photo: Global Jet/Creative Commons
Two important and interesting but unfortunately not encouraging factoids on climate change: Continuing and increasing a trend, in the US record hot temperatures for June outpaced record cool temperatures by 11:1; in the Arctic, June sea ice extent hit a second-lowest point while also hitting the lowest June volume on record. According to the National Snow and Ice Data Center:
Arctic sea ice extent for June 2011 was the second lowest in the satellite data record since 1979, continuing the trend of declining summer ice cover. Average ice extent fell below that for June 2007, which had the lowest minimum ice extent at the end of summer. However, ice extent this year was greater than in June 2010. The sea ice has entered a critical period of the melt season: weather over the next few weeks will determine whether the Arctic sea ice cover will again approach record lows.
More on that: Climate Progress
Sea ice extent and volume (both are important indicators of how the region is changing) are pretty easy to visualize and widely publicize. The ratio of record high to record low temperatures is less easy on both counts.
That's a ratio of nearly 11:1, when the expected ratio over time should be about 1:1. On a yearly basis over the past decade the ratio has been about 2:1, with data showing that part of the issue is that nights aren't cooling as much as they used to.
From the 1950s to 1980s the ratio fluctuated between being slightly above and slightly below 1:1, but since the 80s it began increasing. Under a business-as-usual climate change scenario, we could hit 20:1 record highs to record lows by 2050 and even 50:1 by 2100. Should we successfully reduce emissions enough, by 2050 we may be able to constrain that ratio to 8:1.
In addition to those 2706 daily high temperature records, June say 63 all-June temperature records and 17 yearly high temperature records.