Atmospheric carbon dioxide continues to increase

Update, May 14: You can read Climate Central's take on why this is an important measure here.

Two weeks ago I wrote a post about the Keeling Curve, which measures the concentration of carbon dioxide in the atmosphere and explains why that's important. If you're wondering why NOAA reported that the Earth had, on Friday, the threshold level of 400ppm of carbon dioxide in the atmosphere, but the Scripps Institute of Oceanography  did not, there's a simple explanation - time zones. As a note on the Scripps site puts it:

May 10 Comment: NOAA has reported 400.03 for yesterday, but Scripps has reported 399.73. The difference is similar to other differences we have reported.   The difference partly reflects time zone differences.  NOAA uses UTC, whereas we use local time in Hawaii to define the start and stop of a given day.  Changing to UTC excludes the lower CO₂ period from the baseline on the May 9, shifting it to May 10.

399.73 or 400.03 - both are bad. There's a good roundup of this and other climate news on the blog "Scrapbook of a Climate Hawk," here.

March weather, 2012 and 2013

 

March 2012 was unusually warm, and March 2013 unusually cold. The short-term explanation appears to lie in the Arctic Oscillation, as described in the NOAA video above. The cold March came at the tail end of a cold winter.

But there seems to be a longer-term possible explanation appearing as well. Remember climate and weather are two different things, and this video describes the weather. But yes, the climate is changing. And one of the effects appears to be on sudden stratospheric warming events like the one that occurred last January.

Sudden stratospheric warming events take place in about half of all Northern Hemisphere winters, and they have been occurring with increasing frequency during the past decade, possibly related to the loss of Arctic sea ice due to global warming. Arctic sea ice declined to its smallest extent on record in September 2012.

And yes, sudden stratospheric warming events can affect the Arctic Oscillation. You can read more about them here. As they say, you can expect the climate; the weather is what you get.  

Update, May 6: There's an interesting interview with meteorologist Paul Huttner here. He talks about the unusual weather events we've been seeing, like last week's late snowstorm. And how that's a weather event, but there are lots of signs of regional climate change around the world.

It's official: 2012 hottest year on record

You've probably read news reports yesterday and today stating that 2012 was the hottest year on record in the contiguous United States. You can find NOAA's original release here. Here's part of the discussion:

The above-average temperatures of spring continued into summer. The national-scale heat peaked in July with an average temperature of 76.9°F, 3.6°F above average, making it the hottest month ever observed for the contiguous United States. The eighth warmest June, record hottest July, and a warmer-than-average August resulted in a summer average temperature of 73.8°F, the second hottest summer on record by only hundredths of a degree. An estimated 99.1 million people experienced 10 or more days of summer temperatures greater than 100°F, nearly one-third of the nation’s population.

 Just how hot was it?  Climate Central has developed an interactive graphic showing the changing temperature in each state. The screen shot shows a graph of Iowa's increasing temperatures over the years since records have begun (yes, I know the graph should start at 0 (or 32, since we're talking about temperatures measured in Fahrenheit, but I'm letting it go in this case).
 
2012 was also the second-most tempestuous year. According to NOAA:

The U.S. Climate Extremes Index indicated that 2012 was the second most extreme year on record for the nation. The index, which evaluates extremes in temperature and precipitation, as well as landfalling tropical cyclones, was nearly twice the average value and second only to 1998. To date, 2012 has seen 11 disasters that have reached the $1 billion threshold in losses, to include Sandy, Isaac, and tornado outbreaks experienced in the Great Plains, Texas and Southeast/Ohio Valley.

More climate data from NOAA

Update, April 19: Here's a link to the Early Bloomers Op-Ed in today's NY Times about the how much earlier the plants that Thoreau noted bloom now, and how rare some of them have become.

Image: NY Times

  
After yesterday's post, I took a closer look at NOAA's Climate Services page. It's very useful, with links to reports, data, a news feed, a lookup for historical weather data by zip code, and other material. My favorite: two interactive data dashboards (one for climate change, the other for climate variability). Here's a partial screenshot:

 

The top graph is change in average surface temperature across the earth compared to the average for 1901-2000. The second shows the area of the Northern Hemisphere covered by snow in March and April, shown as the difference from the 1971-2000 average. And the third shows the average mass, together, of 30 reference glaciers from around the world. How do I know this? The little question mark signals a popup that explains what each graph displays in one or two sentences, and then offers a "read more" link for more information.

I encourage my clients to develop and update data dashboards because they let you see, at a glance, the status of your programs. These are particularly glitzy ones, but then they draw on a large number of data points. It's worth going to NOAA's site and experimenting with them directly. And, as I've said before, also here, it's not as if more proof of global warming were needed. Climate change is here, and these depressing numbers show that it's time to take some action.