month phenomenon.

 

My understanding is not flawed. The definition of climate sensitivity to CO2 is the temp rise in deg C for a doubling of the CO2 concentration.

Are you suggesting that tree ring proxies that cannot match the actual temperature data since 1960 can be used to eliminate the MWP and LIA ?? That is what was required to argue that the warming in the mid to late 20th century (nothing of significance in the 21st century yet) is unprecedented. The hockey stick showed this and was instantly adopted with virtually no scrutiny (until McIntyre and McKitrick) because of confirmational bias. It was great advertising.

The graph is the same. It shows the same traces and confirms that the sea level was rising at a higher rate in the 40's and 50's than today.

Again, hiding the decline refers to the divergence problem with the tree rings. The tree rings were used to create the flat shaft of the hockey stick by eliminating the MWP and LIA thus accentuating the blade of the hockey stick using real world temp measurements which were increasing (very few dispute that - I certainly don't) whilst the tree rings temp proxy showed obviously incorrect temperature decreasing. If the tree rings can't even predict temp in the last 60 years why should they be trusted to show temperature hundreds of years ago ??

The reality is that no country will willingly sacrifice economic growth to reduce CO2 emissions. Thus the reality is that the only viable tactic is to monitor and adapt. As the standard of living increases and wealth accumulates new cost effective energy technologies may emerge but that is the only way that the rate of CO2 emissions with time will decrease. And this is not the fault of the "deniers" - countries like Germany and Japan which have virtually no opposition to global warming alarm are making less progress than the US.

 

That's right, it takes at least three months of above average temperatures to be considered El Niño. It is also oscillatory, with the reverse La Niña phase identified by three months of lower than average temperatures. When you look at it over several decades, they pretty much cancel each other out. What El Niño cannot do is explain any significant warming trends over the last century.

 

Natural variability can since it has been doing it long before man came along.

 

Then you understand that equilibrium will not be achieved in a single century, especially when the primary forcing hasn't stopped.

The tree ring divergence problem is not an unknown, and there have been numerous studies like Briffa 1998 and Cook 2004 show that the divergence didn't start until after 1960 and only affects high northern latitudes. Fortunately, that leaves everything between 1880 and 1960 to compare with actual temperature records to establish their accuracy.

Well, other than shifting dates on the horizontal axis by a decade and poorly referencing the sources, I guess it is close enough. But the fact that global temperature and sea level rates have changed at the same amount in the past doesn't disprove AGW.

Mann, Bradley, Hughes 2008 didn't hide the MWP or LIA, it simply showed that they were primarily regional events that are not reflected in the global climate, something that PAGES 2K confirmed in 2013. Besides, the argument is as illogical as saying WW2 deaths were not caused by man because the plague killed more people during the middle ages.

It won't as long as people keep misrepresenting the science.

 

That argument has failed so far.

 

I understand the definition. The sensitivity is derived from real world data and/or computer models (which per the IPCC working group are only able to at best create 30 year maximum scenarios). The A1B CO2 scenario shows a doubling of the CO2 from 350 to 700 ppm for the 21st century (2000 - 2100). The next doubling of the CO2 concentration will occur at a concentration of ~ 1400 ppm. At that time assuming a climate sensitivity of 1.5 the temperature will be 3 deg C above the temp in the year 2000.

The Hockey Stick depends on the bristlecones - the fact that the bristle cone tree rings do not match the actual temperature data eliminates the Hockey Stick from any legitimate consideration. The Hockey Stick was adopted as a propaganda tool because it showed what was desired by the global warming alarmists.

I'm not disputing AGW.

The tree ring proxies do not show what written history has shown to be true. The tree rings were also regional (in fact very much local). Greenland is so named for a reason during the MWP and the Thames River was frozen in the LIA.

It has nothing to do with the science. It is a result of the Kaya Identity: Emissions = GDP X Technology and Pielke Jr.'s Iron Law of Climate Policy which states that 'People are not willing to sacrifice significant economic growth to achieve environmental objectives." Technology is the only viable way to reduce emissions and that technology development is directly proportional to economic growth.

 

What's the source for that ??

Why are the natural factors practically flat since 1975 ??

Look at the graph. In 1975 the CO2 concentration was ~ 330 ppm. In 2000 the CO2 concentration was ~ 370 ppm. And the graph is telling us that the 40 ppm CO2 increase over 25 years has resulted in ~ 1.2 deg F of AGW ??

 

Then why are you saying that global temperature in 2090 will only be 1.5 °C above the current global temperature when we haven't even reached equalization from the CO2 already added to the atmosphere?

Wahl Ammann 2007 showed that the results of Mann, Bradley, Hughes 1998 are unaffected by the inclusion of bristlecone tree ring proxies.

Then why bring up sea level changes from the past?

Again, these are regional events and are not reflected in global climate reconstructions.

The Kaya Identity has four variables (population, GDP, carbon intensity, and energy efficiency), not just two, and it is possible to reduce emissions without sacrificing economic growth or waiting for technological development to just happen. But as long as we keep debating the science, we will never get around to discussing policy.

The chart comes from MIT but is based on Huber Knutti 2012 as stated in the bottom line.

I would suspect this is because Total Solar Irradiance has been declining since about that time.

Again, you appear to believe that the warming from CO2 is immediate. Most of climate is based on feedback which means temperatures will continue to increase long after the increase in CO2.

 

So basically the paper is all about models, not empirical data. Can you answer this question? Why are models unable to model the Earth's climate?

 

Oh, but they can.

http://www2.sunysuffolk.edu/mandias/global_warming/climate_models_accuracy.html
http://blogs.agu.org/wildwildscience/2012/12/11/ipcc-climate-forecast-from-1990-amazingly-accurate/
http://onlinelibrary.wiley.com/doi/10.1029/2012JD017765/abstract

 

Rah, rah, and blogs. Models are incapable of modeling the climate. They hind cast by curve fitting because the are incapable of modeling the climate. There is a reason they average over 100 models because none of them are correct. If you knew anything about computer modeling you would not be so confident.

 

Then why don't you put your science where your mouth is. If current climate models are so bad, then produce a better one. Shouldn't be too hard for someone of your intellectual prowess.

 

His science is pretty much that temperature has changed before humans started pumping tons of Co2 in the atmosphere, therefore it can't be humans changing it now. That's pretty much his argument, lol.

 

Again there is the reliance on computer model scenarios for the next hundreds of years when the IPCC working group states that they are only good for ~ 30 years. And even then they cannot match the real world data. But then what does the IPCC mean when it states that the model consensus is ~ 3 deg C as the value of the climate sensitivity of CO2 - that it's really more like 5 if looking out hundreds of years ??

Wahl & Ammann ?? What are the R**2 verification statistics for their paper - the version of the paper submitted to the IPCC does not include them but the version published in Climate Change does. Wahl & Ammann claim to replicate MBH98 but do not.

In the recent past sea level rise rates have exceeded sea level rise rates of the present. And this is before CO2 emissions took off after WWII. To use sea level rise rates as proof of AGW is incorrect.

The ability to reconstruct temperature history of the past when there were no thermometers is very uncertain. Plus there is no data available from the tropics. The historical record is clear and supports the MWP and the LIA. The Baltic Sea was frozen in winter, the Thames River as well, and the Dutch winters were much colder than they are today. Also Eric the Red settled Greenland where water wells have been discovered which are frozen in the lower parts indicating much warmer conditions then. The hockey stick was accepted by certain parts of the scientific and political community because it was advantageous for them to do so. The basic function of science when a new theory such as the hockey stick temperature reconstruction is proposed is to investigate and determine why the old theories are wrong. This was not done. BTW, the bristlecone data is also local - sometimes only one tree and sometime zero trees.



The Kaya identity consists of population, income, how we obtain our energy and how we use that energy. Population X Income = GDP and Technology in units of emissions per unit GDP is a reflection of our production and consumption of energy. Hence Emissions = GDP X Technology.

 

You have a source to back up any of this? Nobody says that climate models are only good for ~ 30 years. Quite the opposite, studies show the models are more accurate over 30 years then under. Which is not really surprising since climate is defined as change over a 30 year span.

They discuss their verification statistics in section 2.3 if you want to read it.

No, the 26 gigatonnes of CO2 that humans are adding to Earth's atmosphere is proof enough.

Which is why proxies are compared to actual measurements over a sufficiently large time span to reduce that uncertainty. BTW, there are temperature proxies from the tropics in the form of coral reefs, cave sediments, and ice cores.

Last time I checked, the Baltic Sea, the Thames River, the Netherlands, and Greenland are all in the same geographic region. We are talking about GLOBAL warming here, aren't we?

Sorry, but the "hockey stick" temperature reconstruction did not introduce a new theory. Mann, Bradley, Hughes 1998 introduced a new statistical approach to reconstructing past temperatures. The theory of Anthropogenic Global Warming dates all the way back to Svante Arrhenius in 1986 and Guy Callendar in 1938.

But emissions can be reduced without reducing GDP, the only question is how quickly do we need to reduce it.

 

You don't need to produce something that cannot be produced. It is obvious you don't have a clue about computer capability.

 

It's upthread (can't find it now because the search function doesn't seem to work very well) in a post by Hoosier8. The models do not at all predict the real world.

And what does the discussion say on verification statistics ??

Proof of what ?? The total means nothing without a climate sensitivity of CO2.

How are those tropical proxies verified ?? And the tree ring proxies are a failure. They don't agree with the actual temperature measurements from the last ~ 150 years.

We are talking about the LIA and the MWP. The tree ring proxies have been shown to be unreliable.

The Hockey Stick eliminated the MWP and the LIA and is used to also eliminate the concept of climate variability from the discussion of the hockey stick blade. The ClimateGate emails indicated a coordinated attempt to get rid of the MWP.

Sure, emissions can be reduced but not without significantly adversely affecting GDP. The only way to reduce emissions is with technological advances again financed by the wealth created by GDP growth. Developing nations in particular (don't believe the propaganda coming out of China) will not reduce GDP growth to limit CO2 emissions.

 

I'll take that as admission that you cannot do better. Apparently you have a problem understanding what science is capable of.

 

Thanks for proving my point.