Den stora tråden om global uppvärmning/växthuseffekten

Om en organism lever i ett spann på 40 grader så tror jag inte de påverkas om snittet flyttar sig 1 grader.

Hur validerar man modellerna som används för att beräkna temperatur från stråldata?
Man jämför med vad man mäter med termometrar på Jorden. Med de fel som RSS upptäckte och korrigerade för i sina modeller tidigare i år har dom nu kommit ganska nära att få sina framräknade temperaturdata att stämma överens med vad som mäts på Jorden.
Modellerna är fortfarande under utveckling. Att UAH publicerar temperaturdata som avviker mycket från vad som uppmäts på Jorden måste tolkas som att det återstår en hel del arbete innan deras modeller räknar fram något som kan betraktas som ett bra närmevärde för Jordens medeltemperatur.
Såvitt jag vet publicerar inte UAH sina modeller för hur dom räknar om stråldata till temperatur. En viktig del av de justeringar av sin modell som RSS gjorde tidigare i år var att ta hänsyn till hur satelliternas banor förändras med tiden. Någon sådan justering har ännu inte gjorts av UAH.

@skogshuggar3n:
Jag återvänder till din tes:
"Låt mätningar styrka antaganden, inte tvärt om."
Jag har för mig att du skrivit att temperaturökningarna kommer att avta i framtiden. Jag tycker det är svårt att utvärdera en sådan hypotes utan att ha kännedom om t.ex. framtida utsläpp av växthusgaser.
Hur relaterar du antagadet om framtida avtagande temperaturökning till din tes?

De flesta växter är ganska robusta. Tillfälliga fenomen som en ny parasit är betydligt farligare för en art.

Jamen då så, de som får pengarna anser inte att det finns någon intressekonflikt så då finns det ingen intressekonflikt, och om Soon råkar "glömma" att redovisa sin finansiering i publikationer trots att det tydligt står i tidskriftens regler att man skall göra så är det heller inget att orda om.

Använder du samma kriterium när du bedömer eventuella intressekonflikter på andra sidan, och vilka forskare är det i så fall som har intressekonflikter du vill kännas vid och vad grundar du det på?

Mycket talar för att MWP mer varit ett regionalt fenomen kring Nordatlanten. Då finns andra, t ex Soon, som försökt visa att det är globalt men då blandar han friskt både när toppen inträffat i olika regioner och så räknar han in både torr- och våtperioder som bevis på MWP.

Ser man på en del andra rekonstruktioner visar de förvisso på mycket större fluktuationer, men detta skulle vara mer övertygande om dessa fluktuationer överensstämde mellan de olika rekonstruktionerna. Nu ser de mer ut som brus. Felmarginalerna är dock så stora att det är svårt att vara säker.

Beroende då på hur stor inverkan dessa solcykler har, och därom tvistar de lärde. En "skeptiker" som Lennart Bengtsson har t ex inte mycket till övers för alla dessa teorier om solens stora inverkan.

Du verkar missnöjd med The Smithsonians beslut om anslag? Nu vet jag inte exakt vad som har hänt men enligt WS så har han angett var pengarna kommer ifrån vid alla tillfällen utom när det har funnits ett avtal mellan Smithsonian och bidragsgivaren om att inte röja dennes identitet.

I den mån jag överhuvudtaget bedömer författaren så är det främst utifrån karaktär. En snubbe som Lord Monckton till exempel, utstrålar tillit. Håller du inte med om det?

Förhoppningsvis kommer smutsig forskning att vaskas bort genom att resultaten granskas, som jag misstänker är fallet med Mann's hockeyklubba.

En proxy med låg resolution visar väl på korrelationen med temperatur under en längre tidsperiod?

This is the inescapable conclusion of a landmark paper, published in Nature Geoscience, which finally admits that the computer models have overstated the impact of carbon dioxide on climate and that the planet is warming more slowly than predicted.

The paper – titled Emission budgets and pathways consistent with limiting warming to 1.5 °C – concedes that it is now almost impossible that the doomsday predictions made in the last IPCC Assessment Report of 1.5 degrees C warming above pre-industrial levels by 2022 will come true.

In order for that to happen, temperatures would have to rise by a massive 0.5 degrees C in five years.

Since global mean temperatures rarely rise by even as much as 0.25 degrees C in a decade, that would mean the planet would have to do 20 years’ worth of extreme warming in the space of the next five years.

This, the scientists admit, is next to impossible. Which means their “carbon budget” – the amount of CO2 they say is needed to increase global warming by a certain degree – is wrong. This in turn means that the computer models they’ve been using to scare the world with tales of man-made climate doom are wrong too.

One researcher – from the alarmist side of the argument, not the skeptical one – has described the paper’s conclusion as “breathtaking” in its implications.

A new paper suggests a rather significant upward revision of the carbon budget for 1.5°C. This is a potential game changer, but it is too early to reformulate mitigation plans.

The IPCC Synthesis Report suggests the carbon budget to stay below 1.5°C is about 250 billion tonnes CO2 from 2015, and at 2015 emission rates, the carbon budget will be gone by about 2022.

Surely, this must be wrong?

We are currently at around 1°C above pre-industrial levels (based on 1870), but can global average temperatures increase about 0.5°C in five years?

No! There is an obvious inconsistency with the carbon budgets, something I wrote about earlier!

A simple back-of-envelope calculation, with rounded numbers, helps explain the inconsistency.

We know that global average temperatures may increase as much as 0.25°C per decade, and that would mean it would take 20 years (two decades) to go from about 1°C today to 1.5°C. Since we emit about 40 billion tonnes CO2 per year, that would give a budget of about 800 billion tonnes of CO2 if we assumed emissions remained constant.

That very rough ball-park estimate of 800 billion tonnes of CO2, is much larger than the 250 billion tonnes CO2 suggested in the last IPCC report.

There must be an inconsistency somewhere (or a misunderstanding).

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.
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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.

Climate change poses less of an immediate threat to the planet than previously thought because scientists got their modelling wrong, a new study has found. New research by British scientists reveals the world is being polluted and warming up less quickly than 10-year-old forecasts predicted, giving countries more time to get a grip on their carbon output.

An unexpected “revolution” in affordable renewable energy has also contributed to the more positive outlook.

Experts now say there is a two-in-three chance of keeping global temperatures within 1.5 degrees above pre-industrial levels, the ultimate goal of the 2015 Paris Agreement.

I have a number of thoughts about this:

1) We have known for several years that the climate models have been running far too hot.

This rather belated admission is welcome, but a cynic would wonder why it was not made before Paris.

2) I suspect part of the motivation is to keep Paris on track. Most observers, including even James Hansen, have realised that it was not worth the paper it was written on.

This new study is designed to restore the belief that the original climate targets can be achieved, via Paris and beyond.

3) Although they talk of the difference between 0.9C and 1.3C, the significance is much greater.

Making the reasonable assumption that a significant part of the warming since the mid 19thC is natural, this means that any AGW signal is much less than previously thought.

4) Given that that they now admit they have got it so wrong, why should we be expected to have any faith at all in the models?

5) Finally, we must remember that temperatures since 2000 have been artificially raised by the recent record El Nino, and the ongoing warm phase of the AMO.

Given the latest admission, there is every likelihood that global temperatures will remain flat for a good time to come.

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.