What Does Abrupt Climate Change Actually Do To the Weather and What does It Mean?

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So as you all know, we had a rather unprecedented and titanic flood disaster on the Central Plains/Midwest in association with the "bomb" cyclone. Flood records fell for flood stages, surface pressure, wind gusts, etc. It was awful. Nebraska has likely suffered a 2+ billion dollar damaging event in totality (currently preliminary estimates hanging around $1.3-1.5 billion with private property still likely facing more assessment). There is another $1.6 billion estimated in Iowa. Not including damage in Southeast South Dakota. There are major agricultural losses which will have implications on food prices in the US and exports globally (and already suffering impacts from the insane trade war between the US and China). I had planned on a writing up analysis on the events of that superstorm, but I decided a more important and broader subject needed to be discussed.

There has been some discussion among people about whether there is a connection between the events of the megaflood which occurred (and is still ongoing) and climate change. I provided my opinion in a recent write-up HERE.

But I want to answer a more elemental question? What does abrupt climate change actually do to your weather? And what really does that mean for humans and life on this planet?

Over the past few years in particular, I've noticed a couple of statements come up with regards to criticism of connecting increasing extreme weather events to our ongoing destabilizing climate:

1. "These type of events have happened before" 

2. "It's an infrastructure/land use/larger population problem" 

Before I address these directly, I'm going to go over the original question...what does abrupt climate change actually do to your weather?

Climate is a range of environmental conditions which lead to a given frequency of weather events of a given magnitude. In a stable climate, the long-term (decades) climate might, for example support a climate in a location where temperatures greater than 100 degrees F/38 degrees C only occur on average 1 time per year. Some years may be have no 100 degree days. Other years 2-3; One year may have an extreme case with 5-6...then back to 1 to 0...but the long-term average is 1. The same goes for other distributions in temperature, soil moisture, evaporation, precipitation, snow accumulation and water table storage. Etc.

However, say your climate is changing. 

Say, there is long term global warming; then whatever effect such global warming has regionally begins to show up in long-term averages. Perhaps your 100 degree days increase to 5 times per year. This means some years you still get 0-1, but far more years, you get 4-6. Other years, 7-9. An extreme year may be 10-12 or higher! You've shifted the bell curve, allowing for more extreme events, including what would be record events in the previous climate regime, to become a routine part of a newly evolving climate. 

But there's more to the story. 

Events which were rare, but still possible within the previous stable climate become more frequent. Those years where we would have 4-6 days per year? Once "extreme", that is now routine. It happened before, it was part of the records of reported events, but it happens much more frequently, instead of with being a rare occurrence. 

This is the problem I find with the statement #1:  "These type of events have happened before". It forgets 3 cardinal rules of understanding the systemic problems behind GLOBAL climate change. 1) Is it happening more/less often? 2) Is it happening with more/less significant intensity (the magnitude is changing) 3) It is happening more/less frequently and with greater/lesser intensity not only "here" in some locality, but globally, recognizing the global systemic changes? Global changes have implications not only on a locality directly, but indirectly by harming other parts of the world...humans and other species...we are connected with through ecosystems and civilization. 

Let's take our heat example.

How about an event which has happened before. How about a high heat event for the United States. May 1934...up until 2018, this was the warmest May on record in the Contiguous US. 

Temperature anomalies of 2-4.5 degrees C above 1951-1980 climatology over much of the US that May. It was very hot that late spring and summer on the Plains, with an intensification of the Dust Bowl. Similarly very warm Mays occurred in 1936, 1939, and 1941. But more often, it was near normal or below normal. Also note much of the rest of the world. Near normal or modestly above or below normal, with a few cold and hot spots. 

Compare now to May 2018...the current hottest May on record for the Contiguous US.

Widespread anomalies of 2-4 C above normal across the US. But most of the world is above normal, with many more hotspots and a bull's eye of 4-6 C above normal over Northern Europe! Much more widespread heat over the Arctic. For the Contiguous US, 6 of the 10 warmest Mays on record (1895-2018) have been since 1980 (when global warming began to accelerate).  5 of those 6 have been since 1998! What is this? An abruptly increasing frequency of warm to hot Mays in the climate since 1998. Then, finally in 2018, a May which exceeded May 1934 after 84 yrs on the record books.

So what does this actually mean?

Climate change is not simply about breaking new records. Certainly as climate change accelerates, those records are reached and exceeded by new records faster and faster. But it's also about old extremes becoming more typical, and "normal" events "which have happened before" becoming either more frequent and or even diminishing and being replaced by the previous extremes. And changing such frequency distributions of all the variables I mentioned earlier....temperature, moisture, rainfall, etc...and doing so on the order of decades and now years...means catastrophic to existential impacts on both ecosystems and human infrastructure and agricultures. 

For example, Lincoln, NE can get 100 degree weather. Typically only 1-2 days a year in the 1981-2010 climate regime. The current all-time record high for the city is 115 F, set in July 1936. In a world 3-4 degrees C warmer than pre-industrial, the number of days above 100 degrees in summer is expected to increase from 1-2 days/yr to nearly 50 days/yr. A stark example of the "we've had this type of weather before" not recognizing, we haven't that type of "frequency of weather before". 


And actually, this leads to statement #2:  "It's an infrastructure/land use/larger population problem".

At the end of the day, we live in a sea of air on land also dependent upon a massive ocean with incredible heat capacity. And therefore the capacity to heat the planet further. In my above example, crops can't grow here, human health is threatened, the health of local species are threatened...etc. We could never exceed 115 F again and it will still be a cataclysmic disaster which will be permanent (or worsen) as such global temperatures appear inevitable. Yes, other anthropogenic influences play a role in making individual events worse. But the ultimate problem is the pollution problem caused by human-released greenhouse gases which continue to accelerate, as well as Earth-generated feedback monsters we have released from their "cages". 

You cannot have any of that infrastructure/land use changes/growing populations and not acknowledge those very changes to the surface of our planet are directly altering the climate and destroying the biosphere through water pollution, soil degradation and ecological destruction. These events aren't simply a hazard to humans, but to all complex life unable to adapt fast enough to what amount to cataclysmic changes more akin to an asteroid impact than to anything in the fossil record since the last asteroid impact! Such statements are either a diversion from the realities of the situation or a lack of understanding the complex and multi-causal predicament we face.

This is much bigger than dealing with "events which have happened before" with some "improved infrastructure and better farming practices". I hope people understand that sooner rather than later, because sadly our governments certainly will not inform us.

---Meteorologist Nick Humphrey

 Science of Abrupt Climate Change Series: 

1. August 4, 2018:  Earth System Non-Linearity 

2. December 1, 2018:  Accelerators of Change 

3. January 2, 2019:  The Super Exponential 

4. January 26, 2019:  The Wrath of Heat