A science presenter, writer, speaker & former TV host; author of The Skeptic's Handbook (over 200,000 copies distributed & available in 15 languages).



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Global confusion: Turns out global warming doesn’t cause wandering Jet Stream “extreme weather”

It’s a flip on a flop. After all the media headlines, a new paper suggests that some climate scientists are not just wrong, they got cause and effect mixed up, and that the wandering “blocking” jet streams are not caused by warmer arctic, but may be causing the temperature changes instead.

“”The well-publicised idea that Arctic warming is leading to a wavier jet stream just does not hold up to scrutiny,” says Screen.

“With the benefit of ten more years of data and model experiments, we find no evidence of long-term changes in waviness despite on-going Arctic warming.””

The truth is that most big models loosely predicted that global warming would make the jet streams less wiggly, but from the mid 1980s the jet-stream-trend was the other way. As the Arctic warmed the “waviness of jet streams increased”. So in 2012 a few modelers came up with a post hoc rationalization of why, really, truly, actually a warmer Arctic meant that the jets streams would wander more. The media enthusiastically repeated it, though it was contentious and disagreed with most models. But oh dear, by golly, by 2015 the trend started to reverse again. Now in [...]

Settled! Global Warming and the pause, caused by changes in cloud cover, not CO2

That’s it: It was 4% cloudier in 1985, then roughly the same after 2000 — that’s the Pause and the Cause

A new paper in Russian, by OM Pokrovsky, shows that global cloud cover decreased markedly from 1986 to 2000. This is a very large decline in terms of the planetary atmosphere. Pokrovsky uses ISCCP satellite data (the “International Satellite Cloud Climatology Project” — a US program). It’s the best cloud data there is. The effects of clouds are so strong that most of the differences between IPCC-favoured-models comes from the assumptions the models make about clouds. Cloud feedbacks are the “largest source of uncertainty”. [IPCC, 2007]

Clouds cover two-thirds of the Earths surface, reflecting around 30% of the total energy from the Sun back to space. A small change in cloud cover can easily warm or cool the planet, like a giant pop-up shade-sail.

This, on its own, explains all the warming that occurred from 1986 – 2000. It explains the pause. We don’t know why clouds decreased, but we know it wasn’t due to CO2, which kept rising relentlessly year after year, and even faster after the turn of the century.

Something else is driving cloud formation, or [...]

NASA hides page saying the Sun was the primary climate driver, and clouds and particles are more important than greenhouse gases

ZeroHedge asks: What the hell are NASA Hiding?

The NASA site used to have a page titled “What are the primary forcings of the Earth system?“. In 2010 this page said that the Sun is the major driver of Earth’s climate, that it controls all the major aspects, and we may be on the cusp of an ice age. Furthermore NASA Science said things like clouds, albedo and aerosol behaviour can have more powerful cooling effects that outdo the warming effect of CO2.

Today that page says Share the science and stay connected, and “Access Denied”.


Whatever you do, don’t tell the world that NASA says the Sun is more important than CO2.

The Wayback Machine captured the same NASA “Primary Climate Forcings” link in 2010.

Click to enlarge.


Here’s the text from the original page (my bolding).

NASA 2010: What are the primary forcings of the Earth system?

The Sun is the primary forcing of Earth’s climate system. Sunlight warms our world. Sunlight drives atmospheric and oceanic circulation patterns. Sunlight powers the process of photosynthesis that plants need to grow. Sunlight causes convection which carries warmth and water vapor up into [...]

The biggest unnoticed storms in the world cause sudden Polar Vortex havoc

Sudden Stratospheric Warmings

Who knew? The polar vortices are the two strongest and largest “storms” on the planet. These continent scale storms are 600 miles across with winds raging at 300km per hour. Simon Clark is doing (or has done) a PhD in polar vortexes. He describes how each winter they form high over the poles. These are stratospheric, circling far above jet streams and planes. The tight circular pattern keeps the coldest air corralled. But every now again, the neat circle falls apart. In the polar stratosphere sometimes temperatures warm in days by stupid amounts, like 50 degrees C. It’s called a Sudden Stratospheric Warming (SSW) and one started around Christmas time.

As Clark describes it, these are easily the most violent weather events on the planet. (They sound fascinating). As with unbalanced centrifuges, when things unravel, as the high speed system unravels, the arctic cold could spin off anywhere — this week it’s the US, but Europe and Russia are often targets too. There is a lag involved — after an SSW it may take two weeks for things to hit the fan on the surface, so to speak. Generally, when an SSW hits it presages a [...]

The Sahara may flip from desert to grass every 20,000 years. Blame The Sun.

MIT researchers think they have solved a bit of a mystery regarding Sahara dust, but if they’re right it means the Sahara Desert has already come and gone 3 – 5 times since humans walked the Earth. The Sahara is the largest desert on Earth, and this would be the largest and longest drought “ever” on the planet (as far as we know).

UPDATED: Commenter Javier points out these drying cycles were known years ago. (See below)

This would rather redefine the whole idea of “climate change” — 3.5 million square miles of Green Sahara turns into Dust-bowl Sahara — and it’s all thanks to sunlight. The drought doesn’t just last 7 years, but more like 7,000. And it’s happening over 9 million square kilometers, an area larger than Australia. The major climate models leaned towards the monsoonal cycle, rather than the longer ice age one. So this theory may have resolved one of the 495 contradictions in climate models. Or not. But the bigger message here is that the sun causes climate change and on a massive scale.

h/t to Roger Tallbloke.

The Sahara is the largest dust bowl in the world, dumping 10 million trucks of dust across [...]

Study shows we can save the Arctic with ship pollution?

Shipping tracks, cloud patterns over the ocean. | Photo NASA.

Ships leave a trail of sulfur dioxide in the sky behind them which seeds clouds and causes cooling. At the same time, black soot drops out on the arctic ice, absorbs sunlight and causes warming. So which effect is bigger? Scott Stephenson et al tried to figure out that out and the cooling effect won.

The researchers also factored in global anthropogenic (human-caused) greenhouse gas concentration trajectories, adopted by the International Panel on Climate Change (IPCC), at a level closely aligning with today’s trends, along with global economic output that will drive the transport of goods.

“We attempted to fully integrate the interactions between the various components of the climate system in ways that have not been done before,” Stephenson says.

The main result was that the cooling effect won out over the warming effect in the simulations, to the tune of about one degree Celsius.

Zowie. One real degree of Arctic cooling sounds like rather a lot — even undoing greenhouse gas warming as well as soot based warming.

The cooling effect stops if we clean the smoke stack and remove [...]