This week The Climate Show brings you an all news special. We have wet summers for Europe, permafrost warming delivering a methane kick, La Niña driving floods that make sea level fall, a glacier calving in Antarctica, mammoths and sabre tooth tigers — all delivered with Glenn and Gareth’s inimitable panache (!).
Thailand is experiencing its worst monsoon flooding for at least 50 years. The NASA Earth Observatory image above shows the waters piling up to the North of the capital Bangkok, which is already beginning to experience flooding (visit the EO page to see a comparison with earlier floods, and The Guardian for a striking set of flood pictures). The Thai government yesterday declared a five day weekend to allow the city’s inhabitants to make preparations. The intense monsoon season has also brought extensive flooding to Cambodia and northeastern India over the last couple of months, and destroyed a significant part of SE Asia’s rice crop. On the other side of the planet, heavy rain and flooding has been affecting Mexico, El Salvador, Costa Rica, Honduras, Guatemala, and Nicaragua. Jeff Masters reported that in the ten days up to October 20th, Huizucar in El Salvador received an astonishing 1.513 metres of rain.
At first glance, it looks like a continuation of the remarkable series of extreme weather events — especially heavy rainfall and flooding — that we’ve seen over the last few years. But apart from the human suffering and economic dislocation being experienced around the world, it appears there’s another interesting consequence of all this precipitation — it’s causing global sea level to fall.
Tuvalu has declared a state of emergency relating to water shortages in the capital, Funafuti, and a number of outer islands. A New Zealand Defence Force C-130 left this morning to take supplies and personnel to Tuvalu. The supplies include two desalination units as well as water containers. Two Ministry of Foreign Affairs staff on board, including our Wellington-based High Commissioner, will remain in Tuvalu to help assess needs on the ground. New Zealand will be working with partners and other donors to consider the best medium-to-long-term response options.
Tuvalu, with 11,000 inhabitants, is not the only island nation in trouble. Tokelau, with 1400 inhabitants, has declared a state of emergency because fresh water supplies might run out in a few days. Samoa is rationing water also.
There appears to be a reasonable probability that there is a causal link between the drought and water scarcity affecting the islands and climate change.
This astonishing video was shot on Monday as flash flooding hit the Queensland town of Toowoomba after a reported 140mm of rain fell in only 30 minutes. 12 people are confirmed to have been killed in the region, and 90 more are missing according to state premier Anna Bligh. Floodwaters are rising in the state capital Brisbane, with the central business district closed down. Flood levels are expected to top out above the levels reached in 1974 — the previous record holder. I know that Hot Topic‘s readers will join me in wishing the people of Queensland well. This ABC page has a list of relief funds to which you can donate. I can confirm that Skeptical Science’s John Cook is OK, and not expecting any direct impacts. We’ll be talking to him about the floods in the next Climate Show, scheduled for recording next week.
Has global warming had an impact on this event? Watching the deniers quotes The Age saying that the floods are “consistent with (although not proof of) climate change predictions for northern Australia”, and that seems fair. The direct “cause” of the flooding is the current strong La Niña (possibly the strongest since records began, according to AMOS president Prof Neville Nicholls). This phase of ENSO causes warm water to pile up against NE Australia, helping to fuel large rainfall events. The record floods of 1974, for example, were associated with a La Niña event. To make matters worse, over the last year sea surface temperatures around Australia have been running at record levels, as this Bureau of Meteorology chart from their climate summary for 2010 shows:
The recipe seems clear enough: an intense La Niña and record sea surface temperatures combining to cause record floods. A more precise attribution of warming’s influence on the event will have to wait for the studies to be done, but for the time being it certainly looks likely that this is another extreme weather event which has been made worse by recent warming.
Update 13/1/11: Barry Brook at Brave New Climate considers the costs of the floods, and puts them in to the context of the last few years of Aussie weather extremes, and NASA’s Earth Observatory has an image showing rainfall in the Brisbane area, showing that over 200 mm fell in the flash flood regions.