Wednesday, May 23, 2018

A Half Century of Climate Change: Personal Perspective

On the occasion of the 50th reunion of the Class of 1968:

I aspire to be "a man who knows that the world is not given by his fathers, but borrowed from his children" [Wendell Berry].

During the more than 70 years we have borrowed the world, fossil fuels have steadily increased global atmospheric carbon dioxide (CO2) concentration. In 1946 it was 310 parts/million (ppm), 9% above pre-industrial levels, rising continually to above 400 ppm today for the first time in human history, over 40% above pre-industrial levels.

CO2 is a colorless, odorless gas. At 0.04% of the total atmosphere, it might seem insignificant. What does this have to do with a 50th reunion? Actually, it enables our existence and ability to celebrate this occasion. Understanding it also had a profound impact on my own life so far.

Almost a century before we were born, in 1859, John Tyndall discovered that CO2 and water vapor absorb heat (infrared radiation). Paraphrasing Tyndall:
The atmosphere admits of the entrance of the solar heat, but greenhouse gases check its exit; and the result is a tendency to accumulate heat at the surface of the planet.
Otherwise, Earth would be a lifeless ice ball with an average temperature below –19°C/-2°F.
With each decade since 1968, climate science research has become more conclusive, but U.S. national policy reaction has become more resistive. Shortly after our 10th reunion, a National Academy of Sciences report (1979) concluded that increasing atmospheric CO2 would likely cause climate changes. In the summer of our 20th reunion in 1988, NASA scientist James Hansen confirmed that observations showed human activity was in fact increasing global temperatures. In the 30th reunion year of 1998, Yale PhD Michael Mann published the famous "hockey stick" graph that showed an unprecedented rise in global temperatures over the last century compared to the previous millennium. The Kyoto Protocol to reduce greenhouse gas emissions was also adopted that year, but the U.S. Senate rejected it. While 35th reunion classmates celebrated with White House selfies, yet another decade was squandered as a presidential administration run by fossil fuel advocates actively worked to suppress climate research and its policy implications. In the latest decade, the Paris climate agreement pledged 195 countries to non-binding targets for reducing greenhouse gas emissions, but the U.S. repudiated it in 2017.

Yale’s role in my involvement with the climate issue was tangential, but tangible. Far more important than long-forgotten math theorems were the critical thinking skills sharpened through rigorous study of subjects as varied as: history of the novel, causes of the Civil War, roots of tragedy and comedy (food, sex, and money!).

My interest in weather, math/physics major, and threat of the draft led to a NOAA Corps commission in 1969. I spent a year of that service programming weather models at the National Weather Service (NWS). Following my meteorology MS at MIT in 1974, I returned to NWS for 5 years, before wandering off to the computer industry at IBM and AOL. Through the miracle of stock options, I retired early and taught computer programming at the University of Maryland. After the internet bubble burst, I rediscovered my first love of weather by blogging on local weather and climate. I have become more concerned with climate science and policy the more I learned.

Every decade that passes without major CO2 emissions reduction makes the climate change problem more difficult. I'm trying to communicate this issue (twitter.com/capital_climate) for the benefit of Sarah (Duke '00), Jonathan (Yale '03), and Ruth (Yale '38?). What are we doing to preserve the world we’ve borrowed from the children and grandchildren we all cherish and those yet unborn?

Sunday, March 16, 2014

Washington DC Climate: March 2014

Latest update: March 23
For daily updates most days around 6 pm EDT:



March is on track for an average temperature of 42.7°, which would be 4.1° below the long-term average and the coldest since 1993, when it was 42.2°. Precipitation remains below average.

Washington DC daily temperature departures from normal and monthly average to date (click to enlarge):


Washington DC daily precipitation and monthly departure from normal to date (click to enlarge):


CapitalClimate charts from National Weather Service data. Background image from Kevin Ambrose.

Friday, February 28, 2014

Washington DC Climate: February 2014

Latest update: February 28
For daily updates most days around 5 pm EST:



Final February charts:

Washington DC daily temperature departures from normal and monthly average to date (click to enlarge):


Washington DC daily precipitation and monthly departure from normal to date (click to enlarge):


CapitalClimate charts from National Weather Service data. Background image from Kevin Ambrose.

Friday, January 31, 2014

Washington DC Climate: January 2014

Washington DC daily temperature departures and monthly average to date (click to enlarge):


Washington DC daily precipitation and monthly departure to date (click to enlarge):


CapitalClimate charts from National Weather Service data. Background image from Kevin Ambrose.

Sunday, January 19, 2014

Omaha Crushes 119-Year Temperature Record


Image (click to enlarge): U.S. temperatures at 3 pm CST, January 19, 2014, from Unisys

9 PM Update: Added Hastings, Broken Bow, Imperial NE and Salina, Russell KS

Original post:
A mid-winter mini-heatwave tied or broke long-standing high temperature records across at least 3 states on January 19, according to preliminary reports from the National Weather Service (NWS). The 65° at Omaha absolutely crushed the previous record for the date of 60°, which dated back 119 years to 1895. Omaha is one of the original official Weather Bureau observing sites whose climate history began in 1871. An 1895 record also fell at Lincoln, where it was 66°.

The preliminary records reported by the NWS (POR indicates the year in which the period of record began):

Location Record Previous Date POR
NE Lincoln 66 65 1895 1887
Norfolk 66 66 1921 1888
Omaha 65 60 1895 1871
McCook 68 66 1997 1896
Chadron 61 60 2003 1895
Grand Island 68 62 1997 1895
Hastings 67 62 1921 1894
Broken Bow 65 64 1951 1894
Imperial 66 66 1911 1893
KS Hill City 69 66 2006 1896
Salina 68 68 2003 1894
Russell 69 69 1986 0
IA Sioux City 65 59 1921 1889

Friday, December 6, 2013

It Hasn't Cooled Since 1989;
Washington December Daily Low Temperature Records


Images (click to enlarge): December daily record low temperatures for Washington, DC, by year of occurrence; Number of December daily record lows per decade; CapitalClimate charts from National Weather Service data

If you can remember the last time Washington, DC set a daily record low temperature in December, you've been hanging around too long in Babble-On on the Potomac. It was the first year of the G.H.W. Bush administration when a record low of 7° was set on December 23, 1989. The high of 22° that day was also a record low maximum for the date. Since then, there have been no new December record daily lows in the decades of the 1990s, 2000s, or so far in the 2010s. The only other decade with no December cold records was the 1950s.

Here are some other statistics of Washington December low temperature records:
- Half (15) of the daily records were set over 100 years ago, from 1872 through 1904, and 2 more were set 99 years ago.
- The 1880s had the most records of any decade with 7, followed by the 1910s with 5. Interestingly, all of the 1880s records occurred in even-numbered years.
- Except for the 1980s (4 records), no decade since the 1910s has had more than 2 records.
- The all-time coldest December temperature was -13° on December 31, 1880. This was just 2° warmer than the all-time Washington low of -15° on February 11, 1899. It was also a record -7° on December 30, 1880. These are the only December dates with lows below 0°.

Seasonal Outlook

Latest seasonal forecast: Click here.


Latest 3-month temperature outlook from Climate Prediction Center/NWS/NOAA.