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A breakthrough discovery in carbon capture conversion for ethylene production

by University of Illinois Chicago, Sep 9, 2022 in ScienceDaily

A team of researchers led by Meenesh Singh at University of Illinois Chicago has discovered a way to convert 100% of carbon dioxide captured from industrial exhaust into ethylene, a key building block for plastic products.

Their findings are published in Cell Reports Physical Science.

While researchers have been exploring the possibility of converting carbon dioxide to ethylene for more than a decade, the UIC team’s approach is the first to achieve nearly 100% utilization of carbon dioxide to produce hydrocarbons. Their system uses electrolysis to transform captured carbon dioxide gas into high purity ethylene, with other carbon-based fuels and oxygen as byproducts.

The process can convert up to 6 metric tons of carbon dioxide into 1 metric ton of ethylene, recycling almost all carbon dioxide captured. Because the system runs on electricity, the use of renewable energy can make the process carbon negative.

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unclassified

Claim: The World is On the Brink of Five Climate Tipping Points

by E. Worrall, Sep 12, 2022 in WUWT

Is anyone else fed up with us approaching but never actually crossing all those dangerous tipping points?

World on brink of five ‘disastrous’ climate tipping points, study finds

Giant ice sheets, ocean currents and permafrost regions may already have passed point of irreversible change

Damian CarringtonEnvironment editor
@dpcarringtonFri 9 Sep 2022 04.00 AEST

The climate crisis has driven the world to the brink of multiple “disastrous” tipping points, according to a major study.

It shows five dangerous tipping points may already have been passed due to the 1.1C of global heating caused by humanity to date.

These include the collapse of Greenland’s ice cap, eventually producing a huge sea level rise, the collapse of a key current in the north Atlantic, disrupting rain upon which billions of people depend for food, and an abrupt melting of carbon-rich permafrost.

At 1.5C of heating, the minimum rise now expected, four of the five tipping points move from being possible to likely, the analysis said. Also at 1.5C, an additional five tipping points become possible, including changes to vast northern forests and the loss of almost all mountain glaciers.

In total, the researchers found evidence for 16 tipping points, with the final six requiring global heating of at least 2C to be triggered, according to the scientists’ estimations. The tipping points would take effect on timescales varying from a few years to centuries.

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Read more: https://www.theguardian.com/environment/2022/sep/08/world-on-brink-five-climate-tipping-points-study-finds

The abstract of the study;

Exceeding 1.5°C global warming could trigger multiple climate tipping points

David I. Armstrong McKay* https://orcid.org/0000-0002-0020-7461 d.mckay@exeter.ac.uk
Arie Staal https://orcid.org/0000-0001-5409-1436
Jesse F. Abrams https://orcid.org/0000-0003-0411-8519
Ricarda Winkelmann https://orcid.org/0000-0003-1248-3217
Boris Sakschewski https://orcid.org/0000-0002-7230-9723
Sina Loriani https://orcid.org/0000-0001-6660-960X
Ingo Fetzer https://orcid.org/0000-0001-7335-5679
Sarah E. Cornell https://orcid.org/0000-0003-4367-1296
Johan Rockström
Timothy M. Lenton* https://orcid.org/0000-0002-6725-7498 d.mckay@exeter.ac.uk

9 Sep 2022

Vol 377, Issue 6611

DOI: 10.1126/science.abn7950

Climate tipping points occur when change in a part of the climate system becomes self-perpetuating beyond a warming threshold, leading to substantial Earth system impacts. Synthesizing paleoclimate, observational, and model-based studies, we provide a revised shortlist of global “core” tipping elements and regional “impact” tipping elements and their temperature thresholds. Current global warming of ~1.1°C above preindustrial temperatures already lies within the lower end of some tipping point uncertainty ranges. Several tipping points may be triggered in the Paris Agreement range of 1.5 to <2°C global warming, with many more likely at the 2 to 3°C of warming expected on current policy trajectories. This strengthens the evidence base for urgent action to mitigate climate change and to develop improved tipping point risk assessment, early warning capability, and adaptation strategies.

Read more (paywalled): https://www.science.org/doi/10.1126/science.abn7950

Unfortunately the study is paywalled, so I can’t tell you the timeframe of these alleged tipping points. Not that the predicted dates matter that much – in my experience, tipping point predictions are usually quietly ignored or deleted when the deadline expires.

climate-debate

Global models underestimate large decadal declining and rising water storage trends relative to GRACE satellite data

by B.R. Scanlon et al., Jan 22, 2018 in PNAS

Significance

We increasingly rely on global models to project impacts of humans and climate on water resources. How reliable are these models? While past model intercomparison projects focused on water fluxes, we provide here the first comprehensive comparison of land total water storage trends from seven global models to trends from Gravity Recovery and Climate Experiment (GRACE) satellites, which have been likened to giant weighing scales in the sky. The models underestimate the large decadal (2002–2014) trends in water storage relative to GRACE satellites, both decreasing trends related to human intervention and climate and increasing trends related primarily to climate variations. The poor agreement between models and GRACE underscores the challenges remaining for global models to capture human or climate impacts on global water storage trends.

Abstract

Assessing reliability of global models is critical because of increasing reliance on these models to address past and projected future climate and human stresses on global water resources. Here, we evaluate model reliability based on a comprehensive comparison of decadal trends (2002–2014) in land water storage from seven global models (WGHM, PCR-GLOBWB, GLDAS NOAH, MOSAIC, VIC, CLM, and CLSM) to trends from three Gravity Recovery and Climate Experiment (GRACE) satellite solutions in 186 river basins (∼60% of global land area). Medians of modeled basin water storage trends greatly underestimate GRACE-derived large decreasing (≤−0.5 km3/y) and increasing (≥0.5 km3/y) trends. Decreasing trends from GRACE are mostly related to human use (irrigation) and climate variations, whereas increasing trends reflect climate variations. For example, in the Amazon, GRACE estimates a large increasing trend of ∼43 km3/y, whereas most models estimate decreasing trends (−71 to 11 km3/y). Land water storage trends, summed over all basins, are positive for GRACE (∼71–82 km3/y) but negative for models (−450 to −12 km3/y), contributing opposing trends to global mean sea level change. Impacts of climate forcing on decadal land water storage trends exceed those of modeled human intervention by about a factor of 2. The model-GRACE comparison highlights potential areas of future model development, particularly simulated water storage. The inability of models to capture large decadal water storage trends based on GRACE indicates that model projections of climate and human-induced water storage changes may be underestimated.
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