Although it might appear scientists are ‘cooking the books’, experts say the shifts are necessary to avoid biases from station relocations, instrument changes, the time of day and the heat island effect.
Misleading in that the major differences arise in treatment of ocean and not land based records.
The difference between recorded temperatures and reported temperatures has been slowly rising in recent years.
Unsupported assertion. Implication is that adjustments are somehow nefarious. In reality all observations are imperfect and require post-processing and analysis prior to their use. It would be fantastic to have perfect measurements but perfect measurements, like santa, the easter bunny and the tooth fairy don't actually exist.
Satellite data from Remote Sensing Systems (RSS) in California initially showed temperatures which largely flatlined from 1998, but that data has since been adjusted to show a warming trend.
Satellite data records have been shown to be more uncertain than surface records. All major satellite groups who have created multiple versions have at various times adjusted both up and down their estimates of long-term change. Each update reflects new understanding and improved processing.
Climate skeptics argue temperature records have been adjusted in recent years to make the past appear cooler and the present warmer, although the Carbon Brief showed that NOAA has actually made the past warmer, evening out the difference.
Fails to appropriately recognise that the net effect of adjustments is to reduce the longest-term trends.
It later emerged that many of the alarming claims cited in IPCC reports were not based on science but press releases and unfounded reports made by climate activists
The article fails to clarify again the context of where and how these were used. Specifically, they tend to be used in the impacts, adaptation and mitigation reports where regional detail is required and there is often a paucity of peer-reviewed literature.
The panel was forced to retract a statement in its 2007 report saying all Himalayan glaciers could melt entirely by 2035.
The article fails to make clear that this was in an underlying chapter of the impacts and adaptation report and not elevated to the summary for policymakers.
no statistically significant global warming since 1995
Statistically significant change over any 15 year period in the presence of substantial autocorrelation and year-to-year variability would always be unlikely.
In one particularly damning email, CRU director Phil Jones said he had used ‘Mike’s Nature trick’ to ‘hide the decline’ in temperatures in the second half of the 20th century. Just like Dr Mann’s ‘hockey stick’ graph he had cut off the tree-ring data just at the point where it stopped showing an upward trend and swapped in thermometer temperatures for recent decades, making them look much warmer.
There was and still is good reason to do this scientifically and it is not a "trick" it is a method which has passed peer-review.
Contents of the emails suggested scientists had been hiding or manipulating data, preventing people accessing their figures and working to stop papers critical of their findings from being published.
These assertions have long been rebutted and yet this is not even alluded to.
The difference is probably due to the way in which these different groups calculate a global average from the worldwide network of weather stations.
The major differences between the datasets tend to arise over the oceans and not the land.
The difference is probably due to the way in which these different groups calculate a global average from the worldwide network of weather stations.
The major differences between the datasets tend to arise over the oceans and not the land.
it is picked up in the Met Office’s compilation of global temperatures but not in the records compiled by the National Oceanic and Atmospheric Administration (NOAA) and Nasa.
There is no justification for this statement. The datasets are too similar to one another to justify such an assertion.
It wasn’t until the 1970s that satellites picked up the El Niño Southern Oscillation cycle (ENSO) on a global scale.
It wasn't until the 1970s that satellites picked up anything as there were few to no satellites. But understanding of ENSO has been accruing for at least a Century using direct measurements of sea surface temperatures and surface atmospheric pressure. Thus this is misleading.
one to four by 2100.
It is projected to rise by 1 to 4 feet not 1 to 4 inches as implied here. That's an order of magnitude error.
Today the ice is melting at such a dramatic rate that large shipping companies are considering expanding their routes to the top of the world.
Not just large ships. Sailing ships have now circumnavigated the pole in one summer season where once there was perennial multi-year ice
Dr Willie Soon's chart showing a correlation between Sun activity and surface temperature Credit: Dr Willie Soon
Firstly, the correlation isn't particularly compelling. But, secondly, why choose daily high temperature over Mexico? It smacks of a very spectacular cherry-pick. Searching over enough regions and metrics and playing the wiggle matching game one could likely createv similarly impressive graphs for any posited mechanism somewhere on earth. But that doesn't mean that there is a meaningful link between the two.
Dr Willie Soon's chart showing a correlation between Sun activity and surface temperature Credit: Dr Willie Soon
Firstly, the correlation isn't particularly compelling. But, secondly, why choose daily high temperature over Mexico? It smacks of a very spectacular cherry-pick. Searching over enough regions and metrics and playing the wiggle matching game one could likely createv similarly impressive graphs for any posited mechanism somewhere on earth. But that doesn't mean that there is a meaningful link between the two.
Yet a study published just this week, by the Bjerknes Centre for Climate Research in Bergen, Norway, found that the natural climate system can change abruptly, without the need for any external forces.
This falls foul of the single study fallacy. The basis for our understanding is a holistic assessment of multiple lines of evidence. It would take a spectacular new finding to overturn the enormous and compelling body of evidence that underlies our understanding.
The IPCC no longer includes the ‘Hockey stick’ chart in its reports.
Not only does IPCC include a whole family of such estimates but these estimates are now based upon many more sources of data from many more regions of the world. This assertion is verifiably false.
The IPCC no longer includes the ‘Hockey stick’ chart in its reports.
Not only does IPCC include a whole family of such estimates but these estimates are now based upon many more sources of data from many more regions of the world. This assertion is verifiably false.
Skeptics claim such anomalies prove that Earth can quickly warm and cool even in the absence of carbon dioxide, and any warming today may be caused by similar natural events.
Historical variations are well understood to have been caused by changes in solar output, orbital variations, volcanoes and on geological timescales changes in carbon dioxide and continental configuration. None of this remotely disproves the very robust evidence that recent changes are driven almost entirely by our historical emissions of greenhouse gases.
frost fairs were held on the Thames when the river froze.
The cessation of these frost fairs was linked to changes in river management and not to climate change.
The Medieval Warm Period (MWP) and the Little Ice Age.
These periods are now well understood to be at best regional phenomena rather than global-scale changes. Indeed, it is the broad global nature of the recently observed changes that make them unusual. The realisation of these being largely regional phenomena centred on the N. Atlantic region has led to a growing deprecation of these terms.
Even the BBC has admitted to Ofcom that the corporation is now biased on the matter because it no longer thinks there is a counter-argument.
The more pernicious issue that pervades media reporting of not just climate change but also many other fields of science and other issues is the false-balance paradigm that this article itself falls foul of repeatedly.
Dr Willie Soon's comparison of temperature data and water vapour
This follows the physical expectation that water vapour scales with temperature. The temperature change is driving the changes in water vapour (maintaining quasi-constant relative humidity) and not vice-versa. So they are correlated but for precisely the opposite reason than is being reported here.
Carbon Dioxide is playing a minor role in the total greenhouse effect.
Carbon Dioxide is the major contributor to changes in long-lived climate forcers since the industrial revolution.
But by far the largest greenhouse gas is water vapour, which makes 95 per cent of the total.
But water vapour is a feedback and not a long-term forcing. The amount of water vapour in the atmosphere is driven by the temperature (for every 1K increase 7% more water can be held) and water has too short lifetime in the atmosphere (think precipitation).
In its 5th assessment report in 2013, the IPCC estimated that human emissions are probably responsible for more than half of the observed increase in global average temperature from 1951 to 2010.
This is a gross misrepresentation of the assessment. The relevant finding is: It is extremely likely that more than half of the observed increase in global average surface temperature from 1951 to 2010 was caused by the anthropogenic increase in greenhouse gas concentrations and other anthropogenic forcings together. The best estimate of the human-induced contribution to warming is similar to the observed warming over this period. {10.3}
(my italicisation)
The reporter has picked up a commonly used trick to quote just the first sentence of the key finding. The full finding clearly falsifies the assertion here. The best estimate remains that all the warming seen since the mid-20th Century is down to us.
However the warming trend is slower than most climate models have forecast
This is demonstrably untrue. Firstly, the models from the early 1990s have proven remarkably correct in predicting how surface temperatures have subsequently evolved. But, more prescient is to look at current models. The ability of climate models when run with historical changes in important forcings through 2004 and then on to present with a plausible scenario is impressive. The single realisation that is the real-world clearly sits well within the spread of solutions predicted by the models. See e.g. https://twitter.com/GarethSJones1/status/1093827651788263424
1.62F (0.9C)
The latest estimates would place this closer to 1 degree. Mainly as a result of the run of recent warm years.
This is an unsupported assertion and is ignorant to the true process of dataset creation efforts. Estimates of historical changes have been updated but these updates reflect improved knowledge, improved access to observations, and new observational capabilities. Datasets are subject to peer-review and then subsequent review and feedback on a continuous basis by users. No dataset is ever perfect and it is critically important to encourage continuous re-evaluation to ensure the best possible understanding.
Meanwhile, the National Oceanic and Atmospheric Administration has been conducting highly suspicious temperature data manipulation. The changes in the temperature data consistently make the past seem cooler, which in turn makes the present seem warmer.
The NOAA temperature analyses have been thoroughly documented in the peer reviewed literature, independently evaluated, and are comparable to several completely independently produced estimates. The largest adjustment serves to remove an artificial warming in the Ocean temperatures in the mid-20th Century. This adjustment dwarfs all others applied. Unadjusted data show more warming since the late 19th Century than the adjusted records from NOAA and elsewhere do.
They failed to predict a decadelong pause in global temperatures.
Individual runs of individual models did capture such behaviour as has been shown by a wealth of literature on the topic. On a decadal scale natural variability plays an important role as can short-lived forcing effects. The scientific community has a substantial understanding of the "pause" and its causes. This understanding builds rather than diminishes confidence in the climate models.
Houlton has been exploring this possibility for years. Back in 2011, he reported that forest trees can tap into nitrogen found in rock. At the time, he said "the stunning finding that forests can also feed on nitrogen in rocks has the potential to change all projections related to climate change," because it meant there could be more carbon storage on land and less in the atmosphere than climate models say.
It should be noted that much of the Net Primary Productivity arises from grasses and other non-boreal sources. If only trees that are deep rooted enough to reach bed-rock can tap this source then the potential is very much geographically limited.
But climate scientists assumed that the ability to plants to perform this function was limited because the availability of nitrogen in the atmosphere was limited
Given that Nitrogen by volume constitutes 78% of the Earth's atmosphere it could hardly be described as limited.
"there will not be enough nitrogen available to sustain the high carbon uptake scenarios."
This is around whether there may be a reduction in the ability in future of the terrestrial biosphere to uptake Carbon. If Nitrogen is the sole limitation then indeed the risk is a reduction in ability of the biosphere to uptake Carbon. But, it is over-simplistic to consider Nitrogen uptake the sole potential limiting factor as implied by this quotation.
But climate scientists assumed that the ability to plants to perform this function was limited because the availability of nitrogen in the atmosphere was limited.
Climate scientists know that the ability is limited because we can, within uncertainties, close the Carbon budget. This closure shows that roughly for every three Carbon Dioxide molecules emitted by fossil fuel combustion one is ending up in the ocean, one in the terrestrial biosphere, and one remains in the atmosphere. This is an observed and verified behaviour. Plants are removing approximately 1/3 of the excess Carbon added by humans and this has remained broadly stable over several decades.
they've determined that the idea that the only source of nitrogen for plant life came from the air is wrong.
Demonstrably false assertion. We have applied on an industrial scale nitrate fertilisers precisely because the nitrogen is taken up from the soil. Otherwise farmers have wasted a lot of money over the past several decades.
If Houlton's finding about these vast, previously unknown nitrogen stores holds true, then it would have an enormous impact on global warming predictions.
Misleading inference. Nitrogen availability is just one factor in net primary productivity (carbon sequestration over land). Other factors include but are not limited to seasonal temperatures and precipitation patterns and availability of other nutrients. In some areas Nitrogen may well be limiting but to imply it is the limiting factor is without basis.
Scientists just discovered a massive, heretofore unknown, source of nitrogen
That the rocks in the crust of the planet contain Nitrogen has been known for in excess of a Century
Thus, it is impossible to conclude from the three published GAST data sets that recent years have been the warmest ever – despite current claims of record setting warming
That recent years have been the warmest since instrumental records began is shown not just by surface temperature records, but changes in a suite of additional indicators and modern reanalysis systems.
they all use the same corrupted global average temperature (GAST) data
They use overlapping but quasi-distinct sets of raw data but apply different approaches to adjustment and averaging which means this is misleading at best
That’s almost never happened
The largest adjustment is an adjustment which serves to reduce the long-term warming
pushed down the 1940s warming
All datasets actually make pre-1940 values warmer than the raw records and hence reduce centennial timescale warming
Nearly all of the warming they are now showing are in the adjustments.
If there were no adjustments warming would be greater so the nett effect of adjustments is to reduce the long-term warming.
The blue bars show where the raw temperature data has been adjusted downwards to make it cooler; the red bars show where the raw temperature data has been adjusted upwards to make it warmer.
It does no such thing as both the series are adjusted. Hence it is impossible from the graph as constructed to make such an inference. To do so would require taking the adjusted data away from the raw data which is not what is being done here.
This chart gives you a good idea of the direction of the adjustments.
The chart provides solely a view as to the changes in applied adjustments between consecutive versions of one product. It does not reflect the totality of the adustments being applied. Showing total adjustments would highlight that these deltas were dwarfed by the existing adjustments applied to the 2008 version. Specifically, the very large spurious warming resulting from biases in the raw marine data record over the late 1930s / early 1940s. The nett effect of adjustments in all datasets is to reduce the centennial timescale warming in all the surface temperature products
the warming of the last 120 years has been dramatic and unprecedented
The IPCC AR5 concluded that warming was unequivocal. This finding rested upon a wealth of evidence and not solely upon surface records. However, each decade for the past three decades has been warmer than all preceding decades in the instrumental record by a greater extent than quantified uncertainties. This finding applies using older or newer versions of the datasets
fabricated by climate scientists to make it look more frightening
All three major datasets have been rigorously peer-reviewed. Their findings are further substantiated by the changes in a wealth of other indicators of our changing climate and by modern reanalysis systems
peer-reviewed
As far as I can tell the linked report is not accepted for any journal and thus peer-reviewed is wilfully misleading at best