Tag Archives: climate change

How hot was Sept 2021?

From NOAA’s Global Climate Report – September 2021:

The global surface temperature for September 2021 was 0.90°C (1.62°F) above the 20th century average of 15.0°C (59.0°F) and was the fifth highest September temperature in the 142-year record. Only Septembers of 2015, 2016, 2019, and 2020 had a higher September temperature departure. The eight warmest Septembers have all occurred since 2014. September 2021 also marked the 45th consecutive September and the 441st consecutive month with temperatures, at least nominally, above the 20th-century average.

Some regional highlights:

The Southern Hemisphere’s September 2021 surface temperature departure of +0.70°C (+1.26°F) was the warmest September in the 142-year record, surpassing the previous record set in 2018 by 0.02°C (0.04°F).

According to NCEI’s continental analysis, Africa had its warmest September on record at 1.50°C (2.70°F) above average, surpassing the previous record set in 2017 by 0.07°C (0.13°F).

September 2021 was also South America’s warmest September on record at +1.94°C (+3.49°F). This value exceeded the previous record set in 2015 by 0.23°C (0.41°F).

Time series data is available near the top of the page.

What is the Groundswell report?

From the world bank:

This sequel to the Groundswell report includes projections and analysis of internal climate migration for three new regions: East Asia and the Pacific, North Africa, and Eastern Europe and Central Asia. Qualitative analyses of climate-related mobility in countries of the Mashreq and in Small Island Developing States (SIDS) are also provided. This new report builds on the scenario-based modeling approach of the previous Groundswell report from 2018, which covered Sub-Saharan Africa, South Asia, and Latin America. The two reports’ combined findings provide, for the first time, a global picture of the potential scale of internal climate migration across the six regions, allowing for a better understanding of how slow-onset climate change impacts, population dynamics, and development contexts shape mobility trends.

Key projection:

Over 216 million people could move within their countries by 2050 across six regions,

The report discusses their modeling (there is more than this) :

Both Groundswell reports use the same modeling approach, which allows for direct comparison of results and for aggregation to derive the global figure for internal climate migration. They take a scenario-based approach and implement a modified form of a gravity model to isolate the projected portion of future changes in spatial population distribution that can be attributed to slow-onset climate factors up to 2050. The Spotlight discusses the key innovations and scope of the modeling approach.

Quiz question for a class: Is the 216 million people a lot or a little?

 

 

What is the status of Lake Mead?

About two months ago I had the post How low is Lake Mead?  The graph in the post was the yearly minimum end of month elevation. In this post we have a closer look at the end of month elevation since 2011. The last month in the data is July 2021, which is a record low following the previous record low in June 2021. In the previous post I mentioned that this really should be given in some per capita format. I’ll add that presumably the decrease in the volume of water is not linear with the lake elevation. Data here.

How much will tidal flooding increase?

The graph below shows the number of days per year that sea level in Kings Point, NY is projected to exceed 60 cm above MHHW.

Sea level rise will increase the likelihood of tidal flooding. NASA has posted a tool, Flooding Days Projection Tool, to help understand how much tidal flooding may increase. There is a drop down menu for numerous locations in the U.S.  For example, the graph here is for Kings Point, NY.  Along with the value of the data there are calculus terms in the post:

These projections are based on unique, location-specific relationships between annual mean sea level, the top 1% of astronomical tides in each year, and annual counts of threshold exceedances.

An interesting and essential feature of these graphs is that the number of flooding days per year does not necessarily increase smoothly in time. In most cases, there are inflection points where the frequency of flooding days increases rapidly, which may be useful when establishing planning horizons. In many locations around the United States and its territories, there are sharp inflection points around the mid-2030s that are related to the interaction between accelerating sea level rise due to climate change and a long-term, 18.6-year cycle in the amplitude of astronomical tides.

And discussions of probabilistic modeling:

The purpose of this tool is to produce probablistic projections of flood frequency in the future that provide information about the full range of possibilities for a given year, including the potential for the occasional—yet inevitable—severe years. The projections leverage the predictability inherent in certain contributions (e.g., tidal amplitude and climate-change-induced sea level rise) and use statistical methods to account for everything else. The projections are probabilistic, because rather than producing a single, most-likely number of flooding days for a future year, these projections produce a range of plausible numbers with probabilities assigned to each possibility or range of possibilities.

All in all this is a great resources for math classrooms.

 

How do I find climate rankings for my state?

Have you wondered if your state just had the hottest, driest, wettest, etc. month? You can get this information from NOAA’s Statewide Ranking page. For example, the graphic here is for California for July 2021. The output will provide ranking information for 1-12, 18, 24, 36, 48, and 60-month time periods.  The 1, 2, 3, 4, and 5 month periods ending in July 2021 have been the hottest on record going back 127 years. The page allows users to select a state and various periods. Each output also has a link to the data. An overview and definitions of these ranking is given on the Climatological Rankings page.

How hot was July 2021?

From NOAA’s Global Climate Report – July 2021:

As a whole, the July 2021 global surface temperature was the highest for July since global records began in 1880 at 0.93°C (1.67°F) above the 20th-century average of 15.8°C (60.4°F). This value surpassed the previous record set in 2016 (and subsequently matched in 2019 and 2020) by only 0.01°C (0.02°F). Because July is the warmest month of the year from a climatological perspective, July 2021 was more likely than not the warmest month on record for the globe since 1880. Nine of the 10 warmest Julys have occurred since 2010, with the last seven Julys (2015-2021) being the seven warmest Julys on record.

The data is available at the top of the page under Additional Resources.

What are the latest climate projections?

The IPCC sixth assessment report was just released. The graph here is from the summary for policymakers.  The 42 page summary could be used as part of a sustainability or QL type course as there are plenty of graphs.  Page 15 starts the discussion on the different scenarios, which is an opportunity to talk about modeling and assumptions. For a sense of the long term consequences:

In the longer term, sea level is committed to rise for centuries to millennia due to continuing deep ocean warming and ice sheet melt, and will remain elevated for thousands of years (high confidence). Over the next 2000 years, global mean sea level will rise by about 2 to 3 m if warming is limited to 1.5°C, 2 to 6 m if limited to 2°C and 19 to 22 m with 5°C of warming, and it will continue to rise over subsequent millennia (low confidence). Projections of multi-millennial global mean sea level rise are consistent with reconstructed levels during past warm climate periods: likely 5–10 m higher than today around 125,000 years ago, when global temperatures were very likely 0.5°C–1.5°C higher than 1850–1900; and very likely 5–25 m higher roughly 3 million years ago, when global temperatures were 2.5°C–4°C higher (medium confidence).

How dry is Arizona?

From the climate.gov article Western Drought 2021 Spotlight: Arizona by Tom Di Liberto (7/29/2021):

Looking back even farther by using a drought indicator known as the Standardized Precipitation Index, the current drought in Arizona is also the worst on record back to the late 1800s. Going back even farther than THAT by using tree rings across the Southwest as stand-ins for soil moisture, the current drought over the entire region is one of a handful of the worst droughts in the last 1200 years. Other especially bad droughts occurred in the late 1500s and late 1200s (known as the Great Drought). Basically, this is a long-winded way of saying the current drought in Arizona and the Southwest is bad no matter if you look back 10 years, 100 years, or 1,000 years.

The graph copied here shows that it has been 6 years since a wet year with 2020 precipitation the lowest since 1900. And, of course:

According to the Climate Science Special Report, temperatures across the Southwest have increased by 1.61 degrees Fahrenheit since the first half of the 20th century. These increases in temperature contribute to aridification in the Southwest by increasing evapotranspiration, lowering soil moisture, reducing snow cover and impacting snowmelt.

Looking to the future, temperatures in the Southwest are projected to increase by the end of the century by around 5 degrees Fahrenheit if carbon dioxide emissions follow a lower path and up to 9 degrees if emissions follow a much higher path. Increasing temperatures can make soils even drier, amplifying drought.

There are other graph in the article but no direct links to data. Still, there is good information and plenty of material for a QL course.

How hot was June 2021?

From NOAA’s Global Climate Report – June 2021:

The June 2021 global surface temperature was the fifth highest for June in the 142-year record at 0.88°C (1.58°F) above the 20th century average. Only Junes of 2015 (fourth warmest), 2016 (second warmest), 2019 (warmest), and 2020 (third warmest) were warmer and had a global temperature departure above +0.90°C (+1.62°F). Nine of the 10 warmest Junes have occurred since 2010.

But June seemed hot you say? Yup:

The global land-only surface temperature for June 2021 was the highest on record at 1.42°C (2.56°F) above average. This value surpassed the previous record set in 2019 by +0.11°C (+0.20°F). The ten warmest June global land-only surface temperatures have occurred since 2010. The unusually warm June global land-only surface temperature was mainly driven by the very warm Northern Hemisphere land, which also had its highest June temperature departure at +1.69°C (+3.04°F). The now second highest June temperature for the Northern Hemisphere occurred in 2012 (+1.51°C / +2.72°F).

Time series data is available at the link near the top of the page.