Global climate change: Earth nears dangerous tipping point

There’s a right time to stop an avalanche: before it really gets rolling. And there’s a right time to stop climate change: before it becomes irreversible, with multiple positive feedback cycles making widespread disaster and extinctions inevitable. Right now, we may only have five years to implement substantial changes in our greenhouse-gas emissions: Evidence of impending tipping point for Earth.

Global warming in Bangkok

This fall’s flooding in Thailand killed more than 700 people while costing 54 billion dollars in damage and lost revenue.

partial map ofT hailand with northen sections flooded

Flooding in Thailand, Oct. 2011

 

Scientists and weather forecasters are worried about the fate of the capital city, Bangkok. It’s built on a delta of the river Chao Phraya, and has canals as well as roads (flood map).

* Weather patterns are changing and rainfall patterns are becoming more erratic.Typhoons may appear in unexpected places.

* Typhoons have increased from one every 7 or 8 years to one every 3 or 4 years

* The temperature in Thailand has risen two degrees in the last forty years. Consequently, storms have more energy and are more intense.

* Precipitation during the monsoon has risen by 15%. During the rainy season, a metre of rain can fall in less than an hour.

In addition, the city will end up under water:

* The sea level is rising 3 mm per year.

*The city is based on a river delta. Bangkok is sinking into its soft clay substrate about 4 cm a year as water is pumped out.

* In a really big storm, as much as 30 square km will be flooded with overflow from the river and polluted water from the canals.

map of city of Bangkok with winding river through it

Bangkok's flood embankments

The King, a hydrological engineer, has made flood control a priority for thirty years. The city is protected from flooding by overflow ponds and channels that take water from upriver directly to the sea. Pumps can lower the level of the canals 20 cm, helping the city to drain. But it’s not enough to control the damage from typhoons and rising sea levels.  But there’s no magic in mega0projects. People are leaving their homes near the canals. They remember the great flood of 2538 (1995 in our calendar). They’re piling up sandbags and building barriers and raising their houses.

Coastal erosion is fierce and soil is constantly being washed away in the southern part of the city. One temple has been surrounded by water in the last twenty years and the lower levels are flooded. The village it served has been washed away in the last fifteen years.  Only the telephone poles remain.

New York City is another city that is vulnerable to rising sea levels.

Urban Heat Island effect is waning

A big study on the effect of cities on temperature measurements found that the temperature differential is slowly dropping; thus it is not distorting measurements nor exaggerating global warming at all.

The Lousy Canuck explains.

Global warming projections: way worse than we thought

The permafrost, which holds lot of frozen vegetation and keeps it from decaying and contributing to atmospheric CO2, will melt enough to kick into a positive feedback of warming and melting.

NSIDC bombshell: Thawing permafrost feedback will turn Arctic from carbon sink to source in the 2020s, releasing 100 billion tons of carbon by 2100.

Figure:  Carbon emission (in billions of tons of carbon a year) from thawing permafrost.

The thaw and release of carbon currently frozen in permafrost will increase atmospheric CO2 concentrations and amplify surface warming to initiate a positive permafrost carbon feedback (PCF) on climate…. [Our] estimate may be low because it does not account for amplified surface warming due to the PCF itself….  We predict that the PCF will change the arctic from a carbon sink to a source after the mid-2020s and is strong enough to cancel 42–88% of the total global land sink. The thaw and decay of permafrost carbon is irreversible and accounting for the PCF will require larger reductions in fossil fuel emissions to reach a target atmospheric CO2 concentration.

This could triple atmospheric CO2. Translation: we’re screwed.

Climate Progress: “A stunning year in climate science”

Climate Progress has a wrap-up of some of the things we’ve discovered in 2010: A stunning year in climate science.

Predicted droughts

Great Global Warming Swindle exposed

This isn’t new, but someone has done a very nice job of dissecting a British documentary and showing its misinformation, fraudulent graphs, and false data: Great Global Warming Swindle complaint to the U.K. Office of Communications.

Among the breeches of the broadcasting code were misrepresenting the purpose of the film when interviewing; falsification of graphs or data or quotations from reports; selectively editing interviews to misrepresent the positions of the interviewees; making serious (and often false) allegations without giving those accused an opportunity to respond; use of logical fallacies “straw man,” “ad hominem,” and “non sequitur” by a public broadcaster; recycling of long-discredited myths; combining interview and narrator statements to make a misleading narrative; using data that is thirty years out of date; and making false statements.

Left, misrepresented data; right, actual global warming

Left, misrepresented data; right, actual global warming

Realclimate: Instability of ice shelves

Wilkins Ice Shelf breakup - from airRealclimate.org explains what happens when an ice shelf begins to melt and why shelves tend to collapse suddenly in “Ice Shelf Instability.”

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