A few problems with Bolt:

Point 2: Bolt quoted Revelle: ""the scientific basis for a greenhouse warming is too uncertain to justify drastic action at this time (1991)". So what action did Revelle think was NOT drastic in 1991? Revelle's daughter in the Washington Post of 1992/9/13: "In private, he often spoke of a $1.00 a gallon tax as eminently reasonable, not "drastic."" So to Revelle, global warming was "only" certain enough in 1991 to justify a US$1 a gallon tax. Not very certain at all really. Yeah right.

Point 3: Bolt points out that "ice cores show the earth first warmed and only then came more carbon dioxide". He then asks the presumptuous question "So does extra carbon dioxide cause a warming world, or vice versa?" Well, both actually but non-scientist Bolt doesn't have the scientific imagination to realise that it could be both.

Point 4: Bolt says a 2004 "study" in Nature says that Mt Kilimanjaro was losing its snows more than a century ago largely because deforestation has cut the moisture in the air. This "study" was not a scientific article but a news piece about a proposal to save the Kilimanjaro glacier by wrapping it in a giant tarp. It casually mentioned that "researchers think that deforestation of the mountain's foothills is the more likely culprit" but didn't give any references for this claim or who these researchers are. Bolt also pointed out that some glaciers are getting bigger but no-one is arguing that global warming has already overwhelmed natural variation everywhere.

Point 5: Bolt implies Gore is suggesting oceans could rise 6 metres (from Greenland melting) by 2100 when the IPCC contradicts him. Gore does not suggest Greenland could melt by 2100. Even though Greenland's ice will not slide-off for a long time (hundreds of years), Gore is suggesting we think about whether we want to cause this to happen because the consequences are so serious. Bear in mind that Greenland was mainly ice-free 127,000 years ago and that the previous ice-cap probably took less than 2000 years at most to slide off.

continues…

Response to Chris on point 2:

Bolt tried to make us think he was quoting Revelle, but infact these words quote Fred Singer. Again, look at how Bolt carefully uses words to describe a "co-written article", but only mentions the one name. The words in the quotation are not written by Roger Revelle in 1991 but by Fred Singer in 1990. We know this because the words were previously published by Singer in Environmental Science and Technology Magazine:
Index: http://pubs3.acs.org/acs/journals/toc.page?incoden=esthag&indecade=1&involume=24&inissue=8
Scan: http://home.att.net/~espi/Singer_article_solo.pdf

A NASA website says: “In 1957, Revelle and Hans Suess, one of the founders of radiocarbon dating, demonstrated that carbon dioxide had increased in the air as a result of the use of fossil fuels” and “Under Revelle's leadership, [there was publication of] the first authoritative U.S. government report in which carbon dioxide from fossil fuels was officially recognized as a potential global problem.” http://earthobservatory.nasa.gov/Library/Giants/Revelle/revelle_2.html

Tim Lambert describes point 2 as “misleading”. Gore could have certainly learnt from Revelle about global warming.

Bolt is picking up sources and arguments from the anti-environment Internet sites and his writing style indicates he is aware of the weaknesses in his various points, because they are so purposefully papered over. But the weaknesses are also posted elsewhere, eg I've used NASA.

Is NASA "the counter view of the rabid left" Col?

Just in case OLO readers missed it, Bolt yesterday put up a new Lambert post.

See: http://blogs.news.com.au/heraldsun/andrewbolt/index.php/heraldsun/comments/so_what_was_lambert_really_reading/P0/

Instead of engaging Bolt on the issues, Lambert makes one waffly comment (on page two) and then retreats to the safety of his blog, where he posts a waffly response. Unfortunately for Lambert, Tim Blair and Glenn Reynolds have linked to his post so he’s getting some critical comments. Boo hoo.

See: http://scienceblogs.com/deltoid/2007/02/ipcc_ar4_leaks_wrong.php#comment-332682

The moral of this story: never assume anything written by Tim Lambert is accurate; it probably isn’t.

Point 6: Bolt should have stuck to attacking Gore's use of anecdotal evidence to support the claim of adverse effect from rising sea level. Instead Bolt uses a terse quote whose meaning on its own is wrong and thus completely misleading.

Point 7: Bolt thinks most bleaching is caused by El Nino events but ignores the fact that the Great Barrier Reef experienced its worst coral bleaching event on record beginning in January 2002. There was no El Nino that summer.

Point 8: Bolt asserts that most hurricane experts agree with Dr Chris Landsea of the US National Hurricane Centre, who says "there has been no change in the number and intensity of (the strongest) hurricanes around the world in the last 15 years". Bolt doesn't say who these " most hurricane experts" are but Landsea is a sceptic who spat the dummy and left the IPCC. A list of scientific papers showing the increase in cyclone intensity is here: http://www.cleartheair.org/hurricanes.vtml . It includes a paper with Landsea as an author and statements from his co-authors about the problems with his assertions.

Point 9: Reiter refers to http://www.cdc.gov/ncidod/eid/vol8no12/02-0077.htm to support his position that Gore is completely wrong to suggest that warming allows malarial mosquitoes to move to higher altitudes. Reiter's reference shows that in a place where malaria has increased, there hasn't been significant warming. Reiter has his logic messed up, because to prove Gore wrong he would have to find somewhere that has warmed up but which has not had a significant rise in malaria. Reiter is the one being deceitful.

Point 10: Bolt suggests "just one" other possible explanation scientists have given for the warming globe, increased solar activity (the denialists never suggest anything more substantial). Problem is, the increased solar radiation since 1900 (0.28 W/(m^2 of earth surface)) is only a small fraction of the radiation forcing from increased CO2 (1.8 W/m^2). i.e. less than 1/6th as much. You don't need fancy computer climate models to work out the radiation forcing from increased CO2, just knowledge of its radiation physics.

Bolt gets 0/10 for journalism.

BBGun,

Bolt, Blair et al, have again embarrassed themselves by not understanding what has been written (ideologues tend to do that a lot).

From Realclimate

www.realclimate.org/index.php/archives/2007/02/the-ipcc-fourth-assessment-summary-for-policy-makers/#more-394

"Note that some media have been comparing apples with pears here: they claimed IPCC has reduced its upper sea level limit from 88 to 59 cm, but the former number from the TAR did include this ice dynamics uncertainty, while the latter from the AR4 does not, precisely because this issue is now considered more uncertain and possibly more serious than before."

So Bolt, Blair and Reynolds’s, GOTCHA, did nothing other than expose their ignorance. How embarrassing that these are the best the hapless denialists can wheel out.

Apologies for cross-posting, but I posted the following comment earlier today on the David Henderson thread and I think it's equally relevant here (N.B. I have made some minor edits to make the post fit the particularities of this thread):

I'm confused. On the one hand we have major reports released by the most authoritative international sources available, that indicate that global warming is real, is exacerbated by anthropogenic activities, and will have dire consequences on societies and the environment worldwide within decades. These reports include the Stern report and that of the United Nations' Intergovernmental Panel on Climate Change, released yesterday (see http://www.smh.com.au/news/environment/world-wakes-to-climate-calamity/2007/02/02/1169919530831.html ).

On the other hand, we have a minority of mostly non-scientists who are promoted by some pretty obvious interest groups to present a countervailing view, which typically amounts to introducing some degree of doubt about the interpretation of semantic aspects of some report or article, and thus claiming that the overall theory is unproven.

Leaving aside for the moment the motivations of those who argue against the reality of anthropogenic global warming in the face of ever-mounting evidence of its existence, it's clear that this forum is generally biased in that direction - in the material that it publishes on the subject, in the quixotic battle by its chief editor to try and debunk evidence of global warming, and in the pedantic comments posted by denialists in this thread.