You want an inconvenient truth? Try this one.

I see Mark Steyn and Lorne Gunter have joined the throng of global warming deniers in picking up the correction to the GISS data-sets.

Steyn:

They're not issuing any press releases about it. But they have quietly revised their All-Time Hit Parade for US temperatures. The "hottest year on record" is no longer 1998, but 1934. Another alleged swelterer, the year 2001, has now dropped out of the Top Ten altogether, and most of the rest of the 21st century Â-- 2000, 2002, 2003, 2004 Â-- plummeted even lower down the Hot One Hundred. In fact, every supposedly hot year from the Nineties and Oughts has had its temperature rating reduced. Four of America's Top Ten hottest years turn out to be from the 1930s, that notorious decade when we all drove around in huge SUVs with the air-conditioning on full-blast. If climate change is, as Al Gore says, the most important issue anyone's ever faced in the history of anything ever, then Franklin Roosevelt didn't have a word to say about it.

Unhuh. And then Gunter:

In his enviro-propaganda flick, An Inconvenient Truth, Al Gore claims nine of the 10 hottest years on record have occurred in the last decade. That's been a common refrain for environmentalists, too, and one of the centrepieces of global warming hysteria: It's been really hot lately -- abnormally hot -- so we all need to be afraid, very afraid. The trouble is, it's no longer true.

What both of these two are dodging around is that the dataset corrections apply only to U.S. land stations. In fact, Gore is still correct. Even with the corrected data-set, global surface temperatures have risen significantly and 2005 is actually the hottest year on record.

The NASA GISS data correction is being made a big deal among some groups. The trouble is, it's only one part of the science. And therein lies a problem.

Neither Steyn nor Gunter know a shmuck about climate science. They're relying on the word of others, who fall conveniently into their camp, and cherry-picking one event as being significant proof of their... "beliefs". (They don't have a theory.)

While they go about pointing at a data correction, which impact still doesn't change the global picture, they are ignoring other climatological factors and evidence.

Sea levels have risen 15 centimeters in the last 100 years. When I, as the old phart in the class, was studying oceanography, the attribution for that rise fell to 50 percent due to thermal expansion of the water mass and 50 percent due to glacial melt. Even then, we felt the figures were "best guesses" because we knew next to nothing about the dynamics of melting glaciers. As the science grows and the research moves forward corrections have been made. Today thermal expansion of the ocean water mass accounts for only 40 percent of the rise in sea level and 60 percent is attributed to glacial melt.

We know more about how a glacier responds to melting and, well, it's pretty shocking. Glaciers don't just sit there and melt. They actually move. When the melt becomes significant enough, the water provides a grease belt on which the glacier slides towards the shore and causes accelerated calving.

And none of this is happening because the planet is getting any cooler. It takes increasing heat to speed the movement of a glacier. Combine the current rate of disappearing glaciers in Greenland and Antarctica and you could see a rise in sea levels of up to 5 meters. Consider that the loss of the ice face, which reflects heat away from the surface, will cause heat to be absorbed by the now unprotected landmass and the melt will accelerate exponentially. It's possible we could see a 7 to 10 meter rise in sea levels within the next 100 years.

Steyn and Gunter have also ignored other significant facts. There has been a rise in sea surface temperatures and its effect is readily apparent. Mass bleaching of coral reefs is occurring at a rate never seen before. And these are not localized problems caused by small zone stresses. These are mass areas affected by sustained high air temperatures. Coral reefs are a delicate but vital part of the ocean ecosystem. A sea level rise of 1 to 2 millimeters per year is about the rate of growth of a healthy coral reef. If the reef has been bleached it stops growing and as the sea level rises can never recover.

We've already started to witness softer shells on some crustaceans and mollusks. Why? Increased carbon dioxide levels in sea water. CO2 and sea water mix to form an acid. As the carbon dioxide load in the ocean rises, the sea water becomes more acidic. A high proportion of marine life form exoskeletons from calcium carbonate (CaCO3). In order to do that sea water needs a pH of 8.7. Make it more acidic, by increasing CO2 levels, and the CO3 levels decrease as they react with hydrogen. By way of a demonstration, drop a simple piece of chalk into a weak acid like vinegar and watch what happens.

Compared to preindustrial times, the global ocean overall has dropped by .1 of a pH unit. That translates to an increase in acidity of 30 percent in the surface layers over the past 200 years. In the past 15 years alone, the ocean pH level has dropped .025 - and it's accelerating.

The reason we're not experiencing runaway global warming now is because the oceans are absorbing about half of the CO2 being pumped out into the atmosphere. As CO2 saturation levels increase, oxygen levels decrease and the entire marine ecosystem starts to suffocate. Increased acidification will eventually make it impossible for tiny shelled plankton to survive and when it's gone, you can declare the oceans dead.

And all that CO2 is coming from somewhere. Steyn and Gunter can point at U.S. land stations all they want and complain that the Goddard Space Center is diddling with the data-sets. The ocean data is hard, taken directly from the sea and seabeds then studied in the lab. Sea surface temperatures come from research ships, not a land station which might be affected by the "urban island". And every ship at sea records sea temperature at least once per day but more typically, once per watch (every 4 to 6 hours). The ocean data is good - and it's bad news.

You don't even have to believe in global warming to see that the oceans are taking a beating.

But I suppose neither Steyn nor Gunter nor any of their fellow travelers give a tinker's damn about something as insignificant as a prawn. Until they can't order one. Then perhaps they'll pull their heads out from where the sun don't shine.