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Runaway tipping points of no return
Gavin, Real Climate
I wonder if any else has noticed that we appear to have crossed a threshold in the usage of the phrase ‘tipping point’ in discussions of climate? We went from a time when it was never used, to a point (of no return?) where it is used in almost 100% of articles on the subject. Someone should come up with a name for this phenomenon….
Regardless of the recent linguistic trends, the concept has been around for a long time. The idea is that in many non-linear systems (of which the climate is certainly one), a small push away from one state only has small effects at first but at some ‘tipping point’ the system can flip and go rapidly into another state. This is fundamentally tied to the existence of positive feedbacks and is sometimes related to the concept of multiple ‘attractors’ (i.e. at any time two different ‘states’ could be possible and near a transition the system can flip very quickly from one to another). Another ‘tipping point’ in non-linear systems occurs when as some parameter varies, the current attractor changes character or disappears. However it is currently being used interchangeably a number of potentially confusing ways and so I thought I’d try and make it a little clearer.
…Much of the discussion about tipping points, like the discussion about ‘dangerous interference’ with climate often implicitly assumes that there is just ‘a’ point at which things tip and become ‘dangerous’. This can lead to two seemingly opposite, and erroneous, conclusions – that nothing will happen until we reach the ‘point’ and conversely, that once we’ve reached it, there will be nothing that can be done about it. i.e. it promotes both a cavalier and fatalistic outlook. However, it seems more appropriate to view the system as having multiple tipping points and thresholds that range in importance and scale from the smallest ecosystem to the size of the planet. As the system is forced into new configurations more and more of those points are likely to be passed, but some of those points are more globally serious than others.
(5 July 2006)
Good (but still technical) explanation. Recommended by David Roberts at Gristmill.
Vast chunk of rock threatens to fall from Eiger as global warming opens up crack
John Hooper, The Guardian
A vast chunk of Europe’s most ill-famed mountain threatens to break loose and crash down in the next few days, a geologist monitoring the situation told the Guardian yesterday.
Hans-Rudolf Keusen said 2m cubic metres of the Eiger in the Bernese Alps, Switzerland – twice the volume of the Empire State Building – was rapidly working its way loose.
He said the mountain appeared to have cracked open as an indirect result of global warming
(8 July 2006)
Global Warming on Discovery Channel July 16, 22
The Discovery Channel
Comments David Roberts of Grismill:
On Sunday at 9pm, the Discovery Channel will run a special called ”Global Warming: What You Need to Know.” It will break the exciting news — available to you for the first time! — that the scientific community agrees that global warming is happening, quickly, and it’s going to be bad.
Discovery stresses that this is a scientific thing. There’s “no agenda.” They’re not one of those, you know, lefty groups who go on and on about this kind of thing.
That’s how corrupted our national dialogue has become. A handful nutbags can, through their extraordinary media access, politicize the issue for the entire country. Argh.
Anyway, the special is hosted by Tom Brokaw, who, according to the NYT, has become something of a green. Get this:
He’s tried to alter some habits to save fossil fuels: changing light fixtures in his homes, for example. He owns a hybrid car, and so do both of his daughters.
“It’s not affecting our lifestyle at all, not one whit,” he said.
Oh, well … whew! Wouldn’t want to change our lifestyles just because the entire earth is frying.
(10 July 2006)
Global Warming May Shrink Vineyards
Robert Lee Hotz, LA Times via Common Dreams
A climate projection shows ‘enormous losses’ in the state’s prime wine regions this century.
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Global warming could wither many premium vineyards in California and across the nation by the end of the century, according to a new computerized climate projection released Monday.
A predicted rise in the number of days hotter than 95 degrees during the growing season could sharply reduce the amount of areas suitable for vintage wine-grape production, an international team of scientists concluded in the journal Proceedings of the National Academy of Sciences.
Marginal vineyards nationwide might be eliminated and those capable of producing the most expensive premium wines may be reduced by half, the researchers reported. Although wine is produced in 48 states, California’s $16.5-billion industry, with more than 500,000 acres of vineyards, accounts for almost 90% of the nation’s wine grapes.
“We found that at elevated greenhouse gas concentrations, the frequency of extremely hot days increases to the point where it is impossible to grow premium wine grapes in many areas of the country,” said Noah Diffenbaugh, one of the study’s researchers at Purdue University who studies the impact of climate change.
(11 July 2006)
Climate report sees a thirsty future for California
Global warming will shrink state’s water supplies but trigger floods, study warns.
Matt Weiser, Sacramento Bee
As global warming continues and California’s mountain snowpack decreases, the state can expect to see a drastic drop in its drinking and farm water supplies, as well as more frequent winter flooding.
These are among the findings in a report released Monday by the state Department of Water Resources. The report was commissioned in response to Gov. Arnold Schwarzenegger’s order last year for state agencies to begin preparing for an altered climate. The result, a 338-page study, offers the most detailed look yet at how climate change could affect California water supplies.
Under each of four climate-change scenarios examined in the report, warmer temperatures raise the snow level in California mountains, producing a smaller snowpack and more winter runoff.
This means more floodwaters to manage in winter, followed by less snowmelt to bank in reservoirs for drinking water, summer lawns and crop irrigation.
…Along with the reduction of the mountain snowpack, the DWR report found that global warming could pose a grave threat to the health of the Sacramento-San Joaquin Delta.
The Delta is both a vital habitat for endangered fish and birds and a key water conveyor for humans, ferrying fresh water from Northern California reservoirs to farms and cities in the south. It serves 23 million Californians and 5 million acres of farmland that underpin the world’s fifth-largest economy.
Climate scientists predict ocean levels will rise in coming decades as the warming atmosphere accelerates Arctic melting. A 1-foot sea level rise — on the low side of most predictions — would push more salty water into the Delta, contaminating the water supply. This could require water managers to release even more fresh water from reservoirs to keep the Delta water usable
(11 July 2006)
Press release, California Department of Water Resources (DWR):
The report shows that climate change could significantly impact California’s water picture in many ways, including:
• Loss of Sierra snow pack and the seasonal water storage it provides
• More rain and less snow, impacting both water supply reliability and hydropower generation
• More variable precipitation and extreme weather events, such as floods and droughts – the latter resulting in more energy-intensive groundwater pumping
• Rising sea levels that would increase pressure on Delta levees and compound saltwater intrusion into Delta water supplies and coastal aquifers
• Higher water temperatures, possibly affecting listed fish species;
• Changes in annual average State Water Project and Central Valley Project south-of-Delta deliveries.…Copies of DWR’s climate change report are available at baydeltaoffice.water.ca.gov. Hard copies can be ordered by contacting Wanda Headrick at (916) 653-4391 or [email protected].
(11 July 2006)
Supreme Court finally to ponder climate change
Rebeca Chapa, The Providence Journal
THE U.S. SUPREME COURT will take up a controversial case this fall that could dramatically alter the national discourse on climate change.
In the suit Massachusetts v. Environmental Protection Agency, 12 states (including Massachusetts, Rhode Island, and Connecticut), some cities, and various environmental groups are asking the court to rule on whether the federal government must regulate carbon-dioxide emissions as part of the Clean Air Act.
Carbon-dioxide emissions, the plaintiffs assert, are among the primary so-called greenhouse gases responsible for global warming. As such, they say, carbon dioxide should be considered a pollutant and subject to federal regulation — much as smog-producing pollutants are regulated.
(7 July 2006)
