Climate models have performed quite well..

F

futurecurrents

Christy and McNider believe it's climate contrarians like themselves who 'embrace the facts.' To support this claim, they tried to argue that mainstream climate scientists are in denial about the accuracy of climate models.

"We might forgive these modelers if their forecasts had not been so consistently and spectacularly wrong. From the beginning of climate modeling in the 1980s, these forecasts have, on average, always overstated the degree to which the Earth is warming compared with what we see in the real climate."

First of all, modern climate modeling began in the 1970s. It's also wrong to claim that their forecasts have always overstated global warming. Just as one example, NASA's James Hansen published a paper in 1981 with a model that slightly underestimated the ensuing global warming.

Hansen81ModelvsObs.jpg


Hansen et al. (1981) global warming projections under a scenario of high energy growth (red) and slow energy growth (blue) vs. observations (black). Actual energy growth has been between the two Hansen scenarios.

Climate model global warming projections have also far outperformed predictions made by climate contrarians, and have performed fairly well overall (including current climate models).

ProjvsObs450.jpg


IPCC AR5 Figure 1.4. Solid lines and squares represent measured average global surface temperature changes by NASA (blue), NOAA (yellow), and the UK Hadley Centre (green). The colored shading shows the projected range of surface warming in the IPCC First Assessment Report (FAR; yellow), Second (SAR; green), Third (TAR; blue), and Fourth (AR4; red).

On the other hand, Christy and Spencer's estimates of the temperature of the Earth's atmosphere have consistently underestimated global warming. In the 1990s, they initially claimed the lower atmosphere was cooling, and had to make several warming adjustments when other groups identified errors and biases in their data set.
 
In their opinion piece, Christy and McNider present a graph that's supposed to prove their argument that climate models have overestimated global warming. However, rather than compare models and observations of global surface temperature, which are of the greatest importance for those of us living on the Earth's surface, they instead show temperature data from higher up in the atmosphere, the temperature of the mid-troposphere (TMT).

The figure in the Wall Street Journal piece suffers from several problems. First, it improperly averages the data (also known as "baselining") in a way that results in shifting the observational data downwards with respect to the model data, visually exaggerating the discrepancy. Second, it doesn't show any error bars or uncertainty ranges, and the error bars on the TMT data are large. Third, it simply averages together two satellite TMT data sets (presumably from UAH and Remote Sensing Systems), ignoring the fact that there is a large difference in the estimated warming trends from these two data sets, and that other TMT data sets that Christy and McNider excluded show even greater TMT warming, more in line with model projections.

The other problem is that Christy and McNider assume that the observational data are perfect, and thus that any discrepancy must mean the models are wrong. However, a U.S. Climate Change Science Program report co-authored by Christy concluded that the difference between satellite estimates and model projections of atmospheric warming is probably mostly due to errors in the observations.
 
why do you continue to post garbage and lies... when you know we will correct you every time.
you have already been corrected before... but here it is again.

figure-11.png


http://wattsupwiththat.com/2013/10/...ar5-models-are-presented-they-still-look-bad/

Much of what’s presented in the IPCC’s Figure 1.4 is misdirection. The models presented from the IPCC’s 1st, 2nd and 3rd Assessment Reports are considered obsolete, so the only imaginable reason the IPCC included them was to complicate the graph, redirecting the eye from the fact that the CMIP3/AR4 models performed poorly.

Regardless, what it boils down to is the climate scientists who prepared the draft of the IPCC AR5 presented the model-data comparison with the models and data aligned at 1990 (left-hand cell), and that version showed the global surface temperature data below the model ranges in recent years. Then, after the politicians met in Stockholm, that graph is replaced by the one in the right-hand cell. There they used the base years of 1961-1990 for the models and data, and they presented AR4 model outputs instead of a range. With all of those changes, the revised graph shows the data within the range of the models…but way down at the bottom edge with all of the models that showed the least amount of warming. Regardless of how the model-data is presented, the models looked bad…they just look worse in the original version.

While that revised IPCC presentation is how most people will envision model performance, Von Storch, et al. (2013) found that the two most recent generations of climate models (CMIP3/IPCC AR4 and CMIP5/IPCC AR5) could NOT explain the cessation of warming.

Bottom line: If climate models can’t explain the hiatus in warming, they can’t be used to attribute the warming from 1975 to 1998/2000 to manmade greenhouse gases and their projections of future climate have no value.
 
http://www.bbc.co.uk/blogs/paulhudson/posts/The-IPCC-report-is-the-science-settled


IPCC report, Section D1:

‘The observed reduction in surface warming over period 1998-2012 is due roughly in equal measure to a reduced trend in radiative forcing and cooling from internal variability, which includes a possible redistribution of heat within the ocean (medium confidence).’

‘There is low confidence in quantifying the role of changes in radiative forcing in causing the reduced warming trend.'

‘There may also be a contribution from forcing inadequacies and, in some models, an overestimate of the response to increase greenhouse gas and other anthropogenic forcing.’

To highlight this area of uncertainty further, in late 2009, I wrote an article which you can read HERE in which I look at the then apparent slowdown in global warming.

In it, I discuss research from the Met Office Hadley Centre.

In the research the authors discuss why they believe a levelling off of temperatures can be expected at times.

The research shows that near zero temperature trends for intervals of a decade or less can be expected due to the model’s internal climate variability.

But crucially, the research rules out zero (temperature) trends for intervals of 15 years or more.

We are now 15 years into the so called ‘pause’ in global temperatures and the research further illustrates that this crucial part of climate science is far from settled, and it’s disappointing that more time wasn’t given to this issue across the media in the days since the report was published.

That said the authors of this report are in little doubt that over the longer term, man is altering our climate by adding greenhouse gases to the atmosphere.
 
yeah sure jem . All you have is fringe sources and debunked scientists and lies. I have the whole world's science community behind me.

The models have performed quite well. They are not expected to have perfect resolution. Rising CO2 is causing temps to rise. It's that simple.

And here is even more empirical proof that rising CO2 leads temperatures higher.


Co2ClimateChangeAndFossilFuel.jpg
 
It's quite obvious our troll of the year, and queer heater installer hates his job and his life. He's obviously pissed over having to install record numbers of heaters this winter, and it's VERY obvious he's been told what a lunatic he is by the shivering cold people/customers to shut the fuck up while he runs duct work. His only "release" is to come here, and attempt to shove a complete farce called global warming down our throats. This shit can't be made up. A faggot heater installer, who forces his agenda down the throats of people who are shivering cold, is beyond mind-bending.
 
From your article jem. I'm glad you finally admit that rising CO2 is causing and will cause warming.

"That said the authors of this report are in little doubt that over the longer term, man is altering our climate by adding greenhouse gases to the atmosphere."
 
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