The latest arrow in the denier quiver is the story from Shell Oil about how 'Heavy ice could delay the start of Shell's Alaska's Arctic drilling'. The press release states that it is the heaviest polar ice in more than a decade, and could postpone the start of offshore oil drilling in the Arctic Ocean until the beginning of August. The deniers claim this as proof that Global Warming is a hoax. What is never mentioned however is that it is only a delay of up to two weeks.
Global warming, or climate change as the right likes to call it [sounds less menacing] is not about one heavy snow storm or even one hot day, it is about a long term trend and simple proven physics. The US Air Force actually is who discovered the science of the Green House Effect back in the 1950's. They needed a heat seeking missile to shoot down enemy jets. While working on this it was discovered that C02 and water vapor can block heat emissions on certain wavelengths; thereby rendering the missiles useless.
The National Snow and Ice Data Center sees things a bit different than your typical denier. It is their job to measure the 'Cryosphere'. When scientists talk about the Cryosphere, they mean the places where water is in its solid form, frozen into ice or snow. NSIDC scientists participate in research projects that investigate the dynamics of polar sea ice and climate, snow, glaciers, frozen ground, river and lake ice, how changing climate is affecting indigenous people living in the Arctic, remote sensing, and more.
While the NSIDC does take daily measurements with sophisticated tools and satellites, they are more concerned with long term trends. A long term trend is not one bad snow storm or winter, it what is happening 10, 15 or even a hundred years out. What their research shows is while the arctic ice was heavier this year, it was only slightly so and within the expected normal range.It IS however less than the average for the period from 1979 - 2000. The deniers conveniently leave this vital tidbit out.
The graph above shows Arctic sea ice extent as of May 1, 2012, along with daily ice extent data for the previous five years. 2012 is shown in blue, 2011 in orange, 2010 in pink, 2009 in navy, 2008 in purple, and 2007 in green. The gray area around the average line shows the two standard deviation range of the data. Note how average from 1979 - 2000 is much higher than the line for 2012; this shows an overall decline in arctic ice NOT an increase.
This is what is known as 'cherry-picking data'. Rather than include all the data, you only include the very limited parts that boast your view. It would be rather similar to me, a healthy 220 pound 45 year old male, going to an old folk's home and having a weight lifting contest. Upon winning I then declare myself the strongest man in the world. What I am not telling you is that down my street there is a 20 year guy who can bench press 3 times much as me. This is the effect that cherry picking data has; it gives you invalid results on purpose.