Study: We Were Wrong, Climate Scientists Concede – Admit models ‘on the hot side’, overstated CO2 impact


By: - Climate DepotSeptember 19, 2017 5:52 PM

We Were Wrong,
Climate Scientists Concede
How The IPCC And Climate Alarmists Hid The Good New About Global Warming

The world has warmed more slowly than had been predicted by computer models, which were “on the hot side” and overstated the impact of emissions on average temperature, research has found. Michael Grubb, professor of international energy and climate change at University College London and one of the study’s authors, admitted that his previous prediction had been wrong. He stated during the climate summit in Paris in December 2015: “All the evidence from the past 15 years leads me to conclude that actually delivering 1.5C is simply incompatible with democracy.” Speaking to The Times, he said: “When the facts change, I change my mind, as Keynes said. —Ben Webster, The Times, 19 September 2017 

To have the discrepancy between climate model predictions and reality acknowledged in Nature Geoscience is good. It has already resulted in a substantial debate about this most fundamental approach to assessing the impact of man-made climate change, demonstrating once again that ‘the science’ is definitely not settled. Assumptions made about important details of climate science that were accepted a decade ago are becoming increasingly frayed. Let us hope that a new era of scientific reality will replace the far-to-simple messages previously proclaimed to the public. – David Whitehouse, GWPF Observatory, 19 September 2017

1) We Were Wrong, Climate Scientists Concede
Ben Webster, The Times, 19 September 2017 
ot s
2) David Whitehouse: Climate Change Will Take Longer, Say Scientists
GWPF Observatory, 19 September 2017

3) Reminder: How The IPCC And Climate Alarmists Hid The Good News On Global Warming
Global Warming Policy Forum, 18 September 2017 

4) Graham Stringer MP Welcomes ‘Swift’ BBC Rebuke Of Presenter Over Climate Sceptic Tweet
Graham Ruddick, The Guardian, 18 September 2017 

5) Benny Peiser: Climate Realism – A Lukewarm Approach To Global Warming
University of Birmingham

6) Trump Adviser Tells Foreign Ministers U.S. Will Leave Paris Climate Accord
The New York Times, 18 September 2017 

A report published 3 years ago by the Global Warming Policy Foundation showed that the best observational evidence indicates our climate is considerably less sensitive to greenhouse gases than climate models are estimating. “The observational evidence strongly suggest that climate models display too much sensitivity to carbon dioxide concentrations and in almost all cases exaggerate the likely path of global warming,” says Nic Lewis. —Global Warming Policy Forum, 18 September 2017 

Gary D. Cohn, the top White House economic adviser, told ministers from several major allies on Monday that the Trump administration was “unambiguous” about its plans to withdraw from the Paris agreement on climate change unless new terms were met. President Trump announced in a Rose Garden speech in June that the Paris agreement — under which nearly 200 nations pledged voluntary targets to cut planet-warming greenhouse gas emissions and to support poor countries grappling with rising global temperatures — was bad for America’s economy. He said the United States would withdraw from the agreement, but left open the possibility that he might try to “renegotiate” the accord. —The New York Times, 18 September 2017 

1) We Were Wrong, Climate Scientists Concede
Ben Webster, The Times, 19 September 2017 

Catastrophic impacts of climate change can still be avoided, according to scientists who have admitted they were too pessimistic about the chances of limiting global warming.

The world has warmed more slowly than had been predicted by computer models, which were “on the hot side” and overstated the impact of emissions on average temperature, research has found.

New forecasts suggest that the world has a better chance than claimed of meeting the goal set by the Paris Agreement on climate change of limiting warming to 1.5C above pre-industrial levels.

The study, published in the prestigious journal Nature Geoscience, makes clear that rapid reductions in emissions will still be required but suggests that the world has more time to make the necessary changes.

Michael Grubb, professor of international energy and climate change at University College London and one of the study’s authors, admitted that his previous prediction had been wrong.

He stated during the climate summit in Paris in December 2015: “All the evidence from the past 15 years leads me to conclude that actually delivering 1.5C is simply incompatible with democracy.”

Speaking to The Times, he said: “When the facts change, I change my mind, as Keynes said.

“It’s still likely to be very difficult to achieve these kind of changes quickly enough but we are in a better place than I thought.”

Professor Grubb said that the new assessment was good news for small island states in the Pacific, such as the Marshall Islands and Tuvalu, which could be inundated by rising seas if the average temperature rose by more than 1.5C.
“Pacific islands are less doomed than we thought,” he said.

Professor Grubb added that other factors also pointed to more optimism on climate change, including China reducing its growth in emissions much faster than predicted and the cost of offshore wind farms falling steeply in the UK.

He said: “We’re in the midst of an energy revolution and it’s happening faster than we thought, which makes it much more credible for governments to tighten the offer they put on the table at Paris.”

The study found that a group of computer models used by the Intergovernmental Panel on Climate Change had predicted a more rapid temperature increase than had actually occurred.

The global average temperature has risen by about 0.9C since pre-industrial times but there was a slowdown in the rate of warming for 15 years before 2014.

Myles Allen, professor of geosystem science at the University of Oxford and another author of the paper, said: “We haven’t seen that rapid acceleration in warming after 2000 that we see in the models. We haven’t seen that in the observations.”

He said that the group of about a dozen computer models, produced by government research institutes and universities around the world, had been assembled a decade ago “so it’s not that surprising that it’s starting to divert a little bit from observations”.

He said that too many of the models used “were on the hot side”, meaning they forecast too much warming.

According to the models, keeping the average temperature increase below 1.5C would mean the world could afford to emit only about 70 billion tonnes of carbon after 2015. At the current rate of emissions, this so-called “carbon budget” would be used up in three to five years’ time.

Under the new assessment , the world can emit another 240 billion tonnes and still have a reasonable chance of keeping the temperature increase below 1.5C.

“That’s about 20 years of emissions before temperatures are likely to cross 1.5C,” Professor Allen said.

Full story

2) David Whitehouse: Climate Change Will Take Longer, Say Scientists
GWPF Observatory, 19 September 2017

A new paper written by scientists from six nations says that the slowdown in global temperatures in the early 20th century means that global warming will take longer than the IPCC predicted in its last report.

It has resulted in such headlines as that in the Times; We were wrong — worst effects of climate change can be avoided, say experts.

This is bound to infuriate some who maintain that there is no evidence that the slowdown in surface temperatures ever existed – an increasingly difficult stance to justify.

The study is published in the journal Nature Geoscience by a team of scientists led by Richard Millar of the University of Oxford. It has recalculated the carbon budget for limiting the Earth’s warming to 1.5 degrees Celsius above temperatures seen in the late 19th century. It had been widely assumed that this stringent target would prove unachievable, but the new study would appear to give us much more time to act if we want to stay below it.

It says that the world has warmed more slowly than has been forecast by computer models, and that the IPCC had overstated the impact of emissions. One of the authors, Professor Michael Grubb of University College London, admitted past predictions were wrong, and that he had changed his mind about the timescales involved in man-made climate change.

Some have responded to this paper by saying that the computer models were developed a decade or so ago and that they are bound to be looking a little inaccurate a decade later. So much is obvious. But it is far cry from the message by some strident climate scientists who maintain that the models accurately portray the real world — even when the evidence has been strong and growing that they do not. To have the discrepancy between climate model predictions and reality acknowledged in Nature Geoscience is good. It has already resulted in a substantial debate about this most fundamental approach to assessing the impact of man-made climate change, demonstrating once again that ‘the science’ is definitely not settled.

While one group of scientists argue that we have more time, another think we have not.

Weather Not Climate

The news release just issued by the Met Office; “A Pacific flip triggers the end of the recent slowdown,” is one of the most misleading releases I have ever read. It is curiously timed as much of the data for 2017 is obviously not in yet. Mind you, the Met Office has a habit of jumping the gun on temperature data — almost every year — with varying degrees of accuracy, and a habit to predict warmer temperatures than observed.

It says that a new analysis of 15-year running means of global surface temperature reveals that the slowdown in global warming seen between 1999 – 2014 is over thanks to three years of record temperatures. The end of this period was marked by globally high temperatures induced by an intense El Nino.

Must we say once again that using such a strong El Nino – a weather event – to calculate long-term climate trends is comparing apples and oranges? The HadCRUT4 global surface temperature database is flat between 2002 and 2014, a trend bound to be increased by the presence of high temperatures due to weather at the end of the database.

The Met Office has also offered yet another explanation for the slowdown. It is, it claims, due to temperature cycles in the Pacific which went into a cold phase in the 1990s and is now starting a warm phase. Professor Adam Scaife, the head of monthly to decadal prediction at the Met Office Hadley Centre, said: “The end of the recent slowdown in global warming is due to a flip in Pacific sea-surface temperatures. This was due to a change in the Pacific Decadal Oscillation which entered its positive phase, warming the tropics, the west coast of North America and the globe overall.”

However, what the Met Office fails to mention is that we may also be facing a shift in Atlantic temperatures to a cool phase, the so-called Atlantic Multidecadal Oscillation (AMO). In 1995, after a relatively quiet period in the Atlantic, the AMO flipped to the warm phase. In in a few years we are likely to see it flip back to its cool phase again, with its concomitant effect on global temperatures.

Nobody has any real idea what global surface temperatures will do in the near future. There are strong indications that the globe has been cooling. It could be that declining temperatures will revert to what they were before the 2015/16 El Nino event, bringing with it the return of the slowdown.

In short, assumptions made about important details of climate science that were accepted a decade ago are becoming increasingly frayed. Let us hope that a new era of scientific reality will replace the far-to-simple messages previously proclaimed to the public.

Feedback: [email protected]

3) Reminder: How The IPCC And Climate Alarmists Hid The Good News On Global Warming
Global Warming Policy Forum, 18 September 2017 

A report published 3 years ago by the Global Warming Policy Foundation showed that the best observational evidence indicates our climate is considerably less sensitive to greenhouse gases than climate models are estimating.

The clues for this and the relevant scientific papers are all referred to in the Fifth Assessment report (AR5) of the Intergovernmental Panel on Climate Change (IPCC). However, this important conclusion was not drawn in the full IPCC report – it is only mentioned as a possibility – and is ignored in the IPCC’s Summary for Policymakers (SPM).

For over thirty years climate scientists have presented a range for climate sensitivity (ECS) that has hardly changed. It was 1.5-4.5°C in 1979 and this range is still the same today in AR5. The new report suggests that the inclusion of recent evidence, reflected in AR5, justifies a lower observationally-based temperature range of 1.25–3.0°C, with a best estimate of 1.75°C, for a doubling of CO2. By contrast, the climate models used for projections in AR5 indicate a range of 2-4.5°C, with an average of 3.2°C.

This is one of the key findings of the GWPF report Oversensitive: how the IPCC hid the good news on global warming, written by independent UK climate scientist Nic Lewis and Dutch science writer Marcel Crok. Lewis and Crok were both expert reviewers of the IPCC report, and Lewis was an author of two relevant papers cited in it.

In recent years it has become possible to make good empirical estimates of climate sensitivity from observational data such as temperature and ocean heat records. These estimates, published in leading scientific journals, point to climate sensitivity per doubling of CO2 most likely being under 2°C for long-term warming, with a best estimate of only 1.3-1.4°C for warming over a seventy year period.

“The observational evidence strongly suggest that climate models display too much sensitivity to carbon dioxide concentrations and in almost all cases exaggerate the likely path of global warming,” says Nic Lewis.

These lower, observationally-based estimates for both long-term climate sensitivity and the seventy-year response suggest that considerably less global warming and sea level rise is to be expected in the 21st century than most climate model projections currently imply.

“We estimate that on the IPCC’s second highest emissions scenario warming would still be around the international target of 2°C in 2081-2100,” Lewis says.

Full report: Short version

Long version: A Sensitive Matter: How The IPCC Buried Evidence Showing Good News About Global Warming