10 for 10 - Arctic Sea Ice Melt Trend Continues

Every year in October the National Snow and Ice Data Center (www.nsidc.org) releases a report on the minimum sea ice extent for the current year.  This year the NSIDC announced that the minimum summer sea ice extent for 2014 was 5.02 million square kilometers.  OK, so what?

NASA satellites started monitoring sea ice extent in the Arctic Ocean back in 1979.  Satellite data are downloaded each day and sent sent to the National Snow and Ice Data Center at the University of Colorado, Boulder, for analysis.  Thirty-five years of these data are now painting a sobering picture.  Though there is a significant amount of year-to-year variability among the data, a strong trend is emerging.

Average Monthly Sea Ice Extent September 1979-2014.  

Data courtesy of NSIDC.org

The data show that there is significantly less sea ice in the Arctic now than there was only a few decades ago.  The upper end of the trend line tops out around 7.9 million square kilometers of sea ice, and the bottom end of the line reached about 4.9 million square kilometers of sea ice.  The difference?  About 3 million square kilometers of sea ice gone missing.  How much is that?  That's about the same surface area as India, the 7th largest country in the world.

NSIDC also reports that we are currently losing on average 13.3% of sea ice cover per decade and that the ten Septembers with the lowest extents happened in the last ten years!  

Bottom line?  We are progressively losing more sea ice in the Arctic.  

10 for 10?  The last ten years, the ten lowest sea ice extents, and sadly at this rate it's not likely to get better before it gets even worse.

Holy Cow! Look at that decline in Arctic sea ice!

I haven't posted anything about much here lately, though there has been a lot going on.  For example the launch of the Carbon Observatory Satellite (http://www.huffingtonpost.com/2014/07/02/carbon-observatory-2-satellite_n_5550826.html?utm_hp_ref=green), but I just had to place a short post when I checked the Arctic sea ice extent today at the NSIDC.org site.

The graph below shows the relationship between the current sea ice extent (blue line) and the extent in 2012 (green dashed line), the year that generated the smallest sea ice extent so far, and the long-term average sea ice extent (dark gray line).  The rate of sea ice melt through mid-June 2014 wasn't really much out of the ordinary, just 500,000 km2 below the long term average (just!?), but over the past couple of weeks the sea ice extent has plummeted!  It's now about 1.2 million km2 below the average extent for this time of year.  

Yikes!

If this sea ice melt rate keeps up we could see another record low extent or close to it.  And yet another indicator from the high Arctic that the effects of climate change are not going to be going away anytime soon.

This is also the second month running where the atmospheric carbon dioxide level did not dip below 400 ppm, the second month it's ever been this high in human history...at least for the last several hundred thousand years.

Hang on, it could get interesting and exciting to see just how far things will go before there is general acceptance and outcry that something be done, at least in the USA.

Think green!

Don't be fooled, there is scientific consensus on anthropogenic climate change

Many people (almost entirely non-scientists or non-climatologists) inaccurately claim that the scientific community either has not or cannot reach consensus on the topic of anthropogenic climate change (i.e., global warming).  This claim has become a worn and weary diatribe used by some people, yes, I will even go as far  as to say "conspiring men" who are trying to muddy the waters on a topic that is accepted nearly universally by the practicing scientific community.

Why do people believe these conspiring men?  Because it happens to fit their pre-existing notions or opinions on climate, economy, religion, or plays to their benefit in terms of vested interest (e.g., oil industry).

The bottom line is that the scientific community has near unanimous consensus on the topic of climate change.  By the way, what proportion of scientists would it take to constitute a consensus?  50.1%, 60%. 75%, 80%, 90%, 95%, 98%, 99%, 100%?

I think that we can all agree that reaching a 100% consensus on any scientific theory is nigh unto unattainable, but was exactly what was discovered in a study carried out in 2004, and consensus has continued to strengthen since then.

In 2004, a study by the well-resepcted UC San Diego sociologist Naomi Oreskes was published Science, America's most prestigious scientific journal (http://leisureguy.wordpress.com/2007/09/04/the-scientific-consensus-on-global-warming/).  Results described in that study showed that NONE of the 982 peer-reviewed scientific papers on the topic of climate change published between 1993 and 2003 disputed the conclusion of anthropogenic climate change.

Other studies have claimed to show disputations and lack of consensus among scientists regarding anthropogenic climate change.  For example, a paper titled "Scientific Consensus on Global Warming" was published in the latter 2000s http://ruby.fgcu.edu/courses/twimberley/EnviroPol/ScientificConsensusOnGlobalWarming.pdf.

Be advised that the formatting and layout of these kinds of papers are intended to make them appear to be credible sources of information, but they are not comparable to peer-reviewed publications in professional scientific journals.

Back to the Heartland Institute paper...it reported moderate agreement on some topics, but significant disagreement on others.  There are, however, several points of concern related to this report and others like it.  The most important concern is that this report cannot be considered verifiable scientific information since it was never subjected to peer-review and was not published in a reputable scientific journal.  Another note of concern is the source of the paper itself.  It is a product of "The Heartland Institute".  Investigative research into public records shows that this institute and others like it are engaged in carrying out an active campaign to cloud the public's perception of well-documented scientific conclusions regarding climate change.  If you have questions about this I strongly recommend that you take a look at the book "Merchants of Doubt" by Naomi Oreskes (http://www.merchantsofdoubt.org/)

You can also read more about the oil-backed Heartland Institute at this site: http://www.desmogblog.com/heartland-institute.

Getting back to the original point of the posting.  There is clearly near unanimous consensus among climate scientists (98%+) that climate change is happening and more than 90% confident (IPCC report, 2007) that the current trend of global warming is being driven mainly by anthropogenic forcing factors, including greenhouse gas emissions and land-use changes, among other activities.

So what does scientific lack of consensus on verifiable scientific observations on this topic look like?  It looks like this:

(Figure courtesy of NASA http://earthobservatory.nasa.gov/IOTD/view.php?id=80167&src=share#.UQK6EDpBexI.facebook)

Every year, groups of climatologists working independently in the USA, Great Britain, Japan, and other locations around the world, collect temperature data and generate average annual observed temperatures.  They can then plot their data onto one graph, as shown above, and see where differences and variations among their results are.  If there is any lack of consensus it is that some data show slightly warmer temperatures some years, while others show slightly cooler ones, but within a range of acceptable statistical variability, all the data produce the same long-term trends.  In other words - consensus.  

Similar work is done by climatologists investigating causes (also referred to as climate forcing factors), and they also nearly universally conclude that without human-produced effects, we would not currently be experiencing a warming trend.  Instead we would be experiencing a gradual cooling trend.

So whenever you hear someone parroting some out of date or completely unsupportable fallacy that there is no scientific consensus on anthropogenic climate change, ask them about their source of information.  It will inevitably originate in some non-scientific think tank or media outlet that clearly has an agenda that benefits if people do not understand that there is scientific consensus on climate change and that we had better get busy doing something about mitigating the effects of climate change. 

That's all for today.  Cheers!

Are you kidding me!? Arctic sea ice melt is already at a near record level and still going strong

In 2007 the rate and extent of sea ice melt shocked the world of climate scientists.  That year an unusual set of weather events combined to produce a record sea ice melt in the Arctic Ocean.  This year, 2012, that record is almost certainly going to be broken, if not shattered.  What makes this VERY unusual is that the recent conditions in the Arctic, including an Arctic cyclonic storm, normally produce slower sea ice melt conditions, not the record-pace conditions observed over the past several weeks.

The National Snow and Ice Data Center and NASA show that as of yesterday (8-23-2012) the sea ice extent in the Arctic Ocean is already at near record levels. 

This map shows the current area of the Arctic Ocean covered by at least 15% sea ice as of 8-23.

If you follow my blog you've certainly seen maps like this before.  The white area shows sea ice cover, while the orange line shows the historical average (1979-2000) sea ice cover for this date.  As you can see, the amount of sea ice currently existing in the Arctic is WAY below average, and it has been for the past several years. 

What makes this year different, however, is the rate and extent of sea ice melt - it's going crazy!

Normally the Arctic reaches maximum sea ice melt sometime in mid to late September.  The graph below shows some interesting things.  The dark gray line shows the historical rate of Arctic sea ice melt (1979-2000).  The light gray area aound that line shows + 2 standard deviations (i.e., the range that contains 95% of all sea ice extent observations during that 1979-2000 time period).  The dashed green line shows the pattern of sea ice melt during the previous record year, 2007.  The blue line shows the pattern of sea ice melt this year, 2012. 

As you can see, the sea ice extent in the Arctic is already within a hair's breadth of setting a new sea ice melt record.  That this would happen is not a surprise to climate scientists anywhere...what IS a surprise, though, is how early we reached this mark this year.  We are still anywhere from two to three weeks from the date when we observe the maximum sea ice melt for a given year. 

As for the record for this date, the sea ice melt for 2012 is somewhere between 500,000 km2 and 750,000 km2 greater (that's that much less ice) than in the previous record year of 2007!  Only time will tell now by how much the old record will be broken, but if this year's pattern holds it could be more than a record-breaking year, it could be a record-smashing year.

I'll keep you posted as the melt season progresses.