Ocean temperature controls kelp decomposition and carbon sink potential

Abstract Compelling new evidence shows that kelp production contributes an important and underappreciated flux of carbon in the ocean. Major questions remain, however, about the controls on the cycling of this organic carbon in the coastal zone, and their implications for future carbon sequestration. Here we used field experiments distributed across 28° latitude, and the entire range of two dominant kelps in the northern hemisphere, to measure decomposition rates of kelp detritus on the seafloor in relation to environmental factors. Ocean temperature was the strongest control on detritus decomposition in both species, and it was positively related to decomposition. This suggests that decomposition could accelerate with ocean warming under climate change, increasing remineralization and reducing overall kelp carbon sequestration. However, we also demonstrate the potential for high kelp-carbon storage in cooler (northern) regions, which could be targeted by climate mitigation strategies to expand blue carbon sinks.

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Ecological engineering for climate mitigation and adaptation—a case study for the North West Shelf

The APPEA Journal ◽

10.1071/aj10065 ◽

2011 ◽

Vol 51 (2) ◽

pp. 685

Author(s):

Peter Wheen ◽

Shaun Kim ◽

Martin Lawrence ◽

John Ridley

Keyword(s):

Carbon Sequestration ◽

Carbon Sink ◽

Ecological Engineering ◽

Commercial Application ◽

Climate Mitigation ◽

Surface Zone ◽

North West ◽

The North ◽

Mitigation And Adaptation ◽

Marine Productivity

This paper introduces the Australian-developed Ocean Nourishment technology, as well as the science, its regulation, and its potential commercial application for the North West Shelf. Ocean nourishment is a form of ecological engineering, designed to transfer carbon from the ocean's sunlit surface zone to the largest carbon sink on the planet: the ocean. It is a scaleable and economical form of bio-mimicry; simulating the ocean's natural biological processes. Nourishing the surface ocean with macronutrients increases the movement of atmospheric CO2 into the deep-ocean carbon store. Short lifecycle microscopic plants—which are prolific carbon consumers—use sunlight to process the added nutrients. This additional marine productivity leads to reduced CO2 levels in both the upper ocean and in the atmosphere. Dispersing nitrogen alone allows the potential long-term (1,000 years) removal of one tenth (0.8 Gt carbon/annum) of present anthropogenic emissions. In addition to carbon sequestration, there is a desirable by-product of the process. The increased marine productivity will lead to increased fish stocks, which will assist in feeding the world's human population. Individual licensed sites would be capable of sequestering 5–8 Mt of CO2 at $25–35 per tonne. This is estimated to produce an additional harvest of 300,000 tonnes of fish each year. The path to commercialisation for such a promising technology with global reach and untried application requires focussed scientific application. Establishing revenue streams for carbon sequestration or fisheries enhancement is complex. International regulation is being addressed by the LondonConvention/London Protocol of the International Maritime Organisation.

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Large carbon sink potential of Amazonian Secondary Forests to mitigate climate change

10.21203/rs.3.rs-71626/v1 ◽

2020 ◽

Author(s):

Viola Heinrich ◽

Ricardo Dalagnol ◽

Henrique Cassol ◽

Thais Rosan ◽

Catherine Torres de Almeida ◽

...

Keyword(s):

Carbon Sequestration ◽

Spatial Patterns ◽

Environmental Variability ◽

Carbon Sink ◽

Climate Mitigation ◽

Secondary Forests ◽

Old Growth ◽

Mitigation Potential ◽

Old Growth Forests ◽

Mitigate Climate Change

Abstract Secondary forests (SF) have a large climate mitigation potential, given their ability to sequester carbon up to 20 times faster than old-growth forests. Environmental variability and anthropogenic disturbances lead to uncertainties in estimating spatial patterns of SF carbon sequestration rates. Here we quantify the influence of environmental and disturbance drivers on the rate and spatial patterns of regrowth in the Brazilian Amazon, by integrating a 33-year land cover timeseries with a 2017 Aboveground Biomass dataset. Carbon sequestration rates of young Amazonian SF (<20 years old) are at least twice as high in the west (3.0±1.0 MgC ha-1 yr-1) than in the east (1.3±0.3 MgC ha-1 yr-1). Disturbances reduce SF regrowth rates by 8–50% (0.6 – 1.3 MgC ha-1 yr-1). We estimate the 2017 SF carbon stock to be 294 TgC, which could be 8% higher by avoiding fires and repeated deforestation. Maintaining the 2017 SF area has the potential to accumulate ~15 TgC yr-1 until 2030, contributing ~5% to Brazil’s 2030 net emissions reduction target. Supporting SF and old-growth forests conservation alongside the expansion of SF in deforested areas is therefore a viable nature-based climate mitigation solution.

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Mitigation co-benefits of carbon sequestration from MGNREGS in India

PLoS ONE ◽

10.1371/journal.pone.0251825 ◽

2021 ◽

Vol 16 (5) ◽

pp. e0251825

Author(s):

N. H. Ravindranath ◽

Indu K. Murthy

Keyword(s):

Carbon Sequestration ◽

Carbon Sink ◽

National Level ◽

Tree Planting ◽

Climate Mitigation ◽

Cumulative Number ◽

Rural Employment ◽

Future Potential ◽

Employment Guarantee ◽

Employment Guarantee Scheme

Mahatma Gandhi Rural Employment Guarantee Scheme a large social security programme being implemented in India, with an average annual investment of US$ 7 billion. The bulk of the activities under this programme are focused on natural resources such as land, water and trees, which provide adaptation benefits. In this study an attempt is made to estimate the carbon sequestration achieved and future potential, as a co-benefit, from MGNREGS. The total mean carbon sequestered at the national level, considering the cumulative number of natural resource based activities, for the year 2017–18 was estimated to be 102 MtCO2. The annual mean carbon sequestration is projected to increase to about 132 MtCO2 by 2020 and 249 MtCO2 by 2030. Drought proofing is one of the activities implemented under MGNREGS and it includes tree planting, relevant to achieving the NDC carbon sink target. The cumulative carbon sink created by drought proofing activities is projected to be 56 MtCO2 in 2020, 281 MtCO2 in 2025 and 561 MtCO2 in 2030. This study demonstrates the significant carbon sink potential of MGNREGS and highlights the importance of estimation and reporting climate mitigation co-benefits of adaptation actions such as MGNREGS under the Paris Agreement.

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Global Sustainability Crossroads: A Participatory Simulation Game to Educate in the Energy and Sustainability Challenges of the 21st Century

Sustainability ◽

10.3390/su11133672 ◽

2019 ◽

Vol 11 (13) ◽

pp. 3672 ◽

Cited By ~ 1

Author(s):

Iñigo Capellán-Pérez ◽

David Álvarez-Antelo ◽

Luis J. Miguel

Keyword(s):

Mitigation Strategies ◽

Simulation Game ◽

Climate Mitigation ◽

Global Sustainability ◽

Environmental Consequences ◽

Environment Model ◽

Participatory Simulation ◽

Simulation Group ◽

Energy Economy ◽

Sustainability Challenges

There is a general need to facilitate citizens’ understanding of the global sustainability problem with the dual purpose of raising their awareness of the seriousness of the problem and helping them get closer to understanding the complexity of the solutions. Here, the design and application of the participatory simulation game Global Sustainability Crossroads is described, based on a global state-of-the-art energy–economy–environment model, which creates a virtual scenario where the participants are confronted with the design of climate mitigation strategies as well as the social, economic, and environmental consequences of decisions. The novelty of the game rests on the global scope and the representation of the drivers of anthropogenic emissions within the MEDEAS-World model, combined with a participatory simulation group dynamic flexible enough to be adapted to a diversity of contexts and participants. The performance of 13 game workshops with ~420 players has shown it has a significant pedagogical potential: the game is able to generate discussions on crucial topics which are usually outside the public realm such as the relationship between economic growth and sustainability, the role of technology, how human desires are limited by biophysical constraints or the possibility of climate tipping points.

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Towards Understanding Variability in Droughts in Response to Extreme Climate Conditions over the Different Agro-Ecological Zones of Pakistan

Sustainability ◽

10.3390/su13126910 ◽

2021 ◽

Vol 13 (12) ◽

pp. 6910

Author(s):

Adil Dilawar ◽

Baozhang Chen ◽

Arfan Arshad ◽

Lifeng Guo ◽

Muhammad Irfan Ehsan ◽

...

Keyword(s):

Pearson Correlation ◽

Principal Component ◽

Mitigation Strategies ◽

Precipitation Extremes ◽

Climate Mitigation ◽

Mean Annual Temperature ◽

Climate Extreme ◽

Ecological Zones ◽

The Mean ◽

Agro Ecological Zones

Here, we provided a comprehensive analysis of long-term drought and climate extreme patterns in the agro ecological zones (AEZs) of Pakistan during 1980–2019. Drought trends were investigated using the standardized precipitation evapotranspiration index (SPEI) at various timescales (SPEI-1, SPEI-3, SPEI-6, and SPEI-12). The results showed that droughts (seasonal and annual) were more persistent and severe in the southern, southwestern, southeastern, and central parts of the region. Drought exacerbated with slopes of −0.02, −0.07, −0.08, −0.01, and −0.02 per year. Drought prevailed in all AEZs in the spring season. The majority of AEZs in Pakistan’s southern, middle, and southwestern regions had experienced substantial warming. The mean annual temperature minimum (Tmin) increased faster than the mean annual temperature maximum (Tmax) in all zones. Precipitation decreased in the southern, northern, central, and southwestern parts of the region. Principal component analysis (PCA) revealed a robust increase in temperature extremes with a variance of 76% and a decrease in precipitation extremes with a variance of 91% in the region. Temperature and precipitation extremes indices had a strong Pearson correlation with drought events. Higher temperatures resulted in extreme drought (dry conditions), while higher precipitation levels resulted in wetting conditions (no drought) in different AEZs. In most AEZs, drought occurrences were more responsive to precipitation. The current findings are helpful for climate mitigation strategies and specific zonal efforts are needed to alleviate the environmental and societal impacts of drought.

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The Paradox of Climate Change Mitigation and Adaptation in Danish Housing

Open House International ◽

10.1108/ohi-04-2012-b0003 ◽

2012 ◽

Vol 37 (4) ◽

pp. 19-28

Author(s):

Rob Marsh

Keyword(s):

Climate Change ◽

Energy Consumption ◽

Solar Energy ◽

Theoretical Study ◽

Climate Adaptation ◽

Mitigation Strategy ◽

Mitigation Strategies ◽

Space Heating ◽

Climate Mitigation ◽

Passive Solar

Climate change means that buildings must greatly reduce their energy consumption. It is however paradoxical that climate mitigation in Denmark has created negative energy and indoor climate problems in housing that may be made worse by climate change. A literature review has been carried out of housing schemes where climate mitigation was sought through reduced space heating demand, and it is shown that extensive problems with overheating exist. A theoretical study of regulative and design strategies for climate mitigation in new build housing has therefore been carried out, and it is shown that reducing space heating with high levels of thermal insulation and passive solar energy results in overheating and a growing demand for cooling. Climate change is expected to reduce space heating and increase cooling demand in housing. An analysis of new build housing using passive solar energy as a climate mitigation strategy has therefore been carried out in relation to future climate change scenarios. It is shown that severe indoor comfort problems can occur, questioning the relevance of passive solar energy as a climate mitigation strategy. In conclusion, a theoretical study of the interplay between climate adaptation and mitigation strategies is carried out, with a cross-disciplinary focus on users, passive design and active technologies. It is shown that the cumulative use of these strategies can create an adaptation buffer, thus eliminating problems with overheating and reducing energy consumption. New build housing should therefore be designed in relation to both current and future climate scenarios to show that the climate mitigation strategies ensure climate adaptation.

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Sensitivity of black carbon concentrations and climate impact to aging and scavenging

10.5194/acp-2016-782 ◽

2016 ◽

Author(s):

Marianne T. Lund ◽

Terje K. Berntsen ◽

Bjørn H. Samset

Keyword(s):

Nitric Acid ◽

Black Carbon ◽

Radiative Forcing ◽

Mitigation Strategies ◽

The Arctic ◽

Climate Mitigation ◽

Vertical Profiles ◽

The Impact ◽

Model Measurement ◽

Global Mean

Abstract. Despite recent improvements, significant uncertainties in global modeling of black carbon (BC) aerosols persist, posing important challenges for the design and evaluation of effective climate mitigation strategies targeted at BC emission reductions. Here we investigate the sensitivity of BC concentrations in the chemistry-transport model OsloCTM2 with the microphysical aerosol parameterization M7 (OsloCTM2-M7) to parameters controlling aerosol aging and scavenging. We focus on Arctic surface concentrations and remote region BC vertical profiles, and introduce a novel treatment of condensation of nitric acid on BC. The OsloCTM2-M7 underestimates annual averaged BC surface concentrations, with a mean normalized bias of −0.55. The seasonal cycle and magnitude of Arctic BC surface concentrations is improved compared to previous OsloCTM2 studies, but model-measurement discrepancies during spring remain. High-altitude BC over the Pacific is overestimated compared with measurements from the HIPPO campaigns. We find that a shorter global BC lifetime improves the agreement with HIPPO, in line with other recent studies. Several processes can achieve this, including allowing for convective scavenging of hydrophobic BC and reducing the amount of soluble material required for aging. Simultaneously, the concentrations in the Arctic are reduced, resulting in poorer agreement with measurements in part of the region. A first step towards inclusion of aging by nitrate in OsloCTM2-M7 is made by allowing for condensation of nitric acid on BC. This results in a faster aging and reduced lifetime, and in turn to a better agreement with the HIPPO measurements. On the other hand, model-measurement discrepancies in the Arctic are exacerbated. Work to further improve this parameterization is needed. The impact on global mean radiative forcing (RF) and surface temperature response (TS) in our experiments is estimated. Compared to the baseline, decreases in global mean direct RF on the order of 10–30 % of the total pre-industrial to present BC direct RF is estimated for the experiments that result in the largest changes in BC concentrations. We show that globally tuning parameters related to BC aging and scavenging can improve the representation of BC vertical profiles in the OsloCTM2-M7 compared with observations. Our results also show that such improvements can result from changes in several processes and often depend on assumptions about uncertain parameters such as the BC ice nucleating efficiency and the change in hygroscopicity with aging. It is also important to be aware of potential tradeoffs in model performance between different regions. Other important sources of uncertainty, particularly for Arctic BC, such as model resolution has not been investigated here. Our results underline the importance of more observations and experimental data to improve process understanding and thus further constrain models.

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Environmental change impacts on the C- and N-cycle of European forests: a model comparison study

Biogeosciences ◽

10.5194/bg-10-1751-2013 ◽

2013 ◽

Vol 10 (3) ◽

pp. 1751-1773 ◽

Cited By ~ 15

Author(s):

D. R. Cameron ◽

M. Van Oijen ◽

C. Werner ◽

K. Butterbach-Bahl ◽

R. Grote ◽

...

Keyword(s):

Carbon Sequestration ◽

Central Europe ◽

Tree Species ◽

Carbon Sink ◽

N2o Emission ◽

Forest Growth ◽

N2o Emissions ◽

European Forests ◽

Considerable Uncertainty ◽

Carbon And Nitrogen

Abstract. Forests are important components of the greenhouse gas balance of Europe. There is considerable uncertainty about how predicted changes to climate and nitrogen deposition will perturb the carbon and nitrogen cycles of European forests and thereby alter forest growth, carbon sequestration and N2O emission. The present study aimed to quantify the carbon and nitrogen balance, including the exchange of greenhouse gases, of European forests over the period 2010–2030, with a particular emphasis on the spatial variability of change. The analysis was carried out for two tree species: European beech and Scots pine. For this purpose, four different dynamic models were used: BASFOR, DailyDayCent, INTEGRATOR and Landscape-DNDC. These models span a range from semi-empirical to complex mechanistic. Comparison of these models allowed assessment of the extent to which model predictions depended on differences in model inputs and structure. We found a European average carbon sink of 0.160 ± 0.020 kgC m−2 yr−1 (pine) and 0.138 ± 0.062 kgC m−2 yr−1 (beech) and N2O source of 0.285 ± 0.125 kgN ha−1 yr−1 (pine) and 0.575 ± 0.105 kgN ha−1 yr−1 (beech). The European average greenhouse gas potential of the carbon sink was 18 (pine) and 8 (beech) times that of the N2O source. Carbon sequestration was larger in the trees than in the soil. Carbon sequestration and forest growth were largest in central Europe and lowest in northern Sweden and Finland, N. Poland and S. Spain. No single driver was found to dominate change across Europe. Forests were found to be most sensitive to change in environmental drivers where the drivers were limiting growth, where changes were particularly large or where changes acted in concert. The models disagreed as to which environmental changes were most significant for the geographical variation in forest growth and as to which tree species showed the largest rate of carbon sequestration. Pine and beech forests were found to have differing sensitivities to environmental change, in particular the response to changes in nitrogen and precipitation, with beech forest more vulnerable to drought. There was considerable uncertainty about the geographical location of N2O emissions. Two of the models BASFOR and LandscapeDNDC had largest emissions in central Europe where nitrogen deposition and soil nitrogen were largest, whereas the two other models identified different regions with large N2O emission. N2O emissions were found to be larger from beech than pine forests and were found to be particularly sensitive to forest growth.

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Sensitivity of global gross primary production to elevated CO2

10.5194/egusphere-egu21-1744 ◽

2021 ◽

Author(s):

Wenjia Cai ◽

Iain Colin Prentice

Keyword(s):

Field Experiments ◽

Carbon Sink ◽

Gross Primary Production ◽

Light Response ◽

Terrestrial Ecosystems ◽

Percentage Increase ◽

Terrestrial Plants ◽

Fertilization Effect ◽

Vegetation Models ◽

The Impact

Terrestrial ecosystems have accounted for more than half of the global carbon sink during the past decades and offset 25%-30% of current anthropogenic CO2 emissions. The projected increase in CO2 concentration will depend on the magnitude of terrestrial plants&#8217; feedback to CO2: i.e. the sensitivity of plant carbon uptake in response to elevated CO2, and the strength of the CO2 fertilization effect (CFE) in a changing (and warming) environment. Projecting vegetation responses to future increases in CO2 concentration under climate change is a major uncertainty, as ecosystem models, field experiments and satellite-based models show large disagreements. In this study, using a recently developed, parameter-sparse model (the &#8216;P model&#8217;), we assess the sensitivity of GPP to increasing CO2 under idealized conditions, in comparison with other vegetation models and field experiments. We investigate the impact of two central parameters, the ratio of Jmax to Vcmax (at a common temperature) and the curvature of the light response curve, on the sensitivity of GPP to CO2. We also quantified the spatial-temporal trend of CFE using the &#946; factor, defined as the percentage increase in GPP in response to a 100-ppm increase in atmospheric CO2 concentration over a defined period. We show how modelled &#946; has changed over the satellite era, and infer the possible effect of climatic variables on changes of CFE from spatial patterns of the modelled trend in &#946;.

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Progress towards small-scale field trials of coastal enhanced weathering of olivine

10.5194/egusphere-egu21-14112 ◽

2021 ◽

Author(s):

Stephen Romaniello ◽

Shanee Stopnitzky ◽

Tom Green ◽

Francesc Montserrat ◽

Eric Matzner ◽

...

Keyword(s):

Real World ◽

Field Experiments ◽

Ecological Impact ◽

Field Trials ◽

Research Strategy ◽

Unintended Consequences ◽

Ecological Impacts ◽

Small Scale ◽

Climate Mitigation ◽

Stage Of Development

Slow progress towards achieving global greenhouse gas emissions targets significantly increases the likelihood that future climate efforts may require not only emissions cuts but also direct climate mitigation via negative emissions technologies (IPCC AR5). Currently, such technologies exist at only a nascent stage of development, with significant uncertainties regarding their feasibility, cost, and potential unintended consequences and/or co-benefits.Coastal enhanced weathering of olivine (CEWO) has been suggested as one potential pathway for achieving net negative CO2 emissions at scale. CEWO involves the mining of olivine-rich ultramafic rocks (such as dunite) for incorporation during beach augmentation and restoration work. While grinding this rock into increasingly fine particle sizes is essential for increasing its surface area and reactivity, this step is also costly and energetically expensive. CEWO attempts to minimize this cost and energy penalty by relying on wave and tidal action to provide ongoing physical weathering of olivine grains once distributed on beaches. Laboratory experiments and carbon emissions assessments of CEWO suggest that these approaches may be technically feasible and carbon negative, but significant uncertainties remain regarding the real-world kinetics of coastal olivine dissolution. Furthermore, concerns about the fate and ecological impact of nickel (Ni) and chromium (Cr)&#8212;potentially toxic trace metals found in olivine&#8212;require careful evaluation.In 2019, Project Vesta was established as a nonprofit, philanthropically funded effort to evaluate the technical feasibility and ecological impacts of CEWO through a dedicated research program ultimately culminating in small-scale, real-world field trials of CEWO. This presentation will provide an overview and discussion of our overall research strategy, share insights from interim modeling and mesocosm experiments designed to ensure the practicality and safety of future field experiments, and explain our approach for ensuring transparent, responsible, and ethical research oversight and governance.

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