Don
climate4you is a blog site of no substance compared to research which has been peer reviewed or mega Reports.

Don, it is not a matter of reading articles which I liked, if an article does not have hyperlinks to science; then, it holds far less value.

Warm water is undermining the grounding lines of Antarctica, the Larson C Ice Shelf has calfed, a huge event earlier in 2017. An objective fact.

A Guardian article written by a climate scientist; not a lay person, journalist, or political scientist:

http://www.theguardian.com/science/2017/jun/23/melting-and-cracking-is-antarctica-falling-apart-climate-change

http://www.sciencenews.org/article/when-larsen-c-ice-shelf-broke-it-exposed-hidden-world

Pine Island Glaciers are not stable:

http://phys.org/news/2016-11-west-antarctic-ice-shelf.html

http://blog.nationalgeographic.org/2016/11/03/unstoppable-destabilization-of-west-antarctic-ice-sheet-threshold-may-have-been-crossed/

Grounding lines moving:

http://onlinelibrary.wiley.com/doi/10.1002/2014GL060140/full

http://science.sciencemag.org/content/348/6232/327

http://www.nature.com/articles/ncomms13243

http://www.sciencedirect.com/science/article/pii/S0273117717301813

http://earthobservatory.nasa.gov/IOTD/view.php?id=83672

http://www.bas.ac.uk/project/dating-and-modelling-fast-ice-sheet-grounding-line-retreat-in-antarctica/

Over the years I have read many articles about Antarctica; Richard Alley and Eric Rignot are the go to scientists; but, as shown there are numbers of scientists who have researched Antarctica.

When a contrarian provides a reference I go to it; unless its a blog by Watts, and the find critiques on the reference provided.

Regarding the Arctic:

http://www.arctic.noaa.gov/Report-Card

An important comment to remember in relation to sea ice ... "The sea ice cover continues to be relatively young and thin with older, thicker ice comprising only 21% of the ice cover in 2017 compared to 45% in 1985."
It is multi year ice that is an important structural component for sea ice.

The trend line for volume of sea ice is going down, though there are variations from year to year.

Or also in relation to the Arctic:

http://www.amap.no/documents/doc/Snow-Water-Ice-and-Permafrost-in-the-Arctic-SWIPA-2017/1610

Earlier I provided an article about Barrow, where instrumentation was not able to keep up with what had been happening temperature wise.
A descriptive article about temperature in Alaska for December 2017 which provides some credence to the reference provided previously:

http://www.washingtonpost.com/news/capital-weather-gang/wp/2017/12/19/baked-alaska-49th-state-is-having-an-insanely-warm-december/?utm_term=.8912719e5d7c

You stated that: " If you want to argue with what I've written, you need to use data, not assertions."

If you follow climate science you would not need greater explanations.

I provided a reference about an Archeologist working at Barrow, Alaska, if you had read the article you would understand that the Archeological party was having to work extra fast as there was concern about permafrost thawing and erosion taking place destroying their site.

Infra structure in Alaska is being damaged through permafrost thawing:

http://www.nytimes.com/interactive/2017/08/23/climate/alaska-permafrost-thawing.html

The greening of tundra areas in Alaska, Northern Canada and Siberia; along with the formation of ponds, is another aspect displaying thawing of permafrost, "drunken trees" is a further example.

Don, climate science is based on some absolute facts:

.Without greenhouse gases, nobody would exist (Professor K Anderson).
.The four most common greenhouse gases are CO2, methane, nitrous oxide and fluorinated gase (man created). The main feed back greenhouse gas is water vapour.
.Fossil fuels took millions of years to be created through the accumulation and break down of organic matter. We have used those sources of fuel for an exceptionally short geological time frame.
.Physics and Chemistry are also part of the bed rock of climate science.

Don
Earlier I wrote about the trend lines going down in the Arctic, here is an article written by a Physicist, displaying what is occurring:

http://thinkprogress.org/watch-the-arctic-death-spiral-in-this-amazing-video-b63486b99383/#.y6ogew60z

Humlum debunked:

http://www.realclimate.org/index.php/archives/2012/09/el-ninos-effect-onco2-causes-confusion/

http://www.theguardian.com/environment/climate-consensus-97-per-cent/2015/aug/25/heres-what-happens-when-you-try-to-replicate-climate-contrarian-papers

The Guardian provides appropriate hyperlinks.

Sea level Rise:

People having to leave coastal plains in Louisiana:

http://www.bloomberg.com/news/articles/2017-12-22/louisiana-sinking-fast-prepares-to-empty-out-its-coastal-plain

$500 million in infra structure built at Miami to ward off sunny day floods when king tides occur:

http://www.yaleclimateconnections.org/2017/12/life-sea-level-rise-hotspot/

Rain bombs, the article has a hyperlink to Kevin Trenberth:

http://www.flassbeck-economics.com/how-climate-change-is-rapidly-taking-the-planet-apart/

A reference to a mega Report on Oceans:

http://portals.iucn.org/library/sites/library/files/documents/2016-046_0.pdf

Seth Miller, a scientist, provides some history; and then, criteria in relation to how science matters can be rationally evaluated. Seth Miller uses 9 criteria to show the strength of the science in relation to the greenhouse impact of carbon dioxide:

http://extranewsfeed.com/what-climate-skeptics-taught-me-about-global-warming-5c408dc51d32

Humlum does not believe CO2 has an impact on climate; please, show how the 9 criteria used by Seth Miller are wrong.

Ant, you can't debunk Humlum's site without debunking all the official datasets. I give up.

Don you stated:

"you can't debunk Humlum's site without debunking all the official datasets. I give up."

What crap; that is just a cop out.

Several objective factors have been provided in relation to climate change in references provided:

. how contrarians misconstrue data
. erosion of coast land as shown in reference about Archeologist.
. Ocean warming
. how action is required in Louisiana and Miami to ward off sea level rise
. how ice sheets are being undermined in Antarctica with grounding lines moving towards the glaciers feeding the ice sheets (Larson C and Pine Island Glaciers)
. mega Reports sheet home the cause of climate change to CO2
. criteria were provided necessary to debunk CO2 being a greenhouse gas
. water vapour being a secondary greenhouse gas had a reference provided
. A short film about the trend line of sea ice volume in the Arctic Ocean was provided

Just over a year ago a yacht sailed the North East and North West passages of the Arctic Ocean.

http://www.irishtimes.com/news/environment/boat-that-sailed-around-arctic-arrives-in-westport-1.2828736

Experimentation displays how CO2 takes up warmth.

Mythbusters:
http://www.youtube.com/watch?v=pPRd5GT0v0I

http://www.realclimate.org/index.php/archives/2007/06/a-saturated-gassy-argument/

Just prior to the COP23 Conference at Bonn, 15,000 scientists signed a letter stating a second warning had been given in relation to the climate.

http://sydney.edu.au/news-opinion/news/2017/11/14/15000-scientists-warn-time-is-running-out-to-save-the-planet.html

I have provided some references to mega Reports which have been put together by numerous scientists and referenced by numerous peer reviewed research papers. They comply with what is understood about climate change.

Psychological projection has occurred when you state ..."But that doesn't accord with you view of things, so you dismiss it.

You were a good political scientist in your day; but please leave climate science alone, and leave it to scientists such as Trenberth, Rignot, Anderson, Hansen, Box, Francis, Hausfather, Schmidt, Alley, Barber, Rahmstorf, Steffen, Dessler, Emanuel, Cullen et al to provide reliable information.

"you can't debunk Humlum's site without debunking all the official datasets. I give up."

Sorry, ant, you just go on with the same stuff. Most of your references are not data, and you dismiss the official data about Antarctic cooling.

Merry Christmas.