Tilted Forum Project Discussion Community  

Go Back   Tilted Forum Project Discussion Community > Chatter > General Discussion

LinkBack Thread Tools
Old 12-29-2004, 06:32 AM   #1 (permalink)
tecoyah's Avatar
Another piece of the "Warming" pie

This to me is a major indication of the realities of Global Warming, and pretty much closes the case for me. I felt the Data was inconclusive as to the depth of the problem.........Alas, it would seem to be all too real.

Earth's permafrost starts to squelch
By Molly Bentley
in San Francisco

Svalbard drilling in permafrost (Cardiff University)
There is now an active programme of permafrost monitoring
In parts of Fairbanks, Alaska, houses and buildings lean at odd angles.

Some slump as if sliding downhill. Windows and doors inch closer and closer to the ground.

It is an architectural landscape that is becoming more familiar as the world's ice-rich permafrost gives way to thaw.

Water replaces ice and the ground subsides, taking the structures on top along with it.

Alaska is not the only region in a slump. The permafrost melt is accelerating throughout the world's cold regions, scientists reported at the recent Fall Meeting of the American Geophysical Union (AGU) in San Francisco.

In addition to northern Alaska, the permafrost zone includes most other Arctic land, such as northern Canada and much of Siberia, as well as the higher reaches of mountainous regions such as the Alps and Tibet. All report permafrost thaw.

Will the Arctic be a carbon sink, or convert to a carbon source? It's a big unknown
Frederick Nelson, University of Delaware
"It's a very, very widespread problem," said Frederick Nelson, a geographer at the University of Delaware, US.

Scientists attribute the thaw to climate warming. As the air temperature warms, so does the frozen ground beneath it.

Data quest

The observations reiterate the recent findings of the Arctic Climate Impact Assessment report, which attributed the northern polar region's summer sea-ice loss and permafrost thaw to dramatic warming over the past half-century.

Thawing permafrost can cause buildings and roads to droop, and pipelines to crack.

Natural features are also affected. Scientists reported an increased frequency in landslides in the soil-based permafrost of Canada, and an increased instability and slope failures in mountainous regions, such as the Alps, where ice is locked in bedrock.

With the exception of Russia and its long history of permafrost monitoring, global records are insufficient - often too brief or scattered - to determine the precise extent of ice loss, said Dr Nelson.

However, monitoring programmes that are now much larger in scope, such as the Global Terrestrial Network for Permafrost (GTNP), indicate a warming trend throughout the permafrost zone.

Boreholes in Svalbard, Norway, for example, indicate that ground temperatures rose 0.4C over the past decade, four times faster than they did in the previous century, according to Charles Harris, a geologist at the University of Cardiff, UK, and a coordinator of Permafrost and Climate in Europe (Pace), which is contributing data to the GTNP.

"What took a century to be achieved in the 20th Century will be achieved in 25 years in the 21st Century, if this trend continues," he said.

Slip and slide

In Ellesmere Island, Canada, a combination of warmer temperatures and sunny days has triggered an increasing frequency of detachment events, or landslides, over the past 25 years, compared with the previous 75, according to Antoni Lewkowicz, professor of geography at the University of Ottawa.

Permafrost is permanent year-round frozen ground
Soils many cm below surface never rise above 0C
Only top few cm thaw in summer - "active layer"
Many regions have been like this for 1,000s of years
Major thaw changes water distribution in ecosystem
Sequestered carbon released; buildings destabilised
A detachment event occurs on a slope when the bottom of the active layer - the layer of thawing and freezing ground above permafrost - becomes slick with melted ice, causing it to slide off from the permafrost below.

But in this case, the amount of temperature increase is not so important as the rate of increase, Dr Lewkowicz found.

Meltwater from ice that warms slowly drains away. When ice warms quickly, water pools, creating a frictionless surface between the active layer and the permafrost. Like a stroll across a sloping icy sidewalk, a fall is almost certain.

"We have records from this particular site for about 10 or 12 years," said Dr Lewkowicz. "The years when active layer detachments have taken place have been times when we've had this rapid thaw down at the bottom of the active layer."

The slides may cut a wide swath hundreds of metres across, but extend only 50 or 60cm deep.

"They're almost skin-like landslides, moving across the permafrost," said Dr Harris.

The exposed permafrost, warmed by the air, now produces a new active layer.

Sink to source

In steep mountainous regions, permafrost thaw can lead to slope failure and rock falls.

In these areas, the permafrost ice is in hard rock. Where rocks are jointed, the ice serves as a kind of cement holding them together.

When it melts, the rock loses its strength and falls. A dramatic example of this occurred during the European heatwave of 2003 when a huge block of the Matterhorn broke off suddenly, leaving Alpine climbers stranded.

Reindeer (BBC)
Degraded permafrost will impact the migration routes of some Arctic species
"It's not just the general warming trend we need to worry about," said Dr Harris, "but these extreme seasonal events as well."

Dr Nelson says that with human-built structures, proper engineering and land use can mitigate permafrost loss.

Tingun Zhang, a researcher at the US National Snow and Ice Data Center in Boulder, Colorado, reported at the AGU on the particular challenge slumping ground presents to the construction of the Qinghai-Xizang railroad across Tibet, perhaps the most ambitious permafrost-zone project since the Trans-Alaskan pipeline.

Nearly half the railroad will lie across permafrost, and temperatures in the region are expected to rise during this century.

Engineers are using a simple - and long established - trick of cooling the permafrost with crushed rock. Rocks minimise heat intake in summer and promote heat loss in winter.

It is the first time a large-scale project is using the crushed-rock method as its primary solution, according to Dr Zhang.

Permafrost thaw damaged building (ACIA)
Building codes will have to change if the thaw continues
But not all outcomes of permafrost thaw have precedent, or an immediate solution. One considerable variable is the possible release into the air of organic carbon stored in the permafrost.

In the drier areas, most of the emissions would be in the form of carbon dioxide (CO2). But in the wetter areas, it would be methane, a more effective greenhouse gas.

Scientists do not know exactly how much carbon is sequestered in the permafrost regions, but estimates show it could be up to a quarter of the sequestered carbon on Earth, 14% of it in the Arctic, alone.

"Will the Arctic be a carbon sink, or convert to a carbon source?" posed Dr Nelson. "It's a big unknown."

Holding onto anger is like grasping a hot coal with the intent of throwing it at someone else; you are the one who gets burned. - Buddha
tecoyah is offline  
Old 12-29-2004, 06:52 AM   #2 (permalink)
Cue neo-con, big business, isolationist, anti-UN, anti-Kyoto partisans claiming that global warming is "just a theory".

Yeah. Just like evolution is "just a theory"...

Mr Mephisto
Mephisto2 is offline  
Old 12-29-2004, 07:13 AM   #3 (permalink)
kutulu's Avatar
It doesn't matter. They'll never admit that we are right. Now you have some of the same people who said there is no such thing as global warming saying things like "well yes, it's warming, but it's completely natural. We did nothing to cause it"
kutulu is offline  
Old 12-29-2004, 01:54 PM   #4 (permalink)
whocarz's Avatar
Location: Colorado
I won't discount global warming, but some scientists have said that we are coming out of an ice age, which would account for increasing temperatures. Remember that ice ages last for hundreds of thousands of years, which is far outside the scope of recorded human history. Still, it doesn't change the fact that it's roughly 60F in Colorado, in the winter, which is much warmer than normal.
If there exists anything mightier than destiny, then it is the courage to face destiny unflinchingly. -Geibel

Despise not death, but welcome it, for nature wills it like all else. -Marcus Aurelius

Come on, you sons of bitches! Do you want to live forever? -GySgt. Daniel J. "Dan" Daly
whocarz is offline  
Old 12-29-2004, 02:12 PM   #5 (permalink)
Originally Posted by whocarz
I won't discount global warming, but some scientists have said that we are coming out of an ice age, which would account for increasing temperatures.
The rate of temperature increases is enormous. It's no natural phenomenen.

Mr Mephisto
Mephisto2 is offline  
Old 12-29-2004, 02:26 PM   #6 (permalink)
Leave me alone!
Boo's Avatar
Location: Alaska, USA
No heat wave here this week. Maybe next year.

The old timers say that the last few winters have been very warm compared to the 60's and 70's. We have had 2 very nice summers accompanied by the lightning strikes causing wildfires. Fairbanks had smoke in the area for most of the summer.

Houses in Alaska are always tilted or sinking for one reason or another. Poor building codes and lack of available solid land contribute also.
Back button again, I must be getting old.
Boo is offline  
Old 12-29-2004, 02:33 PM   #7 (permalink)
kutulu's Avatar
Don't confuse annual or daily weather fluctuations with global climate.
kutulu is offline  

pie, piece, warming

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -8. The time now is 10:39 AM.

Tilted Forum Project

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
© 2002-2012 Tilted Forum Project

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360