This posting comes via Philip Newell of Climate Nexus, a communication group on climate change:
This winter has been marked by unusual weather extremes. Global warming tends to be forgotten in wintertime, but the changes are happening in winter too, and are connected to these extreme weather events.
Flooding in the U.K.: The jet stream shifted winter rainstorms into a southerly path, in contrast to their more typical varied tracks. These storms drew increased moisture from a warmed sub-tropical Atlantic, according to a report by the U.K. Met Office. As a result, the U.K. set records for its most severe rainfall and most damaging floods in 248 years. Voices across Britain (including Prime Minister David Cameron) are making the connection between this winter’s higher seas, heavier rains, greater floods, unusual storm tracks, and climate change. The Met Office also echoed the “increasing body of evidence that daily extreme rainfall rates are becoming more intense” and stated that this is consistent with both basic physics and climate model predictions.
Drought in California: Since 2007 California has had a series of abnormally dry years. The 2103 calendar year was the drieston record, and the precipitation totals for the 2103/2014 water year are near record lows with only two months left in the rainy season. After this, the state will likely witness no significant precipitation until October. An unprecedented static high pressure “ridge” in the jet stream pushed rainstorms towards Alaska rather than letting them drift over California as usual. Low snowpack and increased evaporation caused by high temperatures are worsening the problem. Climate change is directly connected to the high temperatures, and may be related to the jet stream ridge as well. The drought is hitting farmers hard, threatening 50% unemployment in some farm towns.
Warmth in Russia: The Winter Olympics in Sochi have been abnormally warm, causing delays, injuries, and frustration amongst competitors in the skiing and snowboarding events. In turn, many athletes are speaking out about the way climate change is contributing to this trend and threatening winter sports. Russia’s warmth isn’t limited to Sochi, either. All-time record highs for February temperatures have been set across Siberia. One city experienced its first February day above freezing ever recorded. In line with this warming trend, a new study has shown that the number of cities able to host the Winter Olympics will decline as the century continues.
Cold and Snow in the U.S.: The Eastern United States is one of the only parts of the globe that was colder than average this winter. This is because cold Arctic air is normally confined by the jet stream, but the anomalous waves and shifts in its position (which also influenced other events on this list) allowed pockets to escape and move south. Warm air moved into its vacated position, causing the crazy situation on Jan 26: Homer, Alaska was warmer at 54ºF than any part of the country except southern Florida and southern California. The South was completely unprepared for the unusual snowstorms, resulting in logistical fiascos like the traffic jam in Georgia that left some stranded for over 12 hours.
Heat Wave in Australia: For Australia this heat wave represents an unusual summer rather than winter, but it has been a wild one. Temperatures reaching over 108ºF caused a stoppage in play at the Australian Open, as athletes collapsed and hallucinated. The conditions prompted a catastrophic fire alert, Australia’s highest risk level. It was one of the country’s most significant heat waves on record, following right up on its hottest year on record in 2013. Australia’s Climate Council has recognized that climate change is increasing the frequency, intensity and duration of heat waves.
Heat and Drought in Brazil: A similar heat wave in Brazil threatened coffee, cattle, and chemical production, and raised the threat of water shortages. January was the hottest month on record in much of Brazil, and energy prices are soaring along with the unprecedented demand.