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And Now, Three Consecutive Record Warm Years


2016 was even hotter than 2015!


Figure 1. Source: NASA Goddard Institute for Space Studies.

Figure 1. Graph of Global Average Temperature. Source: NASA Goddard Institute for Space Studies.

Data released by NASA reveals that the average global temperature in 2016 was even hotter than in 2015, and by a substantial margin. The data is shown in Figure 1. 2014 was a record, then 2015 was a new record, and now 2016 is a new record: this marks the first time in the data maintained by NASA that the world has set three consecutive records. The data indicates that the temperature was at record highs during every month of the year.

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In 2016, global surface temperature was 0.12°C warmer than in 2015. In 2016, the temperature was .99°C warmer than during the reference period, from 1951-1980, and about 2.0°C warmer than the late 19th Century.

Figure 2. Map of Annual Temperature Anomaly, 2016. Source: NASA Goddard Institute for Space Studies.

Figure 2. Map of Annual Temperature Anomaly, 2016. Source: NASA Goddard Institute for Space Studies.

Figure 2 shows a map of global temperature anomalies. In terms of heavily populated areas, portions of the United States, Canada, Russia, and Brazil were especially warm. But in truth, the real pattern here is that the farther north you go, the more severe the warming.

The NASA report is based on satellite measurements of temperature over both land and sea. In general, satellite measurement is quite accurate. The report does not address the many other climate variables that are addressed in the State of the Climate report published by the American Meteorological Association. That report, however, takes many months to prepare. In the previous post, I reported on the most recent State of the Climate report, which concerns 2015, not 2016.

Sources:

NASA Goddard Institute for Space Studies. GISS Surface Temperature Analysis: Global Maps from GHCN v3 Data. Downloaded 1/18/2017 from https://data.giss.nasa.gov/gistemp/maps.

NASA Goddard Institute for Space Studies. GISS Surface Temperature Analysis: Analysis Graphs and Plots. Downloaded 1/19/2017 from https://data.giss.nasa.gov/gistemp/graphs.

The Temperature Keeps on Rising


2015 was the hottest year worldwide since record-keeping began. The previous hottest year was 2014.


Figure 1. Map of Average Temperature Anomalies, 2015. Source: Blunden and Arndt 2016.

Figure 1. Map of Average Temperature Anomalies, 2015. Source: Blunden and Arndt 2016.

2015 was the hottest year worldwide since record-keeping began in 1900, according to the State of the Climate in 2015 report by the American Meteorological Society. This is a report that came out in August, 2016, and I’m just catching up to it now. I will summarize a few of the many findings.

Figure 1 shows how much 2015 temperatures around the globe varied from the average temperature for that location (reference years 1981-2010). The yellow and red areas were warmer than average, the blue areas cooler. White represents areas for which there is not enough data to make a characterization. You can see that the map has many more yellow and red areas than blue. The previous record was set the year before, and 2015 was 0.13 – 0.18°C warmer. That is a large jump.

Figure 2. Global Temperature Trends. Source: Blunden and Arndt 2016.

Figure 2. Global Temperature Trends. Source: Blunden and Arndt 2016.

Figure 2 shows the trend in global temperatures from 1880 to 2015. The top two graphs represent different analyses of temperature over both land and ocean, the middle two graphs represent different analyses of temperature over land only, and the bottom two represent different analyses of temperature over ocean only. An inspection of the charts shows considerable year-to-year variation, but all of them show a continuing trend towards warmer temperature. Climate change deniers have been making much of a multi-year pause in the increase in surface temperature at the beginning of the 21st Century. Climate scientist have pointed out that this pause was illusory, as it represented a period during which heat was being shunted from the surface to the depths of the ocean faster than usual, not an actual pause in warming. It now seems that surface temperature has resumed its upward march: 2014 and 2015 show up on the charts as a quite large spike upward.

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Figure 3. Warm Day Anomalies, 2015. Source: Blunden and Arndt 2016.

Figure 3. Warm Day Anomalies, 2015. Source: Blunden and Arndt 2016.

One of the ways global warming has its effect is by increasing the number of warm days, defined as “number of days above the seasonal 90th percentile of daily maximum temperatures over the 1961-1990 base period.” (Blunden and Arndt, 2016, p. S19) Figure 3 shows the map. You can see that there are large blobs of red over Australia, Southeast Asia, China, Siberia, Europe, South Africa, eastern Greenland, and most of North America. That means that all these regions had an above average number of warm days, in most cases by a lot (+30 days or more).

Extreme days are important. In the summer a “warm” day might indicate that it was extremely hot, which is hazardous. During the winter, on the other hand, it might indicate that the day was above freezing.

The map of warm days for 2015 looks quite similar to the map for 2014 (here): many of the same areas were involved.

There is a great deal more information in the report that is beyond the scope of this blog. For those interested in meteorology and climatology, it would make interesting reading.

I’m writing this post in early January, 2017. United States climate data for 2016 should post-up on Climate at a Glance during January, so hopefully by the time this post goes live, I’ll be able to follow up with information about the USA and Missouri.

Source:

Blunden, Jessica and Derek Arndt (eds.) 2016. “State of the Climate in 2015.” Bulletin of the American Meteorological Society, 97 (8) Special Supplement. Downloaded 1/8/17 from https://www.ametsoc.org/ams/index.cfm/publications/bulletin-of-the-american-meteorological-society-bams/state-of-the-climate.

Hot First Half of 2016

Figure 1. Source: Centers for Environmental Information.

Figure 1. Source: Centers for Environmental Information.

The first 6 months of 2016 were the third hottest ever across the United States, according to data from the Centers for Environmental Information (See Figure 1). The average temperature was 50.75°F, which is 3.22°F above the average for the 20th Century.

(Click on chart for larger view.)

 

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Figure 2. Source: Centers for Environmental Information.

Figure 2. Source: Centers for Environmental Information.

During the same period, precipitation across the country was slightly above average, at 15.58 inches (Figure 2), which is 0.27 inches above the average for the 20th Century.

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Figure 3. Source: Centers for Environmental Information.

Figure 3. Source: Centers for Environmental Information.

Combined, the temperature and precipitation resulted in moister than average soil conditions as measured by the Palmer Drought Severity Index. For the first half of 2016, the PDSI was 2.61, which is 2.23 above the average for the 20th Century.

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MO Temp 2016 Jan-Jun

Figure 4. Source: Centers for Environmental Information.

In Missouri, the temperature for January-June was the 7th highest on record, at 52.9°F. It was 3.1°F hotter than the average for the 20th Century.

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Figure 5. Source: Centers for Environmental Information.

Figure 5. Source: Centers for Environmental Information.

Precipitation in Missouri was low, however, at 16.86 inches, a shortfall of 3.70 inches compared to the average for the 20th Century. For those of us here in St. Louis, this may come as a bit of a surprise, as our local rain has been the 5th highest on record for the first half of the year.

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Figure 6. Source: Centers for Environmental Information.

Figure 6. Source: Centers for Environmental Information.

The PDSI in Missouri during January-June was 2.90, which is 2.67 above the average for the 20th Century.

I’m not sure why significantly above average temperature and below average precipitation should result in above average soil moisture. Generally, high temperature and low precipitation is thought to resulting in dry soil conditions. If anybody knows, please write a comment and let us all know.

I also follow the Palmer Hydrologic Drought Index for the Northern Rockies and Plains. The PHDI measures long-term trends in soil moisture, which are thought to affect river and reservoir levels. I follow this region because it is the watershed for the Missouri River, the most important source for drinking water in Missouri. For the first half of 2016, the PHDI in the Northern Rockies and Plains was 1.29, which ranks exactly in the middle of the years measured (since 1895).

In California, which I have also been following, the temperature for January-June was 57.1°F, the 3rd highest on record, 3.8°F above average. Precipitation has been 15.04 inches, which is 0.86 inches above average. The precipitation came primarily in the first 3 months of the year, and the last 3 have been slightly drier than average. Since the bulk of California’s water comes during the winter, it is good that those months were the above average ones. The PDSI is -2.22, which is 2.20 below average. The soil in California is still very dry.

Source:

Centers for Environmental Information. Climate at a Glance. Data accessed and downloaded 7/25/2016 at http://www.ncdc.noaa.gov/cag/time-series/us.

Summary of Climate Projections for St. Louis

In the last 3 posts, I’ve reported on three studies making climate projections for St. Louis or Columbia by Hayhoe, VanDorn, Naik, and Wuebbles (2009), by Posey (2014), and by Anderson, Gooden, Guinan, Knapp, McManus, and Shulski (2015).

Because there is uncertainty associated with all climate projections, and because that uncertainty is magnified when making projections at the local level, there is value in having multiple projections from multiple studies. It can help to reduce some sources of uncertainty, though it cannot eliminate the uncertainty, by any means.

However, it is not always common for different climate studies to replicate methods precisely. Differences in method affect the resulting projections, and it means that the projections from these three studies should only be compared with great care. Some of the methodological differences include studying slightly different regions, making projections for different time periods, and using different climate scenarios.

Perhaps a bit of an amplification on the climate scenarios is in order here. It is thought that changes in climate will be sensitive to how humans respond to climate change, especially how we change or don’t change our greenhouse gas emissions. Climate change is already occurring, and most climate scientists agree that it is going to cause negative effects, no matter what we do – it is already too late to prevent them entirely. If GHG emissions rise from current levels, however, climate change is expected to be more severe. If we significantly curtail GHG emissions, climate change is expected to be less severe. If we follow a middle path, climate change is expected to follow a middle path.

Both climate change itself and mitigating climate change are expected to have implications for a variety of socio-economic factors – economic growth, poverty, social justice, migration, etc. To try to take these factors into account, climate scientists developed what they called scenarios. Each scenario outlined a path the world could take that included GHG emissions and a variety of socio-economic factors.

Figure 1: Total cumulative carbon dioxide emissions under different climate scenarios. Source: IPCC 2000.

Figure 1: Total cumulative carbon dioxide emissions under differing climate scenarios. Source: IPCC 2000.

Three scenarios, the A1fi, the A2, and the B1, were used to make climate projections by these authors. They are shown on Figure 1. This chart is now 16 years old, but it shows the original conceptualization. The lines depict the expected cumulative amount of carbon dioxide emissions projected to occur under various scenarios. The A1fi scenario was projected to result in the highest emissions in the group shown, though by no means the highest possible emissions. The A2 scenario was projected to have somewhat lower emissions, and the B1 lower still, though by no means the lowest possible.

(Click on chart or table for larger view.)

You don’t have to look at this chart for very long before you understand that, other things being equal, climate projections using the A1fi Scenario might be expected to result in larger changes in climate, while those using the A2 scenario might result in smaller changes, and those using the B1 scenario might result in smaller changes yet.

Table 1 summarizes some of the projections from the three studies I’ve been reporting on.

Summary Table

You can’t make direct comparisons between the studies, but some trends can be seen:

  • All three studies project temperature to increase by mid-century. Those that made projections for the end of the century projected it to increase even more by then.
  • The two studies that made projections for mid-century for each of two scenarios found that temperature would increase more under a higher emission scenario than a lower emission scenario.
  • The two studies that made projections related to heat waves agreed that the number of very hot days would increase.
  • All three studies projected that average annual precipitation would increase by a small amount.
  • Four out of five projections were for decreased precipitation in summer, with an increase during other seasons of the year.
  • All three studies projected an increase in the number of days with heavy rain. Both studies that projected the maximum amount of rain over multi-day periods projected an increase.
  • Both studies that projected the number of frost-free days per year projected that they would increase.

Only in two areas were there significant disagreements between the studies. First, the season in which the greatest change in temperature would occur differed, with one study projecting summer, one spring, and one winter. Second, of the two studies that projected seasonal changes in precipitation under the low emission scenario, one predicted a summer decrease and one predicted a summer increase.

Temperature projections using the A1fi, A2, and B1 scenarios followed the trend that would be expected from GHG emissions under those scenarios: higher, middle, and lower. Projections were made for 30-year periods centered on 2035, 2050, 2065, and 2084. The temperature was projected to increase more with each passing period.

Thus, despite their methodological differences, there appears to be a good deal of consistency between the results of these studies. They point to a warmer, slightly wetter local climate, with an increased frequency of heavy rain events.

Sources:

Anderson, Christopher, Jennifer Gooden, Patrick Guinan, Mary Knapp, Gary McManus, and Martha Shulski. 2015. Climate in the Heartland: Historical Data and Future Projections for the Heartland Regional Network. Downloaded 3/15/16 from http://www.marc.org/Government/GTI/pdf/ClimateintheHeartlandReport.aspx.

Hayhoe, K, J VanDorn, V. Naik, and D. Wuebbles. 2009. “Climate Change in the Midwest: Projections of Future Temperature and Precipitation.” Technical Report on Midwest Climate Impacts for the Union of Concerned Scientists. Downloaded from http://www.ucsusa.org/global_warming/science_and_impacts/impacts/climate-change-midwest.html#.VvK-OD-UmfA.

Intergovernmental Panel on Climate Change. 2000. IPCC Special Report: Emissions Scenarios: Summary for Policymakers. https://www.ipcc.ch/pdf/special-reports/spm/sres-en.pdf.

Posey, John. 2014. “Climate Change in St. Louis: Impacts and Adaptation Options.” International Journal of Climate Change: Impacts and Responses. Vol 5, #2. Downloaded 1/15/2016 from http://ijc.cgpublisher.com/product/pub.185/prod.233.

Posey Projects Climate Change for St. Louis

In my last post I reported on climate projections for St. Louis and the Midwest by Hayhoe, VanDorn, Naik, and Wuebbles. Here, I will report on climate projections for St. Louis by John Posey, Director of Research for the East West Gateway Council of Governments. His paper focused on temperature and precipitation changes by the middle of this century in the St. Louis Region, and on the types of socio-economic impacts that would be associated with such a change. Because future climate change is expected to be sensitive to how humans respond, he made projections for a high emissions scenario (A2) and a low emissions scenario (B1). Note that while he used a high emission scenario, the scenario he used does not envision emissions as high as the A1fi scenario used by Hayhoe et al.

Please remember that there is uncertainty associated with all climate change projections, and that with projections for the local level the uncertainty is magnified.

Posey’s results are shown in Table 1. He projects a 3.6°F temperature increase by mid-century under the low emissions scenario, and 4.9°F under the high emissions scenario.

Posey Temp Change

(Click on table for larger view.)

Posey projects that St. Louis will experience a slight increase in annual average precipitation, less than 10%. The analyses he conducted were uncertain about whether summer would see a decrease. Posey also projects an increase in heavy precipitation events, though he projects the increase to be small (1 additional heavy precipitation event per year).

Posey identifies 3 main socio-economic impacts that should be expected from climate change in the St. Louis Region. He expects an increase in flooding, heat stress, and energy consumption. In addition, he expects that other challenges might include agricultural stress, problems with roads (road buckling, etc.), and changes in infections disease vectors.

Given that Posey and Hayhoe et all projected for slightly different regions, and that they used different high emissions scenarios, their results seem more or less consistent. Where they differ, they differ in ways we would expect given the differences in their methods. (Posey’s projected temperature increase under the high emissions scenario should be less than Hayoe et al’s, and it is.)

Because of the differences in their methods, you shouldn’t really compare their projections directly, but I know that you’re gonna do it anyway. So, as you do, keep in mind that Hayhoe et al’s projections for extremely hot days were for one of the higher emission scenarios available, and they were for the end of the century, while Posey’s projections used a somewhat less extreme high emissions scenario, and only extended through mid-century.

In the next post, I will report on a study that made climate projections for Columbia, Missouri.

CORRECTION: In the original version of this post, the second to last paragraph stated that the A1fi Scenario used by Hayhoe et al was the highest emission scenario available. That has been corrected to read “one of the higher emission scenarios available.” See Hayhoe’s comment to the blog post for the specifics.

SECOND CORRECTION: In Paragraph 4, the original version of this post said that summer precipitation in St. Louis would decrease. That has been changed to indicate that projected change in summer precipitation is uncertain.

Sources:

Hayhoe, K, J VanDorn, V. Naik, and D. Wuebbles. 2009. “Climate Change in the Midwest: Projections of Future Temperature and Precipitation.” Technical Report on Midwest Climate Impacts for the Union of Concerned Scientists. Downloaded from http://www.ucsusa.org/global_warming/science_and_impacts/impacts/climate-change-midwest.html#.VvK-OD-UmfA.

Posey, John. 2014. “Climate Change in St. Louis: Impacts and Adaptation Options.” International Journal of Climate Change: Impacts and Responses. Vol 5, #2. Downloaded 1/15/2016 from http://ijc.cgpublisher.com/product/pub.185/prod.233.

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