How extreme weather could create a global food crisis
2010 was among the hottest and wettest years on record – we are entering a period of climate and food insecurity
The US national oceanic and atmospheric administration reported that 2010 tied 2005 for the hottest year on record – and was the wettest year on record. This is no coincidence. As Kevin Trenberth, the head of climate analysis for of the National Centre for Atmospheric Research,explained:
There is a systematic influence on all of these weather events nowadays because there is more water vapour lurking around in the atmosphere than there used to be, say, 30 years ago. It's about a 4% extra amount, provides plenty of moisture for these storms and it's unfortunate that the public is not associating this with the fact that this is one manifestation of climate change. And the prospects are that these kinds of things will only get worse in the future.
Globally, 2010 saw 19 nations – a record number – set temperature records including Pakistan, which hit 53.5 °C, the hottest temperature ever reliably measured in Asia's history. From mid-December to mid-January of this year, the National Centre for Atmospheric Research (NCAR) reported that parts of north-eastern Canada were 21 °C above average, "which are very large values to be sustained for an entire month". In Coral Harbour, in the north-west corner of Hudson Bay, "the town went 11 days without getting down to its average daily high." In mid-December, Greenland experienced the most extreme high-pressure system of its kind ever recorded anywhere on the planet. Last year saw the greatest ice melt on record for Greenland.
In America, Tennessee was devastated by a once-in-1,000-year rain storm leading to what some called Nashville's Katrina. In October, the strongest storm ever recorded in the Midwest broke pressure records.
As Craig Fugate, who heads the US federal emergency management agency, said in December: "The term '100-year event' really lost its meaning this year."
The Moscow heatwave this summer was so severe that the Russian Meteorological Centre reported: "There was nothing similar to this on the territory of Russia during the last 1,000 years in regard to the heat." The Russian president, Dmitry Medvedev, said: "What is happening now in our central regions is evidence of this global climate change, because we have never in our history faced such weather conditions in the past." The country banned grain exports through this year's growing season.
Pakistan was inundated by a deluge that seemed beyond imagination – until an area the size of Germany and France combined was inundated by "biblical" floods in Australia. In Carnarvon, more than a year's rain fell in just 24 hours. In one city in Queensland, six inches fell in just 30 minutes. The Australian Bureau of Meteorology in its annual report for 2010 pointed out:
Very warm sea surface temperatures contributed to the record rainfall and very high humidity across eastern Australia during winter and spring. The most recent decade (2001-10) was also the warmest decade on record for sea surface temperatures following the pattern observed over land.
In January, more than 300 mm fell in just a few hours in many regions of Brazil, causing their deadliest natural disaster in history. Again, a key contributor was the second warmest sea surface temperatures on record for the moisture source region.
Individually, these climate-driven extreme events were disasters, but collectively they contributed to a global food crisis. In early January, theFinancial Times reported the UN Food and Agriculture Organisation's food price index, "a basket tracking the wholesale cost of wheat, corn, rice, oilseeds, dairy products, sugar and meats" had jumped to a record high.
Lester Brown, a leading authority on food insecurity, and author World on the Edge, explained to me what the world is facing. When the real food instability comes – if, for instance, the US or Chinese breadbasket gets hit by the type of heatwave Russia just did – the big grain producers will ban exports, to make sure their people are fed. In this scenario, if you don't have your own food supplies or an important export item to barter – particularly oil – your country is going to have big, big problems feeding its people.
We are entering an era of climate and food insecurity. Munich Re, one of the world's leading reinsurers, issued a news release in late September, entitled "large number of weather extremes as strong indication of climate change," which noted:
Munich Re's natural catastrophe database, the most comprehensive of its kind in the world, shows a marked increase in the number of weather-related events ... it would seem that the only plausible explanation for the rise in weather-related catastrophes is climate change. The view that weather extremes are more frequent and intense due to global warming coincides with the current state of scientific knowledge as set out in the Fourth IPCC Assessment Report.
America's top climatologist, Dr James Hansen, head of Nasa's Goddard Institute of Space Studies, said:
Given the association of extreme weather and climate events with rising global temperature, the expectation of new record high temperatures in 2012 also suggests that the frequency and magnitude of extreme events could reach a high level in 2012. Extreme events include not only high temperatures, but also indirect effects of a warming atmosphere including the impact of higher temperature on extreme rainfall and droughts. The greater water vapour content of a warmer atmosphere allows larger rainfall anomalies and provides the fuel for stronger storms driven by latent heat.
Barring a major volcano, half the years this decade are likely to be warmer than 2010. That means wetter and more extreme weather. And that means more food insecurity.
On our current emissions path, Russia's grain-export-ending heatwave and drought could be a once every decade event – or even more frequent. And that will collide with extreme events around the world.
In 2010, the world received its first global warning, bombarded by multiple events that are considered extreme today, but what will eventually be viewed as the norm – if humanity fails to act.
• Joseph Romm is editor of the US-based blog Climate Progress
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