Zeke Hausfather's research while affiliated with Breakthrough and other places

Publications (35)

Article
The sixth and latest IPCC assessment weights climate models according to how well they reproduce other evidence. Now the rest of the community should do the same. The sixth and latest IPCC assessment weights climate models according to how well they reproduce other evidence. Now the rest of the community should do the same.
Article
The increased concentrations of greenhouse gases in the atmosphere create an increase in Earth’s thermal energy, which is mainly stored in the ocean. Quantification of the rate of increase in ocean heat content (OHC) is vital for understanding the current and future climate of the Earth. Linear trend-lines have been frequently used to quantify long...
Article
Analysis of climate pledges by nations at the COP26 meeting indicates that such commitments could ensure that global warming does not exceed 2 ºC before 2100 — but only if backed up by short-term policies. Pledged climate policies predicted to cap global temperature increase.
Article
On 22 September 2020, within the backdrop of the COVID-19 global pandemic, China announced its climate goal for peak carbon emissions before 2030 and to reach carbon neutrality before 2060. This carbon-neutral goal is generally considered to cover all anthropogenic greenhouse gases. The planning effort is now in full swing in China, but the pathway...
Preprint
Achieving global climate and energy goals will require prodigious increases in non-emitting electricity generation, raising concerns about the scale of materials needed and associated environmental impacts. Here, we estimate power sector demand for materials and related carbon dioxide-equivalent (CO2eq) emissions from 2020-2050 across different cli...
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A global land–ocean temperature record has been created by combining the Berkeley Earth monthly land temperature field with spatially kriged version of the HadSST3 dataset. This combined product spans the period from 1850 to present and covers the majority of the Earth's surface: approximately 57 % in 1850, 75 % in 1880, 95 % in 1960, and 99.9 % by...
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We assess evidence relevant to Earth's equilibrium climate sensitivity per doubling of atmospheric CO2, characterized by an effective sensitivity S . This evidence includes feedback process understanding, the historical climate record, and the paleoclimate record. An S value lower than 2 K is difficult to reconcile with any of the three lines of ev...
Preprint
Full-text available
A global land/ocean temperature record has been created by combining the Berkeley Earth monthly land temperature field with spatially-kriged version of the HadSST3 dataset. This combined product spans the period from 1850 to present and covers the majority of the Earth's surface: approximately 57 % in 1850, 75 % in 1880, 95 % in 1960, and 99.9 % by...
Preprint
Full-text available
Abstract. Increasing attention is focusing upon climate tipping elements – large-scale earth systems anticipated to respond through positive feedbacks to anthropogenic climate change by shifting towards new long-term states. In some but not all cases, such changes could produce additional greenhouse gas emissions or radiative forcing that could com...
Article
Stop using the worst-case scenario for climate warming as the most likely outcome — more-realistic baselines make for better policy. Stop using the worst-case scenario for climate warming as the most likely outcome — more-realistic baselines make for better policy. A rainbow forms behind giant windmills near rain-soaked Interstate 10, Palm Springs,...
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Plain Language Summary Climate models provide an important way to understand future changes in the Earth's climate. In this paper we undertake a thorough evaluation of the performance of various climate models published between the early 1970s and the late 2000s. Specifically, we look at how well models project global warming in the years after the...
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The Paris Agreement introduced an ambitious goal of limiting warming to 1.5 °C above pre-industrial levels. Here we combine a review of modelled pathways and literature on mitigation strategies, and develop a land-sector roadmap of priority measures and regions that can help to achieve the 1.5 °C temperature goal. Transforming the land sector and d...
Article
An analysis of the record of sea surface temperature reveals that some climate variations that are thought to have occurred in the North Atlantic and the North Pacific oceans are an artefact of changes in measurement approaches. Adjustments to measurements of sea surface temperature.
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The early twentieth-century warming (EW; 1910–45) and the mid-twentieth-century cooling (MC; 1950–80) have been linked to both internal variability of the climate system and changes in external radiative forcing. The degree to which either of the two factors contributed to EW and MC, or both, is still debated. Using a two-box impulse response model...
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Removal of atmospheric carbon dioxide (CO2) combined with emission reduction is necessary to keep climate warming below the internationally agreed upon 2°C target. Soil organic carbon sequestration through agricultural management has been proposed as a means to lower atmospheric CO2 concentration, but the magnitude needed to meaningfully lower temp...
Article
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There is overwhelming evidence that the climate system has warmed since the instigation of instrumental meteorological observations. The Fifth Assessment Report of the Intergovernmental Panel on Climate Change concluded that the evidence for warming was unequivocal. However, owing to imperfect measurements and ubiquitous changes in measurement netw...
Article
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Sea surface temperatures form a vital part of global mean surface temperature records. Historical observation methods have changed substantially over time from buckets to engine room intake sensors, hull sensors and drifting buoys, rendering their use for climatological studies problematic. There are substantial uncertainties in the relative biases...
Article
They are useless in evaluating whether research results are correct
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Sea surface temperature (SST) records are subject to potential biases due to changing instrumentation and measurement practices. Significant differences exist between commonly used composite SST reconstructions from the National Oceanic and Atmospheric Administration’s Extended Reconstruction Sea Surface Temperature (ERSST), the Hadley Centre SST d...
Article
Changes in diurnal temperature range (DTR) over global land areas are compared from a broad range of independent data sets. All data sets agree that global-mean DTR has decreased significantly since 1950, with most of that decrease occurring over 1960–1980. The since-1979 trends are not significant, with inter-data set disagreement even over the si...
Article
Numerous inhomogeneities including station moves, instrument changes, and time of observation changes in the U.S. Historical Climatological Network (USHCN) complicate the assessment of long-term temperature trends. Detection and correction of inhomogeneities in raw temperature records have been undertaken by NOAA and other groups using automated pa...
Article
Natural gas has significant potential carbon benefits over coal when used for electricity generation, but these benefits can be offset by emissions of fugitive methane or delays in the adoption of near-zero carbon technologies. We analyze the time-evolution of radiative forcing from both natural gas and coal-based electricity generation by calculat...
Article
Natural gas has been suggested as a “bridge fuel” in the transition from coal to a near-zero emission energy system. However, the expansion of natural gas risks a delay in the introduction of near-zero emission energy systems, possibly offsetting the potential climate benefits of a gas-for-coal substitution. We use a schematic climate model to esti...
Article
The level of agreement between climate model simulations and observed surface temperature change is a topic of scientific and policy concern. While the Earth system continues to accumulate energy due to anthropogenic and other radiative forcings, estimates of recent surface temperature evolution fall at the lower end of climate model projections. G...
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Monckton of Brenchley et al. (Sci Bull 60:122-135, 2015) (hereafter called M15) use a simple energy balance model to estimate climate response. They select parameters for this model based on semantic arguments, leading to different results from those obtained in physics-based studies. M15 did not validate their model against observations, but inste...
Article
Full-text available
The International Surface Temperature Initiative (ISTI) is striving towards substantively improving our ability to robustly understand historical land surface air temperature change at all scales. A key recently completed first step has been collating all available records into a comprehensive open access, traceable and version-controlled databank....
Article
Full-text available
The International Surface Temperature Initiative (ISTI) is striving towards substantively improving our ability to robustly understand historical land surface air temperature change at all scales. A key recently completed first step has been collating all available records into a comprehensive open access, traceable and version-controlled databank....
Article
An assessment quantifying the impact of urbanization on temperature trends from the U.S. Historical Climatology Network (USHCN) is described. Stations were first classified as urban and nonurban (rural) using four different proxy measures of urbanity. Trends from the two station types were then compared using a pairing method that controls for diff...
Article
Metals are used in a variety of ways, many of which lead to dissipative releases to the environment. Such releases are relevant from both a resource use and an environmental impact perspective. We present a historical analysis of copper dissipative releases in the United States from 1975 to 2000. We situate all dissipative releases in copper's life...
Article
Rapid urbanization over the past half century has contributed to a warming bias in some Global Historical Climatological Network (GHCN) temperature records. The extent to which this urban warming bias contributes to global temperature trends remains largely unquantified both in raw and homogenized datasets, and no clear consensus exists on the need...

Citations

... And more recently, the current efforts by the climate community to explain why some models under the CMIP6 initiative show higher climate sensitivity as compared to the previous CMIP5 generation (e.g., Forster et al., 2020;Sherwood et al., 2020;Zelinka et al., 2020). Scientists are investigating if such a high response of global surface temperatures to the external climate forcings arises due to the errors in climate models and the origin of these errors (e.g., Hausfather et al., 2022;Myers et al., 2021;Sherwood et al., 2020;Voosen, 2019Voosen, , 2022. These examples show the importance of curiosity-driven research and the freedom to embark on unknown science territories to push frontiers in climate sciences. ...
... Further, large uncertainties in the Earth climate system prevent ruling out large future warming if conditional and unconditional emissions pledges are not implemented. 115,116 Climate change is projected to extend the nighttime temperature distribution rightwards, resulting in extreme ambient temperatures that exceed our historical observations. Rather than assigning these extreme temperatures the fitted value from the highest temperature bin within the historical distribution, we fit a linear spline to the data-with knots placed at À20 C and 10 C-and forecast behavioral estimates for projected temperatures for 2050 and 2099. ...
... Products used for this assessment are referenced in the caption of Fig. 3 is based on three distinct periods to account for the evolution of the observing system, i.e., 1960-411 2020 (i.e., "historical"), 1993-2020 (i.e., "altimeter era") and 2006-2020 (i.e., "golden Argo era"). To obtain an uncertainty range on the trend estimate, and take into account the sensitivity of the 425 calculation to interannual variability, we implement a Monte-Carlo simulation to generate 1000 426 surrogate series OHCrandom(t), under the assumption of a given mean (our "true" time series 427 OHC(t)) (Cheng et al., 2022). Each surrogate OHCrandom(t) consists of the "true" time serie OHC(t) 428 plus a randomly generated residual which follows a normal (Gaussian) distribution, and which is 429 included in an envelope equal to 2 times the uncertainty associated to the time series. ...
... In the face of the global climate challenge, China eloquently proposed at the 75th Session of the United Nations General Assembly on 22 September 2020 that it would take effective policies and measures at home. China aims to peak its carbon dioxide emissions by 2030 and become carbon neutral by 2060 on the basis of increasing its Nationally Determined Contribution (NDC) [2]. ...
... We employ two homogenized data sets for this analysis. The first is the Berkeley Earth Surface Temperatures (BEST) data set, which utilizes over 40,000 weather stations around the world to create 1° × 1° gridded estimates of daily temperature from 1880 to the present (R. A. Rohde & Hausfather, 2020;R. Rohde et al., 2013). ...
... GCMs included a 1950 to 2005 historical scenario, driven by past solar radiation, atmospheric conditions, and greenhouse gas concentrations, as well as a 2006 to 2099 simulation under either a moderate radiative forcing projection, RCP4.5, or an aggressive scenario (RCP8.5). RCP4.5 is expected to either be a less-than-realistic or realistic scenario resulting from estimated future emissions by midcentury, although recent emissions track RCP8.5 (47,48). ...
... Recent findings on equilibrium climate sensitivity (ECS) (14,24) underline that the magnitude of climate change is uncertain even if we knew future GHG concentrations. According to the IPCC, our best estimate for ECS is a 3°C temperature rise per doubling of CO 2 , with a "likely" range of (66 to 100% likelihood) of 2.5°C to 4°C. ...
... A final global temperature series is produced by the Berkeley Earth group. They use a 1 • by 1 • grid for land data (Rohde & Hausfather, 2020), and use tools of spatial statistics to estimate the temperature in land areas without observations. In addition they do not homogenize data. ...
... Such tipping point cascades are not accounted for in current models that couple emissions to impacts but may explain otherwise poorly predicted shifts in earth's climate history (Lenton et al. 2019, Brovkin et al. 2021, Wunderling et al. 2020, Klose et al. 2020, Pereiro and Viola 2018. If tipping points were better understood, models embracing them could improve predictions about the consequences of climate change and perhaps make possible effective intervention (Pearce 2007, Lenton 2020, Sharpe and Lenton 2020, Swingedouw et al. 2020, Wang and Hausfather 2020. ...
... Globally, RCP 8.5 is the emissions trajectory followed so far (Schwalm, et al., 2020a and2020b); it is also a precautionary choice to avoid path-dependent failure in mitigation due to a potentially optimistic choice of emission trajectory and allows us to identify 'no-regret' planting locations. The upper-limit-to-change assumption which we employ in this study is the use for which RCP 8.5 was originally intended, and should not be confused with the recently criticised application of RCP 8.5 as baseline or business as usual (Hausfather and Peters, 2020). ...