Lord Monckton is a former journalist and policy advisor to Margaret Thatcher.  Though sometimes referred to as a scientist, he has no scientific credentials nor peer-reviewed publications in scientific journals.  He is a major international campaigner and figurehead for the denialists, and the policy advisor for the SPPI.

http://en.wikipedia.org/wiki/Christopher_Monckton,_3rd_Viscount_Monckton_of_Brenchley

What follows is a series of responses to his web page at:

http://scienceandpublicpolicy.org/scarewatch/dangerous_climate_change_is_coming.html 

For a more thorough analysis please see John Abraham's deconstruction of Monckton.

Nature is one of many "scientific" journals that have openly declared an editorial prejudice in favor of a frankly alarmist viewpoint on the climate.

Somehow I don't see Nature doing anything of the sort.  There's no specific reference so it's hard to check, but it's most likely a distortion.  Nature's editorial policy is available here.

Lorenz (1963), in the landmark paper that founded chaos theory, said that because the climate is a mathematically-chaotic object (a point which the UN's climate panel admits), accurate long-term prediction of the future evolution of the climate is not possible "by any method".

No, Lorenz's work related to weather prediction, not climate prediction.  Climate is the overall frequency of different types of weather over decades or longer.  If you run a computer simulation for the weather over the next so many months over and over again with just slightly different starting points each time, you will get significantly different results in different runs.  That's weather.  But the totality of those results describes the climate, and another batch of runs will give much the same picture.

the tropical upper-troposphere "hot-spot" - has never been observed

While more data would be useful, it has now been shown that existing data do not contradict the models.

this single failure of the models reliably to predict an essential feature of the climate removes any notion of "dangerous" climate change.

Even before the apparent conflict was resolved, it only made the notion a little less certain.  It was still a risk that needed addressing.

 

For most of the past 10,000 years, global temperature has been at least 2 C° and sometimes 3 C° greater than the present

This is an outright lie.  We have no direct measurements older than a century or so, but tree rings and ice cores provide the best guide.  These show that during part of the last 10K years (the "climatic optimum") temperatures averaged marginally above the 20th century average.  But the temperature in the 21st century has been persistently above even that.  See http://en.wikipedia.org/wiki/File:Holocene_Temperature_Variations.png

 

Paltridge et al. (2009) have established ... the upper troposphere ... is drier than the models had predicted. ... the UN's climate panel assumes that positive temperature feedbacks will more than triple the initial warming caused by atmospheric CO₂ enrichment.

Although this was contradicted by other evidence, it may well be true.  Unfortunately, this may only be a temporary reprieve.  Until the cause is understood we would be foolish to rely on it.

 

the UN's value for the Planck [feedback] parameter ... is higher than any value in the mainstream literature

Correcting for an inversion here (he means it's lower in magnitude at 3.2Wm^-2K^-1 against a range of 3.3 to 7), this does seem to be an interesting issue.  More research is needed: watch this space.

 

CO₂ concentration is rising not exponentially, as the UN predicts, but in a straight line, and at a rate about half of that which the UN predicts

It is not a straight line, but accelerating; and the IPCC did not predict it would rise exponentially.