Just Read: Understanding Global Methane Emissions as a Family Physician without Diabetes (and hoping to keep it that way)

2018.05 Low Carb and Low Carbon - Ted Eytan MD-1001 776
2018.05 Low Carb and Low Carbon – Ted Eytan MD-1001 776 (View on Flickr.com)

“Methane” is said to me as a statement a lot. When I probe if there’s more information behind the statement, I don’t hear very much.

The overwhelming majority of physicians do not have a good understanding of climate science. It’s okay, we’re all on a learning journey 🙂 .

We should understand:

  • Climate change is a threat to human health
  • Diabetes, now a global epidemic, is also a threat to human health
  • Physicians / health professionals have a role in the mitigation of both, with the right information
2018.05 Low Carb and Low Carbon - Ted Eytan MD 2-1002 770
2018.05 Low Carb and Low Carbon – Ted Eytan MD 2-1002 770 (View on Flickr.com)

Above are calculated global sources of methane as well as modeling of the sources of the increase since 2008.

Methane is a greenhouse gas that is not the same as carbon dioxide. It has 28 times the global warming potential (GWP) of carbon dioxide. At the same time, it also has a much shorter half-life in the atmosphere, typically broken down in 12 years, unlike carbon dioxide with a half life of 1,000 years. Therefore, methane is important as a contributor to climate change, and also an important lever to mitigate it, because a reduction brings benefits much faster. For a deeper look at how this is calculated, see: Photo Friday: Beef Brisket, Brussels Sprouts and GWP*: in search of my/the Sustainable Diet

This paper (reference below) is a discussion piece on the causes of a “massive” increase in methane in the atmosphere in this century, by Robert Howarth, PhD, at Cornell (Twitter:Howarth_Cornell). He does a great job in this video explaining the methodology and the idea that previous descriptions of methane increases being driven by biogenic sources (agriculture) are probably incorrect.

Increases in Methane
Figure 1(a) Global increase in atmospheric methane between 1980 and 2015. (b) Change in δ13C value of atmospheric methane globally between 1980 and 2015. Both adapted from Schaefer et al. (2016). Used under Creative Commons license,Howarth RW. Is Shale Gas a Major Driver of Recent Increase in Global Atmospheric Methane? Biogeosciences Discuss [Internet]. 2019 Apr 23;1–23.

The image on the right, above, shows a steady increase in methane, a plateau, and then a steep rise. Below it is an image of the isotopic composition of the methane. It shows, as Howarth explains, that the rise before the plateau probably has a different cause than the rise after the plateau.

Not shown here are satellite images of global methane emissions….well okay, let’s show the satellite image…

Satellite image of methane emissions
Figure 2: The 2010–2014 trend in U.S. methane enhancements as seen from GOSAT. The methane enhancement (Δ methane) is defined as the difference in the tropospheric column mixing ratio relative to the oceanic background measured in the glint mode over the North Pacific (176–128°W, 25–43°N) and normalized with the 2010 Δ methane. Trends are computed on a 4° × 4° grid. Statistically significant trends (p < 0.01) are indicated by a dot. Source:Turner AJ, Jacob DJ, Benmergui J, Wofsy SC, Maasakkers JD, Butz A, et al. A large increase in U.S. methane emissions over the past decade inferred from satellite data and surface observations. Geophys Res Lett [Internet]. 2016 Mar 16 [cited 2019 Sep 19];43(5):2218–24. Used under Creative Commons license.

They show a signifcant rise coming from the United States, which has not increased its cattle herd, but has significantly increased production of fossil fuel energy.

Given our finding that natural gas (both shale gas and conventional gas) is responsible for much of the recent increases in methane emissions, we suggest that the best strategy is to move as quickly as possible away from natural gas, reducing both carbon dioxide and methane emissions. Natural gas is not a bridge fuel (Howarth, 2014).Howarth RW. Is Shale Gas a Major Driver of Recent Increase in Global Atmospheric Methane? Biogeosciences Discuss [Internet]. 2019 Apr 23;1–23.

Healthy People and Healthy Planet, not one or the other

Climate scientists are urging us to consider a bigger picture than we currently are, in the interest of our survival.

We don’t need to ban cars; we need to electrify them (and we need that electricity to come from clean energy). We don’t need to ban burgers; we need climate-friendly beef…The bigger issue is that focusing on individual choices around air travel and beef consumption heightens the risk of losing sight of the gorilla in the room: civilization’s reliance on fossil fuels for energy and transport overall, which accounts for roughly two-thirds of global carbon emissions.See: Individual Choices Won't Be Enough to Save the Planet | Time@MichaelEMann

Consistent with the views above, I have been witnessing cognitive dissonance in the health professions and society in general: Just Read: Carbon footprint of the global pharmaceutical industry – “Significantly worse than the automotive industry”.

The Climate is Changing

  • Plot your home city temperature and see for yourself. I did, this is Washington, DC:
2018.08.03 Low Carb and Low Carbon, Washington, DC USA 504
2018.08.03 Low Carb and Low Carbon, Washington, DC USA 504 (View on Flickr.com)

Climate models

My generation of physicians trained in an era where we had no choice but to develop insatiable curiosity; as I shared in my TedX talk way back when, the lack of it in the generation before us was devastating.

Besides the work of Robert Howarth, I’d like to acknowledge Peter Ballerstedt, PhD (@GrassBased), our metabolically healthy forage agronomist on call…

As usual, I welcome the checking of my work, feel free to post in the comments.

References

  1. Howarth RW. Is Shale Gas a Major Driver of Recent Increase in Global Atmospheric Methane? Biogeosciences Discuss [Internet]. 2019 Apr 23;1–23.
  2. Turner AJ, Jacob DJ, Benmergui J, Wofsy SC, Maasakkers JD, Butz A, et al. A large increase in U.S. methane emissions over the past decade inferred from satellite data and surface observations. Geophys Res Lett [Internet]. 2016 Mar 16 [cited 2019 Sep 19];43(5):2218–24.
  3. Lifestyle Changes Aren’t Enough to Save the Planet. Here’s What Could
  4. Scientific Consensus | Facts – Climate Change: Vital Signs of the Planet

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