Although the 2009/2010 European winter saw some exceptionally cold and snowy periods, the Arctic polar regions and Canada experienced unusually mild winter conditions. Northern Europe experienced its coldest winter for nearly 30 years, while temperatures in some places in the Arctic and Canada reached +6°C above the long-term average and Canada experienced its mildest winter on record.
Despite a very few cold places, above average winter temperatures were also experienced in most parts of China, South Asia, the Middle East and Africa. Although Europe experienced a very cold winter, the period December 2009 to February 2010 saw temperatures across the whole of the northern hemisphere to be an estimated half a degree over the long-term average. The southern hemisphere also saw above average temperatures during its summer, with Australia experiencing an extended drought and forest fires.
The northern hemisphere summer continued the trend of above average temperatures; Russia suffered under its longest known heatwave with record temperatures experienced in several parts of the country and contributing to a prolonged and expensive drought. The Russian heatwave is an unprecedented weather event that caused more than 4,000 deaths, wrecked a quarter of Russia's grain crop and may eventually see $14 billion cut from the country's gross domestic product. Predictions that global warming may benefit crop yields in the northern hemisphere are appearing to be far from accurate, with one of the world's bread baskets severely hit by drought. Grain prices in Europe are expected to soar as a result. Records continued to tumble in the autumn, with Russia experiencing record November temperatures.
Drought has been felt harshly elsewhere around the globe: as the Amazon basin experienced its worse drought for 40 years, the Rio Negro, an important tributary of the Amazon, fell to a record low. Rafael Cruz, a Greenpeace activist in Manaus, Brazil, told The Guardian that recent years had seen both extreme droughts and flooding become worryingly frequent.
2010 has seen a year of record breaking temperatures around the globe. In July, the Peruvian government declared a state of emergency in many of Peru's regions due to cold weather. In areas in the south of the country, temperatures dropped as low as -24°C and Lima recorded its lowest temperatures in 46 years at 8°C. In the south, hundreds of people, the majority of them very young children, died of cold-related diseases such as pneumonia.
However, the trend in 2010 has been for record breaking highs, with several countries experiencing their highest ever temperatures: 49.6°C in Dongola, Sudan (June); 52°C in Basra, Iraq (June); 44°C in Yashkul, Russia (July); 50.4°C in Doha, Qatar (July); 37.2°C in Joensuu, Finland (July) and 53.5°C in Mohenjo-daro, Pakistan (June), the fourth highest temperature ever recorded. While we expect to see the odd record breaking high each year, this year has been unusual in that we've seen record after record broken.
National Oceanic and Atmospheric Administration (NOAA) figures show that the combined global land and ocean average surface temperature for March, April , May and June all reached their highest ever level this year. The June figure continued another trend by being the 304th consecutive month with a global temperature above the 20th century average.
Perhaps unsurprisingly, 2010 has also seen the largest calving from Greenland's ice sheet in the past 50 years of observations and data. The MODIS sensor on NASA's Aqua satellite detected a large chunk of ice measuring around 260km2 breaking from the Petermann Glacier. The WMO reports that although "tens of thousands of icebergs calve yearly from the glaciers of Greenland... this one is very large and because of its size more typically resembles icebergs in the Antarctic".