15. Climate Change and Soil

Emissions of greenhouse gases have alarmingly increased in the past due to land use changes, cultivation, and burning fossil fuels. Concentrations of CO₂, CH₄, and N₂O in the atmosphere have increased by 37, 156, and 19 % in the atmosphere, respectively, over 1750 values. Global temperature has risen by 0.75 °C since 1850 and projected temperature rise in the twenty-first century ranges from 1.8 to 4 °C. Sea level has risen in many places, arctic ice is melting, and permafrosts are in danger of thawing. Extreme events such as floods and droughts have become more frequent. Changing climate has a crucial role on ecosystems including soil. Soil contains a large stock (1.5 × 10¹⁸ g C) of stabilized carbon in the form of soil organic matter. Rising temperature may enhance decomposition of soil organic matter and might convert soil as a source of atmospheric CO₂. Soil management practices such as no-till or minimum till, using manures and composts, mulching, cover crops, reducing summer fallow, restoration of degraded lands, afforestation, and reforestation would significantly sequester carbon, reduce greenhouse gas emissions from the soil, and help to mitigate climate change and adapt to it.