As Kevin Trenberth, head of climate analysis of 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 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 is unfortunate that public is not associating this with the fact that this is one manifestation of climate change. And 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 53.5C, the hottest temperature ever reliably measured in Asia's history. From mid-December to mid-
January of this year, National Centre for Atmospheric research NCAR reported that parts of north-eastern Canada were 21C above average, "which are very large values to be sustained for an entire month." 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.
Moscow heat wave this summer was so severe that 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 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 & France combined was inundated by “biblical” floods in Australia.
In Carnarvon, more than a year's rain fell in just 24 hours.
Australian Bureau of Meteorology in its annual report for 2010 pointed out: Very warm sea surface temperatures contributed to record rainfall and very high humidity across eastern Australia during winter and spring. Most recent decade (2001-10) was also warmest decade on record for sea surface temperatures following the pattern observed over land.
In January, more than 300mm fell in just a few hours in many regions of Brazil, causing their deadliest natural disaster in history. Again, a key contributor was 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. Un food & Agriculture Organization's food price index, "a basket tracking 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 says when real food instability comes – if, for instance, the US or Chinese breadbasket gets hit by type of heat wave Russia just did – 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.
World is entering an era of climate and food insecurity. The view that weather extremes are more frequent and intense due to global warming coincides with current state of scientific knowledge as set out in Fourth IPCC Assessment Report.
US 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, expectation of new record high temperatures in 2012 also suggests that 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 impact of higher temperature on extreme rainfall and droughts. Greater water vapour content of a warmer atmosphere allows larger rainfall anomalies and provides 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. Russia's grain-export-ending heat wave 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.