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There have been some recent articles about how climate change is harming agriculture. One by Kim Severson in the New York Times (here) says “Drop a pin anywhere on a map of the United States and you’ll find disruption in the fields.” It goes on to discuss the impacts on “11 everyday foods”: tart cherries (Michigan), organic raspberries (New York), watermelons (Florida), chickpeas (Montana), wild blueberries (Maine), organic heirloom popcorn (Iowa), peaches (Georgia and South Carolina), organic apples (Washington), golden kiwi fruit (Texas), artichokes (California), and rice (Arkansas).
Well, that is a sampling of foods from around the country. I’m not so sure how “everyday” many of them are, but rice is certainly one of the basic grains.
A somewhat more convincing article by Chris McGreal in The Guardian interviewed farmers in valley of the Missouri River near Langdon, in northwestern Missouri. These are corn and soybean farmers. Their problem has been moisture: they have had too much rain. In many years, the ground has been so muddy that crops were ruined or not planted at all. In other years, the rain has caused the water table to rise so much that the ground looks dry on top, but is mucky mud just a few inches down. This is something, of course, that would affect river valleys the most, and the big river valleys in Missouri are some of the richest farmland the state has.
Most climate change studies project that climate change will impact agriculture negatively. Given this blog’s focus on the large statistical perspective, I thought it might be interesting to see how crop yields are doing in Missouri. The United States Department of Agriculture publishes the data. This data is a statistical average of yields across Missouri. Results in any one location may be different.
Figure 1 shows the per-acre yield for corn. The data shows that corn yields vary significantly from year-to-year, and that some years are really terrible, with yields being roughly half of what they are in good years. That said, there is a clear trend toward increased yields from 1957 right through 2014. Yields since then have been lower, and it is possible that we are looking at the start of a downward trend, but 4 years is not sufficient to tell.
Figure 2 shows the per-acre yield for soybeans. The yearly variation here may be somewhat less, but the overall pattern is much the same. With soybeans, however, yields increased right through 2017.
This data doesn’t tell us why crop yields are rising. Perhaps they are due to improved farming practices and better seed stock. It is possible that warmer temperatures, an increase in carbon dioxide, and more rain have benefitted crop yields overall, even if they have hurt some farmers in some locations. We just don’t know, at least not from this data.
What we do know is that, overall, the predicted negative effects of climate change do not yet seem to be reducing yields in these two important crops.
McGreal, Chris. 2018. “As Climate Change Bites in America’s Midwest, Farmers Are Desperate to Ring the Alarm.” The Guardian,” 12/12/2018. Viewed online 5/1/2018 at https://www.theguardian.com/us-news/2018/dec/12/as-climate-change-bites-in-americas-midwest-farmers-are-desperate-to-ring-the-alarm.
Severson, Kim. 2019. “From Apples to Popcorn, Climate Change Is Altering the Foods America Grows.” The New York Times, 4/30/2019. Viewed online 5/1/2019 at https://www.nytimes.com/2019/04/30/dining/farming-climate-change.html?rref=collection%2Fsectioncollection%2Fclimate&action=click&contentCollection=climate®ion=rank&module=package&version=highlights&contentPlacement=2&pgtype=sectionfront.
National Agriculture Statistics Service, United States Department of Agriculture. Quick Stats. This is a data portal that can be used to build a customized report. I focused on yield, in bushels per acre, for corn and soybeans from 1957-2018. Data downloaded 5/1/2019 from https://quickstats.nass.usda.gov.
Damage from severe weather in Missouri shows a different pattern than does damage nationwide. As Figure 1 shows, the cost of damage from hazardous weather events in Missouri spiked in 2007, then spiked even higher in 2011. Since then, it has returned to a comparatively low level. The bulk of the damage in 2011 was from 2 tornado outbreaks. One hit the St. Louis area, damaging Lambert Field. The second devastated Joplin, killing 158, injuring 1,150, and causing damage estimated at $2.8 billion. The damages in 2007 came primarily from two winter storms, one early in the year, one late. In both cases, hundreds of thousands were without power, and traffic accidents spiked.
Figure 2 shows deaths and injuries in Missouri from hazardous weather. Deaths are in blue and should be read on the left vertical axis. Injuries are in red and should be read on the right vertical axis. The large number of injuries and deaths in 2011 were primarily from the Joplin tornado. In 2006 and 2007, injuries spiked, but fatalities did not. The injuries mostly represented non-fatal auto accidents from winter ice storms. The fatalities in 1999 resulted from a tornado outbreak.
I understand the trends in both figures this way: once in a while, Missouri has been struck with catastrophic weather events. They cause lots of deaths and a lot of damage, at a whole different scale from years with no catastrophic weather event. In years with no such event, weather-related deaths in Missouri have been around 40 or fewer, and injuries have been roughly 400 or fewer. Damages in such years have been about $150 million or less. In years with catastrophic weather events, the totals can be much higher.
2017 was a year in which Missouri saw no weather disasters that caused such high damages, or killed or injured so many people. That does not mean that Missouri was unaffected, however. The state was included in several billion-dollar weather disasters, the most costly of which was probably the flood of April 25-May 7. That was a historic flood for many of the communities that were affected.
The Missouri data covers fewer years than the national data discussed in my previous post. It also covers all hazardous weather, in contrast to the national data, which covered billion dollar weather disasters only. In addition, for some reason the Missouri data for 2018 has not yet been posted.
While the national data shows a clear trend towards more big weather disasters, Missouri’s data does not. The Missouri data seems to reflect the kind of disaster and where it occurred. Tornadoes, if they hit developed areas, cause injuries, deaths, and lots of damage. Floods cause fewer injuries and deaths; damage can be significant, but it is limited to the floodplain of the river that flooded. Ice storms affect widespread areas; damages come mostly through loss of the electrical grid, which can cause widespread economic loss and from car crashes, which cause many injuries but fewer deaths.
Office of Climate, Water, and Weather Services, National Weather Service. 2016. Natural Hazard Statistics. Data for Missouri downloaded at various dates from https://www.nws.noaa.gov/om/hazstats.shtml#.
CPI inflation Calculator. 2019. 2017 CPI and Inflation Rate for the United States. Data downloaded 4/6/2019 from https://cpiinflationcalculator.com/2017-cpi-and-inflation-rate-for-the-united-states.
National Centers for Environmental Information. 2019. Billion-Dollar Weather and Climate Disasters: Table of Events. Viewed online 4/6/2019 at https://www.ncdc.noaa.gov/billions/events/US/1980-2018.
Descriptions of specific weather events, if they are large and significant, can be found on the websites of the Federal Emergency Management Administration, the Missouri State Emergency Management Agency, and local weather forecast offices. However, in my experience, the best descriptions are often on Wikipedia.
The number of natural disasters in the USA in 2018 declined from 2017, and the amount of damage they did also declined.
Since 1980, there have been 241 severe weather and/or climate events in the USA that have caused damages exceeding $1.6 trillion dollars. The most important of these are the “billion-dollar disasters,” events that caused damages in excess of $1 billion. Figure 1 shows the data. The columns represent the number of events, with each color representing a different type of event. The black line represents a moving 5-year average number of events. They gray line represents the cost of damages, in billions of dollars.
In 2018, there were 14 billion-dollar disasters. That is more than double the long-term average. The 4 years with the most billion dollar disasters have all occurred in the last 8 years, and the last 3 years have ranked #1 (tie), #3, and #4. The last 3 years have been significantly higher than any other years except 2011. The increase comes primarily from severe storms, a category that excludes hurricanes and tropical cyclones, flooding and winter storms. These are tornadoes, thunderstorms, hail, and similar kinds of storms.
The estimated CPI-adjusted losses in 2018 were $91 billion. That’s quite a chunk of change, but it much less than the costs in 2017 ($312.7 billion), 2005 ($220.8 billion), or 2012 ($128.6 billion). 2017 was a terrible year (see here): Hurricanes Harvey, Irma, and Maria struck in 2017, and not only was it far-and-away the most costly year, it also tied for the highest number of disasters. Hurricane Katrina struck in 2005, and Hurricane Sandy struck in 2012. Hurricane Katrina is still the single event that caused more damage than any other, followed by Hurricanes Harvey and Maria. Last year, the most costly natural disaster was the series of wildfires in California, especially the Camp Fire. The fires caused an estimated $24 billion in damage.
Looking at Figure 1, starting somewhere around 2005, the number of billion-dollar disasters starts to trend upward. The amount of damage does, too, though the variation from year-to-year is much greater. The National Centers for Environmental Information, which keeps this data, factors the Consumer Price Index into it, so the change is probably not due to inflation.
Three factors probably account for most of the increase. First, climate change has caused an increase in the amount of energy in the atmosphere, energy that is available to power more and bigger storms. I once calculated that the increased radiative forcing from climate change was equal to the energy output of 1.6 million nuclear power plants. (See here) That’s a lot of energy available to power storms. Second, climate change has caused an increase in droughts throughout the western United States. Even in years like this one, when there has been an abundance of winter snow, the warm temperatures cause the snow to melt earlier in the spring, and they dry out the land faster during the summer. The result is a tinder box, perfect conditions for huge wildfires. And finally, we keep putting ourselves in harm’s way. Development has increased along the Atlantic and Gulf Coasts, where it is in the path of any hurricane that comes ashore. Development has also increased along the fringes of forests, where it is vulnerable to wildfire. And even in the middle of the country, sprawl has increased the built-up area, making tornadoes more likely to grind over it, as opposed to farmland.
Missouri was in the region damaged by some of the big weather events of 2018, so the next post will look at how we fared here in the Show Me State.
The National Centers for Environmental Information Billion-Dollar Weather and Climate Disasters portal has 5 pages available, and I used them all for this post: Overview, Mapping, Time Series, Summary Stats, and Table of Events. Downloaded and viewed online 4/3/2019 at https://www.ncdc.noaa.gov/billions.
This week I returned to St. Louis after being out of town for some time. I was greeted by a chorus of moans and groans about the horrible winter. Such kvetching! Of course, it is easy for somebody who has been in warmer climes to pooh-pooh the harshness of the winter back home. So, I decided to look and see what the statistics say, and since that is the focus of this blog, to do a post on what I found. I’m going to look at the winter in St. Louis and in Kansas City. For weather statistics, winter begins December 1st and ends February 28th (or 29th in leap years). I’m writing on February 21, so the data for this winter extends only through 2/20/2019. One final note: for grammatical reasons, in what follows, “normal” means historical average (mean).
The weather service office in each location keeps its data in slightly different formats, so I will do one, then the other.
Winter 2018-2019 in St. Louis
First, let’s ask if it has been excessively cold in St. Louis this winter. According to the National Weather Service, the record low temperature in St. Louis is -22°F, which occurred 1/5/1884. The observed low this winter was -6°F, on 1/20/19: cold, but nowhere near the record. For the 82 days from 12/1/18 through 2/20/19, on 57 of the days the record cold for that date has been -5°F or colder. This year, the low temperature has been nothing like that.
Well, you may say, perhaps the low temperature has not set records, but on most days it has been lower than normal. Figure 1 shows the daily observed low temperature compared to the normal low temperature for that date. The blue line shows the observed temperature for 2018-19, and the red line shows the normal low temperature for that date. The chart suggests that for much of the winter, the low temperature in St. Louis has actually been above normal. There have been a few cold outbreaks, but not record cold. The observed low temperatures over the period this winter have averaged 27°F. The normal low temperatures over the period have averaged 26°F. So guess what? The average low temperature this year has been about a degree above normal.
Well, you may say, perhaps the low temperature has not been excessively low, but the daily high temperature has been colder than usual. It’s not the deep lows of the night that has gotten to us, it’s the fact that it hasn’t warmed during the day. Figure 2 shows the daily observed high temperatures for 2018-19 (blue line), and the normal high temperature for those dates (red line). The chart shows that during the cold outbreaks noted above, the high temperature has, indeed, been cooler than normal. But much of the winter has also had highs above normal. Over the period, the observed highs this winter have averaged 43°F, while over the period, normal highs averaged 42°F.
Winter 2018-19 in Kansas City
The National Weather Service Office in Kansas City does not seem to publish a data series that contains information similar to the one published by the office in St. Louis. I have used, instead, data from the Climate-at-a-Glance data portal. This data does not include daily values, only monthly averages. Plus, it only extends through the end of January. January 19 was the coldest day of this winter, however, so it is included. Data collection began in 1972-73.
Figure 3 shows the data, with the blue line representing the observed values, and the gray line representing the average. The average temperature in Kansas City this winter was 2.5°F above normal.
The month of February to date can be included by using heating degree days instead of temperatures. Heating degree days are a measure designed to indicate to what degree the interior of buildings will require heating. To calculate it, average a day’s high and low temperature, then subtract the result from 65. This is how many heating degree days there were on that day. Now, to measure a period of time, simply sum the heating degree days for each day in the period.
The problem here is that the data in the climate summaries, where the heating degree data is published, use a different period to determine normal than does the data above. The data above uses values that run from when record keeping started to the current date. The climate summaries use data from 1981-2010. It was around 1980 that the effects of climate change really kicked in. This results in different estimates of “normal,” with the climate summary referencing only recent (warmer) history, and the other data referencing much longer (cooler) periods of time.
That said, it is the only way I can think of to include February for Kansas City in this discussion, so this is what the data shows:
|Observed Heating Degree Days||Normal Heating Degree Days||Difference|
|February 1-20 2019||731||657||
Looked at this way, it would appear that December created about 11% fewer degree days than normal, but January and February (to date) have created about 2% and 11% more, respectively. If you sum the differences for the 3 months together, then the winter to date has created 17 more heating degree days than normal, a trivial amount: in terms of heating degree days, Kansas City’s winter in 2018-19 should be understood to be roughly normal.
Now, none of this speaks to snow or blizzards. I understand that the winter storm at the end of January was a terrible event. In a similar fashion, I was in Hawaii when the winter cyclone came ashore in early February. I saw whole fields of banana trees leveled, just snapped off mid-trunk. On the top of Mauna Kea, the wind was recorded at 190+ mph. None of that changes the fact, however, that Hawaii has a lovely climate, and it was a wonderful place to visit (although too crowded these days, I’d say). Same in St. Louis. This blog is more concerned with statistical trends than individual events, and none of the statistics suggest that this has been, on average, a freakishly cold winter.
I read that people who believe in climate change are being peppered with the question “If the Earth is warming so much, how come it is so cold?” Nobody ever said that climate change would banish all cold, and the predictions are for more intense storms, just like the ones referenced above. But the real answer seems to be that it isn’t actually so cold, at least not here in Missouri. The whole question is nothing but phony baloney, at least here in Missouri.
NOAA National Centers for Environmental information, Climate at a Glance: U.S. Time Series, retrieved on February 21, 2018 from http://www.ncdc.noaa.gov/cag.
NOAA, National Weather Service, Kansas City/Pleasant Hill Forecast Office. 2/21/2019. Daily Climate Report. For this post, I used reports for 12/31/2018, 1/31/2019, and 2/20/2019. Viewed online 2/21/2019 https://w2.weather.gov/climate/index.php?wfo=eax.
NOAA, National Weather Service, St. Louis Forecast Office. 2/21/2019. Climate Graphs. Data retrieved on 2/21/2019 from https://www.weather.gov/lsx/cliplot.
2018 was the 3rd wettest year on record across the contiguous USA.
So says data from Climate-At-A-Glance, the data portal operated by the National Oceanographic and Atmospheric Administration (NOAA). Figure 1 shows the data, with the green line representing actual yearly precipitation, and the blue line representing the trend across time. The left vertical scale shows inches of precipitation, while the right shows millimeters of precipitation. In 2018, the average precipitation across the contiguous USA was 34.62 inches, which was the 3rd highest amount in the record. Over time, precipitation seems to be increasing at about 0.18 inches per decade. The trend towards more precipitation is present in the Eastern Climate Region (+0.30 inches per decade), the Southern Climate Region (+0.24 inches per decade), and the Central Climate Region (+0.23 inches per decade). It is almost absent in the Western Climate Region, however (+0.02 inches per decade). In fact, 2018 was a below-average precipitation year in the West. (Except where noted, data is from the Climate-at-a-Glance data portal.)
(Click on figure for larger view.)
In Missouri, 2018 was the 41st wettest year on record, with 43.04 inches of precipitation. (Figure 2) This puts the year 2.54 inches above the long-term average. As expected, the variation from year-to-year is much larger than the change in precipitation over time, but since 1895 Missouri has trended towards about 0.24 inches more precipitation per decade.
Unlike 2016 and 2017, 2018 did not bring epic flooding to Missouri. Perhaps the most notable thing about Missouri precipitation in 2018 were two almost out of season snow events – one over the Easter weekend in April, and one in mid-November. The latter heralded what has been a very snowy winter so far in 2019 for Missouri and much of the Midwest.
The Northern Rockies and Plains are where most of the water that flows into the Missouri River originates, and the Missouri River provides water to more Missourians than any other source. This region saw 24.83 inches of precipitation in 2017, some 5.82 inches above average. (Figure 3) As expected, the variation between years is much larger than the change over time, but here, too, precipitation has been increasing, though the change has only been +0.07 inches per decade.
What to watch for in Missouri, then, does not appear to be a decrease in average yearly precipitation, but two other issues. First, demand for water has been increasing. Will it grow to outstrip the supply? Second, this winter notwithstanding, climate change is causing precipitation that once fell as snow to fall as rain. This changes the timing of when the Missouri River receives the runoff. Will that affect the ability of the river to supply water to meet the various demands? So far, these answers are not known. (For a more extended discussion, see here.)
The water situation in California is more serious than it is in the Northern Rockies and Plains, Missouri, or contiguous USA. California has a monsoonal precipitation pattern, and it has regions that receive a great deal of precipitation, while other regions receive little, if any. Consequently, the state relies on snowfall during the winter, which runs off during the spring and early summer, and is collected into reservoirs. This water is then distributed around the state. Thus, the amount of water contained in the snowpack on April 1, which is when it historically started melting in earnest, has been seen to be crucial to California’s water status.
After a big water year in 2017, 2018 returned to below-average precipitation. It was the 34th driest year on record, with precipitation 4.54 inches below average. (Figure 4)
As I reported previously, the California snow season started slowly this winter. It has been catching up, and is now nearly average for this date. The snowpack is above average in the Colorado River Basin above Lake Powell, the other major source for California’s water. The snowpack is 110% of the average for this date. (National Resource Conservation Service, 2/14/2018).
California Data Exchange Center, Department of Water Resources. Current Year Regional Snow Sensor Water Content Chart (PDF). Downloaded 1/22/2018 from https://cdec.water.ca.gov/water_cond.html.
Mammoth Mountain Ski Area. 2018. Snow Conditions and Weather: Snow History. Viewed online 1/15/2018 at NOAA National Centers for Environmental information, Climate at a Glance: U.S. Time Series, published January 2018, retrieved on January 15, 2018 from http://www.ncdc.noaa.gov/cag.
Natural Resource Conservation Service, U.S. Department of Agriculture. Upper Colorado River Basin SNOTEL Snowpack Update Report. Viewed online 1/28/2018 at https://wcc.sc.egov.usda.gov/reports/UpdateReport.html?textReport.
NOAA National Centers for Environmental information, Climate at a Glance: U.S. Time Series, published January 2018, retrieved on January 15, 2018 from http://www.ncdc.noaa.gov/cag.
2018 was the 4th warmest year on record globally, and the 14th warmest for the contiguous USA.
Figure 1 shows the average annual temperature for the Earth for each year from 1880-2018. The chart shows the temperature as an anomaly. That means that they calculated the mean annual temperature for the whole series, and then presented the data as a deviation from that mean. Degrees Celsius are on the left vertical axis, and degrees Fahrenhiet are on the right. Because the earth contains very hot regions near the equator and very cold polar regions, the actual mean temperature has relatively little meaning, and Climate-at-a Glance does not include it in their chart. (All data is from NOAA, Climate at a Glance.) 2016 was the highest on record, and the 4 highest readings have all occurred within the last 4 years. You can see that the Earth appears to have been in a cooling trend until around 1910, then a warming trend until mid-Century, then a cooling period until the late 1960s or early 1970s, and then a warming period since 1970. Over the whole series, the warming trend has been 0.07°C per decade, which equals 0.13°F per decade. Since 1970, however, the warming has accelerated to 0.17°C per decade (0.30°F).
(Click on chart for larger view.)
Figure 2 shows the average yearly temperature for the contiguous United States from 1895 to 2018. In this chart and those that follow, the vertical axes are reversed, with °F on the left vertical axis, and °C on the right. The purple line shows the data, and the blue line shows the trend. 2018 was the 14th highest in the record at 54.58°F. The 4 highest readings have all come within the last decade. Over the whole series, the average temperature has increased 0.15°F per decade. Since 1970, however, the rate has increased substantially.
Figure 3 shows the average temperature across Missouri for 2018. Across the state, it was the 35th warmest year on record, with an average temperature of 55.2°F. In Missouri, the warming trend from 1930-1950 was more marked than it was nationally; across the whole time period, the trend has been for a 0.1°F increase in temperature each decade. As was the case nationally, since 1970 the increase has accelerated.
Because conditions in the Northern Rockies and Plains affect how much water flows into the Missouri River, which provides more of Missouri’s water supply than any other source, I have also tracked climate statistics for that region. Figure 4 shows the data. Last year was slightly above average for this region. This region has been warming at a rate of 0.2°F per decade over the whole period, and, since 1970, the rate has accelerated substantially.
Because I have been concerned about the water supply in California, I also track the climate statistics for that state. Figure 5 shows the data. Last year was the 3rd warmest year in the record, with an average temperature of 60.2°F. California has been warming at a rate of 0.2°F each decade. Since 1970 the rate of increase has accelerated substantially.
In all 4 locations the average yearly temperature seems to have increased significantly for several decades, then paused during mid-Century, and then resumed climbing, but at an accelerated rate. There seems to be little doubt that across the country it is warmer than it was. In Missouri, the average yearly temperature has been increasing, but at a rate that is somewhat less than in the other locations I looked at.
NOAA National Centers for Environmental Information, Climate at a Glance. Retrieved on February 1, 2019, from http://www.ncdc.noaa.gov/cag.
Followers of this blog know that I usually report on the snowpack conditions in California once or twice during the winter. I do this because I have family living in California, and because California constitutes an incredibly large percentage of this nation’s economy, and because it provides an incredibly large percentage of the fruits and vegetables we eat.
California depends on its snowpack for about 30% of its water supply. Climate change will reduce the California snowpack by as much as 40%, it is projected, putting the state’s water supply at risk. The snowpack is projected to decline mostly because the increased temperature will cause precipitation to fall as rain instead of snow, and because it will cause increased melting during the winter months.
The snow year got off to a slow start in California this year. The January 24 measurements showed the snowpack at 56-63% of average for that date, depending on which hydrologic region was measured. (See Figure 1.)
(Click on figure for larger view.)
The snowpack is below average despite the fact that California has had significant precipitation. November and December were slow, but at Mammoth Mountain, a ski resort located in the Sierra Nevadas, they have had 93 inches of snow this January. That puts the total for the winter within 2 inches of average for this date, and the month still has 4 days to go as I write.( See Figure 2.)
Because California receives most of its water during the winter, but needs it most during the summer, the state operates many reservoirs. The water content of the most important are shown in Figure 3. The Lake Shasta, Trinity, and Oroville Reservoirs are the three largest, and thus, the most important. In general, the reservoirs appear to be close to normal levels for this time of year. The one exception is the Oroville Reservoir, which is at 39% of capacity. This reservoir was severely damaged in 2017, when storms caused emergency releases, which eroded away major portions of the dam. Repairs were completed last fall, but the dam has yet to refill. Whether it will ever refill given California’s reduction in snowpack is an interesting question to which I don’t know the answer. Oroville is the major water source for the California State Water Project, and, thus, it is important.
The Colorado River is another important source of water for California, and Lake Mead is the principal reservoir at which its level is measured. It is at 1085.21 ft. above sea level, or 40% of its capacity. For this date the average is 1159 ft. above sea level, and the historical low was 1083.46 ft. above sea level, reached in 2016. Lake Mead can be recharged with water from Lake Powell, and that reservoir is also at 40% of capacity. It is usual for these reservoirs to be low during the late fall, and then recharge during the winter. However, Lake Mead continues to flirt with historical lows and with the level at which mandatory water restrictions go into effect.
The bottom line here is that California’s water supply continues to be below historical levels, though not quite as low as during the terrible drought a few years ago. As of right now, signs do not point to a severe water crisis this year, but the state continues to walk a rather fine line. Should drought recur, a severe crisis is likely to occur..
Alexander, Kurtis. 2018. “Oroville Dam Fixed and Ready to Go, Officials Say – But at a Big Price.” San Francisco Chronicle. 10/31/2018.
California Data Exchange Center. California Snowpack Water Content, January 24, 2019, Percent of April 1 Level. Downloaded 1.27.2019 from https://cdec.water.ca.gov/reportapp/javareports?name=PLOT_SWC.pdf.
California Department of Water Resources. Current Reservoir Conditions. Downloaded 1/27/2019 from http://cdec.water.ca.gov/reportapp/javareports?name=rescond.pdf.
Lake Mead Water Database. Viewed online 1/27/2019 at http://lakemead.water-data.com.
Mammoth Mountain Ski Resort. Snow & Weather Report. Viewed online 1/27/2019 at https://www.mammothmountain.com/winter/mountain-information/mountain-information.
The last post reported on 33 climate trends discussed in “State of the Climate 2017,” a report published in the Bulletin of the American Meteorological Society. This post characterizes the 2017 climate in the United States. Be sure to catch that this is for 2017, not 2018, the year just ended. In what follows, “CONUS” means the continental United States. All anomalies compare to the 1981-2010 average.
The annual average temperature in 2017 for the contiguous United States (CONUS) was 12.5°C or 1.0°C above the 1981–2010 average—its third warmest year since records began in 1895, 0.2°C cooler than 2016 and 0.4°C cooler than 2012. Figure 1 shows a map of 2017 temperature anomaly across the United States. Every state was warmer than average except for Washington. Most of Missouri was 1.0-1.5°C warmer than average (1.8-2.7°F). A few areas were even warmer, but the map isn’t sufficiently detailed to determine for sure which areas they were.
Averaged nationally, precipitation was 104% of average, making 2017 the 20th wettest year in the record. The pattern was variable, however, as shown in Figure 2. In particular, winter precipitation was higher than average, with Nevada and Wyoming each having the wettest winters on record. The California mountains were wetter than average (I reported on the large snowpack in the winter of 2017 in previous posts). So was eastern Colorado-New Mexico. On the other hand, much of the Southwest and the northern Plain States were in drought. It was also dry along the Mississippi River from the Missouri Bootheel into central Iowa.
There were 16 weather-related events in 2017 which resulted in damage of more than $1 billion. That tied with 2011 for the highest number of billion-dollar disasters. The total damages they caused was $306 billion, a new record. Figure 3 shows a map of where they were roughly located. There were three major hurricanes across the southern United States, plus catastrophic fires in California and other western states. Missouri and Arkansas were affected by flooding in late April-early May 2017.
Missouri had 13 fatalities and 155 injuries from weather-related disasters in 2017, and a total of $156.20 million in damages. There have been many years when the Missouri’s weather-related damage has been below $100 million, but in 2011 it was over $3.4 billion.
Blunden, J., D. S. Arndt, and G. Hartfield , Eds., 2018: State of the Climate in 2017. Bull. Amer. Meteor. Soc., 99 (8), Si–S332, doi:10.1175/2018BAMSStateoftheClimate.1. Downloaded 12/15/18 from https://www.ametsoc.org/index.cfm/ams/publications/bulletin-of-the-american-meteorological-society-bams/state-of-the-climate.
Office of Climate, Water, and Weather Services, National Weather Service. 2016. Natural Hazard Statistics. Data downloaded 2/10/16 from http://www.nws.noaa.gov/om/hazstats.shtml#.
The IPCC report Global Warming of 1.5°C, and the Fourth National Climate Assessment were not the only climate related reports to be published in the second half of 2018. The American Meteorological Society also published its annual report on the climate, State of the Climate in 2017. Rather than a document assessing the effects of climate change, this documents presents a comprehensive picture of what the climate was like in 2017.
Figure 1 shows in a single graphic the major climate variables that are discussed in the report. I will discuss each very briefly in order, going down each column before moving to the next column. I’ve made the chart to open in a separate browser tab, and you should be able to refer back and forth between my comments and the charts. In the charts, some of the data is shown as anomalies rather than as raw values, and in those cases, the reference period is given in the chart.
Charts (a) and (b) show the level of polar ozone, the 1st in March, the 2nd in October. This ozone is high-altitude ozone, and it is essential for blocking ultraviolet rays, too much of which are harmful. These charts concern the famous ozone hole of the 1980s. In general, the level in March bottomed in the 1980s, partially rebounded, but has again been trending downward. In October, the level bottomed in the 1980s and has been largely moving sideways since then.
Chart (c) shows the average surface temperature in the arctic. It has obviously been warming, some 3°C since the 1950s.
Chart (d) shows the average surface temperature of the whole earth. It has been warming, but not as much as the arctic. The recent several years show a steep spike upward.
Chart (e) shows temperature in the lower troposphere. This is the lowest layer of the earth’s atmosphere, and it is where almost all life occurs, as well as almost all weather. It has been warming, and you can see the same spike in recent years.
Chart (f) shows the temperature in the lower stratosphere. This is the next higher layer of the atmosphere. Near the equator it begins some 66,000 feet up, while at the poles it is lower, some 23,000 feet up. The temperature here has been cooling. I have seen some arguments that the cooling in the stratosphere compensates for the heat in the troposphere. This is like saying that cool weather in San Francisco means people can’t be dying from a heat wave in Chicago. Sorry, but it doesn’t mean any such thing.
Chart (g) plots the number of warm days (solid line) and cool nights (dotted line). Warm days have been increasing, and cool nights have been decreasing.
Chart (h) shows the area covered by arctic sea ice. The maximum is the solid line, the minimum the dotted line. Both have been decreasing, the minimum more severely.
Chart (i) shows antarctic sea ice. The variability between years has grown significantly, and the general trend appears to be increasing.
Chart (j) shows a measure of the amount of water locked-up as ice in all of the world’s glaciers. It has been declining at a significant rate. It will have implications for anyone and anything dependent on glaciers and/or glacial melt for water.
Chart (l) shows the amount of water vapor in the lower stratosphere. It is quite variable, but the trend appears to be toward slightly higher amounts of water vapor.
Chart (m) shows the level of cloudiness across the planet. There are several data sets. The trend appears to be towards convergence, with a slightly downward slope for at least some of the data sets.
Chart (n) shows the amount of water vapor in the entire atmosphere, top to bottom, over land. It has been increasing.
Chart (o) shows the amount of water vapor in the entire atmosphere, top to bottom, over the ocean. It, too, has been increasing.
Chart (p) shows the specific humidity in the upper troposphere. It appears to be declining slightly.
Chart (q) shows the specific humidity over land. It has been increasing. Specific humidity is not the humidity statistic we are used to, that is relative humidity (see below). The specific humidity is a measure of the mass of water vapor in an air sample compared to the mass of the other air in the sample.
Chart (r) shows the specific humidity over the ocean. It, too has been increasing.
Chart (s) shows relative humidity over the land. It has been decreasing. Relative humidity is a measure of the amount of water a sample of air is holding, compared to the maximum it could hold. Air’s ability to hold water increases with temperature, so it is possible for relative humidity to decrease, even while specific humidity increases, if the temperature rises.
Chart (t) Shows relative humidity over the ocean. It has been mostly moving sideways, but perhaps decreasing slightly.
Chart (u) shows the amount of precipitation over land. It moved mostly sideways until the 1980s, at which point it appears to have increased. The recent years have seen a significant spike upward.
Chart (v) shows the Southern Oscillation Index. This is a measure comparing air pressure in the western and eastern South Pacific. It tracks the El Niño phenomenon, with negative values indicating an El Niño, and positive values indicating a La Niña. I see no obvious trend in the data.
Chart shows the amount of heat the ocean is holding. The amount of heat is not the same as the temperature: a 100° pot of water holds much more heat than a 100° pot of air, though both are the same size. The heat content of the oceans has bee increasing.
Chart (x) shows a measure of sea level. It has been rising. The scale is in millimeters, so the chart shows about a 6-inch rise.
Chart (y) shows the tropospheric ozone level in the tropics. It has been increasing. This is not the same as arctic ozone levels, which are measured in the stratosphere, where they help to block ultraviolet light from striking the earth. This is ground level ozone, a harmful pollutant. It is the ozone I track when I report on the Air Quality Index.
Chart (z) shows a measure of the speed of the wind in the troposphere. It has been increasing slightly.
Chart (aa) shows a measure of the speed of the wind over land. It has been decreasing.
Chart (ab) shows a measure of the speed of the wind over the ocean. It has been increasing.
Chart (ac) shows the amount of biomass being burned each year. It has been deecreasing.
Chart (ad) shows a measure of soil moisture across the earth. It has been moving sideways, a surprise to me, as I would have expected increased temperatures to dry the soil.
Chart (ae) shows terrestrial water storage. Though the data series is short, it appears to be declining. This variable concerns fresh water, and reflects ice sheets, glaciers, and lakes. Its decline is a matter of concern for all people, animals, and plants that depend on stored water.
Chart (af) shows global FAPAR. FAPAR is the amount of solar radiation available for absorption by plants during photosynthesis that actually gets absorbed. Though the data series is short, it was declining, but in recent years it has increased.
Chart (ag) shows the albedo of the land surface. Though the data series is short, it appears to be decreasing. Albedo is the reflectivity of the earth. High albedo means most of the light is reflected. Low albedo means most of the light is absorbed, causing the surface to warm. Black paint has a low albedo, white paint has a high albedo.
Blunden, J., D. S. Arndt, and G. Hartfield , Eds., 2018: State of the Climate in 2017. Bull. Amer. Meteor. Soc., 99 (8), Si–S332, doi:10.1175/2018BAMSStateoftheClimate.1.
In my previous post I reported on the 4th National Climate Assessment, Volume 1. That volume deals with the natural science findings. Volume 2 deals with how climate change is projected to impact the United States, and with mitigation and adaptation. Unlike reports by the IPCC, the National Climate Assessment focuses on the United States. As with all of the IPCC and NCA reports, the 4th National Climate Assessment is far too large and substantive to fully summarize in a brief blog post. What follows is a selection of a few of the findings.
Figure 1 projects U.S. economic damage from climate change in 2090 under the low emission scenario (RCP 4.5) and the high emission scenario (8.5). The intangibles that make life worth living, what we call quality of life, are not easy to put a dollar value on, and this chart does not address them.
In the chart, the columns represent various sectors of the economy. The blue portion represents the damages under RCP 4.5, while the whole column represents the damages under RCP 8.5 Thus, the orange portion represents the difference between the two. The largest economic damages come from 3 sectors: Labor, Extreme Temperature Mortality, and Coastal Property. In addition, in most of the sectors, the damages under RCP 8.5 are more than twice the damages under RCP 4.5.
(Click on chart for larger view.)
Figure 2 shows projected carbon emissions, temperature change, and U.S. economic damage from climate change under various emission scenarios. The left side of the chart shows that observed carbon emissions are following the high scenario, and there is no evidence that they are suddenly about to revert to the low emission scenario. The right side shows that the high emissions scenarios lead to larger increases in temperature and correspondingly larger damages to the U.S. economy.
The Overview of the report summarizes some of the specific risks the USA faces from climate change. It is quite a list, but it puts real form to projections that often are statistical or vague. To paraphrase:
- Rising sea levels, higher storm surges, and increased high tide flooding will impact coastal infrastructure, damaging electrical and natural gas supply lines, and causing problems with access to goods from overseas. About $1 trillion in coastal property will be impacted. Coastal cities will experience daily flooding.
- Wildfire in the West will increase, damaging ranches and rangelands; increasingly it will damage property in cities and take human lives. Energy transmission and production will be damaged.
- Thawing permafrost in Alaska will damage roads and buildings, including oil and gas operations. This will be partially offset by a longer ice-free season.
- Yields of major U.S. crops (corn, soybeans, wheat, rice, sorghum, and cotton) are expected to decline due to higher temperatures and changes in water availability, disease, and pests. These will percolate through the economy, resulting in less availability of agricultural products, and increased prices.
- Human productivity equal to almost 2 billion labor hours is expected to be lost annually due to extreme temperatures, resulting in an estimated $160 billion in lost wages. States in the Southeast and Southern Great Plains are expected to be impacted hardest.
- Fresh water quality and quantity are threatened by rising temperatures, reduced mountain snowpack, sea level rise, saltwater intrusion, drought, flooding, and algal blooms. In some places, the availability of safe and dependable water will be threatened.
- Hydropower supplies are expected to decrease as a result of changes in mountain snowpack.
- Drought will impact oil and gas drilling and refining, all of which use water intensely.
- Tourism will be impacted by changes in snowpack and wildfire. Communities dependent on tourism will be impacted.
- Air quality will be impacted by higher temperature, higher humidity, and increased smoke from wildfires. Reduced air quality is expected to adversely impact human health.
- Species already are, and will continue, to shift their growing ranges and growing seasons in response to climate change. Mismatches between species and the availability of the resources they need to survive are expected to occur. Extinctions and transformative impacts on some ecosystems are expected.
- Heavy-to-severe coral bleaching is expected to onset across most of the Hawaiian Islands, Guam, and American Samoa by the late 2030s. This will impact fisheries yields and tourism. (Paradise Lost – where’s John Milton when you need him?)
- Rising temperatures are expected to increase illness and death (especially among older adults, pregnant women, and children), partially (but only partially) offset by a reduction in cold-weather deaths.
- Rising temperatures are expected to reduce electricity generation capacity while simultaneously increasing demand for it and its costs. Power outages and blackouts are expected to increase, and household budgets will be strained. Marginal populations and the economically disadvantaged will be impacted even more severely.
- Rising temperatures are expected to threaten human health by promoting the growth of foodborne and waterborne pathogens. Diseases like Lyme disease, West Nile, chikungunya, dengue, and Zika are expected to spread and become more common.
- Every armed service (but especially the Navy, Marines, and Coast Guard), has many bases located in coastal regions. They are expected to be threatened by climate change, and in some cases made unusable. Many of the transportation routes between these bases are similarly located in coastal regions and may become unusable. Thus, climate change is expected to become a significant challenge to the national security apparatus of this country.
- All of the above expected effects of climate change are expected to cause increased stress, leading to increased rates of stress-related diseases, including mental illness.
In terms of mitigation and adaptation, the report states that power sector emissions were 25% below 2005 levels in 2016, the largest emissions reduction for a sector of the American economy over this time. This decline was in large part due to increases in natural gas and renewable energy generation, as well as enhanced energy efficiency standards and programs. Under continued business-as-usual projections, U.S. carbon dioxide and other greenhouse gas emissions show flat or declining trajectories over the next decade with a central estimate of about 15% to 20% reduction below 2005 levels by 2025. (While it is great that U.S. emission have declined, worldwide emissions continue to increase.)
The report notes that efforts to adapt to climate change and to mitigate its effects have increased across the country, but are not even close to adequate. Adaptation is an issue for local planning, as it must take into account both the specific damages anticipated in the locale and many local characteristics such as topography, local water supply, etc. Mitigation follows pathways that are more common across different locations. Figure 3 shows is a map showing the number of GHG mitigation policies in place in each state, by type of policy.
The fact that Missouri has mitigation policies in place does not necessarily mean that GHG emissions have substantially decreased. I last reported on state GHG emissions using data from 2013. At that time, Missouri’s GHG emissions from fossil fuel were still above their level in 2000. Figure 4 republishes a chart from that post showing GHG emissions over time from Missouri and some neighboring states.
The document contains a great deal more than I can report in this post. Those who are interested can follow the link in the Sources section below to the original document. The whole document is available as a single download, or you can download individual chapters.
USGCRP, 2018: Impacts, Risks, and Adaptation in the United States: Fourth National Climate Assessment, Volume II [Reidmiller, D.R., C.W. Avery, D.R. Easterling, K.E. Kunkel, K.L.M. Lewis, T.K. Maycock, and B.C. Stewart (eds.)]. U.S. Global Change Research Program, Washington, DC, USA, 1515 pp. doi: 10.7930/NCA4.2018. Downloaded 12/5/2018 from https://nca2018.globalchange.gov.