Carbon farming describes a collection of eco-friendly techniques that have the ability to increase carbon sink into soil, i.e. carbon sequestration. Increasing C sink in the soil will help reduce the amount of CO2, CH4 and N2O emissions in the environment. Carbon farming that leads to reduction in greenhouse gas (GHG) emissions is referred to as abatement activities. It holds carbon in vegetation and soils, and reduces GHG emissions. (Correspondence)

Reduced surface–deep ocean exchange and enhanced nutrient consumption by phytoplankton in the Southern Ocean have been linked to lower glacial atmospheric CO2. However, identification of the biological and physical conditions involved and the related processes remains incomplete. Here we specify Southern Ocean surface–subsurface contrasts using a new tool, the combined oxygen and silicon isotope measurement of diatom and radiolarian opal, in combination with numerical simulations. Our data do not indicate a permanent glacial halocline related to melt water from icebergs.

Northern peatlands have been accumulating organic matter since the start of the Holocene, and are now a substantial store of terrestrial carbon. However, their current status as carbon sinks is less clear, because of the possible effects of climate change, air pollution, grazing and drainage etc., and the difficulties of accurate measurement with suitable time resolution. Such measurements are particularly lacking in the UK.