Subscribe in a reader


Username
Password
Keep me logged in
New? Register here


It's the sun
Climate's changed before
There is no consensus
Surface temp is unreliable
It's cooling
Models are unreliable
Ice age predicted in the 70s
Al Gore got it wrong
We're heading into an ice age
CO2 lags temperature
View All Arguments...


Latest Posts


Skeptic of the Week

The award for most skeptic arguments in a single article over the past 7 days goes to:
Global Warming, Blind Faith, and Global Delusion by Bible Study Notes (14 arguments)

Scientific skepticism is a healthy thing. Scientists should always challenge themselves to expand their knowledge, improve their understanding and refine their theories. Yet this isn't what happens in global warming skepticism. Skeptics vigorously criticise any evidence that supports anthropogenic global warming and yet eagerly, even blindly embrace any argument, op-ed piece, blog or study that refutes global warming.

So this website gets skeptical about global warming skepticism. Do their arguments have any scientific basis? What does the peer reviewed scientific literature say?


Monday, 9 June, 2008

Arctic sea ice melt - natural or man-made?

Arctic sea ice has declined steadily since the 1970s. However, the 2007 summer saw a dramatic drop in sea ice extent, smashing the previous record minimum set in 2005 by 20%. This has been widely cited as proof of global warming. However, a popular mantra by climatologists is not to read too much into short term fluctuations - climate change is more concerned with long term trends. So how much of Arctic melt is due to natural variability and how much was a result of global warming?

Read more...

Posted by John Cook at 7:43 PM   |   140 comments


Monday, 2 June, 2008

A new twist on mid-century cooling

A persistent skeptic argument is the global cooling between the 1940's to the 1970's. 30 years of cooling during a period of increasing CO2 levels definitely raises a few questions. One piece of the puzzle has been provided by a new paper A large discontinuity in the mid-twentieth century in observed global-mean surface temperature (Thompson 2008).

Read more...

Posted by John Cook at 9:46 AM   |   16 comments


Thursday, 15 May, 2008

April update on global cooling 2008

Simon Donner makes a valid criticism of the climate blog ritual of scrutinising monthly temperature data. If recent events tell us anything, it's not to draw conclusions about long term climate trends based on short term temperature fluctuations. So is it really instructive to scrutinise monthly records and attempt to infer meaning in data dominated by weather noise? Maybe not. But it is fun.

Read more...

Posted by John Cook at 8:26 PM   |   12 comments


Saturday, 3 May, 2008

Is Pacific Decadal Oscillation the Smoking Gun?

The blogosphere is abuzz with the news that the Pacific Decadal Oscillation is reverting to a cool phase. Hot on the heels of this bombshell, a new climate model predicts a cooling North Atlantic Ocean will slow down global warming. This has led to speculation that man-made global warming is no match for natural cycles or even that Pacific Decadal Oscillation is responsible for most of the climate change over the past century including the warming since the mid-70's.

Read more...

Posted by John Cross at 9:57 AM   |   34 comments


Tuesday, 29 April, 2008

Can animals and plants adapt to global warming?

Guest post by Barry Brook, Director of the Research Institute for Climate Change and Sustainability at the University of Adelaide. Read more at Brave New Climate.

Human are transforming the global environmental. Great swathes of temperate forest in Europe, Asia and North America have been cleared over the past few centuries for agriculture, timber and urban development. Tropical forests are now on the front line. Human-assisted species invasions of pests, competitors and predators are rising exponentially, and over-exploitation of fisheries, and forest animals for bush meat, to the point of collapse, continues to be the rule rather than the exception.

Read more...

Posted by Barry Brook at 11:29 AM   |   25 comments


Sunday, 27 April, 2008

Did global warming stop in 1998?

The argument that global warming stopped in 1998 is making a comeback, riding on the coat-tails of global cooling since January 2007. Last year, a paper in the Bulletin of the Australian Meteorological and Oceanographic Society examined this argument. Now the author Robert Fawcett has co-published an updated version of the paper with fellow scientist David Jones at the Australian Bureau of Meteorology. It takes a similar approach to my original treatment of the subject, although in a more rigorous, peer-reviewed fashion.

Read more...

Posted by John Cook at 8:26 PM   |   13 comments


Tuesday, 22 April, 2008

Do cosmic rays cause clouds?

Satellite observations of Low Cloud Cover (LCC) reveal an 11 year signal that shows some correlation with cosmic radiation measurements. This has led some to conclude that cosmic rays cause cloud formation. However, LCC also correlates with other indices of solar activity such as Total Solar Irradiance and sunspot numbers. Can one determine how much cosmic radiation contributes to cloud formation?

Read more...

Posted by John Cook at 9:47 PM   |   35 comments


Sunday, 13 April, 2008

Cartoon about global warming alarmism

Read more...

Posted by John Cook at 12:00 AM   |   7 comments


Wednesday, 9 April, 2008

La Nina watch: March update

I confess to checking the NASA website like a true data geek the last few days, waiting for them to update the Land Ocean Temperature Index with March's figures. We saw last month how the La Nina cooling experienced through 2007 may have already started to reverse when February showed distinct warming compared to January. But what would March tell us? I must admit, even I was surprised.

Read more...

Posted by John Cook at 1:42 PM   |   11 comments


Tuesday, 8 April, 2008

The Mystery of the Vanishing Ocean Heat

Everyone loves a good mystery. If J.K. Rowling hadn't finished her series so emphatically, "Mystery of the Vanishing Ocean Heat" could've been the 8th Harry Potter book. The latest intrigue is the revelation that the oceans have showed a cooling trend since 2003. As oceans take in 84 percent of the heat absorbed by the Earth, ocean temperature is a good measure of global warming. Does this mean global warming has ended?

Read more...

Posted by John Cook at 8:14 AM   |   22 comments

© John Cook 2008