Machine learning reveals climate forcing from aerosols is dominated by increased cloud cover

Nature Geoscience, Journal Year: 2022, Volume and Issue: 15(8), P. 609 - 614

Published: Aug. 1, 2022

Language: Английский

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Abrupt reduction in shipping emission as an inadvertent geoengineering termination shock produces substantial radiative warming

Communications Earth & Environment, Journal Year: 2024, Volume and Issue: 5(1)

Published: May 30, 2024

Abstract Human activities affect the Earth’s climate through modifying composition of atmosphere, which then creates radiative forcing that drives change. The warming effect anthropogenic greenhouse gases has been partially balanced by cooling aerosols. In 2020, fuel regulations abruptly reduced emission sulfur dioxide from international shipping about 80% and created an inadvertent geoengineering termination shock with global impact. Here we estimate regulation leads to a $$+0.2\pm 0.11$$ +0.2±0.11 Wm −2 averaged over ocean. amount could lead doubling (or more) rate in 2020 s compared since 1980 strong spatiotemporal heterogeneity. is consistent recent observed 2023 expected make anomalously warm. equivalent magnitude measured increase planetary heat uptake 2020. also hemispheric contrast, important implications for precipitation pattern changes. Our result suggests marine cloud brightening may be viable method temporarily its unique challenges due inherent

Language: Английский

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Has Reducing Ship Emissions Brought Forward Global Warming?

Geophysical Research Letters, Journal Year: 2024, Volume and Issue: 51(15)

Published: Aug. 12, 2024

Abstract Ships brighten low marine clouds from emissions of sulfur and aerosols, resulting in visible “ship tracks”. In 2020, new shipping regulations mandated an ∼80% reduction the allowed fuel content. Recent observations indicate that ship tracks have decreased. Model simulations since 2020 induced a net radiative forcing +0.12 Wm −2 . Analysis recent temperature anomalies indicates Northern Hemisphere surface 2022–2023 are correlated with observed cloud is spatially simulated emission changes. Shipping changes could be accelerating global warming. To better constrain these estimates, access to position data understanding aerosol needed. Understanding risks benefits reductions difficultly robust attribution highlights large uncertainty attributing proposed deliberate climate intervention.

Language: Английский

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Microphysical properties of atmospheric soot and organic particles: measurements, modeling, and impacts

npj Climate and Atmospheric Science, Journal Year: 2024, Volume and Issue: 7(1)

Published: March 8, 2024

Abstract Atmospheric soot and organic particles from fossil fuel combustion biomass burning modify Earth’s climate through their interactions with solar radiation modifications of cloud properties by acting as condensation nuclei ice nucleating particles. Recent advancements in understanding individual microscopic composition have led to heightened interest microphysical properties. This review article provides an overview current advanced measurements offers insights into future avenues for studying these To quantify morphology ageing, fractal dimension ( D f ) is a commonly employed quantitative metric which allows characterize morphologies aggregates relation ageing factors like internal mixing state, core-shell structures, phase, heterogeneity. Models been developed incorporate diversity metrics aged particles, enabling assessment optical absorption radiative forcing effects. The are complex they influenced particle sources, process, meteorological conditions. Furthermore, soluble exhibit diverse forms can engage liquid–liquid phase separation sulfate nitrate components. Primary carbonaceous such tar balls warrant further attention due strong light absorbing properties, presence toxic constituents, small size, impact human health. Future research needs include both atmospheric modeling approaches, focusing on changes the structures ensembles, effects dynamics

Language: Английский

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Physical science research needed to evaluate the viability and risks of marine cloud brightening

Science Advances, Journal Year: 2024, Volume and Issue: 10(12)

Published: March 20, 2024

Marine cloud brightening (MCB) is the deliberate injection of aerosol particles into shallow marine clouds to increase their reflection solar radiation and reduce amount energy absorbed by climate system. From physical science perspective, consensus a broad international group scientists that viability MCB will ultimately depend on whether observations models can robustly assess scale-up local-to-global in today's identify strategies ensure an equitable geographical distribution benefits risks associated with projected regional changes temperature precipitation. To address knowledge gaps required societal implications MCB, we propose substantial targeted program research-field laboratory experiments, monitoring, numerical modeling across range scales.

Language: Английский

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Invisible ship tracks show large cloud sensitivity to aerosol

Nature, Journal Year: 2022, Volume and Issue: 610(7930), P. 101 - 106

Published: Oct. 5, 2022

Abstract Cloud reflectivity is sensitive to atmospheric aerosol concentrations because aerosols provide the condensation nuclei on which water condenses 1 . Increased due human activity affect droplet number concentration, liquid and cloud fraction 2 , but these changes are subject large uncertainties 3 Ship tracks, long lines of polluted clouds that visible in satellite images, one main tools for quantifying aerosol–cloud interactions 4 However, only a small by shipping show ship tracks 5,6 Here we even when no emissions change properties substantially. We develop new method quantify effect all clouds, showing increase more positive response there tracks. directly detect shipping-induced property trade cumulus regions Atlantic, known display almost Our results indicate previous studies were suffering from selection biases focusing imagery. The strong path find translates larger cooling climate, potentially masking higher climate sensitivity than observed temperature trends would otherwise suggest.

Language: Английский

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Shipping regulations lead to large reduction in cloud perturbations

Proceedings of the National Academy of Sciences, Journal Year: 2022, Volume and Issue: 119(41)

Published: Oct. 3, 2022

Global shipping accounts for 13% of global emissions SO 2 , which, once oxidized to sulfate aerosol, acts cool the planet both directly by scattering sunlight and indirectly increasing albedo clouds. This cooling due aerosol offsets some warming effect greenhouse gasses is largest uncertainty in determining change Earth’s radiative balance human activity. Ship tracks—the visible manifestation indirect ship on clouds as quasi-linear features—have long provided an opportunity quantify these effects. However, they have been arduous catalog typically studied only particular regions short periods time. Using a machine-learning algorithm automate their detection we more than 1 million tracks provide climatology. We use this investigate stringent fuel regulations introduced International Maritime Organization 2020 prevalence since then, while accounting disruption commerce caused COVID-19. find marked, but clearly nonlinear, decline globally: An 80% reduction x causes 25% number detected.

Language: Английский

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Assessing effective radiative forcing from aerosol–cloud interactions over the global ocean

Proceedings of the National Academy of Sciences, Journal Year: 2022, Volume and Issue: 119(46)

Published: Nov. 7, 2022

How clouds respond to anthropogenic sulfate aerosols is one of the largest sources uncertainty in radiative forcing climate over industrial era. This limits our ability predict equilibrium sensitivity (ECS)-the global warming following a doubling atmospheric CO2. Here, we use satellite observations quantify relationships between and low-level while carefully controlling for meteorology. We then combine with estimates change concentration since about 1850 constrain associated forcing. estimate that cloud-mediated from [Formula: see text] W m-2 ocean (95% confidence). constraint implies ECS likely 2.9 4.5 K (66% Our results indicate aerosol less uncertain probably larger than ranges proposed by recent assessments.

Language: Английский

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Global reduction in ship-tracks from sulfur regulations for shipping fuel

Science Advances, Journal Year: 2022, Volume and Issue: 8(29)

Published: July 22, 2022

Ship-tracks are produced by ship-emitted aerosols interacting with low clouds. Here, we apply deep learning models on satellite data to produce the first global climatology map of ship-tracks. We show that ship-tracks at nexus cloud physics, maritime shipping, and fuel regulation. Our captures major shipping lanes while missing others because background conditions. Ship-track frequency is more than 10 times higher a previous survey, its interannual fluctuations reflect variations in cross-ocean trade, activity, regulations. Fuel regulation can alter both detected routes due cost. The 2020 regulation, together coronavirus disease 2019 pandemic, reduced ship-track lowest level recent decades across globe may have ushered an era frequency. reduces aerosol indirect forcing from ship emissions 46% or between 0.02 0.27 W m −2 given current estimates.

Language: Английский

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Detection of large-scale cloud microphysical changes within a major shipping corridor after implementation of the International Maritime Organization 2020 fuel sulfur regulations

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(14), P. 8259 - 8269

Published: July 25, 2023

Abstract. New regulations from the International Maritime Organization (IMO) limiting sulfur emissions shipping industry are expected to have large benefits in terms of public health but may come with an undesired side effect: acceleration global warming as climate-cooling effects ship pollution on marine clouds diminished. Previous work has found a substantial decrease detection tracks after IMO 2020 went into effect, changes large-scale cloud properties been more equivocal. Using statistical technique that estimates counterfactual fields what and radiative within isolated corridor southeastern Atlantic would absence shipping, we confidently detect reduction magnitude droplet effective radius decreases find evidence for brightening well. The instantaneous forcing due aerosol–cloud interactions is estimated O(1 W m−2) corridor, lending credence O(0.1 m−2). In addition their geophysical significance, our results also provide independent general compliance regulations.

Language: Английский

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