The one bright note in global warming is seemingly that higher carbon dioxide levels will make food crops grow faster. More crops should equal more food. But, as this feature article emphasises, the story is not that simple.

Initial tests have shown that plants grown in high carbon dioxide environments could be less nutritious — with lower protein levels and a different type of protein produced. Other scientists have found a drop in key micronutrients such as chromium, selenium and zinc in high carbon dioxide environments.

Mitigating these changes can involve increasing nitrogen levels to offset protein deficiency, although not all scientists agree on this.

What is clear is that there is very little research in this area and past studies have only looked at carbon dioxide concentrations of 550 parts per million, which is lower than levels predicted by the end of this century.

This report, submitted by the UN Food and Agriculture Organization, looks at how smallholder agriculture could help mitigate climate change. It focuses on soil carbon sequestration, which, say the authors, has high mitigation potential and is relevant to smallholders, although it is currently excluded from the Clean Development Mechanism.

One issue highlighted by the report is how to quantify mitigation through soil carbon sequestration. It proposes a combined measurement and modelling approach and the steps needed to implement this are discussed. These include creating a fund for pilot projects, agreeing field and lab protocols, establishing a common data archive and devising monitoring and evaluation methods.

The report also asks how carbon finance can be linked to the smallholder agricultural sector. It argues that enabling agricultural mitigation from developing countries will mean creating institutions that can aggregate carbon crediting among many stakeholders, facilitating the flow of carbon finance, building capacity and agreeing property rights to the carbon benefits generated.

This article, published by Mongabay.com, discusses the use of forest conservation to reduce greenhouse gas emissions from deforestation in the Amazon. The author describes the 'reducing emissions from deforestation and degradation' (REDD) mechanism included in the Bali roadmap for international agreement on climate change. He gives a brief history of REDD, explains how it could work and discusses complicating factors including land rights, measurement of deforestation rates, displacement effects of conservation and funding.

The author also discusses how promoting ecosystem services could provide a route to conserving rainforests, citing the example of Canopy Capital — a UK private equity firm that recently bought the rights to environmental services generated by a rainforest reserve in Guyana. He also examines other market incentives that could be used, including satellite surveillance to enforce conservation and certification for farmers following conservation rules.