Comments on: The annotated Rodney Hide: treating parliament with contempt

By: Rob Taylor

Rob Taylor — Thu, 01 Apr 2010 22:20:59 +0000

Thanks, CT, for such a clear exposition of the essentials of AGW that even an ACT droid should be able to follow it – not that I'm holding my breath…

By: ctg

ctg — Thu, 01 Apr 2010 20:22:57 +0000

A couple of points, James. First of all, there is no such thing as "global warming theory". There is Greenhouse theory, first proposed by Fourier in the 1820s, subsequently expanded and confirmed, notably by Arrhenius in 1896 and Gilbert Plass in the 1950s. There are no climate scientists who dispute the basics of Greenhouse theory, not even sceptical climate scientists such as Lindzen, Spencer etc. If the Greenhouse effect did not exist, Earth would be a frozen ball of ice with a mean global temperature of about -18°C.
All of the items you have brought up are easily explained by Greenhouse theory, which accepts that there are many factors other than CO2 that influence climate. I wonder why you think a warm MWP would invalidate Greenhouse theory?
Second, Anthropogenic Global Warming (AGW) is a hypothesis (strictly a collection of hypotheses) that posits three things:
1) Atmospheric CO2 has been steadily increasing since the 19th century
2) Mean global temperatures have been increasing since the same time, and
3) The increase in CO2 is caused by fossil fuel emissions.
1 and 2 are observations that have been confirmed by several sources. 3 is confirmed by changes in C12/C13 isotope ratios.
The only real question that is debated by scientists is over exactly what the contribution of CO2 is. Some people suggest that CO2 is only responsible for a tiny fraction of the recent warming, and it is other factors that have been at play. The problem with that is that none of the other known factors have changed enough in recent times to have been the main cause of warming, whereas CO2 has. All of the evidence to date indicates that it is the combination of burning fossil fuels and land use changes that have increased atmospheric CO2, and that this is causing warming of a large enough degree that significant climate changes are in store.

By: philscadden

philscadden — Wed, 31 Mar 2010 20:29:44 +0000

James – please avoid the straw man arguments. This is all addressed in WG1. For a quick look, try
http://www.skepticalscience.com/CO2-is-not-the-on…
for more.

Don't guess the forcings – look them up. Basically, increased CO2 emissions hang around for a long time so you get a cumulative effect whereas aerosols are very short lived.

Lots of factors affect climate. Noone disputes this. The basic issue is not what affected climate in past but what is causing the CURRENT warming because the forcings that we measure suggest that anthropogenic factors, primarily GHG, are to blame. If you are going to insist on "its natural" – then kindly venture WHAT natural cause you think is doing it because so far science struggles to find one. You would also need to explain why an extra 3-4W/m2 of warming from increased GHG concentrations in the atmosphere is NOT warming us.

For the past, see WG1 for papers that have modelled past forcings and compared to temperature record. Chapter 6, 6.6.3, p476 forward.

By: ctg

ctg — Wed, 31 Mar 2010 18:24:53 +0000

There are many factors that influence climate. The major forcings are (in no particular order): solar, CO2, methane, volcanic activity, aerosols. Then there is water vapour and clouds, which actually contribute most of the greenhouse effect - water vapour is considered a feedback rather than a forcing, because water vapour changes in response to other changes, rather than driving changes in the energy balance of the atmosphere itself. See here for instance. If you are interested in attribution, read here and here to start with.

By: nommopilot

nommopilot — Wed, 31 Mar 2010 12:59:12 +0000

so what? of course natural factors have an impact. it's just that in the last few hundred years humans have deforested most of the planet and then dug up and burned much of the carbon that has been sequestered over millions of years and that is having a major measurable and observed impact.

If you really think your logic has the power to disprove AGW please do take your revelations to a higher authority than the comments on a blog. The heartland institute and Exxon urgently need you to get this stuff published because so far there is not a single credible scientific paper that has passed peer-review successfully challenging the basic tenets of AGW. I know you're probably going to go ahead and ring the scientist conspiracy bell. We all love that…

Good luck with that.

This might help answer some of your questions about aerosols: http://en.wikipedia.org/wiki/Global_dimming and there's a good documentary called 'global dimming' to look out for as well.

By: James

James — Wed, 31 Mar 2010 11:58:57 +0000

But what about the warming before the1940s? if that wasn't indeed natural warming then it must have been according to increased co2 emissions according to global warming theory, so why would there be an increase in temperature if the sulphates and soot were still present in coal power stations and domestic fires at the time of the warming? why weren't the aerosols countering the temperature increases from the co2 at that time? and why then would an increased output in the 40s cause aerosols to suddenly become the bigger factor in influencing climate than co2 that doesn't really add up .And if it is to be claimed that the increase in temperature before the 40s wasn't from human emissions etc then that has to be an admission that natural warming was occuring.

By: James

James — Wed, 31 Mar 2010 09:47:22 +0000

And do your averaged out results confirm the common concensus that there has been cooling since 2002?, and include 1940s to 1970s cooling? that would be an appropriate average if it did. the reason my routinized drivel remains routinzed is because it is the achilles heal of global warming alarmists and it can't be answered i'e Medieval warm period, 1940s to 1970s cooling. also the central england temperature records from 1659-2009 show more warming from 1700 to 1730 than the whole of the 20th century thats 9 times the rate of warming. ( i'm not sure if you've heard that particular drivel but have a look) or mayb thats more conspiracy theory from me!

By: James

James — Wed, 31 Mar 2010 09:44:32 +0000

Hi guys thats an intersting comment regarding the 1940s to 1970s cooling and I welcome the fact that someone has actually addressed 1 of my issues and I will endeavour to learn more on this fact. One thing has leapt to my mind and that is this: Saying that aerosol was the cause of the cooling implies that it had and has more of an impact on climate than co2, and infact does much more than neutralise its warming capablity which is as explained by global warming theory.

By: billzog

billzog — Wed, 31 Mar 2010 09:22:27 +0000

I've made it my business to find every temperature station record for every country that keeps them that i can possibley find, and I've noticed one thing; very rarely, infact never do the match up with th IPCC temperature records

The hell you have, son! All you've done is memorize some routinized drivel we've all seen 73 times already (yes, I made it my business to count them all and then averaged out the result!)

Rightwing student-union types – sheesh!

(And: me fail English? That's unpossible?)

By: ben

ben — Wed, 31 Mar 2010 09:00:41 +0000

Gareth has to say that otherwise he is effectively admitting that his book is a load of cobblers.