I mentioned last week that visits to the counties really help me see successes and challenges in context. Today was full of that sentiment.
I had event-free travel from the USDA building in DC to the airport, such that I arrived early enough to catch the flight scheduled to leave 2 hr ahead of my ticketed flight! That sounds great until you realize that the flight was already an hour behind schedule and when we landed in Chicago, the tram that takes you from E to C was not running. But I still managed to get to my flight back to CA ahead of schedule so overall, better than my usual travel luck particularly given that my ticketed flight was delayed such that I would have missed my connection back to CA.
I had spent the day with EPA, ARS, USDA Office of Climate, a few industry representatives and a few other scientists from around the country talking about the Greenhouse Gas Inventory that is open at present for public comment. It was an interesting discussion that reinforced a couple of concepts: 1) poor data in means poor data out; 2) there's no need to perpetuate the problem of poor data if alternatives can be found; and 3) taken out of context, everything appears alarming. The other ‘Ah ha' I had was that despite the fact that the EPA contractor was only paying my travel, I likely have a boat load of paperwork to submit to UCOP now because they wrote the contract as though I was consulting and they will likely send me a 1099-MISC. But that's a challenge for another day.
We started the discussion by looking at a pie chart that illustrated the contribution to methane from various sectors, including manure management (10% of U.S. CH4) and enteric fermentation (25%). Coal represented 9% of U.S. CH4 emissions. Then we looked at a pie chart that did the same for nitrous oxide emissions with about 5% of U.S. N2O emissions attributed to manure management and 75% attributed to agriculture. This was followed by a figure that conveyed agriculture as contributing to 9% of total U.S. greenhouse gas (GHG) production. Immediately concern was raised that in previous inventories, coal surpassed manure management for CH4 contribution. Similarly, in past years, agriculture accounted for 5 to 6% of total U.S. greenhouse gas production. How could this happen? Were the data reliable? As sectors reduce their contribution, because the data are shown as a pie chart and sectors are reported as percent of 100% (total), those sectors that haven't seen as much reduction make up a larger part of the whole pie. But without considering mass of cumulative production, there is insufficient context to see the whole picture. While agriculture may be contributing a greater portion of the total, this doesn't mean agriculture is contributing more than it once did. Furthermore, if all sector data were normalized to something like ‘per capita' we would have even a different picture. Sure, transportation and power generation sectors have seen reduced GHG production per capita over the last few decades and perhaps agriculture's reduction hasn't been as large, but are we really aiming for zero? And if we considered food production per capita, the increased production efficiency may very well exceed increased efficiencies observed in other sectors. This discussion had me thinking about one I had last week in that it mirrored one that focused on a report recently released in CA that has many upset, and not necessarily without reason. I haven't read that report yet but, again, a percent of total sources without trends in mass, doesn't tell the whole story. Instead, a large fraction conveys something bad when in fact it may all be good news – particularly when one considers that the report indicated that agriculture may contribute as much as 45% of the nitrogen oxide production in CA and the EPA GHG inventory reports that, nationally, agriculture contributes 75% of N2O.
Time to board a plane. More later on the impact of poor model inputs.