Global warming scepticism

Still repeating the same thing over and over even though it has been picked apart, old data, reconstructions all using the same dataset based on the Karl et. al. paper that magically makes the pause disappear by warming the good Argo data to match the problematic ship engine intake data.

You should actually do some reading other than SKS.

 

it's the appropriate response to someone that says there's no evidence

there was no pause to begin with


"Between 1998 and 2012, climate scientists observed a slowdown in the rate at which the Earth's surface air temperature was rising. While the rise in global mean surface air temperature has continued, between 1998 and 2012 the increase was approximately one third of that from 1951 to 2012.

This trend — referred to as a "global warming hiatus" — has sparked a lot of debate and given rise to a reasonable question: Is global warming coming to a halt?

According to Norman Loeb, an atmospheric scientist at NASA's Langley Research Center in Hampton, Virginia, and the principal investigator of a space-borne sensor called the Clouds and Earth's Radiant Energy System, or CERES, the answer is almost certainly no.

"Heating is still going on," he said. "It's just not in terms of the surface air temperature."

Loeb explained the science behind that statement Tuesday, Aug. 5, during a talk at NASA Langley titled "The Recent Pause in Global Warming: A Temporary Blip or Something More Permanent?"

Though Loeb believes there are a handful of short-term factors that drive changes in surface air temperature, like the El Niño and La Niña phenomena that cause temperature fluctuations in the tropical eastern Pacific approximately every two years, he thinks there is a longer term factor that is a significant and overlooked contributor.

"The Pacific Decadal Oscillation affects surface temperature," Loeb said. "It's a pattern of temperature shifts, primarily over the Pacific, that occurs about every 20 or 30 years."

Historically, those shifts have coincided with changes in surface temperature.

"The Pacific Decadal Oscillation has a very distinctive pattern. During the positive phase, surface temperature rises more rapidly," he said. "During the negative phase, the rate of temperature increase slows down, hence a hiatus. It's very compelling when you see the actual observations."

Loeb showed measurements during his talk demonstrating steady increases in surface air temperature from 1920 to 1940 and again from 1976 to 2000, periods when the decadal oscillation was in a positive phase. From 1940 to 1975, and again beginning in 2001, temperatures leveled out in concert with negative oscillation phases.

Surface air temperatures have increased by approximately 1.4 degrees Fahrenheit since the early 20th century. On this timescale, the hiatuses look like short ledges along a graph of global average surface air temperature with an otherwise steep upward slope.

"You can't just look at short periods of time," Loeb said. "You have to look at the record over a long period of time to see the pattern. There will be natural fluctuations at shorter time scales, but we really shouldn't conclude that that's a change and global warming is going away."

Even as surface air temperatures are currently holding relatively steady, Loeb believes there's still another issue to take into consideration.

"Observations are showing us the planet is still taking up heat, but it is just showing up in a different place," he said.

That different place is the ocean.

In other words, as humans and nature continue to apply pressure to the Earth's climate through increases in carbon dioxide and other greenhouse gases, temperatures are still rising. But as the Pacific Decadal Oscillation briefly tames temperatures at the planet's surface, the oceans are where the real heating is happening."

http://climate.nasa.gov/news/1141/

 

Wash, rinse, repeat. Same thing over and over and you think someone's opinion is fact. You should widen your reading a bit instead of repeating opinion over and over.

 

that's right, science, facts and evidence

 

Wash, rinse, repeat. You still think opinion is science, facts, and evidence.

 

that's just not true

 

There you go again with your breathtaking evidence born explanation of your position. LOL

 

the science, facts and evidence are in comments #472, 477 and 479

 

Wash, rinse, repeat.

 

sure it is. To date, you still haven't provided any evidence that is factually correct. so until so, all of your posts are opinion on what you think is there. BTW, that isn't.

 

you accusation is completely false, here's the factually correct evidence again

Global temperature rise

All three major global surface temperature reconstructions show that Earth has warmed since 1880.(5) Most of this warming has occurred since the 1970s, with the 20 warmest years having occurred since 1981 and with all 10 of the warmest years occurring in the past 12 years.(6) Even though the 2000s witnessed a solar output decline resulting in an unusually deep solar minimum in 2007-2009, surface temperatures continue to increase.(7)


5) - https://www.ncdc.noaa.gov/indicators/

6) - T.C. Peterson et.al., "State of the Climate in 2008," Special Supplement to the Bulletin of the American Meteorological Society, v. 90, no. 8, August 2009, pp. S17-S18.

7) - I. Allison et.al., The Copenhagen Diagnosis: Updating the World on the Latest Climate Science, UNSW Climate Change Research Center, Sydney, Australia, 2009, p. 11

 

so again, wash rinse repeat is in play. But, what is it that is factual in this post? You still haven't summarized why you think this is fact?

 

it's fact because it has been well-substantiated through the scientific method, repeatedly tested, then confirmed through observation and experimentation

 

Which scientific method, the one where they adjust sensors that are designed for measuring climate because they don't show warming?

 

quit pretending you understand science, it's obvious that you don't


"The scientific method is a body of techniques for investigating phenomena, acquiring new knowledge or correcting and integrating previous knowledge."

https://en.wikipedia.org/wiki/Scientific_method

 

Ya...How do climatologists "Develop testable predictions?" In fact, they haven't. Looks like a missing link to me.

 

They can't and the models are not able to be validated. That is why you see so much of 'if it is true we are doomed' rhetoric. I don't think dujac understands that none of the model runs agree with each other so they average them for their 'predictions'.

 

it looks more like you don't know what you're talking about


Climate models are even more accurate than you thought

The difference between modeled and observed global surface temperature changes is 38% smaller than previously thought

Global climate models aren’t given nearly enough credit for their accurate global temperature change projections. As the 2014 IPCC report showed, observed global surface temperature changes have been within the range of climate model simulations.

Now a new study shows that the models were even more accurate than previously thought. In previous evaluations like the one done by the IPCC, climate model simulations of global surface air temperature were compared to global surface temperature observational records like HadCRUT4. However, over the oceans, HadCRUT4 uses sea surface temperatures rather than air temperatures.



A depiction of how global temperatures calculated from models use air temperatures above the ocean surface (right frame), while observations are based on the water temperature in the top few metres (left frame). Created by Kevin Cowtan.

Thus looking at modeled air temperatures and HadCRUT4 observations isn’t quite an apples-to-apples comparison for the oceans. As it turns out, sea surface temperatures haven’t been warming fast as marine air temperatures, so this comparison introduces a bias that makes the observations look cooler than the model simulations. In reality, the comparisons weren’t quite correct. As lead author Kevin Cowtan told me,

We have highlighted the fact that the planet does not warm uniformly. Air temperatures warm faster than the oceans, air temperatures over land warm faster than global air temperatures. When you put a number on global warming, that number always depends on what you are measuring. And when you do a comparison, you need to ensure you are comparing the same things.

The model projections have generally reported global air temperatures. That’s quite helpful, because we generally live in the air rather than the water. The observations, by mixing air and water temperatures, are expected to slightly underestimate the warming of the atmosphere.

The new study addresses this problem by instead blending the modeled air temperatures over land with the modeled sea surface temperatures to allow for an apples-to-apples comparison. The authors also identified another challenging issue for these model-data comparisons in the Arctic. Over sea ice, surface air temperature measurements are used, but for open ocean, sea surface temperatures are used. As co-author Michael Mann notes, as Arctic sea ice continues to melt away, this is another factor that accurate model-data comparisons must account for.

One key complication that arises is that the observations typically extrapolate land temperatures over sea ice covered regions since the sea surface temperature is not accessible in that case. But the distribution of sea ice changes seasonally, and there is a long-term trend toward decreasing sea ice in many regions. So the observations actually represent a moving target.

A depiction of how as sea ice retreats, some grid cells change from taking air temperatures to taking water temperatures. If the two are not on the same scale, this introduces a bias. Created by Kevin Cowtan.



When accounting for these factors, the study finds that the difference between observed and modeled temperatures since 1975 is smaller than previously believed. The models had projected a 0.226°C per decade global surface air warming trend for 1975–2014 (and 0.212°C per decade over the geographic area covered by the HadCRUT4 record). However, when matching the HadCRUT4 methods for measuring sea surface temperatures, the modeled trend is reduced to 0.196°C per decade. The observed HadCRUT4 trend is 0.170°C per decade.

So when doing an apples-to-apples comparison, the difference between modeled global temperature simulations and observations is 38% smaller than previous estimates. Additionally, as noted in a 2014 paper led by NASA GISS director Gavin Schmidt, less energy from the sun has reached the Earth’s surface than anticipated in these model simulations, both because solar activity declined more than expected, and volcanic activity was higher than expected. Ed Hawkins, another co-author of this study, wrote about this effect.

Combined, the apparent discrepancy between observations and simulations of global temperature over the past 15 years can be partly explained by the way the comparison is done (about a third), by the incorrect radiative forcings (about a third) and the rest is either due to climate variability or because the models are slightly over sensitive on average. But, the room for the latter effect is now much smaller.



Comparison of 84 climate model simulations (using RCP8.5) against HadCRUT4 observations (black), using either air temperatures (red line and shading) or blended temperatures using the HadCRUT4 method (blue line and shading). The upper panel shows anomalies derived from the unmodified climate model results, the lower shows the results adjusted to include the effect of updated forcings from Schmidt et al. (2014).

As Hawkins notes, the remaining discrepancy between modeled and observed temperatures may come down to climate variability; namely the fact that there has been a preponderance of La Niña events over the past decade, which have a short-term cooling influence on global surface temperatures. When there are more La Niñas, we expect temperatures to fall below the average model projection, and when there are more El Niños, we expect temperatures to be above the projection, as may be the case when 2015 breaks the temperature record.

We can’t predict changes in solar activity, volcanic eruptions, or natural ocean cycles ahead of time. If we want to evaluate the accuracy of long-term global warming model projections, we have to account for the difference between the simulated and observed changes in these factors. When the authors of this study did so, they found that climate models have very accurately projected the observed global surface warming trend.

In other words, as I discussed in my book and Denial101x lecture, climate models have proven themselves reliable in predicting long-term global surface temperature changes. In fact, even more reliable than I realized.

[video=youtube;Y_jKXcgR_QA]https://www.youtube.com/watch?v=Y_jKXcgR_QA[/video]

There’s a common myth that models are unreliable, often based on apples-to-oranges comparisons, like looking at satellite estimates of temperatures higher in the atmosphere versus modeled surface air temperatures. Or, some contrarians like John Christy will only consider the temperature high in the atmosphere, where satellite estimates are less reliable, and where people don’t live.

This new study has shown that when we do an apples-to-apples comparison, climate models have done a good job projecting the observed temperatures where humans live. And those models predict that unless we take serious and immediate action to reduce human carbon pollution, global warming will continue to accelerate into dangerous territory.

http://www.theguardian.com/environment/climate-consensus-97-per-cent/2015/jul/31/climate-models-are-even-more-accurate-than-you-thought

 

Modeling is not testing one's hypothesis.

 

the hypotheses have been tested over and over, now they're scientific theory

 

So accurate you have to fudge the data to make it fit the model. Not even the UK MET office has bought into the new denial of the pause.nor do any of the other temperature records show the new 'pause buster' nonsense.

 

watts is the equivalent of glenn beck

here's what reliable sources say:


"Each year, four international science institutions compile temperature data from thousands of stations around the world and make independent judgments about whether the year was warmer or cooler than average. “The official records vary slightly because of subtle differences in the way we analyze the data,” said Reto Ruedy, climate scientist at NASA’s Goddard Institute for Space Studies. “But they also agree extraordinarily well.”

All four records show peaks and valleys in sync with each other. All show rapid warming in the past few decades. All show the last decade has been the warmest on record.

Credit - NASA Climate 365 project - a collaboration of the NASA Earth Science News Team, NASA Goddard and Jet Propulsion Laboratory communications teams, and NASA websites Earth Observatory and Global Climate Change."




http://climate.nasa.gov/climate_resources/9/

 

Which experiment proves that humans can control global climate? An hypothesis is tested through experimentation. Where is the controlled experiment that proves humans can do anything at all about global climate. Heck, we can't even bring rain to CA.

 

agw is mostly caused by co2, reduction of carbon emissions helps reduce warming

 

Slight adjustments every year making current temperature warmer and past temperature cooler. LOL BTW, the MET just announce the hiatus may continue.