How Bad Is Global Warming?

[justdrew]

So they believe the world is presently at end of a global warming period.

in the millions of years time scale, yes, we are probably near the end of a warm period, this was figured out many decades ago in the 70s IIRC, but the rate of change is slow and left to themselves, things would remain nice most likely for at least tens of thousands more years. Most likely. Although I think back in the day, you could find a few crackpotish people talking up "the coming Ice Age" - that's why "anthropogenic climate change" has sometimes been called "countercyclical warming" IIRC. although I think I may have just made that term up It's been a rough week.

[Ben D]

Not in millions JD...

http://www.geocraft.com/WVFossils/ice_ages.html


Over the past 750,000 years of Earth's history, Ice Ages have occurred at regular intervals, of approximately 100,000 years each.

But then there are so called little ice ages, such as recent as from 1400 to about 1860...


Example of regional variations in surface air temperature for the last 1000 years, estimated from a variety of sources, including temperature-sensitive tree growth indices and written records of various kinds, largely from western Europe and eastern North America. Shown are changes in regional temperature in ° C, from the baseline value for 1900.

[justdrew]

so yeah, technically I guess we are in an ice-age currently, though we're in an interglacial period.

http://en.wikipedia.org/wiki/Ice_age

[justdrew]

Antarctic ice sheet warming faster than thought
By Agence France-Presse | Sunday, December 23, 2012 15:20 EST

The West Antarctic Ice Sheet, whose melt may be responsible for 10 percent of the sea-level rise caused by climate change, is warming twice as quickly as previously thought, a study said Sunday.

A re-analysis of temperature records from 1958 to 2010 revealed an increase of 2.4 degrees Celsius (36.3 degrees Fahrenheit) over the period — three times the average global rise.

The increase was nearly double what previous research had suggested, and meant this was one of the fastest-warming regions on Earth, according to paper co-author David Bromwich of the Byrd Polar Research Center.

“Our record suggests that continued summer warming in West Antarctica could upset the surface balance of the ice sheet, so that the region could make an even bigger contribution to sea-level rise than it already does,” he said.

Scientists believe the shrinking of the West Antarctic Ice Sheet is responsible for about 10 percent of global warming-related sea-level rise, which if unchecked threatens to flood many coastal cities within a few generations.

The sheet, a huge mass of ice up to four kilometres (2.5 miles) thick that covers the land surface and stretches into the sea, is melting faster than any other part of Antarctica.

Data records kept at Byrd Station in the central West Antarctic had been incomplete.

Since being established in 1957, the research station has not been consistently occupied and has seen frequent power outages, especially during the long polar night, when its solar panels cannot recharge.

Bromwich and a team from several US-based research institutions used weather data from different sources to plug holes in the Byrd data and corrected calibration errors.

The updated log was published in the journal Nature Geoscience.

“Aside from offering a more complete picture of warming in West Antarctica, the study suggests that if this warming trend continues, melting will become more extensive in the region in the future,” said Bromwich.

The UN Intergovernmental Panel on Climate Change in 2007 had projected sea level rise of 18 to 59 centimetres (seven to 23 inches) worldwide by the year 2100.

But a study by the US National Research Council said in June the actual rise could be two to three times higher, with polar ice-cap melt speeding up the process.

[JackRiddler]

How come this Little Ice Age started right after the Black Plague?

[Ben D]

Some would say the Little Ice Age was due to reduced Solar activity...

http://www.eh-resources.org/climate3.html

What caused the Little Ice Age?

The earth does not have some magical average natural temperature to which it always returns. If it warms, the earth must be receiving more heat or retaining more heat. If it cools, then it must be receiving less heat from the Sun or radiating more into space, or both. Is that what happened during the Little Ice Age?

Maunder Minimum

The exact cause of the Little Ice Age is unknown, but there is a striking coincidence in the sunspot cycle and the timing of the Little Ice Age. During the Little Ice Age, there is a minimum in sunspots, indicating an inactive and possibly cooler sun. This absence of sunspots is called the Maunder Minimum.


Source: Wikipedia/ Robert A. Rohde

The Maunder Minimum occurred during the coldest period of the Little Ice Age between 1645 and 1715 AD, when the number of sunspots was very low. It is named after British astronomer E.W. Maunder who discovered the dearth of sunspots during that period. The lack of sunspots meant that solar radiation was probably lower at this time, but models and temperature reconstructions suggest this would have reduced average global temperatures by 0.4ºC at most, which does not explain the regional cooling of the climate in Europe and North America.

Of interest is the present decreasing Solar activity, some scientists are of the opinion that we are moving into another Maunder Minimum,..and that could account for the lack of increase in warming over the last 16 years.

[freemason9]

This could be a dumb question . . . but do we have any reason to believe there were accurate sunspot counts prior to 1750? I've seen this referenced quite often in relation to the so-called "Maunder Minimum," but I question the validity of those counts.

[Ben D]

Seems the Chinese first recorded sunspot activity in 800 BC...

http://www.windows2universe.org/sun/activity/sunspot_history.html

And there's this source...Historical Sunspot Observation - A Review

[Hammer of Los]

...

Clever them chinese.

They invented gunpowder and used it for fireworks and amusements.

...

[wintler2]

This could be a dumb question . . . but do we have any reason to believe there were accurate sunspot counts prior to 1750? I've seen this referenced quite often in relation to the so-called "Maunder Minimum," but I question the validity of those counts.

With good reason - measurement techniques varied, there are numerous gaps, etc. Sunspots are interesting but trivial, even if so-called 'Maunder minimum' were to recur, it would make much less than 1C difference.

http://www.realclimate.org/index.php/archives/2011/06/what-if-the-sun-went-into-a-new-grand-minimum/
In our study we find that a new Maunder Minimum would lead to a cooling of 0.3°C in the year 2100 at most – relative to an expected anthropogenic warming of around 4°C. (The amount of warming in the 21st century depends on assumptions about future emissions, of course).

According to these results, a 21st-century Maunder Minimum would only slightly diminish future warming. Moreover, it would be only a temporary effect since all known grand solar minima have only lasted for a few decades. ..

A temporary slight dip, whoop-de-do. Sunspots are a distraction, the 2nd most common AGW-denier canard, nicely offplanet and so a long way from those actually responsible.

[DrEvil]

IPCC's climate projections on target so far

http://arstechnica.com/science/2012/12/ ... et-so-far/

[Iamwhomiam]

Bendy wrote:
Yeh fru, many people get their reality from a video screen, good luck with that...

Ben, your logic never fails to astound me.

You criticize most unfairly frumenschen for relating his impression of a most impressionable movie, Chasing Ice, a still from which I posted some time ago in the images only thread and afterward slad posted its trailer here and Allegro followed, posting a video of a song sung by Scarlett Johanssen featured in the movie.

What so astounds me is your willingness to criticize someone about a video source of visual information they find remarkable and then almost immediately you begin posting your own video representations, first about sunspots and then about the Maunder Minimum. Everything you've shared and communicated on this site has appeared upon a video screen and it seems to me that all of your research has been conveyed to you on a video screen, too.

Do you not see the idiocy of accusing one of what you, yourself is guilty of? Shame on you is building up faster than icebergs are being cleaved off from the ice sheet, and that's pretty fast.

Here's frumenschen's post:
Well folks, just saw the new documentary CHASING ICE and gotta tell you all I am packing my bags
and taking the next shuttle to the ISS.

This film is a cinch to win the 2012 Academy Award for Best Documentary.
Any Global Warming/Holocaust denier should get the message in this film.
Put this movie on your bucket list now, if we live that long,

Imagine if Ansel Adams had made a film about Global Warming,
Jaw dropping cinematography and still film shots.
Watching a glacier calve/break off a piece of ice larger than lower Manhattan, eh?

http://www.chasingice.com/

There's a gallery of splendid photographs at the link.

Meanwhile, if our Canadian neighbors don't stop exploiting the Tar Sands, it's game over.

[wintler2]

Bushfires savage towns as heatwave hits five states
BUSHFIRE season arrived in force yesterday as emergency fire crews in five states fought blazes amid record temperatures and ominously dry conditions.

In Tasmania, east of Hobart, fires destroyed as many as 65 buildings at Dunalley and 15 at Boomer Bay. There were also unconfirmed reports that one life had been lost. Fires burned out of control in Victoria and South Australia where temperatures were well above 40C and strong southwesterly winds worsened conditions.

Tasmanian fire authorities were making comparisons to the conditions that led to the 2009 Black Saturday fires in Victoria that left 173 people dead, state fire chief Mike Brown declaring "we reached catastrophic fire danger ratings at times this afternoon".

http://www.smc.org.au/2013/01/heatwave-experts-respond/

“Extreme heat events, such as this one, have wide ranging impacts across agricultural and horticultural sectors, infrastructure and transport, and not least human health and safety. Locations including Alice Springs, Adelaide, Renmark, Melbourne, Mildura, Echuca, Albury, Broken Hill and Wagga Wagga all have temperatures of 40 degrees or higher forecast for today [104F].
..

“The current heatwave is unusual due to its areal extent. More than 70% of the continent is currently experiencing heatwave conditions. Apart from the required slow moving synoptic weather pattern required for any heatwave, the spatial extent of this event can be attributed to the extent of dry soils across the Australian landscape.

“Low antecedent rainfalls across much of the continent (see figure left) along with the late arrival of the Australian monsoon have resulted in drier soils. Without the ability to remove latent heat through evaporation from moist soils, surface temperatures rise above normal, with the daily heating cycle building a deeper body of stagnating hot air over the interior.

“Breaking the heatwave cycle will require a combination of the onset of the rain bearing monsoon trough and the penetration of cooler Southern Ocean air masses. Severe heatwave conditions across the interior of Australia are set to continue for a while yet.”

So the causes are a big Spring rainfall deficit in southern Aus & delay in northern Aus monsoon. According this interview with BoM-SA rep, it'll be 3 weeks before next possible break in monsoon and real relief. We don't even have an El Nino running, so it should be cooler, not recordbreakinglyhot.

[Ben D]

Yep, the bipolarity of climate in action...

Mercury drops to record low in much of China

Record cold kills more than 100 in India

[DrEvil]

In other news (via nextbigfuture):

The United States could see a surge in oil production that could make it the world’s leading oil producer within a decade, according to a new report from the International Energy Agency.

http://www.technologyreview.com/news/50 ... ependence/