I visit leftist blogs and news sites fairly regularly.

I can’t remember who it was who said ‘If you only read one paper, read the opposition’s,’  but it was good advice. If we only read the opinions of people who agree with us, we run the risk of arguing with what we imagine our opponents’ arguments are, instead of what they really are.

But visits to leftist blogs are trying, because they are so often simply nasty.

Tim Lambert’s recent treatment of Ian Plimer is a perfect example.

Ian Plimer is Australia’s most respected earth scientist. His book Heaven and Earth: Global Warming, the Missing Science is a densely packed book of over 500 pages and 2,000 footnotes.

Lambert is almost bursting with glee as he announces that Professor Plimer has plagiarised Ferdinand Engelbeen’s work on CO2 levels. And furthermore that Plimer deliberately misrepresented the evidence, and did not cite Engelbeen because if he had done so he would have been forced to admit that Engelbeen’s work undermines his (Plimer’s) view of changes in atmospheric CO2.

Engelbeen does not believe in catastrophic global warming, but he does believe human activity has lead to measurable increases in atmospheric CO2.

It is true that some of the figures in a paragraph in Plimer’s book are identical to figures used by Engelbeen, that Engelbeen appears to have published these figures first, and that there is no attribution to Engelbeen. There are numerous possible reasons for this. Possibly Plimer and Engelbeen discussed these figures informally. Possibly they both sourced them from somewhere else. Or perhaps Dr Plimer forgot a footnote.

One footnote out of 2,000 forgotten! And not only is this enough to cause a gloating leap to call Professor Plimer a plagiarist who should be sacked, but Lambert tells us he has worked out the real reason the footnote is missing, and it is because Plimer is dishonest. I’m surprised Professor Plimer hasn’t sued for defamation.

Then, of course, and tediously, Plimer’s integrity is called into question because he has (shock, horror) done some consulting work for mining companies.

Never mind that whatever income Professor Plimer may have received from mining companies is entirely unrelated to, and unaffected by, his research and opinions on climate change, whereas the IPCC bureaucrats’ employment, and the lecture income of Al Gore and Tim Flannery depends completely on maintaining the global warming scare.

Lambert’s isn’t the only offensive misrepresentation of Heaven and Earth: Global Warming, the Missing Science.

Michael Ashley’s review in the Australian is extraordinarily vindictive.

There are more off the cuff charges of unattributed use of data.

Accusations of plagiarism can destroy someone’s career. Claims like this are serious. They should not be made lightly, and especially not in public by another academic, who understands what their consequences can be. Doing so is a sign of malice, or irresponsibility, or both.

Ashley then picks two very minor points, neither of which impacts on the main argument of the book, and claims that because Plimer has those wrong, there is no science in his book, and the whole thing can be disregarded.

The two points are about minor local changes in CO2 concentration, and the composition of the sun. Ashley’s comments about the first seem to me to misrepresent the point Professor Plimer was making. I am not in a position to judge the second. But really, even if Ashley is right in both cases, it seems to me to be verging on the desperate to dismiss the whole of a substantial and tightly argued book bceause you have found two minor errors.

Finally, Ashley claims that all the points in Plimer’s book have been answered by the IPCC (they haven’t) and says that if Plimer had anything worthwhile to say, he would have published it in a peer reviewed journal, because that is the way science advances. Since he wote a book instead, he obviously has nothing real to offer.

Professor Plimer has a substantial list of peer reviewed articles. He is clearly not shy about subjecting his research to the critical judgement of his academic peers, or of the public.

The IPCC’s work, by contrast, is not properly peer reviewed.

But Ashley (again) misses the point completely. Heaven and Earth is not about presenting new research for the first time. It is a comprehensive and accessible summary of the massive body of peer reviewed research relating to climate change, which has so far not been easily available to the general public.

Plimer’s work is not always easy to read. He is clearly a scientist rather than a writer. But he and his book deserve better than the carping and vindictive treatment they have received at the hands of leftist academics and journalists.

The key points of the book are that there is no discernible human impact on global climate, that changes over the last century are well within the normal range of natural change, and that they are almost certainly due entirely to natural cyclic changes which we are only now beginning to understand.

There has been no challenge to Professor Plimer on these points.