Research Group
Curriculum Vitae
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Steven J. Davis
Publications    Google Scholar Profile
Effects of COVID on satellite observations of CO2
Geophysical Research Letters | October 29, 2020

We study the changes in human carbon emissions using spaceborne observations from NASA's second Orbiting Carbon Observatory (OCO‐2) from February to May 2020 and discuss needs for future carbon‐dioxide observing systems that will monitor such emissions.

Wang et al. 2020

Carbon Monitor
Scientific Data | November 9, 2020

The data and methods of our research collaborative, Carbon Monitor. Using hourly to daily electrical power generation data of 31 countries, monthly production data and production indices of industry processes of 62 countries/regions, and daily mobility data and mobility indices for the ground transportation of 416 cities, we estimate daily national emissions worldwide.

Liu et al. 2020

African fossil fuel CO2 emissions 1990-2017
Environmental Research Letters | November 3, 2020

African CO2 emissions were just 4% of global fossil fuel emissions in 2017, but have grown by nearrly 5% per year for nearly two decades. If the continent-wide such growth persists, by 2030 the continent's emissions will have risen by ~30% (to 1.6 Gt CO2), a sizeable quantity very much at odds with international climate targets.

Ayompe et al. 2020

Near real-time estimates of global CO2 emissions
Nature Communications | October 14, 2020

We present daily estimates of country-level CO2 emissions for different sectors based on near-real-time activity data. This is a new dataset developed during the COVID pandemic that substantially advances the frontier of emissions monitoring. It also represents the genesis of a new international research collaborative, Carbon Monitor.

Liu et al. 2020

Selected Press: SciAm, C&EN
Global climate effects of China's clean air efforts
Environmental Research Letters | September 29, 2020

China’s success in improving air quality by cutting polluting emissions may have a negative knock-on effect on climate change overall. We estimate that Chinese policies implemented between 2006 and 2017 has had tremendous health benefits, but will also "unmask" >0.1 °C warming as well as precipitation changes over the northern hemisphere.

Zheng et al. 2020

Selected Press: WIRED
Would firm generators facilitate or deter variable renewables in a carbon-free electricity system?
Applied Energy | December 1, 2020

Using an idealized electricity system model and historical weather data, we show that cost reductions in firm generation technologies uniformly result in greater penetration of the firm technologies and less penetration of variable renewables, with limited effects on system costs when firm technologies have high fixed costs.

Yuan et al. 2020
Research Brief

Effects of super-cheap storage on wind-solar-only electricity systems
iScience | September 25, 2020

In least-cost systems that rely on wind and solar only, energy storage fills hourly gaps when storage costs are high (>$100/kWh) but does not fill seasonal gaps until storage is nearly free. For high reliability with minimal curtailment in such systems, energy storage costs need to decrease several hundred-fold from current costs (to ~$1/kWh).

Tong et al. 2020
Research Brief

Inter-county transport of U.S. air pollution
Environmental Research Letters | September 5, 2020

About 30% of all U.S. counties receive 90% of their air pollution health damages from emissions in other counties, and damage-importing counties tend to have lower median incomes. Our results support continued state and federal cooperation to meet air quality standards and reduce the damages caused by PM2.5 from transported air pollution.

Sergi et al. 2020

Committed emissions of the U.S. power sector
AGU Advances | September 3, 2020

Although U.S. annual CO2 emissions fell by 24% between 2000 and 2018, committed emissions of the U.S. power sector decreased only 12% over the period. This is due to large changes in the age and composition of the U.S. generating fleet: old coal plants were replaced by brand new gas ones that can be expected to operrate for 30-40 years.

Shearer et al. 2020

Selected Press: EOS, HuffPo
Long-duration storage reduces costs of
wind-solar-battery systems

Joule | August 6, 2020

Using 39 years of hourly U.S. weather data and a macro-scale energy model, we show that currently available long-duration storage technologies like power-to-gas-to-power lower the cost of solar-wind-battery electricity systems.

Dowling et al. 2020
Research Brief

Radiative effects of aerosols may offset the air quality penalty of climate change in China
Nature Climate Change | August 3, 2020

We show that direct radiative effects of short-lived aerosols may substantially offset the "climate penalty" that prior studies have shown (i.e. that future climate change is likely to worsen air quality and thereby human health in most regions by favoring weather conditions that increase concentrations of air pollution).

Diffenbaugh et al. 2020

COVID-19 lockdowns: window into the Earth system
Nature Reviews Earth & Environment | July 29, 2020

In the modern era of global observing networks, pervasive sensing and tracking of human mobility and behaviour, unprecedented COVID-19 disruptions are an opportunity for understanding the Earth System. We hypothesize Earth System responses along cascades of energy, emissions, climate and air quality, and poverty, globalization, food and biodiversity.

Diffenbaugh et al. 2020

Air pollution effects of COVID-19 lockdown in China
National Science Review | June 18, 2020

By combining ground- and satellite-based observations with chemical transport modeling, we show why haze pollution increased over parts of China during the COVID-19 lockdown. Decreases in transportation NOx emissions increased ozone and nighttime NO3 radical formation, and these increases in atmospheric oxidizing capacity in turn facilitated the formation of secondary particulate matter.

Fofrich et al. 2020

Economic impacts of COVID-19 lockdowns
Nature Human Behaviour | June 3, 2020

We show that stricter, shorter COVID lockdowns reduce overall losses relative to weaker but longer ones. But even a lengthy period of moderate restrictions is economically preferable to lifting all restrictions if it can avoid the need for another round of strict lockdowns. Regardless, losses propagate via global supply chains; best case responses are globally coordinated.

Guan et al. 2020

Selected Press: Brookings, India Tribune
Power plants retirements in mitigation scenarios
Environmental Research Letters | May 27, 2020

We show that ambitious climate mitigation scenarios entail drastic, and perhaps un-appreciated, changes in the operating and/or retirement schedules of power infrastructure. For example, in 1.5 or 2°C scenarios, the median age of global coal plants at retirement is <10 years.

Fofrich et al. 2020
Research Brief

Data and analysis toolbox for modeling the nexus of food, energy, and water
Sustainable Cities and Society | May 22, 2020

Former postdoc Sadegh and team present an interactive analysis toolbox, Nexus of Food, Energy, and Water (NeFEW), that synthesizes global data for modeling and analysis of resources and their interdependencies at country-level and for user-specified categories and quantities:
Download NeFEW toolbox

Diffenbaugh et al. 2020

Aligning climate and health benefits of power plant siting and retirement decisions in the U.S.
Environmental Science & Technology | May 11, 2020

By analyzing integrated health and climate benefits, we show that reducing U.S. CO2 emissions by 30% could yield $21−68 billion in annual health benefits depending on the locations of coal plants that are replaced with wind, solar, or natural gas.

Sergi et al. 2020

Agricultural vulnerability to changing snowmelt
Nature Climate Change | April 20, 2020

Future changes in the fraction of precipitation falling as snow and the timing of snowmelt jeopardize food production in basins where irrigated agriculture relies heavily on snowmelt runoff. We assess the most at-risk basins and crops worldwide, where adaptation of water management and agricultural systems may be especially critical in a changing climate.

Qin et al. 2020

Selected Press: Weather Channel, Yale360
Ozone and climate impacts on California's key crops
Nature Food | March 16, 2020

By analyzing 35 years of temperature, ozone levels, and crop yield data, we estimate the impacts of warming and ozone pollution on perennial fruits and nuts in California. These crops, which represent ~38% of the state's agriculture by value, suffer damages of about $1 billion per year due to ozone in recent years. With 2°C of warming, almond yields will drop by ~10%.

Hong et al. 2020
Research Brief
Selected Press: c&en, Fast Co.
Climate adaptation by crop migration
Nature Communications | March 6, 2020

We show that shifts in crop areas worldwide 1973-2012 have substantially avoided increases in growing season temperatures that would have otherwise have been experienced by rainfed maize, wheat, rice and soybean. This suggests that crop "migration" has thus far been an important adaptive mechansim.

Sloat et al. 2020

Climate effects of aerosols reduce economic equality
Nature Climate Change | February 17, 2020

Despite their large negative impacts on human health, anthropogenic aerosols have masked some of the global warming induced by GHGs. Our simulations show that--although the net effects of this cooling on the global economy are small--they benefit developing tropical economies while harming developed high-latitude economies, thereby diminishing national inequality.

Zheng et al. 2020

Effects of urbanization on net primary productivity
Nature Communications | December 5, 2019

Analyzing a high resolution dataset of global land use/cover, we find that urban expansion has reduced terrestrial net primary production worldwide between 2000-2010, offsetting 30% of climate-driven increases over the same period. Our results highlight the carbon cycle impacts of urban expansion, and the need to enhance natural carbon sinks and increase agricultural productivity

Liu et al. 2019

Income-based accounting of China's air pollution
Nature Communications | September 25, 2019

Of more than 1 million annual deaths in China due to air pollution, about 44% can be attributed to consumption activities of Chinese households. We show that the more deaths are related rural than urban consumers, largely due to direct emissions from solid fuel combustion in rural China. Our results may inform more effective and equitable clean air policies in China.

Hong et al. 2019

Climate effects on Chinese air pollution deaths
PNAS | August 12, 2019

Future climate change may exacerbate the impacts of Chinese air pollution by increasing the frequency and duration of weather conditions that enhance pollution exposure. Under a scenario that avoids 3°C of mean warming but holds emissions constant, we estimate 12,100 and 8,900 more Chinese will die each year from PM2.5 and ozone exposure, respectively.

Hong et al. 2019

Committed emissions from existing energy infrastructure jeopardize 1.5°C climate target
Nature | July 1, 2019

If operated as historically, existing fossil energy infrastructure will emit >650 Gt of CO2, well over the most recent 1.5°C carbon budgets and 2/3 of the remaining 2°C budget. There is thus little or no room for new fossil infrastructure under the targets; rather existing infrastructure must be retired early.

Tong et al. 2019

Selected Press: NPR, NatGeo, LA Times, MIT Tech, Reuters, WaPo
Flexibility and intensity of global water use
Nature Sustainability | June 3, 2019

Some water uses are more or less flexible than others due to larger curtailment costs or social impacts. We construct and present a new water stress index that integrates water scarcity, flexibility, and variability, and use it to evaluate the most-stressed basins worldwide.

Qin et al. 2019

Selected Press: Nature
Emissions from federal lands
Nature Climate Change | January 28, 2019

New research from the USGS shows that fossil fuels produced on federal lands accounted for over 20% of U.S. emissions in recent years. Yet there are numerous ways in which federal lands might instead lead decarbonization.

Ratledge et al. 2019

Human carbon cycle feedbacks
PNAS | December 17, 2018

Climate change impacts on the biosphere tend to increase carbon emissions (a postive feedback). Meanwhile, the impacts on human activities may reduce carbon emissions by a similar amount (a negative feedback). Bad news for both nature and humans, but the feedbacks may largely offset each other.

Woodard et al. 2018

Selected Press: ArsTechnica
Climate impacts on beer supply
Nature Plants | October 15, 2018

Concurrent drought and heat extremes in the future may cause substantial decreases in barley yields, leading to dramatic regional decreases in beer consumption (e.g., -32%) and increases in beer prices (e.g., +193%) in some years.

Xie et al. 2018

Selected Press: AP, WSJ, WIRED, ArsTechnica, NY Times, SciAm
Without a back-up plan
Nature Sustainability | October 15, 2018

Despite increasing access to electricity, the reliability of electricity remains poor in many developing countries. We explain new research showing the magnitude of economic and environmental costs of electricity outages in sub-Saharan Africa.

Xie et al. 2018

Future climate impacts of Arctic shipping
Geophysical Research Letters | September 12, 2018

In the first study to use a fully-coupled Earth system model to look at the future climatic effects of trans-Arctic shipping, we find that clouds formed in response to shipping emissions may offset ~1°C of the overall warming trend in the Arctic by the end of the century.

Stephenson et al. 2018

Structural decline in China’s CO2 emissions through transitions in industry and energy systems
Nature Geoscience | July 2, 2018

China's emissions decreased between 2013-2016. Our analysis shows the decline was largely due to changes in industrial structure and a decline in the share of coal for energy production. Decreases may persist if nascent industrial and energy system transitions continue.

Guan et al. 2018

Selected Press: Bloomberg, Reuters, ArsTechnica
Net-zero emissions energy systems
Science | June 29, 2018

Although there are many options for reducing energy-related CO2 emissions, some energy services entail emissions that are much more difficult to eliminate. We review technological opportunities and barriers for eliminating and/or managing difficult-to-decarbonize services, and critical areas for further research, development, demonstration and deployment.

Davis et al. 2018

Selected Press: MIT Tech, InsideClimate, SciAm
City-level climate change mitigation in China
Science Advances | June 27, 2018

We present new, city-level estimates of CO2 emissions for 182 Chinese cities, decomposed into 17 different fossil fuels, 46 socioeconomic sectors, and 7 industrial processes, and examine three scenarios of technological progress to show that large reductions (up to 31%) are possible by updating a disproportionately small fraction of existing infrastructure.

Shan et al. 2018

Selected Press: Reuters
The rise of South-South trade and its effect of global CO2 emissions
Nature Communications | May 14, 2018

"South-South" trade among developing countries is increasing, and helping to reduce China’s emissions by shifting energy-intensive production to less developed regions. But this may make climate mitigation more challenging; emissions are spread among more and less-developed countries.

Meng et al. 2018

Selected Press: Wired, Reuters
Infrastructure shapes differences in the carbon intensities of Chinese cities
ES&T | April 25, 2018

Differences in Chinese cities’ carbon intensity are largely due to disparities in economic structure that can in turn be traced to past investment-led growth. Related carbon lock-in may hinder China’s efforts to reduce emissions from activities in urban areas.

Zheng et al. 2018

Predicting unpredictability in the U.S. energy sector
Nature Energy | March 26, 2018

Analysts and markets have struggled to predict a number of phenomena in U.S. energy markets over the last decade or so, such as the rise of natural gas. I explain new research that shows this may be a result of the industry--and consequently the market--becoming increasingly volatile.

Davis 2018

Selected Press: NPR
Eliminating natural gas at the UC
Nature Climate Change | February 27, 2018

The Paris Agreement highlights the need for local climate leadership. The University Of California’s approach to deep decarbonization offers lessons in efficiency, alternative fuels and electrification. Bending the emissions curve globally requires efforts that blend academic insights with practical solutions.

Victor et al., 2018

Geophysical constraints on reliability of U.S. solar and wind power
Energy & Environmental Science | February 27, 2018

Analysis of hourly weather data shows that meeting >80% of U.S. electricity demand with only solar and wind would require days' or weeks' worth of energy storage--even assuming a continental-scale transmission grid. Today this would be very costly.

Shaner et al., 2018

Selected Press: MIT Tech Rev, VICE
Global super-polluting power plants
Nature Sustainability | January 8, 2018

We assess fuel- and region-specific opportunities for reducing undesirable air pollutant emissions using a newly developed emission dataset at the level of individual generating units. Retiring or installing emission control technologies on units representing 0.8% of the global coal-fired power plant capacity could reduce levels of PM2.5 emissions by 8–14%.

Tong et al., 2017

Land-use change emissions from soybean feed embodied in Brazilian pork and poultry meat
Journal of Cleaner Production | November 20, 2017

We find that 17% and 39% of the greenhouse gas emissions related to the cultivation of soybean feed for Brazilian pork and poultry, respectively, are embodied in exports to other countries, especially Eastern Europe, Asia and elsewhere in South America.

Caro et al., 2017

Effects of atmospheric transport and trade on air pollution mortality in China
Atmospheric Chemistry and Physics | September 5, 2017

33% of premature deaths in China in 2010 (338,600 deaths) were caused by pollutants emitted in a different region of the country and transported in the atmosphere, and 56% (568,900 deaths) was related to consumption in another region.

Zhao et al., 2017

Probabilistic estimates of drought impacts on agricultural production
Geophysical Research Letterrs | August 5, 2017

Using a multivaritate probabilistic model, we quantify the average annual yields of major rainfed crops in Australia as a function of precipitation and soil moisture indices during the growing season. In the period 1980-2012, yields were 25–45% lower in dry seasons.

Madadgar et al., 2017

Evaluating Jacobson et al.'s "WWS" proposal
PNAS | June 19, 2017

Jacobson et al. argue that wind, solar and hydro power alone could meet all U.S. energy demands at "low-cost." Unfortunately, their work contains errors, incorrect and unsupported assumptions, and inappropriate methods. It's possible to get all our energy from renewables, but Jacobson et al. haven't proven it'll be reliable or affordable.

Clack et al., 2017

Selected Press: NY Times,WaPo, MIT Tech Rev
Increasing probability of mass mortality during Indian heatwaves
Science Advances | June 7, 2017

We show that small increases mean temperatures may lead to big increases in heatwave deaths in India. For example, if summer mean temperatures increase by 0.5 °C, the chances of a heatwave that kills >100 people goes from roughly 1 in every 8 years to 1 in 3 years.

Mazdiyasni et al., 2017

Selected Press: NY Times, Climate Central, SciAm
Future CO2 emissions and electricity generation from proposed coal-fired power plants in India
Earth's Future | April 25, 2017

With its growing population, industrializing economy, and large coal reserves, India represents a critical unknown in global projections of future CO2 emissions. As of mid-2016, proposed coal-fired power plants in India are incompatible with its NDC to reduce carbon intensity 33-35% by 2030.

Shearer et al., 2017

Selected Press: Carbon Brief, E&E, VICE, E360
Trade affects location of air pollution deaths
Nature | March 30, 2017

In a groundbreaking interdisciplinary analysis, we quantify the global links among consumption of goods and services, production of air pollution, atmospheric transport of that pollution, and human mortality due to the pollution. We find that roughly a quarter of air pollution deaths are related to goods produced in one world region for consumption in another.

Zhang et al., 2017

Selected Press: New Scientist, Guardian, WaPo, Economist
Global carbon uptake by cement carbonation
Nature Geoscience | November 21, 2016

Globally, carbonating cement materials are a large, overlooked and growing sink of CO2, which has offset 43% of the total process CO2 emissions (excluding those from related fossil energy inputs) from production of cement between 1930 and 2013.

Xi et al., 2016

Selected Press: Science, Architect, MIT Tech Rev
Earth system response to negative emissions
Environmental Research Letters | September 20, 2016

Earth system models suggest significant weakening, even potential reversal, of the ocean and land carbon sinks under future negative emission scenarios. Weakening of natural carbon sinks will hinder the effectiveness of negative emissions technologies and therefore increase their required deployment to achieve a given climate stabilisation target.

Jones et al., 2016

Global climate forcing of aerosols embodied in international trade
Nature Geoscience | September 9, 2016

In recent years, international trade has displaced radiative forcing related to aerosols such as black carbon, sulfate, nitrate and ammonium from developed, net-importing nations like the U.S. to emerging, net-exporting nations like China. We quantify this shift and discuss its policy implications.

Lin et al., 2016

Selected Press: CTV, South China Morning Post
Carbon lock-in
Annual Review of Envt. and Resources | September 2, 2016

Existing technologies, institutions, and behavioral norms constrain the rate and magnitude of carbon emissions reductions in the coming decades. We review the implications of research on "carbon lock-in" for decarbonization efforts and propose a research agenda to bridge the gaps among science, knowledge and policy-making.

Seto et al., 2016

Quantifying expert consensus against the existence of a 'chemtrails' conspiracy
Environmental Research Letters | August 10, 2016

76 of the 77 (98.7%) scientists we surveyed had not encountered evidence of a secret, large-scale atmospheric spraying program, and said that purported evidence are more easily explained by well-understood physics and chemistry associated with aircraft contrails and atmospheric aerosols.

Shearer et al., 2016
Selected Press: NY Times, Forbes, Vice, Slate, Science
Dislocated interests and climate change
Environmental Research Letters | May 31, 2016

Benefits and costs of CO2 emissions are often dislocated across space, time, and organizational level. When beneficiaries have greater political influence than those impacted, the result will be tragically suboptimal. Appeals to the consciences of beneficiaries will not solve the problem.

Smith et al., 2015

Correspondence: Reply to Kotchen and Mansur
Nature Communications | March 18, 2016

Commenting on our work decomposing drivers of recent trends in U.S. CO2 emissions, Kotchen and Mansur confirm our results but take a 'glass is half-full' perspective on natural gas's role in the decline. Our reply further highlights what we think is wishful thinking.

Feng et al., 2016

Biophysical and economic limits to negative CO2 emissions
Nature Climate Change | December 7, 2015

Most scenarios that avoid 2°C of global warming require large-scale deployment of negative emissions technologies. We review the impacts and resource demands of such deployment, and conclude that it's cheaper, easier and less risky to tackle global warming before fossil CO2 is in the atmosphere.

Smith et al., 2015

Selected Press: Climate Central, WaPo
Developing country finance in a post-2020 global climate agreement
Nature Climate Change | October 23, 2015

Emerging markets like China are increasingly financing expansion of fossil energy infrastructure in less-developed countries. The climate finance regime of the future should draw upon the resources of developing (as well as developed) countries to accelerate global low-carbon development.

Hannam et al., 2015

Addressing the climate-trade dilemma in China
Nature Climate Change | September 28, 2015

China's coal-based energy system and emissions-intensive manufacturing technologies produce drastically more CO2 emissions the same sectors in developed countries. We identify specific industries and provinces where improvements are most needed to reduce the CO2-penalty of trade with China.

Liu et al., 2015

Selected Press: Sinosphere, SciAm, ClimateWire
Climate constraints on carbon intensity of economic growth
Environmental Research Letters | September 8, 2015

Using a simple model that includes infrastructural carbon lock-in, we show that avoiding 2 °C of warming with continued economic growth will require extremely low carbon intensity of new infrastructure--even with immediate action, relatively short infrastructure lifetimes, and the possibility of large negative emissions after 2050.

Rozenberg et al., 2015

Rate and velocity of climate change caused by cumulative carbon emissions
Environmental Research Letters | August 28, 2015

Peak warming will be proportional to cumulative CO2 emissions, but the rate and velocity of climate change may be very different under different emissions pathways, even when cumulative emissions are equal. Thus, the ability of ecosystems to adapt or migrate is sensitive to the pathway of emissions.

LoPresti et al., 2015

Reduced estimates of Chinese carbon emissions
Nature | August 20, 2015

Several thousand measurements of Chinese coal and clinker indicate that CO2 emissions in China have been overestimated by 14% in recent years, or about 2.5 billion tons of CO2 per year. This is a very large revision with important implications for international climate negotiations and assessments of the global carbon cycle.

Liu et al., 2015

Selected Press: NY Times, ClimateProgress, BBC
Cost-effective ecological restoration
Restoration Ecology | August 13, 2015

Ecological restoration is big business, but there are few studies looking at the cost-effectiveness of different restoration methods. Using results from a large field experiment, we assess the resulting % native cover per dollar spent according to different methods of site prep, seeding and planting.

Kimball et al., 2015

Relevance of methodological choices for accounting of land use change carbon fluxes
Global Biogeochemical Cycles | July 21, 2015

We present the results of a new bookkeeping model of land-use change emissions, BLUE, and use the model to show the large effects of different accounting decisions on estimated carbon fluxes.

Hansis et al., 2015

Drivers of the decline in US CO2 emissions
Nature Communications | July 21, 2015

US CO2 emissions dropped 11% between 2007-2013;            a trend has been widely attributed to the increased use of natural gas over coal. We decompose the drivers of the decline and show that the recent economic downturn and not the gas boom deserves most of the credit for the decrease in emissions.

Feng et al., 2015

Selected Press: Climate Central, LA Times, CBS, SciAm, BBC
Outsourcing air pollution within China
Atmospheric Chemistry and Physics | May 19, 2015

Large amounts of air pollution produced in the northern and central regions of China are embodied in goods imported by its affluent coastal provinces. This consumption-based accounting suggests that economically optimal pollution abatement efforts may need to assess embodied emissions.

Zhao et al., 2015

Systems integration for global sustainability
Science | February 26, 2015

Sustainable development depends upon understanding interactions among multiple complex subsystems, but scientific research tends to focus on one (or part of one) subsystem at a time. This review describes recent progress toward more integrated, interdisciplinary science that is problem-driven, solution-oriented, and intentionally policy-relevant, and then discusses future directions for this science.

Liu et al., 2015

Non-CO2 emissions embodied in traded meat
Environmental Research Letters | November 13, 2014

More than 30 Mt CO2-equivalent CH4 and N2O emissions were embodied in meat traded internationally in 2010, increasing at 4% per year. This reflects a trend of increasing livestock production in countries with lower input costs, less efficient practices, and more permissive environmental regulations, which decrease global food costs and increase demand.

Caro et al., 2014

Selected Press: environmentalresearchweb
A crack in the gas bridge
Nature | October 15, 2014

A suite of global models show that, without new climate policies, abundant natural gas will not act to reduce GHG emissions or mitigate climate change. Consistent with our earlier findings for the US, abundant (and therefore cheap) gas may delay deployment of low-carbon energy sources and increase overall energy use.

Davis and Shearer, 2014

Selected Press: SciAm, The Guardian, CSMonitor
Bridge or detour?
Natural gas and US CO2 emissions

Environmental Research Letters | September 24, 2014

Leaking methane isn't the only reason natural gas may not reduce GHG emissions: gas also competes against lower-carbon energy sources. Without targeted policy, gas substitutes for both coal and renewables and future US GHG emissions do not decline much even assuming no leakage.

Shearer et al., 2015
Selected Press: Science, WaPo, ClimateProgress
Sharing a quota of cumulative emissions
Nature Climate Change | September 21, 2014

We can estimate carbon budgets for different warming targets, but the lingering and contentious question is how to divvy up that budget among countries. Industrialized countries don't want to stop emitting and developing countries want to emit more. This paper proposes a quantitative method for doing the sharing.

Raupach et al., 2014

Selected Press: NatGeo, Vox
Commitment accounting of CO2 emissions
Environmental Research Letters | August 26, 2014

Worldwide, existing power plants represent roughly 300 billion tons of future CO2 emissions if all plants operate for 40 years, and these "committed emissions" in the power sector have been growing at a rate of ~4% per year. This paper proposes tracking these commitments to quantify future emissions implied by current investments.

Shearer et al., 2015
Selected Press: Science, Dot Earth, Newsweek, Guardian
Attributing land-use emissions to products
Carbon Management | August 12, 2014

Land use and use changes produce GHG emissions over years, during which the land may be used to produce different products. We review several methods of assigning land use emissions to specific products, which have dramatically different results. Analysts should communicate their choices and consider the implications in light of their goals.

Caro et al., 2014

Global and regional trends in greenhouse gas
emissions from livestock

Climatic Change | July 12, 2014

A global accounting of GHG emissions from 11 livestock categories and 237 countries. Beef produces far more emissions than does pork or chicken. Emissions per unit of meat produced is decreasing in most places, but not quickly enough to keep up with rising global demand.

Caro et al., 2014

Selected Press: LA Times, AP, CBS News
Export-related Chinese air pollution affects
US air quality

PNAS | January 20, 2014

As much as a third of Chinese air pollution is related to goods exported from China, and some of that pollution blows across the Pacific to the US. Thus, outsourcing of manufacturing from the US to China has improved air quality in the eastern US, but has worsened air quality in the western US. [Cozzarelli Prize]

Lin et al., 2014

Selected Press: NY Times, The Atlantic, LA Times
Climate policy and dependence on traded carbon
Environmental Research Letters | July 24, 2013

Goods and services consumed in one country increasingly depend upon fossil carbon extracted or burned in other countries. This limits the effectiveness of national climate policies that regulate only domestic emissions. Similarly, nations that depend on imports of fuels or emissions-intensive goods will bear costs of climate policies in exporting nations.

Andrew et al., 2013

Selected Press: Shrink That Footprint
Outsourcing CO2 within China
PNAS | June 10, 2013

Rich coastal provinces in China outsource emissions to poorer interior provinces. China's province-specific emissions targets may encourage this dynamic even though the cheapest and easiest emissions reductions are in the less-developed interior provinces where the energy technologies in use are unsophisticated and inefficient.

Feng et al., 2013

Selected Press: The Guardian, BBC, SciAm, Nature CC
Rethinking Wedges
Environmental Research Letters | January 9, 2013

Building on the influential "wedge" paper by Pacala and Socolow, we emphasize that stabilizing emissions is only the first step in solving climate change. Ultimately we have to stop dumping CO2 into the atmosphere altogether; a phase-out of emissions over the next 50 years would require 19 wedges, and more if historical rates of technology improvement falter.

Davis et al., 2013

Selected Press: Science, USA Today
Carbon Budget of Australia
Biogeosciences | February 7, 2013

As part of the Global Carbon Project's RECCAP effort, Vanessa Haverd and co-authors quantified the terrestrial carbon budget of Australia, including emissions embodied in Aussie trade.

Haverd et al., 2012

A Synthesis of Carbon in International Trade
Biogeosciences | August, 2012

This paper synthesizes key differences between studies of CO2 emissions in trade and provide a consistent set of estimates using the same definitions, modeling framework, and data. Included are new calculations of carbon physically present in trades wood, crop and livestock products.

Peters et al., 2012

Cretaceous−Paleogene evolution of the Utah foreland
Geosphere | August 1, 2012

Data from detrital zircon ages, paleocurrent trends, and sandstone petrofacies show that the Colton Formation in northeastern Utah represents the culmination of a persistent pattern of sediment transport northward during Cretaceous and Paleogene time (70-60 Ma).

Dickinson et al., 2012

CO2 from Fossil-fuel Combustion
Biogeosciences | May 29, 2012

CO2 emissions from burning fossil fuels has increased steadily since fossil fuels were first used by humans. Despite international efforts, global emissions continue to increase at a rate of ~3% per year. This synthesis describes how emissions are calculated; calculates global, regional, and national emissions at different spatial and temporal scales; and discusses associated uncertainties.

Andres et al., 2012

Cenozoic Topography of Western North America
AJS | February 1, 2012

Using nearly 5,000 oxygen isotope analyses performed over the past decade, we reconstruct the topographic development of western North America over the past 60 million years. The data shows that the landscape west of the modern Rockies grew into a rugged and high mountain range bordered on the west by a high Sierra Nevada Mountains and on the east by large lake basins that captured water draining these growing highlands.

Chamberlain et al., 2012

The Supply Chain of CO2 Emissions
PNAS | October 17, 2011

Nations report CO2 emissions from fossil fuels that are burned within their sovereign terrritory. But both fossil fuels and consumer goods manufactured with fossil energy are commonly transported internationally. We map global emissions according to where fossil fuel resources are extracted and where the goods made with fossil energy are consumed.

Davis et al 2011

Selected Press: The Guardian, BBC, SciAm

The California River
Geology | October 4, 2010

Fifty-five million years ago a river as big as the modern Colorado flowed through Arizona into Utah in the opposite direction from the present-day river. By analyzing the uranium and lead isotopes in sand grains made of the mineral zircon, we show that sediments in northeast Utah came from igneous bedrock in the Mojave region of southern California.

Davis et al., 2010

Selected Press: Discovery News, LiveScience

Infrastructural Inertia of Climate Change
Science | September 10, 2010

What if we never built another CO2-emitting device, but the ones already in existence lived out their normal lives? We calculated the amount of carbon dioxide expected to be released from existing energy infrastructure worldwide, and then used a global climate model to project its effect on the Earth’s atmosphere and climate.

Davis et al., 2010

Selected Press: Wired, TIME, SciAm
Climate Benefits of Increased Agricultural Yields
PNAS | June 15, 2010

Agricultural intensification since 1961 has increased yields so much that the area in crops has not needed to change, even as demand has soared. As a consequence, intensification of agriculture has prevented deforestation that we estimate would otherwise have emitted 161 billion tons of carbon to the atmosphere.

Burney et al., 2010

Selected Press: New Scientist, TIME, BBC, SciAm
Consumption-based Accounting of CO2 Emissions
PNAS | March 8, 2010

Over a third of carbon dioxide emissions associated with consumption of goods and services in developed countries of western Europe, Japan, and the United States are emitted outside their borders, often in China. In contrast, ~24% of the emissions produced in China are exported.

Davis and Caldeira, 2010

Selected Press: The Economist, NPR, NYTimes, TIME
Drainage Patters of the Laramide Cordillera
AJS | September, 2009

This paper synthesizing hundreds of isotopic measurements from the Paleogene (~65-40 Ma) North American Cordillera to reconstruct the evolving hydrology of the Eocene Green River Lake system and shifting Cordilleran drainage patterns as the modern topography of the Rocky Mountains developed.

Davis et al., 2009

Cordilleran Landscape Evolution in the Paleogene
GSA Bulletin | January, 2009

The isotopic composition of 40-60 million year-old lake deposits in Utah may reflect the north-to-south progression of topography and drainage rearrangements as magmatism swept southward through Montana and Nevada and increased the mean elevation of catchments that drained east into the lakes of Utah.

Davis et al., 2009

Drainage Reorganization and Paleoaltimetry
EPSL | November, 2008

Lakes in the Laramide foreland co-evolved with drainage patterns. Such shifting drainages could confound isotopic estimates of paleoaltimetry. In the North American Cordillera of the Paleogene, for instance, it's likely that (1) changing topography in areas hundred of kilometers from foreland lakes altered isotopic composition of lake water.

Davis et al., 2008

Carbon Footprint of New Belgium Fat Tire Ale
Climate Conservancy | March, 2008

A report of The Climate Conservancy, which I co-founded with a goal to label consumer products with their carbon footprints. This work was conducted with data from New Belgium Brewing Company, for whom we assessed the carbon footprint of the well-known Fat Tire Amber Ale. We prepared a detailed report.

Davis et al., 2008

Selected Press: New Belgium, Beer Activist
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