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 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? Saturday, 3 May, 2008Is 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. Posted by John Cross at 9:57 AM | 18 commentsTuesday, 29 April, 2008Can 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. Posted by Barry Brook at 11:29 AM | 21 commentsSunday, 27 April, 2008Did 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. Posted by John Cook at 8:26 PM | 7 commentsTuesday, 22 April, 2008Do 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? Posted by John Cook at 9:47 PM | 34 commentsSunday, 13 April, 2008Cartoon about global warming alarmism
Posted by John Cook at 12:00 AM | 5 commentsWednesday, 9 April, 2008La Nina watch: March updateI 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. Posted by John Cook at 1:42 PM | 10 commentsTuesday, 8 April, 2008The Mystery of the Vanishing Ocean HeatEveryone 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? Posted by John Cook at 8:14 AM | 15 commentsMonday, 31 March, 2008Global warming stopped in 1981... no, wait! 1991!The modern global warming trend began around 1975 and has shown a long term warming trend of 0.18°C per decade since. That's not to say the warming trend has been monotonically constant with each year slightly warmer than the previous. Short term weather fluctuations cause a noisy signal. Large volcanic eruptions lead to dramatic cooling over several years. El Nino/La Nina has a cycle of warming and cooling lasting 4 to 5 years. To demonstrate climate's variability, let's examine a 6 year record early in the global warming period. Posted by John Cook at 7:50 PM | 8 commentsTuesday, 25 March, 2008Determining the long term solar trendThe most precise measurements of solar activity are satellite observations of Total Solar Irradiance (TSI). TSI is also a useful proxy for other solar activity such as solar flares, cosmic radiation, sunspots, radio flux, UV radiation and x-ray flares - all of which correlate with TSI. However, there is no single continuous record since satellites began taking measurements in 1978. Instead, scientists have had to splice various satellite data together into a single composite record. The two most cited composites are by Frolich and Lean 1998 (PMOD) and Willson 1999 (ACRIM). ACRIM shows a slight increase in solar activity while PMOD shows an even slighter cooling trend. Posted by John Cook at 8:39 PM | 13 commentsMonday, 17 March, 2008Comparing IPCC projections to observationsThe best way to check the reliability of climate models is to compare projections to actual observations. However, this is a catch-22. You need a decent time period to accurately discern climate trends amid the noise of weather fluctuations. Over that time, the climate model would've been superseded by new models running on faster computers at higher resolutions using better understood science. Nevertheless, a paper recently published in Science, Recent Climate Observations Compared to Projections (Rahmstoorf 2007), gives it a shot, comparing 2001 IPCC projections to observations up to 2007. Posted by John Cook at 8:42 AM | 31 comments |
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Skeptic of the Week
The award for most skeptic arguments in a single article over the past 7 days goes to:Is Global Cooling Next? by Human Events (8 arguments)