Negative emissions technologies and carbon capture and storage to achieve the Paris Agreement commitments

How will the global atmosphere and climate be protected? Achieving net-zero CO2 emissions will require carbon capture and storage (CCS) to reduce current GHG emission rates, and negative emissions technology (NET) to recapture previously emitted greenhouse gases. Delivering NET requires radical cost and regulatory innovation to impact on climate mitigation. Present NET exemplars are few, are at small-scale and not deployable within a decade, with the exception of rock weathering, or direct injection of CO2 into selected ocean water masses. To keep warming less than 2°C, bioenergy with CCS (BECCS) has been modelled but does not yet exist at industrial scale. CCS already exists in many forms and at low cost. However, CCS has no political drivers to enforce its deployment. We make a new analysis of all global CCS projects and model the build rate out to 2050, deducing this is 100 times too slow. Our projection to 2050 captures just 700 Mt CO2 yr−1, not the minimum 6000 Mt CO2 yr−1 required to meet the 2°C target. Hence new policies are needed to incentivize commercial CCS. A first urgent action for all countries is to commercially assess their CO2 storage. A second simple action is to assign a Certificate of CO2 Storage onto producers of fossil carbon, mandating a progressively increasing proportion of CO2 to be stored. No CCS means no 2°C.This article is part of the theme issue ‘The Paris Agreement: understanding the physical and social challenges for a warming world of 1.5°C above pre-industrial levels'

Seasonality in carbon chemistry of Cochin backwaters

Seasonality in carbon chemistry of Cochin backwaters, Southern India, was investigated between 2018 and 2019. Dissolved inorganic carbon (DIC) showed strong seasonal variations. Lowest DIC was observed during the Southwest Monsoon (SWM), in conjunction with low salinity in surface waters, suggesting strong freshwater influence. The maximum concentration of partial pressure of carbon dioxide in water (pCO 2w) was recorded from polluted waters of Vembanad Lake (16,000 atm). Excluding the SWM, the inner most stations (freshwater) showed lower pCO 2w levels compared with the outermost (estuarine) ones. With regard to sampling stations, all the environmental properties, except silicate and phosphate, exhibited significant variation, pointing to large spatial heterogeneity across the stations. Redundancy analysis suggested salinity to be inversely related to surface pCO 2w. High pH and low pCO 2w observed in some of the inner most stations indicates role of pH in carbonate speciation. Our study indicates large seasonal fluctuation in biogeochemical parameters and strong heterogeneity between individual stations which therefore necessitates development of local biogeochemical models for better understanding of carbon budget in these waters

The chick embryo test as used in the study of the toxicity of certain dithiocarbamates

The toxicities of six dithiocarbamates: bis(dimethyl thiocarbamoyl) disulfide (thiram), zinc dimethyldithiocarbamate (ziram), ferric dimethyldithiocarbamate (ferbam), bis(dimethyl thiocarbamoyl) ethylene bis(dithiocarbamate) (triaram), sodium diethyl dithiocarbamate (NaDEDC), and sodium ethylene bis(dithiocarbamate) (nabam) were determined in the chick embryo. The substances were dissolved in propylene glycol and injected in the air chamber prior to incubation. Injection in the yolk sac on any day of development or in the air chamber after the first day was unsuitable for the assessment of an LD50. With the exception of nabam, the dithiocarbamates were extremely toxic for the early chick embryo. Cysteine injected simultaneously in the air chamber protected the embryos from the toxic effect of thiram or ziram but not from the action of triaram. It is suggested that the former two dithiocarbamates are reduced by cysteine to less toxic compounds