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What have you observed lately?

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Abstract

This study assesses three different measures of radiative forcing (instantaneous: IRF; stratospheric-temperature adjusted: SARF; effective: ERF) for future changes in ozone. These use a combination of online and offline methods. We separate the effects of changes in ozone precursors and ozone-depleting substances (ODSs) and configure model experiments such that only ozone changes (including consequent changes in humidity, clouds and surface albedo) affect the evolution of the model physics and dynamics.

In the Shared Socioeconomic Pathway 3-7.0 (SSP3-7.0) we find robust increases in ozone due to future increases in ozone precursors and decreases in ODSs, leading to a radiative forcing increase from 2015 to 2050 of 0.268 ± 0.084 W m−2 ERF, 0.244 ± 0.057 W m−2 SARF and 0.288 ± 0.101 W m−2 IRF. This increase makes ozone the second largest contributor to future warming by 2050 in this scenario, approximately half of which is due to stratospheric ozone recovery and half due to tropospheric ozone precursors.

Increases in ozone are found to decrease the cloud fraction, causing an overall negative adjustment to the radiative forcing (positive in the short wave but negative in the long wave). Non-cloud adjustments due to water vapour and albedo changes are positive. ERF is slightly larger than the offline SARF for the total ozone change but approximately double the SARF for the ODS-driven change (0.156 ± 0.071 W m−2 ERF, 0.076 ± 0.025 W m−2 SARF). Hence ERF is a more appropriate metric for diagnosing the climate effects of stratospheric ozone changes.9

Professor Jason Hickel argues that the mindless pursuit of Gross Domestic Product (GDP) growth isn’t just a bad thing, but is leading humanity to catastrophe

For the first time, a study maps safe areas that can practically be used for underground carbon storage, and estimates that using them all would only cut warming by 0.7°C. The result is almost ten times lower than previous estimates of around 6°C,

So much for CCS.

Abstract

Geologically storing carbon is a key strategy for abating emissions from fossil fuels and durably removing carbon dioxide (CO2) from the atmosphere1,2. However, the storage potential is not unlimited3,4. Here we establish a prudent planetary limit of around 1,460 (1,290–2,710) Gt of CO2 storage through a risk-based, spatially explicit analysis of carbon storage in sedimentary basins. We show that only stringent near-term gross emissions reductions can lower the risk of breaching this limit before the year 2200. Fully using geologic storage for carbon removal caps the possible global temperature reduction to 0.7 °C (0.35–1.2 °C, including storage estimate and climate response uncertainty). The countries most robust to our risk assessment are current large-scale extractors of fossil resources. Treating carbon storage as a limited intergenerational resource has deep implications for national mitigation strategies and policy and requires making explicit decisions on priorities for storage use.

cross-posted from: https://slrpnk.net/post/27008855

Significance

Long-term monitoring of barystatic sea level (BSL) changes is essential for understanding the present-day global mean sea level (GMSL) rise. GMSL has been measured continuously by satellite altimetry since 1993, while BSL records based on satellite gravimetry are generally lacking before the launch of GRACE in 2002. Here, we present 30 y of BSL estimates using time-variable gravity fields from satellite laser ranging (SLR), a traditional space gravimetry technique for determining long-wavelength gravity fields over decades. The SLR estimates provide an important global constraint on the individual mass change components obtained from different techniques prior to GRACE, and serve as an independent parallel dataset for gap-filling and cross-validation between GRACE and GRACE-FO.

Abstract

Using time-variable gravity fields determined from satellite laser ranging (SLR) and the Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow-On (GRACE-FO), we derive three decades of barystatic sea level (BSL) change estimates since 1993, providing a long record of satellite gravimetry-based BSL estimates comparable in duration to satellite altimetry. Over the 1993–2022 altimetry era, the BSL change rate is 1.75 ± 0.59 mm/y (2σ) as observed by SLR. The rate increases to 2.16 ± 0.59 mm/y (SLR) and 2.13 ± 0.38 mm/y (GRACE/-FO) over 2003–2022, mainly due to accelerated ice loss in Greenland since the 2000s. The remarkable agreement between SLR and GRACE/-FO estimates over the joint period cross-validates each other, suggesting that both work well in monitoring BSL changes. We also compare our satellite gravimetry estimates with the sum of individual mass change components (ice sheets, glaciers, and land water storage) obtained from multisource datasets (in situ, remote sensing and geophysical modeling). The differences are within 0.2 mm/y over the three decades, highlighting the global consistency of different techniques for observing Earth’s surface mass changes. Moreover, we reconcile the global mean sea level (GMSL) rise budget using reprocessed altimetry data and updated thermosteric sea level ensembles. From 1993 to 2022, the sum of thermosteric and SLR-based barystatic contributions (3.16 ± 0.64 mm/y) agrees well with altimetry-observed GMSL rate (3.22 ± 0.28 mm/y), suggesting that the GMSL rise budget can be closed within uncertainties over the last three decades.

Abstract

Methane has been identified as the second-largest contributor to climate change, accounting for approximately 30% of global warming. Countries have established targets and are implementing various measures to curb methane emissions. However, our understanding of the trends in methane emissions and their drivers remains limited, particularly from a consumption perspective (i.e. accounting for all emissions along the entire global supply chain). This study investigates the most recent dynamics of methane emissions across 120 sectors from both production and consumption viewpoints in 164 countries. It also discusses the status of decoupling of production- and consumption-based methane emissions from economic growth. Our results indicate that there is no foreseeable slowdown in the momentum of global methane emissions growth. Only a few developed countries have managed to reduce both production- and consumption-based emissions while maintaining economic growth (i.e., strong decoupling) during the observed period (1990-2023). Global trade accounts for approximately 30% of global methane emissions, but major trade patterns are shifting from North-North and North-South to South-South countries, reflecting the increasing participating of developing countries in global supply chains. The study further reveals the changing drivers of global methane emissions from 1998 to 2023 in five-year intervals. It identifies that the reduction in emission coefficient (i.e., emissions per unit of output), driven by advancements in improved energy efficiency and cleaner production technologies, is the main determinant for reducing emissions over the observation period, partly offsetting the increasing effects from growth of final demand. Changes in demand structure have played a considerable role in the increase of emissions since 2008. This study enhances our understanding of the changes and drivers of methane emissions and supports countries in incorporating methane emissions into their climate mitigation strategies.

Abstract

The Amazon rainforest is one of Earth’s most diverse ecosystems, playing a key role in maintaining regional and global climate stability. However, recent changes in land use, vegetation, and the climate have disrupted biosphere-atmosphere interactions, leading to significant alterations in the water, energy, and carbon cycles. These disturbances have far-reaching consequences for the entire Earth system. Here, we quantify the relative contributions of deforestation and global climate change to observed shifts in key Amazonian climate parameters. We analyzed long-term atmospheric and land cover change data across 29 areas in the Brazilian Legal Amazon from 1985 to 2020, using parametric statistical models to disentangle the effects of forest loss and alterations of temperature, precipitation, and greenhouse gas mixing ratios. While the rise in atmospheric methane (CH4) and carbon dioxide (CO2) mixing ratios is primarily driven by global emissions (>99%), deforestation has significantly increased surface air temperatures and reduced precipitation during the Amazonian dry season. Over the past 35 years, deforestation has accounted for approximately 74% of the ~ 21 mm dry season−1 decline and 16.5% of the 2°C rise in maximum surface air temperature. Understanding the interplay between global climate change and deforestation is essential for developing effective mitigation and adaptation strategies to preserve this vital ecosystem.

U.S. cities are facing a growing threat that goes beyond hot weather or hazy air. New research from the University of Oklahoma reveals that "compound events"—periods when heat wave conditions coincide with high air pollution levels—are becoming more frequent and intense in urban areas across the United States.

Abstract

In 2023, sea surface temperatures (SSTs) reached record highs, partly due to a strong El Niño. Based on historical responses to elevated global mean SSTs, oceanic CO2 uptake in 2023 should have increased (−0.11 ± 0.04 PgC yr−1), driven by reduced outgassing in the tropical Pacific Ocean. However, using observation-based estimates of ocean CO2 fugacity, we show here that the global non-polar ocean absorbed about 10% less CO2 than expected (+0.17 ± 0.12 PgC yr−1). This weakening was caused by the anomalous outgassing of CO2 in the subtropical and subpolar regions, especially in the Northern Hemisphere, driven primarily by elevated SSTs reducing the solubility of CO2. In most regions, this SST-induced outgassing was mitigated by the depletion of dissolved inorganic carbon in the surface mixed layer. Such negative feedbacks caused an overall muted response of the ocean carbon sink to the record-high SSTs, but this resilience may not persist under long-term warming or more severe SST extremes.

cross-posted from: https://slrpnk.net/post/26915070

Former security leaders warn major threat going ignored Former Defence chief Chris Barrie said Australia needed to reorder its foreign policy priorities, with traditional geopolitical risks set to be displaced by climate change.

Australia has put all its eggs in the AUKUS basket, risking entanglement in a war with China, while the far greater threat to Australians' security is being ignored," he said.

Which is essentially what The Greens Nick Minchin said last year and was poo poohed for not understaning "defence". I wonder if his detractors will say the same thing of Admiral Barrie (retired) ?

Hong Kong Polytechnic University (PolyU) researchers have utilized advanced space geodetic technologies to deliver the first precise 30-year (1993–2022) record of global ocean mass change (also known as barystatic sea level), revealing its dominant role in driving GMSL rise.

Their research further indicates that GMSL has been increasing at an average rate of approximately 3.3 mm per year with a notable acceleration observed, highlighting the growing severity of climate change. The findings have been published in the Proc

Abstract

A transition to low-carbon energy sources is pivotal in addressing the escalating challenges of climate change and environmental degradation. Solar energy, particularly photovoltaic (PV) technology, stands out as a prominent solution because of its potential for clean and sustainable electricity generation with minimal greenhouse gas emissions. However, accurately assessing the carbon footprint of PV modules is essential for guiding policy, industry practices, and research. This paper reviews the state of the current literature and highlights the difficulties in estimating the carbon footprint of PV modules manufactured in China. It emphasises the inherent limitations of Process-Based Life Cycle Assessments (PLCAs), including data collection challenges, dynamic environmental changes, and subjective methodological choices. Through the case study of Ecoinvent 3.7 the study underscores the need for improved transparency, standardisation, and reproducibility in Life Cycle Assessments (LCAs) to provide more accurate and reliable environmental impact evaluations.

Keywords: photovoltaic; life cycle assessment; carbon footprint; ecoinvent; environmentally extended input–output analysis

Interview with Nick Breeze