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Is This a Trump Bump?

Air pollution and greenhouse gas emissions have increased during the Trump presidency.

The EPA just released the latest greenhouse gas (GHG) inventory. This is a massive report and public dataset tracking all major categories of US GHG emissions through 2018. A riveting read for nerds like us! The inventory confirms what others had been projecting. After several years of decline, U.S. emissions bumped up in 2018.

U.S. Greenhouse Gas Emissions Allocated to Economic Sectors (MMT CO2 Eq.) 
Notes: Domestic emissions increased by 2.9% between 2017 and 2018. The biggest emissions increase came from the industrial sector. Source: US GHG Inventory Tables ES-6 and 6-13.

There’s a similar (but more striking) pattern in local air pollution. A recent paper by economists Karen Clay and Nick Muller shows an increase in monitored particulate matter (PM2.5) pollution after years of air quality improvements:

Notes: This figure plots the annual average changes in particulate matter pollution levels relative to 2016. Broken lines show the 95-percent confidence intervals. Paper can be found here.

Given how hard the current administration has been working to rescind/revoke/revile regulations that limit air pollution and mitigate climate change, it’s tempting to conclude that these recent jumps are all due to Trump. The truth, of course, is more complicated.  

In today’s blog, I look into the data behind these pictures. One or two years of increasing emissions does not a trend make. But the underlying drivers tell us something about where we need to be focusing our attention. As electricity sector emissions go down, emissions from some other sectors are going up. These are sectors and sources we need to reckon with if we’re looking to pick up the pace (versus lose more ground) on air quality improvements and GHG reductions in the years ahead.  

Mobile sources emissions overtake the power sector

Much of the progress we’ve made in reducing emissions over the past decade has happened in the electric power sector. This is especially true with respect to CO2. With the rise of cheap natural gas and increasing renewable energy penetration, the carbon intensity of electricity production has decreased by more than 25% since 2008. Sulfur dioxide intensity has dropped by more than 80%!

In past years, big reductions in power sector emissions have been more than enough to offset increased emissions from other sectors. But this seems to be changing.

On the local air pollution front, researchers have documented evidence of the growing importance of other sectors and sources. Different types of economic activities (e.g., driving, coal plant operations) can be associated with different types of particulate matter pollution. In their paper, Karen and Nick find that the changing chemical composition of monitored air pollution is consistent with decreases in coal emissions and significant increases in the combustion of natural gas and transportation fuels.

Similar patterns can be seen in the GHG data. The graph below shows how the transportation sector officially surpassed the power sector to become the largest source of GHG emissions in 2017. Our insatiable appetite for driving is one important factor. But in recent years, the net increase in transportation sector emissions can be traced back to commercial airplanes and heavy-duty trucks (modes that are relatively hard to electrify….)

Source: US GHG Inventory of Greenhouse Gas Emissions and Sinks

Industrials and buildings are sources to be reckoned with

GHG emissions from the industrial sector have recently been increasing even faster than transportation. This growth has been driven primarily by increases in total manufacturing output (which increased by 3.9 percent in 2018). Can we break the link between domestic industrial activity/productivity and industrial GHG emissions?

Past experience with industrial air pollution emissions (excluding GHGs) offers some reason for optimism. Between 1990 and 2008, air pollution emissions from U.S. manufacturing fell by 60 percent despite a substantial increase in manufacturing output.

Source: Why is Pollution from U.S. Manufacturing Declining? The Roles of Trade, Regulation, Productivity, and Preferences (by Joe Shapiro and Reed Walker)

My Berkeley colleagues Joe Shapiro and Reed Walker have investigated the underlying causes of this remarkable decline in manufacturing air pollution. They find that most of the decrease can be explained by increasingly stringent environmental regulation of air pollution emissions over this period (versus changes in industry composition, productivity, or trade). In contrast to air pollution emissions, industrial GHG emissions are still unregulated in most states. Requiring firms to internalize their climate impacts would provide a strong incentive to find less carbon-intensive ways of operating. 

Finally, GHG emissions from residential and commercial buildings (which include emissions from space heating, hot water heating, and cooking with gas) are relatively small but steady. The more pronounced 2018 bump was presumably weather-related (2018 was a relatively cold year). Lucas recently documented some slow progress towards heating electrification. The pace of this change will need to pick up if we want to make a dent in building sector emissions.

Now is not the time for environmental de-regulation:

The recent uptick in U.S. emissions should be a wake-up call for us to double down on efforts to address climate change and local air quality. But this is not what we are seeing at the federal level. The list of air quality and climate change regulations that have been dismantled since 2016 is long and getting longer. And the White House is calling for a 26% budget cut at the agency charged with the task of safeguarding our air and water quality and leading federal efforts to mitigate climate change. The current EPA budget is $8 billion (less than $25 per person per year).  

I am really hoping that the recent jump in U.S. emissions is just a bump on the road to more substantive reductions versus a permanent change in direction. Reigning in our emissions will require a concerted and coordinated policy effort – one that taps emissions abatement potential across all sectors of the economy.  Let’s hope that 2020 puts us on that road.

Keep up with Energy Institute blogs, research, and events on Twitter @energyathaas

Suggested citation: Fowlie, Meredith. “Is This a Trump Bump?” Energy Institute Blog, UC Berkeley, February 24, 2020,





6 thoughts on “Is This a Trump Bump? Leave a comment

  1. The reversal of falling PM2.5 levels at the beginning of 2016 Granger causes Trump’s election, not the other way around.

  2. Ah! For sure the tRump Dump. Could it also be just that as the economy ‘grew’ and there was greater activity less effective/ older equipment was being put to use? [productivity declines as capacity utilization rises]

  3. Is there any way to disaggregate Industry emissions?

    Key areas to look at…

    1) Increased flaring of associated gas in real terms. Also a source of particulate emissions.
    2) Increased production of LNG, fueled primarily by natural gas with “behind the meter” generation and reported outside Electric Power Industry.
    3) Increased capacity of ethane crackers, also fueled primarily by natural gas.
    4) Increased volumes of natural gas (with a circa 30% increase from 2010 and a much larger increase within the past few years), again largely powered by “self-consumption” in the Midstream.

    Within the Electric Power Sector, a key sector to look for the reversal from a downward trend, would be the increased electric demand (in real terms) producing crude and pumping it.

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