The extraordinary sequence of extreme weather events during the last 18 months is probably the worst run of natural disasters since 1816, when a huge volcanic eruption at Mt Tambora cooled the earth enough to cause the famous “year without a summer“, according to a powerful blog post by Weather Underground founder Jeff Masters. He runs through the list, giving details of each:
- Earth’s hottest year on record
- Most extreme winter Arctic atmospheric circulation on record
- Arctic sea ice: lowest volume on record, 3rd lowest extent
- Record melting in Greenland, and a massive calving event
- Second most extreme shift from El NiÃ±o to La NiÃ±a
- Second worst coral bleaching year
- Wettest year over land
- Amazon rainforest experiences its 2nd 100-year drought in 5 years
- Global tropical cyclone activity lowest on record
- A hyperactive Atlantic hurricane season: 3rd busiest on record
- A rare tropical storm in the South Atlantic
- Strongest storm in Southwestern U.S. history
- Strongest non-coastal storm in U.S. history
- Weakest and latest-ending East Asian monsoon on record
- No monsoon depressions in India’s Southwest Monsoon for 2nd time in 134 years
- The Pakistani flood: most expensive natural disaster in Pakistan’s history
- The Russian heat wave and drought: deadliest heat wave in human history
- Record rains trigger Australia’s most expensive natural disaster in history
- Heaviest rains on record trigger Colombia’s worst flooding disaster in history
- Tennessee’s 1-in-1000 year flood kills 30, does $2.4 billion in damage
Masters argument is straightforward:
…it is highly improbable that the remarkable extreme weather events of 2010 and 2011 could have all happened in such a short period of time without some powerful climate-altering force at work. The best science we have right now maintains that human-caused emissions of heat-trapping gases like CO2 are the most likely cause of such a climate-altering force.
There’s more heat accumulating in the system, and more water vapour in the atmosphere to drive weather events.
A naturally extreme year, when embedded in such a changed atmosphere, is capable of causing dramatic, unprecedented extremes like we observed during 2010 and 2011. That’s the best theory I have to explain the extreme weather events of 2010 and 2011–natural extremes of El NiÃ±o, La NiÃ±a and other natural weather patterns combined with significant shifts in atmospheric circulation and the extra heat and atmospheric moisture due to human-caused climate change to create an extraordinary period of extreme weather.
However Masters doesn’t think that this sort of weather is the new normal — at least not yet — but it does suggest where we may be heading in 20-30 years time:
…the ever-increasing amounts of heat-trapping gases humans are emitting into the air puts tremendous pressure on the climate system to shift to a new, radically different, warmer state, and the extreme weather of 2010 – 2011 suggests that the transition is already well underway.
You don’t have to be an alarmist to find that alarming.
[Update: 30/6: The Guardian turns Masters’ list into a slideshow of compelling images.]